996 research outputs found
Recommended from our members
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 10â19 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
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
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
Epistemic freedom and education
First of all, I define the concept of epistemic freedom in the light of the changing nature of educational practice that prioritise over-prescriptive conceptions of learning. I defend the ârealityâ of this freedom against possible determinist-related criticisms. I do this by stressing the concept of agency as characterised by âbecomingâ. I also discuss briefly some of the technical literature on the subject. I then move on to discuss Gramsciâs concept of hegemony and Foucaultâs idea of âproductive powerâ: I argue for the need of a counter-narrative of freedom that takes the form of a genealogy. Finally I discuss in more detail the nature of epistemic freedom and briefly discuss the ethical implications of the concept
Core transcriptional regulatory circuitry in human hepatocytes
We mapped the transcriptional regulatory circuitry for six master regulators in human hepatocytes using chromatin immunoprecipitation and high-resolution promoter microarrays. The results show that these regulators form a highly interconnected core circuitry, and reveal the local regulatory network motifs created by regulatorâgene interactions. Autoregulation was a prominent theme among these regulators. We found that hepatocyte master regulators tend to bind promoter regions combinatorially and that the number of transcription factors bound to a promoter corresponds with observed gene expression. Our studies reveal portions of the core circuitry of human hepatocytes
Core transcriptional regulatory circuitry in human hepatocytes
We mapped the transcriptional regulatory circuitry for six master regulators in human hepatocytes using chromatin immunoprecipitation and high-resolution promoter microarrays. The results show that these regulators form a highly interconnected core circuitry, and reveal the local regulatory network motifs created by regulatorâgene interactions. Autoregulation was a prominent theme among these regulators. We found that hepatocyte master regulators tend to bind promoter regions combinatorially and that the number of transcription factors bound to a promoter corresponds with observed gene expression. Our studies reveal portions of the core circuitry of human hepatocytes
- âŠ