964 research outputs found

    Volunteer-based coral reef monitoring: reliability of data, environmental education and implications for conservation

    Get PDF
    Coral reefs are the most biodiverse ecosystems of the ocean and they provide notable ecosystem services. Nowadays, they are facing a number of local anthropogenic threats and environmental change is threatening their survivorship on a global scale. Large-scale monitoring is necessary to understand environmental changes and to perform useful conservation measurements. Governmental agencies are often underfunded and are not able of sustain the necessary spatial and temporal large-scale monitoring. To overcome the economic constrains, in some cases scientists can engage volunteers in environmental monitoring. Citizen Science enables the collection and analysis of scientific data at larger spatial and temporal scales than otherwise possible, addressing issues that are otherwise logistically or financially unfeasible. “STE: Scuba Tourism for the Environment” was a volunteer-based Red Sea coral reef biodiversity monitoring program. SCUBA divers and snorkelers were involved in the collection of data for 72 taxa, by completing survey questionnaires after their dives. In my thesis, I evaluated the reliability of the data collected by volunteers, comparing their questionnaires with those completed by professional scientists. Validation trials showed a sufficient level of reliability, indicating that non-specialists performed similarly to conservation volunteer divers on accurate transects. Using the data collected by volunteers, I developed a biodiversity index that revealed spatial trends across surveyed areas. The project results provided important feedbacks to the local authorities on the current health status of Red Sea coral reefs and on the effectiveness of the environmental management. I also analysed the spatial and temporal distribution of each surveyed taxa, identifying abundance trends related with anthropogenic impacts. Finally, I evaluated the effectiveness of the project to increase the environmental education of volunteers and showed that the participation in STEproject significantly increased both the knowledge on coral reef biology and ecology and the awareness of human behavioural impacts on the environment

    Environmental awareness gained during a citizen science project in touristic resorts is maintained after 3 years since participation

    Get PDF
    The research leading to these results has received funding from Project AWARE Foundation, ASTOI Association, Milano, Ministry of Tourism of the Arab Republic of Egypt, Settemari S. p. A Tour Operator, Scuba Nitrox Safety International, Viaggio nel Blu Diving Center.Tourism is one of the largest economic sectors in the world. It has a positive effect on the economy of many countries, but it can also lead to negative impacts on local ecosystems. Informal environmental education through Citizen Science (CS) projects can be effective in increasing citizen environmental knowledge and awareness in the short-term. A change of awareness could bring to a behavioral change in the long-term, making tourism more sustainable. However, the long-term effects of participating in CS projects are still unknown. This is the first follow-up study concerning the effects of participating in a CS project on cognitive and psychological aspects at the basis of pro-environmental behavior. An environmental education program was developed, between 2012 and 2013, in a resort in Marsa Alam, Egypt. The study directly evaluated, through paper questionnaires, the short-term (after 1 week or 10 days) retention of knowledge and awareness of volunteers that had participated in the activities proposed by the program. After three years, participants were re-contacted via email to fill in the same questionnaire as in the short-term study, plus a new section with psychological variables. 40.5% of the re-contacted participants completed the follow-up questionnaires with a final sample size of fifty-five people for this study. Notwithstanding the limited sample size, positive trends in volunteer awareness, personal satisfaction regarding the CS project, and motivation to engage in pro-environmental behavior in the long-term were observed.Publisher PDFPeer reviewe

    A global fit to determine the pseudoscalar mixing angle and the gluonium content of the eta' meson

    Full text link
    We update the values of the eta-eta' mixing angle and of the eta' gluonium content by fitting our measurement R_phi = BR(phi to eta' gamma)/ BR(phi to eta gamma) together with several vector meson radiative decays to pseudoscalars (V to P gamma), pseudoscalar mesons radiative decays to vectors (P to V gamma) and the eta' to gamma gamma, pi^0 to gamma gamma widths. From the fit we extract a gluonium fraction of Z^2_G = 0.12 +- 0.04, the pseudoscalar mixing angle psi_P = (40.4 +- 0.6) degree and the phi-omega mixing angle psi_V = (3.32 +- 0.09) degree. Z^2_G and psi_P are fairly consistent with those previously published. We also evaluate the impact on the eta' gluonium content determination of future experimental improvements of the eta' branching ratios and decay width.Comment: 13 pages, 7 figures to submit to JHE

    Measurement of the ϕπ0e+e\phi \to \pi^0 e^+e^- transition form factor with the KLOE detector

    Get PDF
    A measurement of the vector to pseudoscalar conversion decay ϕπ0e+e\phi \to \pi^0 e^+e^- with the KLOE experiment is presented. A sample of 9500\sim 9500 signal events was selected from a data set of 1.7 fb1^{-1} of e+ee^+e^- collisions at smϕ\sqrt{s} \sim m_{\phi} collected at the DAΦ\PhiNE e+ee^+e^- collider. These events were used to obtain the first measurement of the transition form factor Fϕπ0(q2)| F_{\phi \pi^0}(q^2) | and a new measurement of the branching ratio of the decay: BR(ϕπ0e+e)=(1.35±0.050.10+0.05)×105\rm{BR}\,(\phi \to \pi^0 e^+e^-) = (\,1.35 \pm 0.05^{\,\,+0.05}_{\,\,-0.10}\,) \times 10 ^{-5}. The result improves significantly on previous measurements and is in agreement with theoretical predictions.Comment: 13 pages, 4 figures; matches published versio

    Search for dark Higgsstrahlung in e+ e- -> mu+ mu- and missing energy events with the KLOE experiment

