22,348 research outputs found
Factors associated with failed treatment : an analysis of 121,744 women embarking on their first IVF cycles
Peer reviewedPublisher PD
Star Cluster Formation and Disruption Time-Scales -- I. An empirical determination of the disruption time of star clusters in four galaxies
We present a new method to derive the cluster disruption time in selected
regions of galaxies from the mass or age distribution of magnitude-limited
cluster samples. If the disruption time of clusters in a region of a galaxy
depends on their initial mass as t_4 x (M_cluster/10^4 M_sun)^gamma and if the
cluster formation rate is constant, then the mass and age distributions of the
observed clusters will each show two powerlaw relations. The values of t_4 and
gamma can be derived from these relations. We used this method to derive the
cluster disruption time in specific regions in four galaxies: the inner region
of M51, a region of M33, the SMC and the solar neighbourhood. The values of
gamma are the same in the four galaxies within the uncertainty and the mean
value is gamma= 0.62 +- 0.06. However the disruption time t_4 of a cluster of
10^4 M_sun is very different in the different galaxies. The clusters in the SMC
have the longest disruption time, t_4 = 8 Gyr, and the clusters at 1 to 3 kpc
from the nucleus of M51 have the shortest disruption time of t_4 = 0.04 Gyr.
The disruption time of clusters 1 to 5 kpc from the nucleus of M33 is t_4 =
0.13 Gyr and for clusters within 1 kpc from the Sun we find t_4 = 1.0 Gyr.Comment: 18 pages, 18 figures. Accepted for publication by Monthly Notice
Bone marrow mesenchymal stem cells do not enhance intra-synovial tendon healing despite engraftment and homing to niches within the synovium
Intra-synovial tendon injuries display poor healing, which often results in reduced functionality and pain. A lack of effective therapeutic options has led to experimental approaches to augment natural tendon repair with autologous mesenchymal stem cells (MSCs) although the effects of the intra-synovial environment on the distribution, engraftment and functionality of implanted MSCs is not known. This study utilised a novel sheep model which, although in an anatomically different location, more accurately mimics the mechanical and synovial environment of the human rotator cuff, to determine the effects of intra-synovial implantation of MSCs
Occupational exposure to gases/fumes and mineral dust affect DNA methylation levels of genes regulating expression
Many workers are daily exposed to occupational agents like gases/fumes, mineral dust or biological dust, which could induce adverse health effects. Epigenetic mechanisms, such as DNA methylation, have been suggested to play a role. We therefore aimed to identify differentially methylated regions (DMRs) upon occupational exposures in never-smokers and investigated if these DMRs associated with gene expression levels. To determine the effects of occupational exposures independent of smoking, 903 never-smokers of the LifeLines cohort study were included. We performed three genome-wide methylation analyses (Illumina 450 K), one per occupational exposure being gases/fumes, mineral dust and biological dust, using robust linear regression adjusted for appropriate confounders. DMRs were identified using comb-p in Python. Results were validated in the Rotterdam Study (233 never-smokers) and methylation-expression associations were assessed using Biobank-based Integrative Omics Study data (n = 2802). Of the total 21 significant DMRs, 14 DMRs were associated with gases/fumes and 7 with mineral dust. Three of these DMRs were associated with both exposures (RPLP1 and LINC02169 (2x)) and 11 DMRs were located within transcript start sites of gene expression regulating genes. We replicated two DMRs with gases/fumes (VTRNA2-1 and GNAS) and one with mineral dust (CCDC144NL). In addition, nine gases/fumes DMRs and six mineral dust DMRs significantly associated with gene expression levels. Our data suggest that occupational exposures may induce differential methylation of gene expression regulating genes and thereby may induce adverse health effects. Given the millions of workers that are exposed daily to occupational exposures, further studies on this epigenetic mechanism and health outcomes are warranted
How do you say ‘hello’? Personality impressions from brief novel voices
