628 research outputs found
Labor-associated gene expression in the human uterine fundus, lower segment, and cervix
Background
Preterm labor, failure to progress, and postpartum hemorrhage are the common causes of maternal and neonatal mortality or morbidity. All result from defects in the complex mechanisms controlling labor, which coordinate changes in the uterine fundus, lower segment, and cervix. We aimed to assess labor-associated gene expression profiles in these functionally distinct areas of the human uterus by using microarrays.
Methods and Findings
Samples of uterine fundus, lower segment, and cervix were obtained from patients at term (mean +/- 6 SD = 39.1 +/- 0.5 wk) prior to the onset of labor (n = 6), or in active phase of labor with spontaneous onset (n = 7). Expression of 12,626 genes was evaluated using microarrays ( Human Genome U95A; Affymetrix) and compared between labor and non-labor samples. Genes with the largest labor-associated change and the lowest variability in expression are likely to be fundamental for parturition, so gene expression was ranked accordingly. From 500 genes with the highest rank we identified genes with similar expression profiles using two independent clustering techniques. Sets of genes with a probability of chance grouping by both techniques less than 0.01 represented 71.2%, 81.8%, and 79.8% of the 500 genes in the fundus, lower segment, and cervix, respectively. We identified 14, 14, and 12 those sets of genes in the fundus, lower segment, and cervix, respectively. This enabled networks of coregulated and co-expressed genes to be discovered. Many genes within the same cluster shared similar functions or had functions pertinent to the process of labor.
Conclusions
Our results provide support for many of the established processes of parturition and also describe novel-to-labor genes not previously associated with this process. The elucidation of these mechanisms likely to be fundamental for controlling labor is an important prerequisite to the development of effective treatments for major obstetric problems - including prematurity, with its long-term consequences to the health of mother and offspring
Superconductivity in Ultrasmall Metallic Grains
We develop a theory of superconductivity in ultrasmall (nm-scale) metallic
grains having a discrete electronic eigenspectrum with a mean level spacing of
order of the bulk gap. The theory is based on calculating the eigenspectrum
using a generalized BCS variational approach, whose applicability has been
extensively demonstrated in studies of pairing correlations in nuclear physics.
We discuss how conventional mean field theory breaks down with decreasing
sample size, how the so-called blocking effect weakens pairing correlations in
states with non-zero total spin, and how this affects the discrete
eigenspectrum's behavior in a magnetic field, which favors non-zero total spin.
In ultrasmall grains, spin magnetism dominates orbital magnetism, just as in
thin films in a parallel field; but whereas in the latter the magnetic-field
induced transition to a normal state is known to be first-order, we show that
in ultrasmall grains it is softened by finite size effects. Our calculations
qualitatively reproduce the magnetic-field dependent tunneling spectra for
individual aluminum grains measured recently by Ralph, Black and Tinkham. We
argue that previously-discussed parity effects for the odd-even ground state
energy difference are presently not observable for experimental reasons, and
propose an analogous parity effect for the pair-breaking energy that should be
observable provided that the grain size can be controlled sufficiently well.
Finally, experimental evidence is pointed out that the dominant role played by
time-reversed pairs of states, well-established in bulk and in dirty
superconductors, persists also in ultrasmall grains.Comment: 21 pages RevTeX, 12 EPS figures included, uses epsf.st
'It's a Form of Freedom': The experiences of people with disabilities within equestrian sport
This paper explores the embodied, gendered experiences of disabled horse‐riders. Drawing on data from five in‐depth interviews with paradressage riders, the ways in which their involvement in elite disability sport impacts upon their sense of identity and confidence are explored, as well as the considerable health and social benefits that this involvement brings. Social models of disability are employed and the shortcomings of such models, when applied to disability sport, are highlighted. The data presented here demonstrates the necessity of seeing disability sport as an embodied experience and acknowledging the importance of impairment to the experiences of disabled athletes. Living within an impaired body is also a gendered experience and the implications of this when applied to elite disability sport are considered
Structural brain abnormalities in postural tachycardia syndrome: A VBM-DARTEL study
