The near-Earth asteroid 162173 Ryugu, the target of the Hayabusa2 sample-return mission, is thought to be a primitive carbonaceous object. We report reflectance spectra of Ryugu's surface acquired ...with the Near-Infrared Spectrometer (NIRS3) on Hayabusa2, to provide direct measurements of the surface composition and geological context for the returned samples. A weak, narrow absorption feature centered at 2.72 micrometers was detected across the entire observed surface, indicating that hydroxyl (OH)-bearing minerals are ubiquitous there. The intensity of the OH feature and low albedo are similar to thermally and/or shock-metamorphosed carbonaceous chondrite meteorites. There are few variations in the OH-band position, which is consistent with Ryugu being a compositionally homogeneous rubble-pile object generated from impact fragments of an undifferentiated aqueously altered parent body.
Context.
The Hayabusa2 spacecraft launched by Japan Aerospace Exploration Agency has been conducting observations of the asteroid (162173) Ryugu since June 2018. The Telescopic Optical Navigation ...Camera (ONC-T) onboard Hayabusa2 has obtained thousands of images under a variety of illumination and viewing conditions.
Aims.
Our objective is to examine and validate the camera calibration, derive a photometric correction for creating global albedo maps, and to interpret the photometric modeling results to characterize the surface of Ryugu.
Methods.
We observed (162173) Ryugu with the Gemini-South telescope, and combined these measurements with other published ground-based observations of the asteroid. The ground-based observations were compared with the data obtained by ONC-T in order to validate the radiometric calibration mutually. We used a combination of the Hapke disk-integrated and disk-resolved model equations to simultaneously analyze the combined ground- and spacecraft-based data.
Results.
The average spectrum of Ryugu was classified as Cb-type following the SMASSII taxonomy and C/F-type following the Tholen taxonomy based on spacecraft observations. We derived Hapke model parameters for all seven color filters, which allowed us to photometrically correct images to within an error of <10% for ~80% of the image pixels used in the modeling effort. Using this model, we derived a geometric albedo of 4.0 ± 0.5% (
v
band) for Ryugu. The average reflectance factor at the standard illumination condition was 1.87 ± 0.14% in the
v
band. Moreover we measured a phase reddening of (2.0 ± 0.7) × 10
−3
μ
m
−1
deg
−1
for Ryugu, similar to that observed for the asteroid (101955) Bennu.
Conclusions.
The global color map showed that the general trend was for darker regions to also be redder regions, however there were some distinct exceptions to this trend. For example, Otohime Saxum was bright and red while Kibidango crater was dark and blue. The darkness and flatness of Ryugu’s reflectance might be caused by a high abundance of organic materials.
Purpose
To investigate whether pre-operative magnetic resonance imaging (MRI) of the lumbar multifidus muscle (LMM) would predict clinical outcomes following lumbar spinal decompression for ...symptomatic spinal stenosis.
Methods
A prospective cohort of patients with symptomatic neurogenic claudication, documented spinal stenosis on pre-operative MRI underwent spinal decompression. All subjects completed standardised outcome measures (Core Outcome Measures Index (COMI), Oswestry Disability Index (ODI v2.1) pre-operatively, 1 and 2 years post-surgery. Surgery was performed using a standardised lumbar spinous process osteotomy for access, followed by a decompression of the central canal, lateral recess and foraminal zones as indicated by the pre-operative MRI. Lumbar MRI scans were evaluated by two independent observers who assessed the axial CSA of the LMM bilaterally and the degree of muscle atrophy according to the Kader classification (2000). Changes in COMI and ODI scores at 1 and 2 years were investigated for statistically significant correlations with CSA of LMM and Kader grading. Statistical analyses utilised Student’s
t
test, kappa coefficient for inter-observer agreement and Bland–Altman Limits of Agreement (BALOA).
Results
66 patients (41 female) aged between 29 and 86 years underwent single-level decompression in 44, two-level decompression in 16 and three-level decompression in 6 cases. No significant correlation was observed between improvements in ODI and COMI relative to age, degree of stenosis, posterior fat thickness or psoas CSA. Those subjects with the greatest LMM atrophy relative to psoas CSA and L5 vertebral body area on pre-operative MRI had the least absolute improvement in both ODI and COMI scores (
p
= 0.006).
Conclusions
Reduced LMM CSA (<8.5 cm
2
) and muscle atrophy were associated with less favourable outcomes following lumbar spinal decompression. Pre-operative CSA of LMM appeared to be a more reliable predictor of post-operative clinical outcomes compared to the Kader Grading Score. This is the first study to investigate the prognostic value of pre-operative MRI appearance and CSA of LMM with respect to post-operative outcome following lumbar decompression surgery. Healthy pre-operative LMM is associated with better outcomes following lumbar spinal decompression.