On hearing a novel voice, listeners readily form personality impressions of that speaker. Accurate or not, these impressions are known to affect subsequent interactions; yet the underlying psychological and acoustical bases remain poorly understood. Furthermore, hitherto studies have focussed on extended speech as opposed to analysing the instantaneous impressions we obtain from first experience. In this paper, through a mass online rating experiment, 320 participants rated 64 sub-second vocal utterances of the word ‘hello’ on one of 10 personality traits. We show that: (1) personality judgements of brief utterances from unfamiliar speakers are consistent across listeners; (2) a two-dimensional ‘social voice space’ with axes mapping Valence (Trust, Likeability) and Dominance, each driven by differing combinations of vocal acoustics, adequately summarises ratings in both male and female voices; and (3) a positive combination of Valence and Dominance results in increased perceived male vocal Attractiveness, whereas perceived female vocal Attractiveness is largely controlled by increasing Valence. Results are discussed in relation to the rapid evaluation of personality and, in turn, the intent of others, as being driven by survival mechanisms via approach or avoidance behaviours. These findings provide empirical bases for predicting personality impressions from acoustical analyses of short utterances and for generating desired personality impressions in artificial voices
Male breast cancer
Male breast cancer (MBC) is a rare disease representing less than 1% of all breast cancers (BC) and less than 1% of cancers in men. Age at presentation is mostly in the late 60s. MBC is recognized as an estrogen-driven disease, specifically related to hyperestrogenism. About 20% of MBC patients have family history for BC. Mutations in BRCA1 and, predominantly, BRCA2, account for approximately 10% of MBC cases.
Because of its rarity, MBC is often compared with female BC (FBC). Based on age-frequency distribution, age-specific incidence rate patterns and prognostic factors profiles, MBC is considered similar to late-onset, postmenopausal estrogen/progesterone receptor positive (ER+/PR+) FBC. However, clinical and pathological characteristics of MBC do not exactly overlap FBC. Compared with FBC, MBC has been reported to occur later in life, present at a higher stage, and display lower histologic grade, with a higher proportion of ER+ and PR+ tumors.
Although rare, MBC remains a substantial cause for morbidity and mortality in men, probably because of its occurrence in advanced age and delayed diagnosis. Diagnosis and treatment of MBC generally is similar to that of FBC. Men tend to be treated with mastectomy rather than breast-conserving surgery. The backbone of adjuvant therapy or palliative treatment for advanced disease is endocrine, mostly tamoxifen.
Use of FBC-based therapy led to the observation that treatment outcomes for MBC are worse and that survival rates for MBC do not improve like FBC. These different outcomes may suggest a non-appropriate utilization of treatments and that different underlying pathogenetic mechanisms may exist between male and female BC
Antimicrobial susceptibility of organisms causing community-acquired urinary tract infections in Gauteng Province, South Africa
Background. Patients with community-acquired urinary tract infections (UTIs) frequently present to healthcare facilities in South Africa (SA).Aim. To provide information on UTI aetiology and antimicrobial susceptibility of pathogens.Methods. We recruited women with UTI-related symptoms, who tested positive for .2 urine dipstick criteria (proteinuria, blood, leucocytes or nitrites) at 1 public and 5 private primary healthcare facilities in 2011. Demographic and clinical data were recorded and mid-stream urine (MSU) specimens were cultured. UTI pathogens were Gram-stained and identified to species level. Etest-based antimicrobial susceptibility testing was performed for amoxicillin/clavulanic acid, cefixime, cefuroxime, ciprofloxacin, fosfomycin, levofloxacin, nitrofurantoin, norfloxacin and trimethoprim/sulphamethoxazole.Results. Of the 460 women recruited, 425 MSU samples were processed and 204 UTI pathogens were identified in 201 samples. Most pathogens were Gram-negative bacilli (GNB) (182; 89.2%) and 22 (10.8%) were Gram-positive cocci (GPC). Escherichia coli was the most frequent GNB (160; 79.6%), while Enterococcus faecalis was the predominant GPC (8; 4.0%). The UTI pathogens had similar susceptibility profiles for fosfomycin (95.5%; 95% confidence interval (CI) 92.6 - 98.4), the 3 fluoroquinolones (94.1%; 95% CI 90.8 - 97.4), nitrofurantoin (91.7%; 95% CI 87.8 - 95.6), cefuroxime (90.1%; 95% CI 86.0 - 94.3) and cefixime (88.2%; 95% CI 83.7 - 92.6). UTI pathogens were less susceptible to amoxicillin/clavulanic acid (82.8%; 95% CI 77.5 - 88.0) when compared with fluoroquinolones and fosfomycin. Trimethoprim/ sulphamethoxazole was the least efficacious antimicrobial agent (44.3% susceptible; 95% CI 37.4 - 51.2).Conclusion. This study provides relevant data for the empirical treatment of community-acquired UTIs in SA
Who Watches the Watchmen? An Appraisal of Benchmarks for Multiple Sequence Alignment
Multiple sequence alignment (MSA) is a fundamental and ubiquitous technique
in bioinformatics used to infer related residues among biological sequences.
