119 research outputs found
Floating with seeds: understanding hydrochorous mangrove propagule dispersal: a field and modeling approach
PrĂ©sentation avec posterinfo:eu-repo/semantics/publishedYoung Marine Scientistsâ Day Vlaams Instituut voor de Zee (VLIZ), 24 fĂ©vrier, Brugge, Belgiqu
Caught in transit: offshore interception of seafaring propagules from seven mangrove species
Many organisms are transported passively and make use of the energy of natural phenomena or other organisms to disperse. However, not all species are equally likely to disperse over long distances. In mangroves, which possess seafaring propagules, it is largely unknown which species are more likely to reach the ocean and contribute to longâdistance dispersal. This is because dispersal has been mainly studied under reductionist laboratory conditions and via localized releaseârecapture experiments. Direct interceptions of propagules at sea have hardly been attempted because of the high labor intensity. Here, we set up a local citizenâscience network and engaged local fishermen to collect floating mangrove propagules over a period of 27 months. By comparing the dispersing community of propagules from the local stands in which they were produced, the open water of the bay, and the open ocean beyond the coral reef barrier, we could study the transition between local and longâdistance dispersal. The composition of the dispersing community changed from the local stands toward the ocean, suggesting that this transition imposes an important selective filter for leaving the local system. With the exception of three rare species (Lumnitzera racemosa, Pemphis acidula, and Xylocarpus moluccensis), we intercepted dispersing propagules of every mangrove species occurring in the East African region. Most intercepted propagules were produced by Rhizophora mucronata and Ceriops tagal, followed by Bruguiera gymnorrhiza and Avicennia marina, which also represent the most abundant species in the nearby mangrove forest. A larger number of propagules were intercepted during the wet season, with fewer propagules recovered during the dry season. Overall, our study indicates that differences in the dispersal capacity of mangrove propagules are not straightforward and that some species may better disperse at local scales within an estuary or embayment, while others might be more suitable for dispersal over longer distances. The presence of such tradeâoffs may help explain why current attempts to use mangrove traits to predict mangrove species distributions at different scales have remained only moderately successful
Shapes, contact angles, and line tensions of droplets on cylinders
Using an interface displacement model we calculate the shapes of
nanometer-size liquid droplets on homogeneous cylindrical surfaces. We
determine effective contact angles and line tensions, the latter defined as
excess free energies per unit length associated with the two contact lines at
the ends of the droplet. The dependences of these quantities on the cylinder
radius and on the volume of the droplets are analyzed.Comment: 26 pages, RevTeX, 10 Figure
The Effects of Voluntary, Involuntary, and Forced Exercises on Brain-Derived Neurotrophic Factor and Motor Function Recovery: A Rat Brain Ischemia Model
Author name used in this publication: Xiao-Xiang ZhengAuthor name used in this publication: Kai-Yu Tong2010-2011 > Academic research: refereed > Publication in refereed journalpublished_fina
On the importance of long-term functional assessment after stroke to improve translation from bench to bedside
Despite extensive research efforts in the field of cerebral ischemia, numerous disappointments came from the translational step. Even if experimental studies showed a large number of promising drugs, most of them failed to be efficient in clinical trials. Based on these reports, factors that play a significant role in causing outcome differences between animal experiments and clinical trials have been identified; and latest works in the field have tried to discard them in order to improve the scope of the results. Nevertheless, efforts must be maintained, especially for long-term functional evaluations. As observed in clinical practice, animals display a large degree of spontaneous recovery after stroke. The neurological impairment, assessed by basic items, typically disappears during the firsts week following stroke in rodents. On the contrary, more demanding sensorimotor and cognitive tasks underline other deficits, which are usually long-lasting. Unfortunately, studies addressing such behavioral impairments are less abundant. Because the characterization of long-term functional recovery is critical for evaluating the efficacy of potential therapeutic agents in experimental strokes, behavioral tests that proved sensitive enough to detect long-term deficits are reported here. And since the ultimate goal of any stroke therapy is the restoration of normal function, an objective appraisal of the behavioral deficits should be done
A monovalent chimpanzee adenovirus Ebola vaccine boosted with MVA
BACKGROUND
The West African outbreak of Ebola virus disease that peaked in 2014 has caused more than 11,000 deaths. The development of an effective Ebola vaccine is a priority for control of a future outbreak.
