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Coarse‐grained (>3–5 μm) gray hematite particles occur at Vera Rubin ridge (VRR) within Gale crater, Mars. VRR has likely undergone multiple episodes of diagenesis, at least one of which resulted in the formation of gray hematite. The precursor mineralogy and nature of the diagenetic fluids that produced coarse‐grained hematite remain unknown. Analog laboratory experiments were performed on a variety of iron(III) minerals to assess the potential fluid conditions and precursor mineralogy that form coarse‐grained hematite. Gray hematite formed from the transformation of jarosite after 20 days at 200°C. Conversion was complete in chloride‐rich fluids; however, modeling indicates that at lower jarosite‐to‐water ratios, conversion is complete even in chloride‐free, sulfate‐rich conditions. No transformations of jarosite occurred when aged at 98°C. All other precursor minerals (akaganeite, ferrihydrite, goethite, and schwertmannite) did not transform or produced red, fine‐grained hematite under all conditions assessed. Additionally, seeding precursor iron(III) phases with red hematite and coarsening pre‐existing red hematite failed to produce gray hematite. These results suggest that jarosite could have been the precursor of gray hematite at VRR and that transformation is possible in both sulfate‐bearing and chloride‐bearing fluids. Jarosite produces gray hematite because the acidic conditions it generates yield both a low degree of hematite supersaturation, producing few nuclei, and high dissolved iron concentrations, enabling rapid hematite growth. Gray hematite readily forms under oxic conditions and its occurrence at VRR is not a marker for a redox interface. The associated diagenetic event was thus unlikely to have generated substantial new chemical energy for life. Hematite is often formed from other pre‐existing iron‐bearing minerals in water‐rich environments. Depending on its grain size, hematite can be either red (fine‐grained) or gray (coarse‐grained) and these grain sizes likely indicate distinct past conditions. Gray hematite has been observed at Vera Rubin ridge (VRR) in Gale crater, Mars, but how it formed is currently unknown. Laboratory experiments in this study demonstrate that jarosite, an iron‐ and sulfur‐bearing mineral, converts to gray hematite in fluids at elevated temperatures. Increased chloride in the fluid promotes more complete transformation but complete transformation will also occur in systems with sufficiently low jarosite‐to‐water ratios. Other iron‐bearing minerals assessed (akaganeite, ferrihydrite, goethite, schwertmannite, and fine‐grained hematite) did not transform or coarsen to gray hematite under any experimental conditions studied. The gray hematite at VRR likely formed by conversion from jarosite during alteration after the sediments in Gale crater had already formed. The conditions associated with this event did not provide any new chemical energy for life. Jarosite transforms to gray hematite at 200°C in both sulfate‐ and chloride‐bearing fluidsGoethite, akaganeite, ferrihydrite, schwertmannite, and red hematite do not form gray hematite after 20 days in the conditions assessedJarosite may be a viable precursor mineral to the gray hematite at Vera Rubin ridge due to the acidity it generates during dissolution Jarosite transforms to gray hematite at 200°C in both sulfate‐ and chloride‐bearing fluids Goethite, akaganeite, ferrihydrite, schwertmannite, and red hematite do not form gray hematite after 20 days in the conditions assessed Jarosite may be a viable precursor mineral to the gray hematite at Vera Rubin ridge due to the acidity it generates during dissolution

The Opportunity rover investigated a gentle swale on the rim of Endeavour crater called Marathon Valley where a series of bright planar outcrops are cut into polygons by fractures. A wheel scuff performed on one of the soil‐filled fracture zones revealed the presence of three end‐members identified on the basis of Pancam multispectral imaging observations covering ~0.4 to 1 μm: red and dark pebbles, and a bright soil clod. Multiple overlapping Alpha Particle X‐ray Spectrometer (APXS) measurements were collected on three targets within the scuff zone. The field of view of each APXS measurement contained various proportions of the Pancam‐based end‐members. Application of a log maximum likelihood method for retrieving the composition of the end‐members using the 10 APXS measurements shows that the dark pebble end‐member is compositionally similar to average Mars soil, with slightly elevated S and Fe. In contrast, the red pebble end‐member exhibits enrichments in Al and Si and is depleted in Fe and Mg relative to average Mars soil. The soil clod end‐member is enriched in Mg, S, and Ni. Thermodynamic modeling of the soil clod end‐member composition indicates a dominance of sulfate minerals. We hypothesize that acidic fluids in fractures leached and oxidized the basaltic host rock, forming the red pebbles, and then evaporated to leave behind sulfate‐cemented soil. The Opportunity rover investigated a region on the rim of Endeavour crater on Mars called Marathon Valley where a series of bright outcrops are cut by fractures. A scuff performed by one of the rover wheels on the fractures revealed the presence of three different compositional end‐members. A novel technique was applied to retrieve the composition of the end‐members using measurements by the rover's Alpha Particle X‐ray Spectrometer and Pancam instruments. The presence of a magnesium‐sulfate‐rich soil end‐member and hematite‐rich pebbles in the scuffed fracture imply alteration in an acid‐sulfate environment. Results add to growing evidence of alteration along the rim of Endeavour crater that was concentrated along fractures, which likely provided a conduit for subsurface fluid flow. The timing of formation of these altered deposits is unclear; they could have formed during transient postimpact hydrothermal activity or perhaps significantly later utilizing groundwater from the southern highlands. A log maximum likelihood method was used to determine end‐member compositions of a fracture in Marathon Valley, Endeavour crater, MarsA Mg‐sulfate‐rich soil end‐member and hematite‐rich pebbles in the fracture imply alteration in an acid‐sulfate environmentResults add to growing evidence of alteration along the rim of Endeavour crater by enhanced fluid flow along fracture zones