Postural tachycardia syndrome (PoTS), a form of dysautonomia, is characterized by orthostatic intolerance, and is frequently accompanied by a range of symptoms including palpitations, lightheadedness, clouding of thought, blurred vision, fatigue, anxiety, and depression. Although the estimated prevalence of PoTS is approximately 5–10 times as common as the better-known condition orthostatic hypotension, the neural substrates of the syndrome are poorly characterized. In the present study, we used magnetic resonance imaging (MRI) with voxel-based morphometry (VBM) applying the diffeomorphic anatomical registration through exponentiated lie algebra (DARTEL) procedure to examine variation in regional brain structure associated with PoTS. We recruited 11 patients with established PoTS and 23 age-matched normal controls. Group comparison of gray matter volume revealed diminished gray matter volume within the left anterior insula, right middle frontal gyrus and right cingulate gyrus in the PoTS group. We also observed lower white matter volume beneath the precentral gyrus and paracentral lobule, right pre- and post-central gyrus, paracentral lobule and superior frontal gyrus in PoTS patients. Subsequent ROI analyses revealed significant negative correlations between left insula volume and trait anxiety and depression scores. Together, these findings of structural differences, particularly within insular and cingulate components of the salience network, suggest a link between dysregulated physiological reactions arising from compromised central autonomic control (and interoceptive representation) and increased vulnerability to psychiatric symptoms in PoTS patients
Sperm design and variation in the New World blackbirds (Icteridae)
Post-copulatory sexual selection (PCSS) is thought to be one of the evolutionary forces responsible for the rapid and divergent evolution of sperm design. However, whereas in some taxa particular sperm traits are positively associated with PCSS, in other taxa, these relationships are negative, and the causes of these different patterns across taxa are poorly understood. In a comparative study using New World blackbirds (Icteridae), we tested whether sperm design was influenced by the level of PCSS and found significant positive associations with the level of PCSS for all sperm components but head length. Additionally, whereas the absolute length of sperm components increased, their variation declined with the intensity of PCSS, indicating stabilizing selection around an optimal sperm design. Given the diversity of, and strong selection on, sperm design, it seems likely that sperm phenotype may influence sperm velocity within species. However, in contrast to other recent studies of passerine birds, but consistent with several other studies, we found no significant link between sperm design and velocity, using four different species that vary both in sperm design and PCSS. Potential reasons for this discrepancy between studies are discussed
Post-release reforms for short prison sentences: re-legitimising and widening the net of punishment
Transforming Rehabilitation (TR) promised a ‘revolution’ in the way offenders are managed, providing a renewed focus on short sentence prisoners. The TR reforms extends mandatory post-release supervision and tailored through-the-gate resettlement provisions to a group that has predominately faced a ‘history of neglect’ yet often present with the most acute needs within the criminal justice system. However, existing literature underlines that serving short sentences lack ‘utility’ and can be counter-productive to facilitating effective rehabilitation.
This article explores the purposes of providing post release supervision for short sentences, firstly exploring a previous attempt to reform short sentences; (the now defunct) ‘Custody Plus’ within the 2003 Criminal Justice Act and then the Offender Rehabilitation Act 2014 within the TR reforms. This article contends that both post release reforms have sought to re-affirm and re-legitimise prison as the dominant form of punishment in society- or what Carlen refers to as ‘carceral clawback’. This article will also use Cohen’s analysis on social control to establish that post release supervision will serve to ‘widen the net’ extend the period of punishment and oversight and will only reinforce a form of enforced ‘state obligated rehabilitation’ that will undermine efforts made to resettle short sentence prisoners
Floral advertisement scent in a changing plant-pollinators market
Plant-pollinator systems may be considered as biological markets in which pollinators choose between different flowers that advertise their nectar/pollen rewards. Although expected to play a major role in structuring plant-pollinator interactions, community-wide patterns of flower scent signals remain largely unexplored. Here we show for the first time that scent advertisement is higher in plant species that bloom early in the flowering period when pollinators are scarce relative to flowers than in species blooming later in the season when there is a surplus of pollinators relative to flowers. We also show that less abundant flowering species that may compete with dominant species for pollinator visitation early in the flowering period emit much higher proportions of the generalist attractant β-ocimene. Overall, we provide a first community-wide description of the key role of seasonal dynamics of plant-specific flower scent emissions, and reveal the coexistence of contrasting plant signaling strategies in a plant-pollinator market
Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.
BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112
Direct Reaction Measurements Using GODDESS
GODDESS is a coupling of the charged-particle detection system ORRUBA to the gamma-ray detector array Gammasphere. This coupling has been developed in order to facilitate the high-resolution measurement of direct reactions in normal and inverse kinematics with stable and radioactive beams. GODDESS has been commissioned using a beam of 134Xe at 10 MeV/A, in a campaign of stable beam measurements. The measurement demonstrates the capabilities of GODDESS under radioactive beam conditions, and provides the first data on the single-neutron states in 135Xe, including previously unobserved states based on the orbitals above the N=82 shell closure
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