Meniscus treatment and age associated with narrower radiographic joint space width 2–3 years after ACL reconstruction: data from the MOON onsite cohort

SummaryObjectiveTo identify risk factors for radiographic signs of post-traumatic osteoarthritis (OA) 2–3 years after anterior cruciate ligament (ACL) reconstruction through multivariable analysis of minimum joint space width (mJSW) differences in a specially designed nested cohort.MethodsA nested cohort within the Multicenter Orthopaedic Outcomes Network (MOON) cohort included 262 patients (148 females, average age 20) injured in sport who underwent ACL reconstruction in a previously uninjured knee, were 35 or younger, and did not have ACL revision or contralateral knee surgery. mJSW on semi-flexed radiographs was measured in the medial compartment using a validated computerized method. A multivariable generalized linear model was constructed to assess mJSW difference between the ACL reconstructed and contralateral control knees while adjusting for potential confounding factors.ResultsUnexpectedly, we found the mean mJSW was 0.35 mm wider in ACL reconstructed than in control knees (5.06 mm (95% CI 4.96–5.15 mm) vs 4.71 mm (95% CI 4.62–4.80 mm), P < 0.001). However, ACL reconstructed knees with meniscectomy had narrower mJSW compared to contralateral normal knees by 0.64 mm (95% C.I. 0.38–0.90 mm) (P < 0.001). Age (P < 0.001) and meniscus repair (P = 0.001) were also significantly associated with mJSW difference.ConclusionSemi-flexed radiographs can detect differences in mJSW between ACL reconstructed and contralateral normal knees 2–3 years following ACL reconstruction, and the unexpected wider mJSW in ACL reconstructed knees may represent the earliest manifestation of post-traumatic osteoarthritis and warrants further study

Jupiter's X-ray Emission 2007 Part 2:Comparisons with UV and Radio Emissions and In-Situ Solar Wind Measurements

We compare Chandra and XMM‐Newton X‐ray observations of Jupiter during 2007 with a rich multi‐instrument dataset including: upstream in‐situ solar wind measurements from the New Horizons spacecraft, radio emissions from the Nançay Decametric Array and Wind/Waves, and UV observations from the Hubble Space Telescope. New Horizons data revealed two corotating interaction regions (CIRs) impacted Jupiter during these observations. Non‐Io decametric bursts and UV emissions brightened together and varied in phase with the CIRs. We characterise 3 types of X‐ray aurorae: hard X‐ray bremsstrahlung main emission, pulsed/flared soft X‐ray emissions and a newly identified dim flickering (varying on short‐timescales, but quasi‐continuously present) aurora. For most observations, the X‐ray aurorae were dominated by pulsed/flaring emissions, with ion spectral lines that were best fit by Iogenic plasma. However, the brightest X‐ray aurora was coincident with a magnetosphere expansion. For this observation, the aurorae were produced by both flickering emission and erratic pulses/flares. Auroral spectral models for this observation required the addition of solar wind ions to attain good fits, suggesting solar wind entry into the outer magnetosphere or directly into the pole for this particularly bright observation. X‐ray bremsstrahlung from high energy electrons was only bright for one observation, which was during a forward shock. This bremsstrahlung was spatially coincident with bright UV main emission (power> 1TW) and X‐ray ion spectral line dusk emission, suggesting closening of upward and downward current systems during the shock. Otherwise, the bremsstrahlung was dim and UV main emission power was also lower(<700 GW), suggesting their power scaled together

Jupiter's X-ray Emission During Solar Minimum

The 2007–2009 solar minimum was the longest of the space age. We present the first of two companion papers on Chandra and XMM‐Newton X‐ray campaigns of Jupiter through February–March 2007. We find that low solar X‐ray flux during solar minimum causes Jupiter's equatorial regions to be exceptionally X‐ray dim (0.21 GW at minimum; 0.76 GW at maximum). While the Jovian equatorial emission varies with solar cycle, the aurorae have comparably bright intervals at solar minimum and maximum. We apply atomic charge exchange models to auroral spectra and find that iogenic plasma of sulphur and oxygen ions provides excellent fits for XMM‐Newton observations. The fitted spectral S:O ratios of 0.4–1.3 are in good agreement with in situ magnetospheric S:O measurements of 0.3–1.5, suggesting that the ions that produce Jupiter's X‐ray aurora predominantly originate inside the magnetosphere. The aurorae were particularly bright on 24–25 February and 8–9 March, but these two observations exhibit very different spatial, spectral, and temporal behavior; 24–25 February was the only observation in this campaign with significant hard X‐ray bremsstrahlung from precipitating electrons, suggesting this may be rare. For 8–9 March, a bremsstrahlung component was absent, but bright oxygen O6+ lines and best‐fit models containing carbon, point to contributions from solar wind ions. This contribution is absent in the other observations. Comparing simultaneous Chandra ACIS and XMM‐Newton EPIC spectra showed that ACIS systematically underreported 0.45‐ to 0.6‐keV Jovian emission, suggesting quenching may be less important for Jupiter's atmosphere than previously thought. We therefore recommend XMM‐Newton for spectral analyses and quantifying opacity/quenching effects

