Mars simulated exposure and the characteristic Raman biosignatures of amino acids and halophilic microbes

Though Raman bands of α-amino acids (AA) are well documented, often only the strongest intensity bands are quoted as identifiers (e.g. Jenkins et al., 2005; De Gelder et al., 2007; Zhu et al., 2011). Unknown regolith mixtures on Mars-sampling missions could obscure these bands. Here the case is made for determining, via a statistical method, sets of characteristic bands to be used as identifiers, independent of band intensity or number of bands (Rolfe et al., 2016). AA have upwards of 25 potentially identifying bands and this method defines sets of 10–19 bands per AA. Examination of AA-doped Mars-like basalt resulted in a maximum of eight bands being identified, as some characteristic bands were obscured by mineral bands, including the strongest intensity band in some cases. This proved the need for characteristic bands to be defined, enabling successful identification of AA. The ESA ExoMars Rover mission will crush and then pass the sample to the Raman Laser Spectrometer. We crushed a Mars-like basalt to a similar grain size expected to be created by the rover. Our samples were doped with 1 % (by weight) AA samples, resulting in no detection of AA, because of loss of original spatial context and spaces between the grains. We recommend that Raman spectroscopy on future missions should be conducted before the sample is crushed. Halite-entombed halophilic microbes, known to survive being entombed, were exposed to Mars-like surface (including temperature, pressure, atmospheric composition and UV) and freeze-thaw cycle (plus pressure and atmospheric composition) conditions. This test on the survival of the microbes showed that survival rates quickly deteriorated in surface conditions, but freeze-thaw cycle samples had well preserved Raman biosignatures, indicating that similar signatures could be detectable on Mars if similar life persists in evaporitic material or brines today

Evaluating the potential of biochar for reducing bioavailable heavy metal fractions in polluted soil

Previous studies have proposed biochar as a natural adsorbent material with potential to be used in the remediation of polluted soils. Its application for adsorption of pollutants may reduce the bioavailability of harmful compounds in the soil media by limiting its chemical distribution and reducing the risk of uptake by organisms. Therefore, biochar has been suggested for the attenuation of heavy metals (HMs) in soil, minimizing the possibility of accumulation through the trophic chain (Figure ). Please click on the file below for full content of the abstract

Detecting biomarkers on Mars using Raman spectroscopy

Raman spectroscopy is a powerful technique for the characterisation of organic molecules as it provides a unique ‘fingerprint’ spectrum. Incident monochromatic light on a sample is shifted in wavelength giving rise to the Raman spectrum, with peaks that are attributable to the specific vibrational bonds within the molecule. Raman spectroscopy is useful for analysing not only geological samples but also biological molecules, and has been recommended for use as a detection method (among others) for biomarkers on missions to planetary bodies [1]. The ExoMars Rover mission is due to launch in 2018 with a Raman spectrometer as part of its scientific payload [2]. Amino acids, the ‘building-blocks’ of proteins, have been identified as a high priority biomarker in the search for evidence of life on planetary bodies [3]. Raman spectroscopy is often a qualitative method, but if signatures of biomarkers are detected by Raman spectroscopy, it is critical that correct identification of such biomarkers can be undertaken. To aid in molecule identification, we take a statistical approach to determine the position of characteristic peaks of several amino acids. We present evidence for statistically significant changes in the peak positions when using different excitation wavelengths. Furthermore, we present evidence that martian conditions have an effect on the Raman spectra of amino acids, which could have implications when performing in situ measurements on Mars. 1. Jehlicka, J., H.G.M. Edwards, and P. Vítek, Assessment of Raman spectroscopy as a tool for the non-destructive identification of organic minerals and biomolecules for Mars studies. Planetary and Space Science, 2009. 57(5-6): p. 606-613. 2. Edwards, H.G.M., I. Hutchinson, and R. Ingley, The ExoMars Raman spectrometer and the identification of biogeological spectroscopic signatures using a flight-like prototype. Analytical and Bioanalytical Chemistry, 2012. 404(6-7): p. 1723-1731. 3. Parnell, J., et al., Searching for Life on Mars: Selection of Molecular Targets for ESA's Aurora ExoMars Mission. Astrobiology, 2007. 7(4): p. 578-604

Local birthing services for rural women: Adaptation of a rural New South Wales maternity service.

