144 research outputs found
Spectator Sport and Population Health: A Consultation with U.S. College Athletics Employees
A growing number of studies have been published to understand how spectator sport may influence the health of a population. However, it is unknown if these studies address research questions relevant to professionals engaging in the promotion of spectator sport. We conducted a web-based survey with 136 practitioners employed in U.S. college athletics to identify their research priorities and needs regarding spectator sport’s influence on population health. The combination of qualitative and quantitative analyses show that future research needs to be focused particularly on one of the following research themes: (a) social psychological benefits of sport spectatorship and (b) psychological impact of sport spectatorship. The findings further suggest the integration of environmental well-being and eudaimonic well-being into the domain of population health. Based on these findings, we propose future research directions as informed and guided by the practitioners’ perspectives
Collective sensing and collective responses in quorum-sensing bacteria
Bacteria often face fluctuating environments, and in response many species have evolved complex decision-making mechanisms to match their behaviour to the prevailing conditions. Some environmental cues provide direct and reliable information (such as nutrient concentrations) and can be responded to individually. Other environmental parameters are harder to infer and require a collective mechanism of sensing. In addition, some environmental challenges are best faced by a group of cells rather than an individual. In this review, we discuss how bacteria sense and overcome environmental challenges as a group using collective mechanisms of sensing, known as ‘quorum sensing’ (QS). QS is characterized by the release and detection of small molecules, potentially allowing individuals to infer environmental parameters such as density and mass transfer. While a great deal of the molecular mechanisms of QS have been described, there is still controversy over its functional role. We discuss what QS senses and how, what it controls and why, and how social dilemmas shape its evolution. Finally, there is a growing focus on the use of QS inhibitors as antibacterial chemotherapy. We discuss the claim that such a strategy could overcome the evolution of resistance. By linking existing theoretical approaches to data, we hope this review will spur greater collaboration between experimental and theoretical researchers
Meiotic Pairing and Segregation of Achiasmate Sex Chromosomes in Eutherian Mammals: The Role of SYCP3 Protein
In most eutherian mammals, sex chromosomes synapse and recombine during male meiosis in a small region called pseudoautosomal region. However in some species sex chromosomes do not synapse, and how these chromosomes manage to ensure their proper segregation is under discussion. Here we present a study of the meiotic structure and behavior of sex chromosomes in one of these species, the Mongolian gerbil (Meriones unguiculatus). We have analyzed the location of synaptonemal complex (SC) proteins SYCP1 and SYCP3, as well as three proteins involved in the process of meiotic recombination (RAD51, MLH1, and γ-H2AX). Our results show that although X and Y chromosomes are associated at pachytene and form a sex body, their axial elements (AEs) do not contact, and they never assemble a SC central element. Furthermore, MLH1 is not detected on the AEs of the sex chromosomes, indicating the absence of reciprocal recombination. At diplotene the organization of sex chromosomes changes strikingly, their AEs associate end to end, and SYCP3 forms an intricate network that occupies the Y chromosome and the distal region of the X chromosome long arm. Both the association of sex chromosomes and the SYCP3 structure are maintained until metaphase I. In anaphase I sex chromosomes migrate to opposite poles, but SYCP3 filaments connecting both chromosomes are observed. Hence, one can assume that SYCP3 modifications detected from diplotene onwards are correlated with the maintenance of sex chromosome association. These results demonstrate that some components of the SC may participate in the segregation of achiasmate sex chromosomes in eutherian mammals
Y-Chromosome Variation in Hominids: Intraspecific Variation Is Limited to the Polygamous Chimpanzee
The original publication is available at www.plosone.orgBackground: We have previously demonstrated that the Y-specific ampliconic fertility genes DAZ (deleted in azoospermia)
and CDY (chromodomain protein Y) varied with respect to copy number and position among chimpanzees (Pan troglodytes).
In comparison, seven Y-chromosomal lineages of the bonobo (Pan paniscus), the chimpanzee’s closest living relative,
showed no variation. We extend our earlier comparative investigation to include an analysis of the intraspecific variation of
these genes in gorillas (Gorilla gorilla) and orangutans (Pongo pygmaeus), and examine the resulting patterns in the light of
the species’ markedly different social and mating behaviors.
Methodology/Principal Findings: Fluorescence in situ hybridization analysis (FISH) of DAZ and CDY in 12 Y-chromosomal
lineages of western lowland gorilla (G. gorilla gorilla) and a single lineage of the eastern lowland gorilla (G. beringei graueri)
showed no variation among lineages. Similar findings were noted for the 10 Y-chromosomal lineages examined in the
Bornean orangutan (Pongo pygmaeus), and 11 Y-chromosomal lineages of the Sumatran orangutan (P. abelii). We validated
the contrasting DAZ and CDY patterns using quantitative real-time polymerase chain reaction (qPCR) in chimpanzee and
bonobo.
