569 research outputs found
C-FAR - Carbon footprinting of archaeological research: Data collection methodology and interim report
Carbon Footprinting of Archaeology Research (C-FAR) focused on developing a method of determining the carbon footprint of university-led archaeological training expeditions.British Academ
Analysis and characterisation of human chorionic gonadotropin glycoforms in pregnancy and trophoblastic disorders
Human chorionic gonadotropin (hCG) is a heterogeneous glycoprotein hormone with a varying degree of carbohydrate moieties. Its glycosylation arrangements are increasingly recognized as a common and important element of disease pathophysiology and are associated with many disorders including gestational trophoblastic diseases (GTDs). This study aimed to optimise methodologies to permit the characterisation of hCG N-linked glycans from urine samples collected throughout normal pregnancy and GTD using matrix-assisted laser desorption ionisation time of flight mass spectrometry (MALDI-TOF MS). hCG isolated from pooled pregnancy urine was used in this study. All the stages in pregnancy urine preparation were optimised; including conditions for hCG immunopurification, deglycosylation, solid-phase extraction of resulting glycan:protein mixture and application of N-glycans for MALDI-TOF MS analysis. GlycoQuest software was used to characterise specific N-glycans configurations from the resulting MALDI-TOF MS spectra. This methodology was then applied to urine samples collected throughout normal singleton pregnancy and urine collected from patients with choriocarcinoma. The relative abundance of glycans of different molecular weights and specific types (i.e. fucosylated, sialylated, bisected and sulphated) at each stage of normal pregnancy and in GTD were compared. Each stage of optimisation increased the number of N-glycans detected such that we were ultimately able to detect 50 different glycans in normal pregnancy urine. In these samples, advancing gestation was associated with an increase in the proportion of branched N-glycans and multi-fucosylated N-glycans. Also, a significant increase in the proportion of high molecular weight glycans (>2100 Da) between choriocarcinoma and first-trimester normal pregnancy was observed. Further striking differences in the repertoire of glycan expression were also seen in choriocarcinoma urine compared with first-trimester pregnancy urine. The proportion of multi-fucosylated and tri-and tetra antennal, glycans was increased 3 and 2 fold respectively. In addition, 14 unique N-linked glycan structures were identified in choriocarcinoma samples. These included hyperfucosylated (7 fucose groups) and hypersialylated (4 sialic acid groups) glycans. A feature of this unique set of glycans was that they contained a combination of multiple branching, fucosylation, sialylation, sulphation and glycans with Lewis X terminal epitopes. In summary, we have successfully developed a methodology for the detection of a diverse range of N-linked glycans from hCG. These results suggest that this approach can be successfully used for the detection of novel glyco-biomarkers for the early detection of choriocarcinoma and may be applied to other GTDs associated with a dysregulation of hCG expression
Examining Mental Health and Well-being Provision in Schools in Europe: Methodological Approach
Schools are considered an ideal setting for community-based mental health and well-being interventions for young people. However, in spite of extensive literature examining the effectiveness of such interventions, very few studies have investigated existing mental health and well-being provision in schools. The current study aims to extend such previous research by surveying primary and secondary schools to investigate the nature of available provision in nine European countries (Germany, Ireland, the Netherlands, Poland, Serbia, Spain, Sweden, the UK and Ukraine). Furthermore, the study aims to investigate potential barriers to mental health and well-being provision and compare provision within and between countries
Eccentricities of Double Neutron Star Binaries
Recent pulsar surveys have increased the number of observed double neutron
stars (DNS) in our galaxy enough so that observable trends in their properties
are starting to emerge. In particular, it has been noted that the majority of
DNS have eccentricities less than 0.3, which are surprisingly low for binaries
that survive a supernova explosion that we believe imparts a significant kick
to the neutron star. To investigate this trend, we generate many different
theoretical distributions of DNS eccentricities using Monte Carlo population
synthesis methods. We determine which eccentricity distributions are most
consistent with the observed sample of DNS binaries. In agreement with
Chaurasia & Bailes (2005), assuming all double neutron stars are equally as
probable to be discovered as binary pulsars, we find that highly eccentric,
coalescing DNS are less likely to be observed because of their accelerated
orbital evolution due to gravitational wave emission and possible early
mergers. Based on our results for coalescing DNS, we also find that models with
vanishingly or moderately small kicks (sigma < about 50 km/s) are inconsistent
with the current observed sample of such DNS. We discuss the implications of
our conclusions for DNS merger rate estimates of interest to ground-based
gravitational-wave interferometers. We find that, although orbital evolution
due to gravitational radiation affects the eccentricity distribution of the
observed sample, the associated upwards correction factor to merger rate
estimates is rather small (typically 10-40%).Comment: 9 pages, 8 figures, accepted by ApJ. Figures reduced and some content
changed, references adde
The influence of repeated cold water immersion on adaptations to strength and power training
Introduction
Cold Water Immersion (CWI) is a popular recovery strategy utilised by athletes in order to attenuate the negative influence of strenuous exercise on subsequent performance. One of the proposed physiological mechanisms underpinning the use of CWI is the potential to limit the inflammatory response after acute exercise. Given that the inflammatory cascade ultimately leads to muscle regeneration and repair, it is pertinent to investigate the longer term impact of regular cryotherapy exposure on adaptations to strength and power training.