OBJECTIVE: To describe the outcomes of a public hospital maternity unit in rural New South Wales (NSW) following the adaptation of the service from an obstetrician and general practitioner-obstetrician (GPO)-led birthing service to a low-risk midwifery group practice (MGP) model of care with a planned caesarean section service (PCS). DESIGN: A retrospective descriptive study using quantitative methodology. SETTING: Maternity unit in a small public hospital in rural New South Wales, Australia. PARTICIPANTS: Data were extracted from the ward-based birth register for 1172 births at the service between July 2007 and June 2012. MAIN OUTCOME MEASURES: Birth numbers, maternal characteristics, labour, birthing and neonatal outcomes. RESULTS: There were 750 births over 29 months in GPO and 277 and 145 births over 31 months in MGP and PCS, respectively, totalling 422 births following the change in model of care. The GPO had 553 (73.7%) vaginal births and 197 (26.3%) caesarean section (CS) births (139 planned and 58 unplanned). There were almost universal normal vaginal births in MGP (>99% or 276). For normal vaginal births, more women in MGP had no analgesia (45.3% versus 25.1%) or non-invasive analgesia (47.9% versus 38.6%) and episiotomy was less common in MGP than GPO (1.9% versus 3.4%). Neonatal outcomes were similar for both groups with no difference between Apgar scores at 5 min, neonatal resuscitations or transfer to high-level special care nurseries. CONCLUSION: This study demonstrates how a rural maternity service maintained quality care outcomes for low-risk women following the adaptation from a GPO to an MGP service

Neighbourhood walkability, road density and socio-economic status in Sydney, Australia

Background Planning and transport agencies play a vital role in influencing the design of townscapes, travel modes and travel behaviors, which in turn impact on the walkability of neighbourhoods and residents\u27 physical activity opportunities. Optimising neighbourhood walkability is desirable in built environments, however, the population health benefits of walkability may be offset by increased exposure to traffic related air pollution. This paper describes the spatial distribution of neighbourhood walkability and weighted road density, a marker for traffic related air pollution, in Sydney, Australia. As exposure to air pollution is related to socio-economic status in some cities, this paper also examines the spatial distribution of weighted road density and walkability by socio-economic status (SES). Methods We calculated walkability, weighted road density (as a measure of traffic related air pollution) and SES, using predefined and validated measures, for 5858 Sydney neighbourhoods, representing 3.6 million population. We overlaid tertiles of walkability and weighted road density to define sweet-spots (high walkability-low weighted road density), and sour- spots (low walkability-high weighted road density) neighbourhoods. We also examined the distribution of walkability and weighted road density by SES quintiles. Results Walkability and weighted road density showed a clear east-west gradient across the region. Our study found that only 4 % of Sydney\u27s population lived in sweet-spot neighbourhoods with high walkability and low weighted road density (desirable), and these tended to be located closer to the city centre. A greater proportion of neighbourhoods had health limiting attributes of high weighted road density or low walkability (about 20 % each), and over 5 % of the population lived in sour-spot neighbourhoods with low walkability and high weighted road density (least desirable). These neighbourhoods were more distant from the city centre and scattered more widely. There were no linear trends between walkability/weighted road density and neighbourhood SES. Conclusions Our walkability and weighted road density maps and associated analyses by SES can help identify neighbourhoods with inequalities in health-promoting or health-limiting environments. Planning agencies should seek out opportunities for increased neighbourhood walkability through improved urban development and transport planning, which simultaneously minimizes exposure to traffic related air pollution

Relationship of Metabolizable Protein Balance, Purine Derivative Excretion, and 3-Methyl Histidine Excretion to Feed Efficiency in Individually Fed Finishing Heifers

Individually fed heifers were used to determine the relationship of 3-methyl histidine, purine derivatives, and metabolizableprotein balance to feed efficiency. Heifers were fed finishing dietsthat were either deficient or sufficient in metabolizable protein. Urine samples were collected and analyzed for early, late, and entire feeding period concentrations of 3-methyl histidine, purine derivatives, and creatinine. Results from this study indicated a negative relationship between feed efficiency and metabolizable protein balance, and no relationship between 3-methyl histidine excretion and feed efficiency, suggesting that protein turnover and microbial protein synthesis are not related to feed efficienc

Relationship of Metabolizable Protein Balance, Purine Derivative Excretion, and 3-Methyl Histidine Excretion to Feed Efficiency in Individually Fed Finishing Heifers

Individually fed heifers were used to determine the relationship of 3-methyl histidine, purine derivatives, and metabolizableprotein balance to feed efficiency. Heifers were fed finishing dietsthat were either deficient or sufficient in metabolizable protein. Urine samples were collected and analyzed for early, late, and entire feeding period concentrations of 3-methyl histidine, purine derivatives, and creatinine. Results from this study indicated a negative relationship between feed efficiency and metabolizable protein balance, and no relationship between 3-methyl histidine excretion and feed efficiency, suggesting that protein turnover and microbial protein synthesis are not related to feed efficienc