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941.
Carlos Carroll Brett Hartl Gretchen T. Goldman Daniel J. Rohlf Adrian Treves Jeremy T. Kerr Euan G. Ritchie Richard T. Kingsford Katherine E. Gibbs Martine Maron James E. M. Watson 《Conservation biology》2017,31(5):967-975
Government agencies faced with politically controversial decisions often discount or ignore scientific information, whether from agency staff or nongovernmental scientists. Recent developments in scientific integrity (the ability to perform, use, communicate, and publish science free from censorship or political interference) in Canada, Australia, and the United States demonstrate a similar trajectory. A perceived increase in scientific‐integrity abuses provokes concerted pressure by the scientific community, leading to efforts to improve scientific‐integrity protections under a new administration. However, protections are often inconsistently applied and are at risk of reversal under administrations publicly hostile to evidence‐based policy. We compared recent challenges to scientific integrity to determine what aspects of scientific input into conservation policy are most at risk of political distortion and what can be done to strengthen safeguards against such abuses. To ensure the integrity of outbound communications from government scientists to the public, we suggest governments strengthen scientific integrity policies, include scientists’ right to speak freely in collective‐bargaining agreements, guarantee public access to scientific information, and strengthen agency culture supporting scientific integrity. To ensure the transparency and integrity with which information from nongovernmental scientists (e.g., submitted comments or formal policy reviews) informs the policy process, we suggest governments broaden the scope of independent reviews, ensure greater diversity of expert input and transparency regarding conflicts of interest, require a substantive response to input from agencies, and engage proactively with scientific societies. For their part, scientists and scientific societies have a responsibility to engage with the public to affirm that science is a crucial resource for developing evidence‐based policy and regulations in the public interest. 相似文献
942.
K.H. Roucoux I.T. Lawson T.R. Baker D. Del Castillo Torres F.C. Draper O. Lähteenoja M.P. Gilmore E.N. Honorio Coronado T.J. Kelly E.T.A. Mitchard C.F. Vriesendorp 《Conservation biology》2017,31(6):1283-1292
Large, intact areas of tropical peatland are highly threatened at a global scale by the expansion of commercial agriculture and other forms of economic development. Conserving peatlands on a landscape scale, with their hydrology intact, is of international conservation importance to preserve their distinctive biodiversity and ecosystem services and maintain their resilience to future environmental change. We explored threats to and opportunities for conserving remaining intact tropical peatlands; thus, we excluded peatlands of Indonesia and Malaysia, where extensive deforestation, drainage, and conversion to plantations means conservation in this region can protect only small fragments of the original ecosystem. We focused on a case study, the Pastaza‐Marañón Foreland Basin (PMFB) in Peru, which is among the largest known intact tropical peatland landscapes in the world and is representative of peatland vulnerability. Maintenance of the hydrological conditions critical for carbon storage and ecosystem function of peatlands is, in the PMFB, primarily threatened by expansion of commercial agriculture linked to new transport infrastructure that is facilitating access to remote areas. There remain opportunities in the PMFB and elsewhere to develop alternative, more sustainable land‐use practices. Although some of the peatlands in the PMFB fall within existing legally protected areas, this protection does not include the most carbon‐dense (domed pole forest) areas. New carbon‐based conservation instruments (e.g., REDD+, Green Climate Fund), developing markets for sustainable peatland products, transferring land title to local communities, and expanding protected areas offer pathways to increased protection for intact tropical peatlands in Amazonia and elsewhere, such as those in New Guinea and Central Africa which remain, for the moment, broadly beyond the frontier of commercial development. 相似文献
943.
944.
945.