Systematics of the Neotropical Genus Leptodactylus Fitzinger, 1826 (Anura: Leptodactylidae): Phylogeny, the Relevance of Non-molecular Evidence, and Species Accounts

A phylogeny of the species-rich clade of the Neotropical frog genus Leptodactylus sensu stricto is presented on the basis of a total evidence analysis of molecular (mitochondrial and nuclear markers) and non-molecular (adult and larval morphological and behavioral characters) sampled from > 80% of the 75 currently recognized species. Our results support the monophyly of Leptodactylus sensu stricto, with Hydrolaetare placed as its sister group. The reciprocal monophyly of Hydrolaetare and Leptodactylus sensu stricto does not require that we consider Hydrolaetare as either a subgenus or synonym of Leptodactylus sensu lato. We recognize Leptodactylus sensu stricto, Hydrolaetare, Adenomera, and Lithodytes as valid monophyletic genera. Our results generally support the traditionally recognized Leptodactylus species groups, with exceptions involving only a few species that are easily accommodated without proposing new groups or significantly altering contents. The four groups form a pectinate tree, with the Leptodactylus fuscus group diverging first, followed by the L. pentadactylus group, which is sister to the L. latrans and L. melanonotus groups. To evaluate the impact of non-molecular evidence on our results, we compared our total evidence results with results obtained from analyses using only molecular data. Although non-molecular evidence comprised only 3.5% of the total evidence matrix, it had a strong impact on our total evidence results. Only one species group was monophyletic in the molecular-only analysis, and support differed in 86% of the 54 Leptodactylus clades that are shared by the results of the two analyses. Even though no non-molecular evidence was included for Hydrolaetare, exclusion of that data partition resulted in that genus being nested within Leptodactylus, demonstrating that the inclusion of a small amount of non-molecular evidence for a subset of species can alter not only the placement of those species, but also species that were not scored for those data. The evolution of several natural history and reproductive traits is considered in the light of our phylogenic framework. Invasion of rocky outcrops, larval oophagy, and use of underground reproductive chambers are restricted to species of the Leptodactylus fuscus and L. pentadactylus groups. In contrast, larval schooling, larval attendance, and more complex parental care are restricted to the L. latrans and L. melanonotus groups. Construction of foam nests is plesiomorphic in Leptodactylus but their placement varies extensively (e.g., underground chambers, surface of waterbodies, natural or excavated basins). Information on species synonymy, etymology, adult and larval morphology, advertisement call, and geographic distribution is summarized in species accounts for the 30 species of the Leptodactylus fuscus group, 17 species of the L. pentadactylus group, eight species of the L. latrans group, and 17 species of the L. melanonotus group, as well as the three species that are currently unassigned to any species group.Se presenta una filogenia del género Leptodactylus, un ciado neotropical rico en especies, basada en análises combinados de datos moleculares (marcadores nuclear y mitocondriales) y no moleculares (caracteres de la morfología de adultos y larvas así como de comportamiento) se muestrearon > 80% de las 75 especies reconocidas. Los resultados apoyan la monofília de Leptodactylus sensu stricto, con Hydrolaetare como su grupo hermano. La monofília recíproca de Hydrolaetare y Leptodactylus no requiere considerar a Hydrolaetare como un subgénero o sinónimo de Leptodactylus sensu lato. Se reconocen Leptodactylus sensu stricto, Hydrolaetare, Adenomera y Lithodytes como géneros monofiléticos válidos. Los resultados en general resuelven los grupos tradicionalmente reconocidos de Leptodactylus, con excepciones de algunas especies que son reasignadas sin la necesidad de proponer nuevos grupos o alterar significativamente el contenido de los grupos tradicionales. Los cuatro grupos de especies forman una topología pectinada donde el grupo de L. fuscus tiene una posición basal, seguido por el grupo de L. pentadactylus que es el grupo hermano al clado formado por los grupo de L. latrans y L. melanonotus. Se estimó el impacto de los datos no moleculares en los resultados, comparándose los resultados de evidencia total con los de los análises de datos moleculares solamente. Los datos no moleculares representan un 3.5% de la matriz de evidencia total, pero estos datos tuvieron un impacto significativo en los resultados del análisis de evidencia total. En el análisis estrictamente molecular solamente un grupo de especies resultó monofilético, y el apoyo difirió en 86% de los 54 ciados de Leptodactylus compartidos entre los dos análises. A pesar que datos no moleculares no fueron incluidos para Hydrolaetare, la exclusión de evidencia no molecular resultó en el género estar dentro de Leptodactylus, demostrando que la inclusión de evidencia no molecular pequeña para un subgrupo de especies altera no solamente la posición topológica de esas especies, sino tambien de las especies para las cuales dichos datos no fueron codificados. La evolución de patrones de historia natural y reprodución se evalúan en el contexto filogenético. La invasión de afloramientos rocosos y la construción de cámaras de reprodución subterraneas está limitada a los grupos de Leptodactylus fuscus y L. pentadactylus, mientras que la oofagia larval está restringida al grupo de L. pentadactylus. Por otro lado, los cárdumenes larvales, la proteción del cárdumen, y otros comportamientos parentales complejos carecterizan al clado formado por los grupos de especies de L. latrans y L. melanonotus. Los resúmenes de especies incluyen información de sinonimias, etimología, morfología de adultos y larvas, cantos, y distribución geográfica para las 30 especies del grupo de Leptodactylus fuscus, 17 especies del grupo L. pentadactylus, ocho especies del grupo de L. latrans, 17 especies del grupo de L. melanonotus, así como para las tres especies que actualmente no se encuentran asociadas a ninguno de los grupos de especies.Taran Grant was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico Proc. 307001/2011-3 and Fundação de Amparo à Pesquisa do Estado de São Paulo Proc. 2012/10000-5