Since July 2009, there has been a community outbreak of leishmaniasis in the south-west area of the Madrid autonomous community, Spain, affecting residents from four towns that are geographically ...close together and share extensive park areas. As of December 2012, 446 cases were reported (6 in 2009, 97 in 2010, 196 in 2011 and 147 in 2012), a mean incidence rate of 22.2 per 100,000 inhabitants during July 2009 and December 2012. The mean age was 44 years (range: 2 months to 95 years); 61.0% were male. A total of 68 (15.2%) had immunosuppressive conditions; 160 (35.9%) had visceral leishmaniasis and 286 (64.1%) cutaneous. A total of 421 (94.4%) cases were confirmed. Leishmania infantum was identified as the agent. Monitoring revealed high densities of the vector Phlebotomus perniciosus. The surveillance system for canine leishmaniasis did not detect any increase in prevalence during the period. Environmental control measures have been taken, such as improvements in sanitation and disinsection in the risk areas and control of the overpopulation of Leporidae, as xenodiagnosis studies have shown that hares play a role as active reservoirs. This is the largest reported community outbreak of leishmaniasis in Europe. The discovery of the new reservoir stands out in the multifactorial aetiology of the outbreak. Epidemiological research and environmental intervention measures are continuing.
•BZN mitigated T. cruzi-induced weight loss and death in S. mansoni co-infected mice.•Co-infection attenuated the levels of cytokines induced by T. cruzi and S. mansoni.•BZN reduced blood and tissue ...parasitism by T. cruzi even among co-infected mice.•Co-infection and BZN impacted T. cruzi and S. mansoni-induced organ remodeling.
The adequate management of parasite co-infections represents a challenge that has not yet been overcome, especially considering that the pathological outcomes and responses to treatment are poorly understood. Thus, this study aimed to evaluate the impact of Schistosoma mansoni infection on the efficacy of benznidazole (BZN)-based chemotherapy in Trypanosoma cruzi co-infected mice. BALB/c mice were maintained uninfected or co-infected with S. mansoni and T. cruzi, and were untreated or treated with BZN. Body weight, mortality, parasitemia, cardiac parasitism, circulating cytokines (Th1/Th2/Th17); as well as heart, liver and intestine microstructure were analyzed. The parasitemia peak was five times higher and myocarditis was more severe in co-infected than T. cruzi-infected mice. After reaching peak, parasitemia was effectively controlled in co-infected animals. BZN successfully controlled parasitemia in both co-infected and T. cruzi-infected mice and improved body mass, cardiac parasitism, myocarditis and survival in co-infected mice. Co-infection dampened the typical cytokine response to either parasite, and BZN reduced anti-inflammatory cytokines in co-infected mice. Despite BZN normalizing splenomegaly and liver cellular infiltration, it exacerbated hepatomegaly in co-infected mice. Co-infection or BZN exerted no effect on hepatic granulomas, but increased pulmonary and intestinal granulomas. Marked granulomatous inflammation was identified in the small intestine of all schistosomiasis groups. Taken together, our findings indicate that BZN retains its therapeutic efficacy against T. cruzi infection even in the presence of S. mansoni co-infection, but with organ-specific repercussions, especially in the liver.
Ria de Vigo is a funnel-shaped, fault-bounded coastal embayment in Galicia, NW Spain. There are a number of important centres of population and industrial activity along its margins, which serve as ...sources of pollution. Sixty-six subtidal sediment samples have been collected in the Ria. The samples have been subjected to a total digestion technique and analysed for major and trace elements (Al, Fe,Ti, Mn, Cu, Pb, Cr, Zn, Co, As, Ni, Cd and Sr). Variations of absolute metal concentrations reflected variations in textural and/or carbonate and organic matter content. Geoaccumulation indexes and enrichment factors have been calculated to assess whether the concentrations observed represent background or contaminated levels. It is proved that the choice of the background plays an important role in the interpretation of the geochemical data. PCA was a very useful tool to define background values for metals in the Ria de Vigo area. These values were similar to regional values given by other authors. It is concluded that the Ria is slightly to moderately polluted for some of the studied metals. The spatial extent of pollution was examined, and it was found that the most polluted area is located in the inner and southern parts of the Ria.
In this work a method of analysis for synthetic dyes was developed using capillary electrophoresis in alcoholic beverages. The analyses were carried out with fused silica capillary, with 73
cm ...effective length, at 35
°C, buffer phosphate solution of 10
mmol/L with sodium dodecyl sulphate 10
mmol/L, pH 11, and +25
kV of voltage. For dye analyses, three wavelengths in the visible region were used for the qualitative and quantitative determination of the 11 synthetic dyes allowed in Brazil: 450, 525 and 625
nm for the yellow, red and blue dyes, respectively. The detection limits varied from 0.4 to 2.5
μg/mL and the quantification limits varied from 1.3 to 7.1
μg/mL. The average recovery was 92.6 and 104.0% at two levels of concentration. Repeatability for standards and spiked sample showed that the calculated values were greater than the observed values, demonstrating the precision of the method. The proposed and validated method was used to analyze some alcoholic beverage samples, consisting of 12 red wines, 9 coolers, 6 aromatized spirits, 7 bitters, 3 cocktails and 8 liquors from different Brazilian manufacturers. The results showed the coolers, bitters and red wines did not have synthetic dyes, but dyes were found in six of the eight analyzed liquor samples. In all the samples of cocktails and spirits, the presences of dyes were observed. No analyzed sample exceeded the limit established by Brazilian legislation (maximum 30
mg/100
mL).