Methods
Thirteen resistance trained males (mean age 25.8 ± 5.5 years; height 1.8 ± 0.1 m; mass 83.6 ± 15.7 kg; 4RM back squat 146.2 ± 38.5 kg) completed an 8 week (1 x 4 week strength and 1 x 4 week power block) lower body resistance training program. Participants were match-paired into either the CWI (10 min at 10° ± 0.5°) or placebo group based on a ratio of lean mass to 4RM back squat. Participants completed 2 training sessions per week and completed their allocated recovery intervention after each training session. Measures of muscle fibre pennation angle, maximal voluntary isometric contraction (MVIC) at 90°, peak torque of the knee extensors (60deg∙s), and isometric squat parameters (peak force and rate of force development (RFD))were measured at baseline, midpoint and post training intervention. Results were analysed using magnitude based inferences.
Results
At the post testing session, CWI demonstrated a likely moderate harmful effect on muscle fibre pennation angle compared to the placebo group (CWI: 11.4; ±4.8%; placebo: 21.5; ±8.4%). However, CWI demonstrated a likely large beneficial effect on peak torque (60deg∙s) compared to the placebo group (CWI: 7.5; ±6.5%; placebo: -2.4; ±4.0%) at midpoint. There were trivial differences between groups for isometric peak force and peak torque (60deg∙s) from baseline to post. All other effects were unclear.
Discussion
The greater increase in muscle fibre pennation angle in the placebo group compared to the CWI group would indicate a greater increase lean muscle mass. However, CWI still demonstrated a positive impact on peak torque at 60 deg∙s compared to the placebo group. Blood sample analyses are ongoing and may offer further insight into the underpinning mechanisms. Further investigation is warranted to better understand the potential negative impact of repeated cryotherapy exposure on functional adaptations to strength and power training stimuli
Whole body cryotherapy, cold water immersion, or a placebo following resistance exercise: a case of mind over matter?
PURPOSE: The use of cryotherapy as a recovery intervention is prevalent amongst athletes. Performance of high volume, heavy load resistance exercise is known to result in disturbances of muscle function, perceptual responses and blood borne parameters. Therefore, this study investigated the influence of cold water immersion (CWI), whole body cryotherapy (WBC) or a placebo (PL) intervention on markers of recovery following an acute resistance training session.
METHODS: 24 resistance trained males were matched into a CWI (10 min at 10 °C), WBC (3- and 4 min at - 85 °C) or PL group before completing a lower body resistance training session. Perceptions of soreness and training stress, markers of muscle function, inflammation and efflux of intracellular proteins were assessed before, and up to 72 h post exercise.
RESULTS: The training session resulted in increased soreness, disturbances of muscle function, and increased inflammation and efflux of intracellular proteins. Although WBC attenuated soreness at 24 h, and positively influenced peak force at 48 h compared to CWI and PL, many of the remaining outcomes were trivial, unclear or favoured the PL condition. With the exception of CRP at 24 h, neither cryotherapy intervention attenuated the inflammatory response compared to PL.
CONCLUSION: There was some evidence to suggest that WBC is more effective than CWI at attenuating select perceptual and functional responses following resistance training. However, neither cryotherapy intervention was more effective than the placebo treatment at accelerating recovery. The implications of these findings should be carefully considered by individuals employing cryotherapy as a recovery strategy following heavy load resistance training
Jacobi-like bar mode instability of relativistic rotating bodies
We perform some numerical study of the secular triaxial instability of
rigidly rotating homogeneous fluid bodies in general relativity. In the
Newtonian limit, this instability arises at the bifurcation point between the
Maclaurin and Jacobi sequences. It can be driven in astrophysical systems by
viscous dissipation. We locate the onset of instability along several constant
baryon mass sequences of uniformly rotating axisymmetric bodies for compaction
parameter . We find that general relativity weakens the Jacobi
like bar mode instability, but the stabilizing effect is not very strong.
According to our analysis the critical value of the ratio of the kinetic energy
to the absolute value of the gravitational potential energy for compaction parameter as high as 0.275 is only 30% higher than the
Newtonian value. The critical value of the eccentricity depends very weakly on
the degree of relativity and for is only 2% larger than the
Newtonian value at the onset for the secular bar mode instability. We compare
our numerical results with recent analytical investigations based on the
post-Newtonian expansion.Comment: 15 pages, 8 figures, submitted to Phys. Rev.
Stability of strange stars (SS) derived from a realistic equation of state
A realistic equation of state (EOS) leads to realistic strange stars (ReSS)
which are compact in the mass radius plot, close to the Schwarzchild limiting
line (Dey et al 1998). Many of the observed stars fit in with this kind of
compactness, irrespective of whether they are X-ray pulsars, bursters or soft
repeaters or even radio pulsars. We point out that a change in the
radius of a star can be small or large, when its mass is increasing and this
depends on the position of a particular star on the mass radius curve. We carry
out a stability analysis against radial oscillations and compare with the EOS
of other strange star (SS) models. We find that the ReSS is stable and an M-R
region can be identified to that effect.Comment: 16 pages including 5 figures. Accepted for publication in MPL
- …