Arctic cold spring mineralogy as an indicator of spring deposits, water, and habitable environments on Mars

Springs exist in many terrestrial settings and have supported microbial communities throughout Earth’s history. There is mounting evidence for spring deposits on Mars from Noachian age to present, implying that water may be circulating in Mars’ subsurface despite current cold, arid conditions. Current datasets for most of Mars are limited to mineralogy via orbital spectroscopy and geomorphology from visual imagery and laser altimetry. Much is known about terrestrial spring morphology, but few springs exist in Mars analogue settings, and of those, few have been investigated for mineralogy. This study reports on two sets of cold spring sites in the Canadian arctic where permafrost, frigid temperatures, and arid conditions approximate Mars’ environment. The first are acidic cold seeps forming the jarosite-rich Golden Deposit (GD) in Northwest Territories, Canada. The second are perennial saline spring systems associated with three gypsum/anhydrite diapirs on Axel Heiberg Island, Nunavut, Canada: Wolf spring (WS; also known as Lost Hammer), Colour Peak (CP), and Gypsum Hill (GH) springs. Reflectance spectra were collected to determine how similar spring deposits would appear from Mars orbit, and compared to X-ray diffraction (XRD) and inductively coupled plasma emission spectrometry (ICP-ES) results. Spectrally, GD appears to consist only of jarosite, but XRD analysis also detected natrojarosite, hydronium jarosite, goethite, quartz, clays, and hematite. In samples from WS gypsum and mirabilite are spectrally visible via strong features in the ranges of all current Mars orbital datasets, owing to their hydrated states. Halite and thenardite are spectrally detectable, but the strongest absorption features lay outside the ranges of the highest resolution Mars datasets. XRD analysis of WS samples detected primarily halite, thenardite, gypsum, and mirabilite, with other sulfates and elemental sulfur. Results from this study are applied in the search for potential spring sites on Mars, and an ovoid jarosite-rich deposit in Mawrth Vallis is proposed as a landing site for future Mars missions. Jarosite, gypsum, and thenardite facilitate preservation of organic material, and thus suspected spring deposits containing these sulfate minerals are excellent candidates in the search for evidence of life on Mars

Range of normal values for left and right ventricular ejection fraction at rest and during exercise assessed by radionuclide angiocardiography

In order to reach a world-wide consensus on the normal range of left (LV) and right ventricular (RV) ejection fraction (EF) at rest and during exercise, pooled data of 1200 normal subjects from 28 leading centres in the field of nuclear cardiology (68% of those contacted) was analysed. Weighted mean normal values for LVEF at rest were 62.3±6.1% (1SD) with a lower limit of normal of 50% and for RVEF 52.3±6.2% (N=365) with a lower limit of normal of 40%. During exercise, LVEF increased in 475 subjects by +8.0 EF% (range 3-15%), a normal increase being accepted to be ≥5% over a normal resting value for both LVEF and RVEF. Subgroup analysis of results at rest revealed no significant differences regarding selection of normal subjects (based on normal catheterization findings vs. normal volunteers with low probability of disease), age or sex. During exercise, however, significantly larger increases in LVEF measurements were noted for men versus women (P<0.01), for normal volunteers versus subjects selected as ‘normals' based on a normal coronary angiogram (P<0.001) and for younger versus older subjects (P<0.001). Data on reproducibility and variability showed that radionuclide angiocardiography can be considered to be a reliable method today. No consensus was found for measurements of regional LV function or wall motion mainly because of differences in methodology used. These normal values may serve as general guidelines for future applications of these techniques but factors which may influence the normal range as defined and discussed in this study should be recognize

Fluorochrome Bone Labeling in Sheep

As an efficacy model. thirty-four female Merino sheep underwent transpedicular lumbar interbody fusion with three different materials for augmentation of the spine. Fluorochrome analysis was used to evaluate differences in bone deposition and fusion processes between the three study groups. During the post-operative follow-up period ofeight weeks, the fluorescent dyes xylenol orange. calcein green, and doxyeycline yellow were given at two, four. and six weeks, respectively. All dyes were administered intravenously after sedation with xylazine. The objective of this paper is to provide a methodical description of preparation quality control, administration, efficacy, and observed adverse events from the use of these bone labels in sheep.Both xylenol orange and calcein green dyes provided satisfying results but doxycyeline yellow led to only weak fluorescence in the first ten animals. Consequently, higher dosing was introduced to obtain bright bands in the histological sections. Also, during administration of doxycyeline yellow, mild to severe adverse events occasionally occured: Eight of the first ten sheep suffered from respiratory distress, and in severe cases several stopped breathing, thus requiring immediate intervention. Minimizing the sedative dose and elongating the sedation/doxycycline administration interval were effective changes to the original procedure. We conclude that these adverse events may have been caused by too high a close of sedative, as well as a drug interaction between xylazine and doxycycline yellow