Thus alignment accuracy is crucial to a vast range of analyses, often in ways
difficult to assess in those analyses. To compare the performance of different
aligners and help detect systematic errors in alignments, a number of
benchmarking strategies have been pursued. Here we present an overview of the
main strategies--based on simulation, consistency, protein structure, and
phylogeny--and discuss their different advantages and associated risks. We
outline a set of desirable characteristics for effective benchmarking, and
evaluate each strategy in light of them. We conclude that there is currently no
universally applicable means of benchmarking MSA, and that developers and users
of alignment tools should base their choice of benchmark depending on the
context of application--with a keen awareness of the assumptions underlying
each benchmarking strategy.Comment: Revie
Brain ultrasonography findings in neonates with exposure to cocaine during pregnancy
Background: Cocaine exposure during pregnancy has been reported to have detrimental effects on the fetus. Objective: To describe the findings on cranial ultrasonography (CUS) as part of a neonatal screening programme for exposed neonates. Materials and methods: The study was a semiprospective analysis of a 12-year cohort of neonates born to mothers who had used cocaine during their pregnancy and who had follow-up according to a strict clinical protocol. Results: In total, 154 neonates (78 boys, 76 girls) were included, of whom 29 (19%) were born preterm, and 125 (81%) were born full-term. Abnormalities on CUS were seen in 37 neonates (24%; 95% CI 18-31%). The abnormalities were classified as minor in 20 (13%; 95% CI 9-19%) and mildly abnormal in 17 (11%; 95% CI 7-17%). None of the infants showed severe abnormalities. The abnormalities were not associated with the duration or maximum amount of cocaine use during pregnancy. Conclusion: None of the infants had severe abnormalities. Detected abnormalities were not correlated with the duration or maximum amount of cocaine use. Given these findings, we feel that routine cranial ultrasonography in this population is not warranted
Coping with loneliness: What do older adults suggest?
Objectives: A limited amount of information is available on how older adults cope with loneliness. Two ways of coping are distinguished here, i.e. active coping by improving relationships and regulative coping by lowering expectations about relationships. We explore how often older adults suggest these options to their lonely peers in various situations and to what extent individual resources influence their suggestions. Method: After introducing them to four vignettes of lonely individuals, discriminating with regard to age, partner status, and health, 1187 respondents aged 62 to 100 from the Longitudinal Aging Study Amsterdam were asked whether this loneliness can be alleviated by using various ways of coping. Results: In general, both ways of coping were often suggested. However, regression analyses revealed that active coping was suggested less often to people who are older, in poor health, or lonely and by older adults who were employed in midlife and have high self-esteem. Regulative coping was suggested more often to people who are older and by older adults with a low educational level and with low mastery. Conclusions: Coping with loneliness by actively removing the stressor is less often seen as an option for and by the people who could benefit most from it. This underlines the difficulty of combating loneliness
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