Rotationally driven magnetic reconnection in Saturn's dayside

Magnetic reconnection is a key process that explosively accelerates charged particles, generating phenomena such as nebular flares, solar flares and stunning aurorae. In planetary magnetospheres, magnetic reconnection has often been identified on the dayside magnetopause and in the nightside magnetodisc, where thin-current-sheet conditions are conducive to reconnection. The dayside magnetodisc is usually considered thicker than the nightside due to the compression of solar wind, and is therefore not an ideal environment for reconnection. In contrast, a recent statistical study of magnetic flux circulation strongly suggests that magnetic reconnection must occur throughout Saturn’s dayside magnetosphere. Additionally, the source of energetic plasma can be present in the noon sector of giant planetary magnetospheres. However, so far, dayside magnetic reconnection has only been identified at the magnetopause. Here, we report direct evidence of near-noon reconnection within Saturn’s magnetodisc using measurements from the Cassini spacecraft. The measured energetic electrons and ions (ranging from tens to hundreds of keV) and the estimated energy flux of ~2.6 mW m–2 within the reconnection region are sufficient to power aurorae. We suggest that dayside magnetodisc reconnection can explain bursty phenomena in the dayside magnetospheres of giant planets, which can potentially advance our understanding of quasi-periodic injections of relativistic electrons6 and auroral pulsations

Reconnection acceleration in Saturn's dayside magnetodisc:a multicase study with Cassini

Recently, rotationally driven magnetic reconnection was firstly discovered in Saturn’s dayside magnetosphere (Guo et al. 2018). This newly confirmed process could potentially drive bursty phenomena at Saturn, i.e., pulsating energetic particles and auroral emissions. Using Cassini’s measurements of magnetic fields and charged particles, we investigate particle acceleration features during three magnetic reconnection events observed in Saturn’s dayside magnetodisc. The results suggest that the rotationally driven reconnection process plays a key role in producing energetic electrons (up to 100 keV) and ions (several hundreds of keV). In particular, we find that energetic oxygen ions are locally accelerated at all three reconnection sites. Isolated, multiple reconnection sites were recorded in succession during an interval lasting for much less than one Saturn rotation period. Moreover, a secondary magnetic island is reported for the first time at the dayside, collectively suggesting that the reconnection process is not steady and could be ‘drizzle-like’. This study demonstrates the fundamental importance of internally driven magnetic reconnection in accelerating particles in Saturn’s dayside magnetosphere, and likewise in the rapidly rotating Jovian magnetosphere and beyond

On the Relation Between Jovian Aurorae and the Loading/Unloading of the Magnetic Flux:Simultaneous Measurements From Juno, Hubble Space Telescope, and Hisaki

We present simultaneous observations of aurorae at Jupiter from the Hubble Space Telescope and Hisaki, in combination with the in situ measurements of magnetic field, particles, and radio waves from the Juno Spacecraft in the outer magnetosphere, from ~ 80RJ to 60RJ during 17 to 22 March 2017. Two cycles of accumulation and release of magnetic flux, named magnetic loading/unloading, were identified during this period, which correlate well with electron energization and auroral intensifications. Magnetic reconnection events are identified during both the loading and unloading periods, indicating that reconnection and unloading are independent processes. These results show that the dynamics in the middle magnetosphere are coupled with auroral variability