Plasma ACTH, α-MSH and cortisol variations in the dog during the oestrous cycle in different photoperiods

The hypothalamic-pituitary-adrenal axis (HPA) is a complex system regulated by multiple factors.Sexual dimorphism of this axis has been described in different species under physiological conditions and it hasbeen proposed that sexual hormones could have an effect on it. There are only a few reports about sex-linkedvariations in HPA axis hormones in the dog. Thus, studying the impact of sexual hormones on the HPA axis wouldbroaden the knowledge about its function in this species. Therefore, the objective of this study was to determinewhether there are variations in HPA plasma hormones (ACTH, alfa-melanocyte-stimulating hormone [α-MSH]and cortisol) according to the sex and photoperiod (positive or negative photoperiod were considered when theduration of the light hours of the day was more than 12 or less than 12, respectively) under basal conditions (likeanoestrus) and throughout the oestrous cycle in the female dog. The population under study consisted of 11 intactfemale and 14 intact male dogs. Under basal conditions neither ACTH nor α-MSH concentrations showed differencesbetween sexes and different photoperiods. Cortisol showed greater values in the negative photoperiod thanin the positive, both in females and males (P = 0.03 and P = 0.015, respectively). Throughout the oestrous cycle,all the studied hormones showed variations (P < 0.0001). The greatest concentrations of ACTH were observed atproestrus, while α-MSH and cortisol showed their greatest concentrations at oestrus. The three hormones decreasedin diestrus. ACTH and cortisol concentrations were higher in the negative photoperiod (P = 0.04 and P < 0.0001,respectively), while α-MSH concentrations were higher in the positive photoperiod (P = 0.012). In the group offemales oestradiol and progesterone correlated with ACTH (r = 0.75, P < 0.0001; r = 0.34, P < 0.01, respectively),α-MSH (r = 0.49, P < 0.0001; r = 0.52, P < 0.0001, respectively) and cortisol (r = 0.33, P < 0.01; r = 0.5, P < 0.0001,respectively). These results show that in females, HPA axis hormones vary during the oestrous cycle in relation tooestradiol and progesterone fluctuations. The ACTH, α-MSH and cortisol concentrations also showed differencesbetween photoperiods in females, but only cortisol did so in males. These findings suggest that sexual hormonescould have an effect on the HPA axis. Further research needs to be done to fully understand this interaction andthe mechanisms involved.Fil: Gallelli, María Florencia. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Monachesi, N.. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Miceli, Diego Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Cabrera Battler, M. F.. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Gomez, N. V.. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Meikle, A.. Universidad de Montevideo; UruguayFil: Castillo, V, A.. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; Argentin

The second Euro Heart Survey on acute coronary syndromes: characteristics, treatment, and outcome of patients with ACS in Europe and the Mediterranean Basin in 2004

Aims Our study aimed to examine the management of acute coronary syndromes (ACS) in Europe and the Mediterranean basin, and to compare adherence to guidelines with that reported in the first Euro Heart Survey on ACS (EHS-ACS-I), 4 years earlier. Methods and results In a prospective survey conducted in 2004 (EHS-ACS-II), data describing the characteristics, treatment, and outcome of 6385 patients diagnosed with ACS in 190 medical centres in 32 countries were collected. ACS with ST-elevation was the initial diagnosis in 47% of patients, no ST-elevation in 48%, and undetermined electrocardiographic pattern in 5% of patients. Comparison of data collected in 2000 and 2004 showed similar baseline characteristics, but greater use of recommended medications and coronary interventions in EHS-ACS-II. Among patients with ST-elevation, the use of primary reperfusion increased slightly (from 56 to 64%), with a significant shift from fibrinolytic therapy to primary percutaneous coronary intervention (PPCI). The use of PPCI rose from 37 to 59% among those undergoing primary reperfusion therapy. Analysis of data in 34 centres that participated in both surveys showed even greater improvement with respect to the use of recommended medical therapy, interventions, and outcome. Conclusion Data from EHS-ACS-II suggest an increase in adherence to guidelines for treatment of ACS in comparison with EHS-ACS-I