The ~100 m wide Marathon Valley crosscuts the Cape Tribulation rim segment of the 22 km diameter, Noachian‐age Endeavour impact crater on Mars. Single‐scattering albedo spectra retrieved from three Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) Full‐Resolution Targeted (FRT, regularized to 18 m/pixel) and two Along Track Oversampled (ATO, regularized to 12 m/pixel) observations indicate the presence of Fe3+‐Mg2+smectite exposures located in Marathon Valley with combination vibration metal‐OH absorption strength comparable to smectite spectral signatures in Mawrth Vallis. The Opportunity rover was directed to the exposures and documented the presence of Shoemaker formation impact breccias that have been isochemically altered, likely by fracture‐controlled aqueous fluids. Fe3+‐Mg2+smectites detected in Marathon Valley using five CRISM observationsOpportunity found that Shoemaker formation breccias dominate Marathon ValleyBreccias were isochemically altered to generate Fe3+‐Mg2+smectites

Compact Reconnaissance Imaging Spectrometer for Mars hyperspectral (1.0–2.65?µm) along-track oversampled observations covering Victoria, Santa Maria, Endeavour, and Ada craters were processed to 6?m/pixel and used in combination with Opportunity observations to detect and map hydrated Mg and Ca sulfate minerals in the Burns formation. The strongest spectral absorption features were found to be associated with outcrops that are relatively young and fresh (Ada) or preferentially scoured of dust, soil, and coatings by prevailing winds. At Victoria and Santa Maria, the scoured areas are on the southeastern rims and walls, opposite to the sides where wind-blown sands extend out of the craters. At Endeavour, the deepest absorptions are in Botany Bay, a subdued and buried rim segment that exhibits high thermal inertias, extensive outcrops, and is interpreted to be a region of enhanced wind scour extending up and out of the crater. Ada, Victoria, and Santa Maria outcrops expose the upper portion of the preserved Burns formation and show spectral evidence for the presence of kieserite. In contrast, gypsum is pervasive spectrally in the Botany Bay exposures. Gypsum, a relatively insoluble evaporative mineral, is interpreted to have formed close to the contact with the Noachian crust as rising groundwaters brought brines close to and onto the surface, either as a direct precipitate or during later diagenesis. The presence of kieserite at the top of the section is hypothesized to reflect precipitation from evaporatively concentrated brines or dehydration of polyhydrated sulfates, in both scenarios as the aqueous environment evolved to very arid conditions. Hydrated Mg and Ca sulfate Burns formation minerals mapped with MRO and MER data

La fracture-arrachement de la tubérosité tibiale antérieure associée à une désinsertion du tendon patellaire est rare. Peu de données existent sur l’évolution clinique et la récupération musculaire quadricipitale dans les suites de ce type de traumatisme. Les quelques cas rapportés font état d’une évolution fonctionnelle favorable entre 12 et 15 mois postopératoire. Cependant, nous n’avons pas retrouvé d’étude évaluant la récupération musculaire quadricipitale de manière objective par méthode isocinétique. Nous rapportons un cas de fracture-arrachement de la tubérosité tibiale antérieure, associée à une désinsertion basse du tendon patellaire, chez un footballeur âgé de 15 ans au moment du traumatisme, avec suivi de l’évolution clinique et de la récupération musculaire quadricipitale isocinétique sur 2 ans.

On the basis of promising results that were reported in several phase 2 trials, we investigated whether the addition of the monoclonal antibody rituximab to first-line chemotherapy with fludarabine and cyclophosphamide would improve the outcome of patients with chronic lymphocytic leukaemia.