Z. Mokhtari-Shourijeh L. Montazerghaem M. E. Olya 《Journal of Polymers and the Environment》2018,26(9):3550-3563
The high surface area of porous nanofibers enhances their performance for many applications. The present study investigated electrospinning and dye adsorption properties of polymeric nanofibers which were porous by various types of salts. The salt/polyacrylonitrile/polyvinylidene fluoride composite nanofibers were electrospun, and the inexpensive salts such as sodium chloride (NaCl), sodium bicarbonate (NaHCO3), or calcium chloride (CaCl2) was used to manufacture the porous fibers. Subsequently, the salt was removed by a selective dissolution, and salt extraction of nanofibers was performed with the solution of hydrochloric acid (10 wt%). Salt/PVDF/PAN and porous PVDF/PAN composite nanofibers have been applied to dye adsorption of solution. The characteristics of nanofibers were studied by Fourier transform infrared microscopy (FTIR) and scanning electron microscopy (SEM) analysis. FTIR showed that the salt was extracted from PVDF/PAN nanofibers successfully, and SEM indicated that many pores were aligned with the nanofibers. The adsorption capacity of salt nanofibers webs and porous nanofibers webs for Basic Blue 41 were compared with each other, and porous fibers were obtained from NaHCO3 having the highest dye adsorption value. Adsorption of dyes follows the Langmuir isotherm and pseudo-second order kinetics. 相似文献
946.
María Pía Areal M. Lorena Arciniegas Fernanda Horst Verónica Lassalle Francisco H. Sánchez Vera A. Alvarez Jimena S. Gonzalez 《Journal of Polymers and the Environment》2018,26(8):3129-3138
Scientific and technological researches are devoted to obtain materials capable of retaining different kinds of pollutants, contributing to contamination solutions. In this context, hydrogels have emerged as great candidates because of their excellent absorption properties as well as good mechanical, thermal and chemical properties. More specifically, ferrogels (magnetic gels) present the extra advantage of being easily manipulated by a permanent magnet. Here, we present the results derived from the application of ferrogels as efficient tools to extract heavy metal pollutants from wastewater samples. The gels were prepared following the method of freezing and thawing of a polyvinyl alcohol aqueous solution with magnetic nanoparticles coated with polyacrylic acid. Ferrogels were fully characterized and their ability to retain Cu2+ and Cd2+, as model heavy metals, was studied. Thus kinetics and mechanisms of adsorption were evaluated and modeled. The concentration of MNPs on the PVA matrix was key to improve the adsorption capability (approximately the double of retention is improved by the MNPs addition). The adsorption kinetics was determined as pseudo-second order model, whereas the Langmuir model was the most appropriate to explain the behavior of the gels. Finally reuse ability was evaluated to determine the real potential of these materials, the ferrogels demonstrated high efficiency up to about five cycles, retaining about 80–90% of their initial adsorption capability. All the results indicated that the materials are promising candidates able to compete with the commercial technology regarding to water remediation. 相似文献
947.
Zawawi E. M. A. Yusof Nor Syazwani Ismail Zulhabri 《Journal of Material Cycles and Waste Management》2018,20(1):223-236
Journal of Material Cycles and Waste Management - Malaysia is one of the Asian countries which are prone to disaster: flooding is one of the natural disasters that are becoming more common in... 相似文献
948.
Phylogeographic structure of false clownfish, Amphiprion ocellaris, explained by sea level changes on the Sunda shelf 总被引:3,自引:0,他引:3
The phylogenetic structure of the anemonefish Amphiprion ocellaris was established based on sequence data generated for the 5′ end of the cytochrome b (cytb) gene at 11 sites throughout Southeast Asia. Considerable genetic structuring was observed throughout the range of
A. ocellaris. The region has a complex geography, with the Sunda shelf having been exposed during the lower sea levels associated with
periods of glaciation. The direction of subsequent flooding of the Sunda shelf, as a direct consequence of the retreating
glacial sheets, can be predicted based on the major river drainage systems in the region. Much of the phylogeographic structure,
including levels of intra-site genetic variation, can be explained in terms of the “seeding” of sites on the Sunda shelf,
by those on the shelf rim, as sea levels rose. We often found surface ocean currents in the region, which should influence
larval dispersal, to be poorly correlated with phylogeographic structure. Several geographically close sites, which appear
to be connected by surface currents, showed significant genetic stratification. We hypothesise that the phylogeographic structure
of A. ocellaris is more reminiscent of the Pleistocene sea level changes than surface currents. The high contribution of sea level changes
to the phylogeographic structure was also supported by several missing haplotypes in the generated spanning network. Cytb
DNA sequences generated for recently recruited A. ocellaris individuals sampled from Singapore indicate that, on a local scale, there is a directional inflow of recruits, which is dependent
on the monsoon seasons. The nature of dispersal and genetic structure of reef fish species found on the Sunda shelf is clearly
complex, and should take into consideration past phylogeographic events.