Overview of SAND-E: Semi-Autonomous Navigation for Detrital Environments

Rovers are the state of the art for the exploration and detection of past habitability and life on other worlds. One of the most basic functions of a rover is terrain navigation. Information collected by the rover is used autonomously to mitigate terrain hazards such large rocks, while humans qualitatively assess hazardous geologic terrain such as soil type and degree of rock cover. Planetary scientists use the same information to select targets such as drill sites, and for basic scientific analysis such as characterization of rock outcrops. Although the data is complementary, data from terrain analysis for navigation and terrain analysis for scientific investigations are poorly integrated. The lack of integration creates science and operation inefficiencies that limit exploration of habitable environments. As new modes of exploration come online, such as unmanned aerial systems (UAS) (e.g., the Mars Helicopter Scout and Titan Dragonfly), a need exists to integrate terrain data and science analysis to improve operational and scientific outcomes during exploration. We present an overview of a project aimed at evaluating the effectiveness and capability rover and UAS-based semi-automated terrain analysis using the Automated Soil Assessment Systems (ASAS) developed by Mission Control Space Services for navigating, selecting targets for sampling, and characterizing mafic detrital sediments along glacio-fluvial-aeolian sand transport pathways in Iceland. We describe recent advances in automated terrain analysis in sandy environments and scientific uses of terrain assessment from sandy environments. We assess fluvial and aeolian terrains in Iceland and show how terrain analysis data can inform scientific characterization of these environments

Expression of Mipu1 in Response to Myocardial Infarction in Rats

Myocardial ischemic preconditioning up-regulated protein 1 (Mipu1) was cloned in our laboratory. Male Wistar rats were subjected to left anterior coronary artery ligation and sham-operation and sacrificed at 1 h, 3 h, 6 h, 12 h, 24 h, 3 d or 5 d after ligation. Expression of Mipu1 mRNA and protein were assessed by Northern blotting, real-time quantitative RT-PCR, In Situ hybridization and Western blotting. Expression of Mipu1 was up-regulated at 3 h and lasted to 12 h with a peak at 6 h. Mipu1 mRNA and protein signals express in the endothelium and myocardium in normal and infarcted heart, mainly in infarcted zone. Fluorescent immunocytochemistry showed that Mipu1 protein was localized to the nuclei of H9c2 myogenic cells and was upregulated after the cells being exposed to H2O2. These observations indicates that Mipu1 may play a role in maintaining vascular homeostasis and protecting the myogenic cells from being injured by ischemia-reperfusion or oxidation stress

Characterization of the acidic cold seep emplaced jarositic Golden Deposit, NWT, Canada, as an analogue for jarosite deposition on Mars

Surficial deposits of the OH-bearing iron sulfate mineral jarosite have been observed in several places on Mars, such as Meridiani Planum and Mawrth Vallis. The specific depositional conditions and mechanisms are not known, but by comparing martian sites to analogous locations on Earth, the conditions of formation and, thus, the martian depositional paleoenvironments may be postulated. Located in a cold semi-arid desert ~100 km east of Norman Wells, Northwest Territories, Canada, the Golden Deposit (GD) is visible from the air as a brilliant golden-yellow patch of unvegetated soil, approximately 140 m x 50 m. The GD is underlain by permafrost and consists of yellow sediment, which is precipitating from seeps of acidic, iron-bearing groundwater. On the surface, the GD appears as a patchwork of raised polygons, with acidic waters flowing from seeps in troughs between polygonal islands. Although UV-Vis-NIR spectral analysis detects only jarosite, mineralogy, as determined by X-Ray Diffraction and Inductively Coupled Plasma Emission Spectrometry, is predominantly natrojarosite and jarosite, with hydronium jarosite, goethite, quartz, clays, and small amounts of hematite. Water pH varies significantly over short distances depending on proximity to acid seeps, from 2.3 directly above seeps, to 5.7 several m downstream from seeps within the deposit, and up to 6.5 in ponds proximal to the deposit. Visual observations of microbial filament communities and phospholipid fatty acid analyses confirm that the GD is capable of supporting life for at least part of the year. Jarositic-bearing sediments extend beneath vegetation up to 70 m out from the deposit and are mixed with plant debris and minerals presumably weathered from bedrock and glacial till. This site is of particular interest because mineralogy (natrojarosite, jarosite, hematite, and goethite) and environmental conditions (permafrost and arid conditions) at the time of deposition are conceivably analogous to jarosite deposits on Mars. Most terrestrial analogues for Mars jarosites have been identified in temperate environments, where evaporation rates are very high and jarosites form along with other sulfates due to rapid evaporation (e.g. Rio Tinto, Spain; Western Australian acidic saline lake deposits). The GD is a rare example of an analogue site where jarosite precipitates under dominant freezing processes similar to those which could have prevailed on early Mars. Thus, the GD offers a new perspective on jarosite deposition by the upwelling of acidic waters through permafrost at Meridiani Planum and Mawrth Vallis, Mars. The GD also demonstrates that martian deposits may show considerably more chemical and mineral variability than indicated by the current remote sensing data sets