    Get PDF
    We searched for evidence of a Higgsstrahlung process in a secluded sector, leading to a final state with a dark photon U and a dark Higgs boson h', with the KLOE detector at DAFNE. We investigated the case of h' lighter than U, with U decaying into a muon pair and h' producing a missing energy signature. We found no evidence of the process and set upper limits to its parameters in the range 2m_mu<m_U<1000 MeV, m_h'<m_U.Comment: 16 pages, 7 figures, submitted to Physics Letters

    Limit on the production of a new vector boson in e+eUγ\mathrm{e^+ e^-}\rightarrow {\rm U}\gamma, Uπ+π\rightarrow \pi^+\pi^- with the KLOE experiment

    Get PDF
    The recent interest in a light gauge boson in the framework of an extra U(1) symmetry motivates searches in the mass range below 1 GeV. We present a search for such a particle, the dark photon, in e+eUγ{\rm e^+ e^-}\rightarrow {\rm U}\gamma, Uπ+π\rightarrow \pi^+\pi^- based on 28 million e+eπ+πγ\mathrm{e^+ e^-} \rightarrow \pi^+ \pi^-\gamma events collected at DAΦ\PhiNE by the KLOE experiment. The π+π\pi^+ \pi^- production by initial-state radiation compensates for a loss of sensitivity of previous KLOE Ue+e{\rm U} \rightarrow \mathrm{e^+ e^-}, μ+μ\mu^+\mu^- searches due to the small branching ratios in the ρω\rho-\omega resonance region. We found no evidence for a signal and set a limit at 90\% CL on the mixing strength between the photon and the dark photon, ε2\varepsilon^2, in the U mass range between 527527 and 987987~MeV. Above 700 MeV this new limit is more stringent than previous ones.Comment: 6 pages, 9 figures, 1 table, submitted to Phys. Lett.

    Study of the process e+e- -> omega pi0 in the phi-meson mass region with the KLOE detector

    Get PDF
    We have studied the e+e- -> omegapi0 cross section in the sqrt(s) interval 1000-1030 MeV using the pi+pi-pi0pi0 and pi0pi0gamma final states with a sample of ~600 pb^-1 collected with the KLOE detector at DAFNE. By fitting the observed interference pattern around M_phi for both final states, we extract the ratio of the decay widths Gamma(omega->pi0gamma)/Gamma(omega->pi+pi-pi0) = 0.0897 +- 0.0016 and derive the branching fractions BR(omega -> pi+pi-pi0)= (90.24 +- 0.19)%, BR(omega -> pi0gamma) = (8.09 +- 0.14)%. The parameters describing the e+e- -> omegapi0 reaction around M_\phi are also used to extract the branching fraction for the OZI and G-parity violating phi -> omegapi0 decay: BR(phi->omegapi0) = (4.4 +- 0.6)x10^-5.Comment: 12 Pages, 4 figures, submitted to Physics Letter

    Search for the K_S -> e+e- decay with the KLOE detector

    Full text link
    We present the result of a direct search for the decay K_S -> e+e-, obtained with a sample of e+e- -> phi -> K_S K_L events produced at DAFNE, the Frascati phi-factory, for an integrated luminosity of 1.9 fb^-1. The search has been performed using a pure K_S beam tagged by the simultaneous detection of a K_L interaction in the calorimeter. Background rejection has been optimized by using both kinematic and particle identification cuts. We find BR(K_S -> e+e-) < 9x10^-9 at 90% CL, which improves by an order of magnitude on the previous best limit.Comment: 13 pages, 11 figures, submitted to Physics Letters

    Study of the a_0(980) meson via the radiative decay phi->eta pi^0 gamma with the KLOE detector

    Full text link
    We have studied the phi->a_0(980) gamma process with the KLOE detector at the Frascati phi-factory DAPhNE by detecting the phi->eta pi^0 gamma decays in the final states with eta->gamma gamma and eta->pi^+ pi^- pi^0. We have measured the branching ratios for both final states: Br(phi->eta pi^0 gamma)=(7.01 +/- 0.10 +/- 0.20)x10^-5 and (7.12 +/- 0.13 +/- 0.22)x10^-5 respectively. We have also extracted the a_0(980) mass and its couplings to eta pi^0, K^+ K^-, and to the phi meson from the fit of the eta pi^0 invariant mass distributions using different phenomenological models.Comment: 17 pages, 6 figures, submitted to Physics Letters B. Corrected typos in eq.

    Precision measurement of σ(e+eπ+πγ)/σ(e+eμ+μγ)\sigma(e^+e^-\rightarrow\pi^+\pi^-\gamma)/\sigma(e^+e^-\rightarrow \mu^+\mu^-\gamma) and determination of the π+π\pi^+\pi^- contribution to the muon anomaly with the KLOE detector

    Full text link
    We have measured the ratio σ(e+eπ+πγ)/σ(e+eμ+μγ)\sigma(e^+e^-\rightarrow\pi^+\pi^-\gamma)/\sigma(e^+e^-\rightarrow \mu^+\mu^-\gamma), with the KLOE detector at DAΦ\PhiNE for a total integrated luminosity of \sim 240 pb1^{-1}. From this ratio we obtain the cross section σ(e+eπ+π)\sigma(e^+e^-\rightarrow\pi^+\pi^-). From the cross section we determine the pion form factor Fπ2|F_\pi|^2 and the two-pion contribution to the muon anomaly aμa_\mu for 0.592<Mππ<0.9750.592<M_{\pi\pi}<0.975 GeV, Δππaμ\Delta^{\pi\pi} a_\mu= (385.1±1.1stat±2.7sys+theo)×1010({\rm 385.1\pm1.1_{stat}\pm2.7_{sys+theo}})\times10^{-10}. This result confirms the current discrepancy between the Standard Model calculation and the experimental measurement of the muon anomaly.Comment: 18 pages, 8 figures, minor text corrections, one table added, version to appear on Physics Letters
    corecore