Received: 13 November 1999 / Accepted: 12 July 2000 相似文献
949.
A method was developed for measurement of active oxygen production in embryonic stages of the brown seaweed Fucus spiralis, using the label CM-DCFH-DA. Active oxygen species convert the label into the green fluorescent CM-DCF (exc/em 488/530 nm)
that is detected via confocal laserscan microscopy and quantitative image analysis. Loading of the label did not harm the
embryos; loading efficiency was age-independent, and the esterases needed for conversion to CM-DCFH were not inhibited by
the effective UV dose (2 W m−2) applied in the experiments. After correction for daily variation of the laser power, and calibration with DCF standard solutions,
this automated analysis of confocal images rendered active oxygen concentrations in fucoid embryos (μM DCF). An experiment
was designed for the assessment of active oxygen production following irradiance stress in the light-sensitive embryos. Dim-light-acclimated,
1-, 2- and 4-day-old embryos were transferred for 60 min to defined high-light conditions (4π-irradiance 300 μmol photons
m−2 s−1), optionally without UV radiation, including UVA, or including UVA plus UVB. PSII yield measurements (PAM fluorometer) were
carried out in order to assess the degree of photoinhibition under these light conditions. The imposed light stress initially
caused a rapid decrease of the PSII yields (ΦP). With increasing embryo age, minimum ΦP values attained under light stress remained higher. Consequently, electron transport rates (ETR) would increase with embryo
age, i.e., with the development of their photosynthetic apparatus. Active oxygen production increased with ETR, and when UVB
was included, relatively greater amounts of active oxygen were produced. A slow, second-phase decrease of ΦP under light stress that was proportional to active oxygen production indicated that some photooxidative damage was caused,
in particular during UVB exposure. Recovery from light stress was a rapid process in the absence of UVB; in such cases ΦP was almost restored to the initial values within 60 min. The relative state of recovery of ΦP was correlated with both the effective UV dose and active oxygen production rate (DCF). Recovery was slowest in embryos exposed
for 60 min to an experimental UVB dose, which was representative of a situation at low tide, on a sunny day. The results suggest
that active oxygen may cause an in situ inhibition of growth of the earliest life stages of F. spiralis.
Received: 26 January 2000 / Accepted: 4 September 2000 相似文献
950.
We examined the vertical distributions of scallop (Placopecten magellanicus) veligers in deep (0.6 m diameter, 9.5 m deep) polyethylene mesocosms from December 1991 to January 1992. In the mesocosms
temperature stratification varied from 0 to 1.5 °C. Profiles of vertical distribution revealed several repeated patterns.
Peaks in veliger numbers often appeared at the water surface and just above the thermocline. Higher density patches were seen
below the surface peaks, and revealed the presence of bio-convective cells. Distribution away from these discontinuities was
usually even. Distribution of veligers was affected by thermoclines above 1.0 °C. Responses to thermoclines varied with larval
age and time of day, and 28 to 30 d veligers passed in both directions through a 1.5 °C thermocline. We conclude that larval
behaviour is a major determinant of whether veligers pass through a thermocline. Kinematic viscosity may play a role in perception
of temperature changes. Two potential consequences of such behaviour are (1) remaining in more productive upper water layers,
where feeding opportunities are enhanced, and (2) increased horizontal transport in the region of the thermocline, which may
enhance recruitment.
Received: 15 May 1996 / Accepted: 11 May 2000 相似文献