This paper summarizes the evidence for the optical effects of space weathering, as well as the properties of the surface that control optical changes, on asteroid (101955) Bennu. First, we set the ...stage by briefly reviewing what was known about space weathering of low-albedo materials from telescopic surveys, laboratory simulations, and sample return analysis. We then look at the evidence for the nature of space weathering on Bennu from recent spacecraft imaging and spectroscopy observations, including the visible to near-infrared and thermal infrared wavelengths, followed by other measurements such as normal albedo measurements from LIDAR scans. We synthesize these different lines of evidence in an effort to describe a general model of space weathering processes and resulting color effects on dark C-complex asteroids, with hypotheses that can be tested by analyzing samples returned by the mission.
A working hypothesis that synthesizes findings thus far is that the optical effects of maturation in the space environment depend on the level of hydration of the silicate/phyllosilicate substrate. Subsequent variations in color depend on surface processes and exposure age. On strongly hydrated Bennu, in color imaging data, very young craters are darker and redder than their surroundings (more positive spectral slope in the wavelength range 0.4–0.7μm) as a result of their smaller particle sizes and/or fresh exposures of organics by impacts. Solar wind, dehydration, or migration of fines may cause intermediate-age surfaces to appear bluer than the very young craters. Exposed surfaces evolve toward Bennu’s moderately blue global average spectral slope. However, in spectroscopic and LIDAR data, the equator, the oldest surface on Bennu, is darker and redder (wavelength range 0.55–2.0μm) than average and has shallower absorption bands, possibly due to dehydration and/or nanophase and/or microphase opaque production.
Bennu is a rubble pile with an active surface, making age relationships, which are critical for determining space weathering signals, difficult to locate and quantify. Hence, the full story ultimately awaits analyses of the Bennu samples that will soon be delivered to Earth.
•We present evidence for the nature of space weathering on Bennu from recent spacecraft observations.•Bennu is a rubble pile with an active surface, making surface age relationships difficult to identify.•We synthesize evidence to describe a general model of space weathering on C-complex asteroids.•Optical effects of maturation depend on the level of hydration of the (phyllo)silicate substrate.•Subsequent variations in color depend on exposure age.
•Examined visible/near infrared spectra (0.4–3.1μm) of Phobos and Deimos.•Fe2+ electronic absorptions diagnostic of olivine and pyroxene were not detected.•Absorptions centered around 0.65μm and ...2.8μm are detected on both moons.•Both absorptions are similar to features on low-albedo asteroids.•Absorptions caused by phyllosilicates or Fe-particles/solar wind implantation of H.
Absorption features on Phobos and Deimos in the visible/near infrared wavelength region (0.4–3.9μm) are mapped using observations from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM). Fe2+ electronic absorptions diagnostic of olivine and pyroxene are not detected. A broad absorption centered around 0.65μm within the red spectral units of both moons is detected, and this feature is also evident in telescopic, Pathfinder, and Phobos-2 observations of Phobos. A 2.8μm metal–OH combination absorption on both moons is also detected in the CRISM data, and this absorption is shallower in the Phobos blue unit than in the Phobos red unit and Deimos. The strength, position, and shape of both of the 0.65μm and 2.8μm absorptions are similar to features seen on red-sloped, low-albedo primitive asteroids. Two end-member hypotheses are presented to explain the spectral features on Phobos and Deimos. The first invokes the presence of highly desiccated Fe-phyllosilicate minerals indigenous to the bodies, and the second invokes Rayleigh scattering and absorption of small iron particles formed by exogenic space weathering processing, coupled with implantation of H from solar wind. Both end-member hypotheses may play a role, and in situ exploration will be needed to ultimately determine the underlying causes for the pair of spectral features observed on Phobos and Deimos.
During the declining phase of the longest solar minimum in a century, the arrival of the MESSENGER spacecraft at superior conjunction allowed the measurement of magnetohydrodynamic (MHD) waves in the ...solar corona with its 8 GHz radio frequency signal. MHD waves crossing the line of sight were measured via Faraday rotation fluctuations (FRFs) in the plane of polarization (PP) of MESSENGER’s signal. FRFs in previous observations of the solar corona (at greater offset distances) consisted of a turbulent spectrum that decreased in power with increasing frequency and distance from the Sun. Occasionally a spectral line, a distinct peak in the power spectral density spectrum around 4 to 8 mHz, was also observed in these early data sets at offset distances of about 5 to 10 solar radii. The MESSENGER FRF data set shows a spectral line at an offset distance between 1.55 to 1.85 solar radii with a frequency of 0.6±0.2 mHz. Other possible spectral lines may be at 1.2, 1.7, and 4.5 mHz; MHD waves with these same frequencies have been observed in X-ray data traveling along closed coronal loops at lower offset distances. An initial analysis of the MESSENGER spectral line(s) shows behavior similar to turbulent spectra: decreasing power with increasing frequency and distance from the Sun. Here we detail the steps taken to process the MESSENGER change in PP data set for the MHD wave investigation.
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