METHODS
In this phase 1 study, we administered a single dose of the chimpanzee adenovirus 3 (ChAd3) vaccine encoding the surface glycoprotein of Zaire ebolavirus (ZEBOV) to 60 healthy adult volunteers in Oxford, United Kingdom. The vaccine was administered in three dose levels â 1Ă1010 viral particles, 2.5Ă1010 viral particles, and 5Ă1010 viral particles â with 20 participants in each group. We then assessed the effect of adding a booster dose of a modified vaccinia Ankara (MVA) strain, encoding the same Ebola virus glyco- protein, in 30 of the 60 participants and evaluated a reduced primeâboost interval in another 16 participants. We also compared antibody responses to inactivated whole Ebola virus virions and neutralizing antibody activity with those observed in phase 1 studies of a recombinant vesicular stomatitis virusâbased vaccine expressing a ZEBOV glycoprotein (rVSV-ZEBOV) to determine relative potency and assess durability.
RESULTS
No safety concerns were identified at any of the dose levels studied. Four weeks after immunization with the ChAd3 vaccine, ZEBOV-specific antibody responses were similar to those induced by rVSV-ZEBOV vaccination, with a geometric mean titer of 752 and 921, respectively. ZEBOV neutralization activity was also similar with the two vaccines (geo- metric mean titer, 14.9 and 22.2, respectively). Boosting with the MVA vector increased virus-specific antibodies by a factor of 12 (geometric mean titer, 9007) and increased glycoprotein-specific CD8+ T cells by a factor of 5. Significant increases in neutralizing antibodies were seen after boosting in all 30 participants (geometric mean titer, 139; P<0.001). Virus-specific antibody responses in participants primed with ChAd3 remained positive 6 months after vaccination (geometric mean titer, 758) but were significantly higher in those who had received the MVA booster (geometric mean titer, 1750; P<0.001).
CONCLUSIONS
The ChAd3 vaccine boosted with MVA elicited B-cell and T-cell immune responses to ZEBOV that were superior to those induced by the ChAd3 vaccine alone. (Funded by the Wellcome Trust and others; ClinicalTrials.gov number, NCT02240875.
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Sexual (Dis)satisfaction and Its Contributors Among People Living with HIV Infection in Sweden
Earlier research reports lower sexual satisfaction among people living with HIV (PLHIV) compared to HIV-negative persons. A number of psychosocial factors directly associated with sexual dissatisfaction have been identified. Little is known about sexual satisfaction and their contributors among PLHIV in Sweden. The aim of this study was to examine direct and indirect effects of variables within sociodemographic, clinical HIV-related, psychological, and sexual domains on sexual(dis)satisfaction among PLHIV in Sweden. Data for this study was derived from a national representative, anonymous survey among PLHIV conducted in 2014 (n=1096). Statistical analysis included four steps: descriptive analyses, identification of variables associated with sexual (dis)satisfaction, identification of variables associated with those contributors of sexual (dis)satisfaction, and a path model integrating all these analyses. A total of 49% of participants reported being sexually dissatisfied and no significant differences were observed when non-heterosexual men, heterosexual men and women were compared. Among women, a negative change in sex life after HIV diagnosis and distress with orgasmic difficulties were directly associated with sexual dissatisfaction. For men, hopelessness, high HIV stigma, sexual inactivity in the last 6 months, and a negative change in sex life after HIV diagnosis were directly associated with sexual dissatisfaction. Path analyses showed in both men and women significant indirect association between not being involved in an intimate relationship, lower self-reported CD4 cell counts, and perceiving obligation to disclose HIV status to sexual partners as a barrier to look for a long-term partner and sexual dissatisfaction. Our results show that despite good treatment outcomes, the HIV diagnosis has a negative bearing on sexual satisfaction. The need for gender-tailored interventions and clinical implications of these findings are discussed
Microbial inhibition of oral epithelial wound recovery: potential role for quorum sensing molecules?
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