Long-chain sodium polyphosphate compounds have been recently proposed as a ‘time-released’ source of phosphate for precipitation of uranium-phosphate minerals. Elevated sodium concentrations presented by this technique promote the formation of sodium autunite relative to the more common calcium autunite mineral phase. In order to evaluate sodium autunite minerals as a long-term ‘sink’ for in-situimmobilization of uranium, it is necessary to quantify their longevity under environmentally relevant conditions. This paper describes a direct method for precipitating sodium autunite and provides a comparative analysis of the structural and chemical properties of direct versusindirectly precipitated sodium autunite. Extended X-ray absorption fine structure (EXAFS) spectroscopy, chemical digestion followed by inductively-coupled plasma-optical emission spectroscopy (ICP-OES) and inductively-coupled plasma-mass spectroscopy (ICP-MS) for elemental analyses, X-ray diffraction (XRD), scanning electron microscopy (SEM), multi point Brunauer–Emmett–Teller (BET) analyses and helium pyconometry were used to characterize the precipitate phases. Morphological differences are discussed in the context of conducting subsequent solubility and dissolution investigations. Research presented here is part of a larger effort to quantify the solubility and dissolution properties of uranium-phosphate minerals.

Aeolis Mons (informally, Mount Sharp) exhibits a number of canyons, including Gediz and Sakarya Valles. Poorly sorted debris deposits are evident on both canyon floors and connect with debris extending down the walls for canyon segments that cut through sulphate‐bearing strata. On the floor of Gediz Vallis, debris overfills a central channel and merges with a massive debris ridge located at the canyon terminus. One wall‐based debris ridge is evident. In comparison, the floor of Sakarya Vallis exhibits a complex array of debris deposits. Debris deposits on wall segments within Sakarya Vallis are mainly contained within chutes that extend downhill from scarps. Lateral debris ridges are also evident on chute margins. We interpret the debris deposits in the two canyons to be a consequence of one or more late‐stage hydrogeomorphic events that increased the probability of landslides, assembled and channelized debris on the canyon floors, and moved materials down‐canyon. The highly soluble nature of the sulphate‐bearing rocks likely contributed to enhanced debris generation by concurrent aqueous weathering to produce blocky regolith for transport downslope by fluvial activity and landslides, including some landslides that became debris flows. Subsequent wind erosion in Gediz Vallis removed most of the debris deposits within that canyon and partially eroded the deposits within Sakarya Vallis. The enhanced wind erosion within Gediz Vallis was a consequence of the canyon's alignment with prevailing slope winds. Debris deposits on the walls and floors of canyons cut into Mount Sharp are a consequence of late stage precipitation, with ground water infiltration that triggered landslides and debris flows of blocky regolith. This is supported by their morphologies, and by calculations of slope stability in the presence of groundwater. The relatively soluble nature of the sulphate‐bearing strata facilitated chemical weathering to produce material conditioned to fail as landslides. Subsequent wind‐driven erosion degraded many of these features, including differential stripping of wall and floor rocks to generate debris ridges. Debris deposits on the walls and floors of canyons cut into Mount Sharp were a consequence of late stage, water‐related eventsWind‐driven erosion degraded many of these features, including differential stripping of wall and floor deposits to generate debris ridges Debris deposits on the walls and floors of canyons cut into Mount Sharp were a consequence of late stage, water‐related events Wind‐driven erosion degraded many of these features, including differential stripping of wall and floor deposits to generate debris ridges

The present review concerns certain Human Factors aspects of sport activities. Particular emphasis is given to evaluating experimental work in which the relationship between equipment design and performance capability has been examined. The criterion for inclusion in the current synthesis was the use of a cognitive or behavioral measure as a dependent variable in an empirical investigation. Although this excludes studies reporting physiological parameters, it is not to say such work may not form an important element of any future review. Where possible research was grouped according to some common theme or topic. In addition, the potential benefits of a cohesive study of Human Factors in sport are briefly outlined.

Although lipid phosphoric acid mediators such as lysophosphatidic acid (LPA) are now recognized widely as intercellular signaling molecules, the medicinal chemistry of these mediators is poorly developed. With the goal of achieving a better understanding of the structure activity relationships in LPA, we have synthesized and tested a series of LPA analogs that lack the 2-hydroxyl moiety. Our series consisted of compounds with 2, 3, or 4 carbon diol or amino alcohol backbones and oleoyl or palmitoleoyl acyl groups. These molecules cannot be acylated further to form phosphatidic acids, nor do they have chiral centers. The rank order potency of these compounds in mobilization of calcium in MDA MB-231 cells suggested a maximum optimal chain length of 24-25 atoms. However, high potency for the inhibition of adenylyl cyclase in these cells was achieved only by one compound that also contained a dissociable proton five bond lengths from the phosphorus atom. That compound, N-oleoyl-2-hydroxyethyl-1-phosphate, was nearly equipotent to 1-oleoyl LPA in both assays. The striking mimicry of LPA by the ethanolamine-based compound and the presence of fatty acid amides in tissue prompts us to propose that phosphorylated N-acyl ethanolamides occur naturally.