Conclusion/Significance: High intraspecific variation in copy number and position of the DAZ and CDY genes is seen only in
the chimpanzee. We hypothesize that this is best explained by sperm competition that results in the variant DAZ and CDY
haplotypes detected in this species. In contrast, bonobos, gorillas and orangutans—species that are not subject to sperm
competition—showed no intraspecific variation in DAZ and CDY suggesting that monoandry in gorillas, and preferential
female mate choice in bonobos and orangutans, probably permitted the fixation of a single Y variant in each taxon. These
data support the notion that the evolutionary history of a primate Y chromosome is not simply encrypted in its DNA
sequences, but is also shaped by the social and behavioral circumstances under which the specific species has evolved.Funded by the Deutsche Forschungsgemeinschaft (SCHE 214/8)Publisher's versio
The Acute Phase Protein Ceruloplasmin as a Non-Invasive Marker of Pseudopregnancy, Pregnancy, and Pregnancy Loss in the Giant Panda
After ovulation, non-pregnant female giant pandas experience pseudopregnancy. During pseudopregnancy, non-pregnant females exhibit physiological and behavioral changes similar to pregnancy. Monitoring hormonal patterns that are usually different in pregnant mammals are not effective at determining pregnancy status in many animals that undergo pseudopregnancy, including the giant panda. Therefore, a physiological test to distinguish between pregnancy and pseudopregnancy in pandas has eluded scientists for decades. We examined other potential markers of pregnancy and found that activity of the acute phase protein ceruloplasmin increases in urine of giant pandas in response to pregnancy. Results indicate that in term pregnancies, levels of active urinary ceruloplasmin were elevated the first week of pregnancy and remain elevated until 20–24 days prior to parturition, while no increase was observed during the luteal phase in known pseudopregnancies. Active ceruloplasmin also increased during ultrasound-confirmed lost pregnancies; however, the pattern was different compared to term pregnancies, particularly during the late luteal phase. In four out of the five additional reproductive cycles included in the current study where females were bred but no birth occurred, active ceruloplasmin in urine increased during the luteal phase. Similar to the known lost pregnancies, the temporal pattern of change in urinary ceruloplasmin during the luteal phase deviated from the term pregnancies suggesting that these cycles may have also been lost pregnancies. Among giant pandas in captivity, it has been presumed that there is a high rate of pregnancy loss and our results are the first to provide evidence supporting this notion
Oxygen tension regulates the miRNA profile and bioactivity of exosomes released from extravillous trophoblast cells - liquid biopsies for monitoring complications of pregnancy
Our understanding of how cells communicate has undergone a paradigm shift since the recent recognition of the role of exosomes in intercellular signaling. In this study, we investigated whether oxygen tension alters the exosome release and miRNA profile from extravillous trophoblast (EVT) cells, modifying their bioactivity on endothelial cells (EC). Furthermore, we have established the exosomal miRNA profile at early gestation in women who develop pre-eclampsia (PE) and spontaneous preterm birth (SPTB). HTR-8/SVneo cells were used as an EVT model. The effect of oxygen tension (i.e. 8% and 1% oxygen) on exosome release was quantified using nanocrystals (Qdot®) coupled to CD63 by fluorescence NTA. A real-time, live-cell imaging system (Incucyte™) was used to establish the effect of exosomes on EC. Plasma samples were obtained at early gestation (<18 weeks) and classified according to pregnancy outcomes. An Illumina TrueSeq Small RNA kit was used to construct a small RNA library from exosomal RNA obtained from EVT and plasma samples. The number of exosomes was significantly higher in EVT cultured under 1% compared to 8% oxygen. In total, 741 miRNA were identified in exosomes from EVT. Bioinformatic analysis revealed that these miRNA were associated with cell migration and cytokine production. Interestingly, exosomes isolated from EVT cultured at 8% oxygen increased EC migration, whilst exosomes cultured at 1% oxygen decreased EC migration. These changes were inversely proportional to TNF-α released from EC. Finally, we have identified a set of unique miRNAs in exosomes from EVT cultured at 1% oxygen and exosomes isolated from the circulation of mothers at early gestation, who later developed PE and SPTB. We suggest that aberrant exosomal signalling by placental cells is a common aetiological factor in pregnancy complications characterised by incomplete SpA remodeling and is therefore a clinically relevant biomarker of pregnancy complications.Grace Truong, Dominic Guanzon, Vyjayanthi Kinhal, Omar Elfeky, Andrew Lai, Sherri Longo, Zarin Nuzhat, Carlos Palma, Katherin Scholz-Romero, Ramkumar Menon, Ben W. Mol, Gregory E. Rice, Carlos Salomo
Within-host microevolution of Pseudomonas aeruginosa in Italian cystic fibrosis patients
Inefficient purifying selection: the mammalian Y chromosome in the rodent genus Mus
Two related genes with potentially similar functions, one on the Y chromosome and one on the X chromosome, were examined to determine if they evolved differently because of their chromosomal positions. Six hundred fifty-seven base pairs of coding sequence of Jarid1d ( Smcy ) on the Y chromosome and Jarid1c ( Smcx ) on the X chromosome were sequenced in 13 rodent taxa. An analysis of replacement and silent substitutions, using a counting method designed for samples with small evolutionary distances, showed a significant difference between the two genes. The different patterns of replacement and silent substitutions within Jarid1d and Jarid1c may be a result of evolutionary mechanisms that are particularly strong on the Y chromosome because of its unique properties. These findings are similar to results of previous studies of Y chromosomal genes in these and other mammalian taxa, suggesting that genes on the mammalian Y evolve in a chromosome-specific manner.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46987/1/335_2005_Article_50.pd
Specific patterns of histone marks accompany X chromosome inactivation in a marsupial
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