Total body irradiation (TBI) is a highly emetogenic component of the majority of conditioning regimens in use for bone marrow transplantation. Conventional antiemetic therapy fails to control nausea and vomiting induced by single fraction TBI in as many as 50% of patients. In a double blind study of 20 patients undergoing marrow transplantation, a single 8 mg ondansetron dose was compared with placebo given immediately prior to TBI. Our routine premedication of phenobarbitone and corticosteroid was also administered to all patients. All patients had received high dose melphalan the previous evening. Only 1 of the 10 patients in the ondansetron group experienced an emetic event compared with 5 of the 10 in the comparison group (p = 0.029). No significant adverse events were observed. Ondansetron appears to have extremely useful antiemetic activity during single fraction low dose rate TBI.

The acute tumour lysis syndrome is a well recognised complication of chemotherapy for lymphoid malignancies. There are few reports, however, of this complication after corticosteroid therapy alone. We report a case of T-cell acute lymphoblastic leukaemia who developed the biochemical picture of tumour lysis after two doses of hydrocortisone given prior to platelet transfusion. Prophylactic corticosteroids prior to blood product infusion should be reserved for patients who have experienced febrile or allergic reactions in the past and it is suggested that they should only be administered to patients with active lymphoid malignancies with due caution.

This paper provides an overview of the Curiosityrover's exploration at Vera Rubin ridge (VRR) and summarizes the science results. VRR is a distinct geomorphic feature on lower Aeolis Mons (informally known as Mount Sharp) that was identified in orbital data based on its distinct texture, topographic expression, and association with a hematite spectral signature. Curiosityconducted extensive remote sensing observations, acquired data on dozens of contact science targets, and drilled three outcrop samples from the ridge, as well as one outcrop sample immediately below the ridge. Our observations indicate that strata composing VRR were deposited in a predominantly lacustrine setting and are part of the Murray formation. The rocks within the ridge are chemically in family with underlying Murray formation strata. Red hematite is dispersed throughout much of the VRR bedrock, and this is the source of the orbital spectral detection. Gray hematite is also present in isolated, gray‐colored patches concentrated toward the upper elevations of VRR, and these gray patches also contain small, dark Fe‐rich nodules. We propose that VRR formed when diagenetic event(s) preferentially hardened rocks, which were subsequently eroded into a ridge by wind. Diagenesis also led to enhanced crystallization and/or cementation that deepened the ferric‐related spectral absorptions on the ridge, which helped make them readily distinguishable from orbit. Results add to existing evidence of protracted aqueous environments at Gale crater and give new insight into how diagenesis shaped Mars' rock record. Vera Rubin ridge is a feature at the base of Mount Sharp with a distinct texture and topography. Orbiter observations showed hematite, a mineral that sometimes forms by chemical reactions in water environments, was present atop the ridge. The presence of both water and chemical activity suggested the area preserved a past habitable environment. In this paper, we detail how the Curiosityscience team tested this and other orbital‐based hypotheses. Curiositydata suggested that most ridge rocks were lain down in an ancient lake and had similar compositions to other Mount Sharp rocks. Curiosityconfirmed that hematite was present in the ridge but no more abundantly than elsewhere. Larger grain size or higher crystallinity probably account for the ridge's hematite being more visible from orbit. We conclude Vera Rubin ridge formed because groundwater recrystallized and hardened the rocks that now make up the ridge. Wind subsequently sculpted and eroded Mount Sharp, leaving the harder ridge rocks standing because they resisted erosion compared with surrounding rocks. The implication of these results is that liquid water was present at Mount Sharp for a very long time, not only when the crater held a lake but also much later, likely as groundwater. We summarize Curiosity's campaign at Vera Rubin ridge (Sols 1726–2302) and the high‐level results from articles in this special issueVera Rubin ridge formed when diagenesis hardened rocks along the base of Aeolis Mons; wind subsequently etched the feature into a ridgeResults add evidence for protracted aqueous environments at Gale crater and give new insight into how diagenesis shaped Mars' rock record

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

DURING A two month period, September and October 1968, plastic bell clamps were used for routine circumcision in the newborn at the Naval Hospital in Pensacola, Fla. Approximately 100 circumcisions were done using this method. They were performed on the second hospital day.Numerous minor complaints of appearance and not falling off soon enough (less than ten days) were made during this period. These were expected, and appropriate corrective measures were taken.On one occasion, the plastic bell did not separate, and on the 33rd day the child was brought into the clinic for evaluation. The "ring" portion had become fixed on the glans of the penis resulting in an artificial sulcus on the distal portion of the glans. The bell was removed without difficulty and the child dismissed. Five days later, he was again brought to the clinic with the complaint that the ridge had not disappeared (Fig 1).