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471.
Haeldermans Tom Samyn P. Cardinaels R. Vandamme D. Vanreppelen K. Cuypers A. Schreurs S. 《Journal of Polymers and the Environment》2021,29(8):2478-2491
Journal of Polymers and the Environment - Biochar is an excellent, but less-used candidate to serve as an alternative filler in poly(3-hydroxybutyrate) (PHB)-based composites. Increasing amounts of... 相似文献
472.
473.
Jedediah F. Brodie Midori Paxton Kangayatkarasu Nagulendran G. Balamurugan Gopalasamy Reuben Clements Glen Reynolds Anuj Jain Jason Hon 《Conservation biology》2016,30(5):950-961
We examined the links between the science and policy of habitat corridors to better understand how corridors can be implemented effectively. As a case study, we focused on a suite of landscape‐scale connectivity plans in tropical and subtropical Asia (Malaysia, Singapore, and Bhutan). The process of corridor designation may be more efficient if the scientific determination of optimal corridor locations and arrangement is synchronized in time with political buy‐in and establishment of policies to create corridors. Land tenure and the intactness of existing habitat in the region are also important to consider because optimal connectivity strategies may be very different if there are few, versus many, political jurisdictions (including commercial and traditional land tenures) and intact versus degraded habitat between patches. Novel financing mechanisms for corridors include bed taxes, payments for ecosystem services, and strategic forest certifications. Gaps in knowledge of effective corridor design include an understanding of how corridors, particularly those managed by local communities, can be protected from degradation and unsustainable hunting. There is a critical need for quantitative, data‐driven models that can be used to prioritize potential corridors or multicorridor networks based on their relative contributions to long‐term metacommunity persistence. 相似文献
474.
Five challenges to reconcile agricultural land use and forest ecosystem services in Southeast Asia
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L.R. Carrasco S.K. Papworth J. Reed W.S. Symes A. Ickowitz T. Clements K.S.‐H. Peh T. Sunderland 《Conservation biology》2016,30(5):962-971
Southeast Asia possesses the highest rates of tropical deforestation globally and exceptional levels of species richness and endemism. Many countries in the region are also recognized for their food insecurity and poverty, making the reconciliation of agricultural production and forest conservation a particular priority. This reconciliation requires recognition of the trade‐offs between competing land‐use values and the subsequent incorporation of this information into policy making. To date, such reconciliation has been relatively unsuccessful across much of Southeast Asia. We propose an ecosystem services (ES) value‐internalization framework that identifies the key challenges to such reconciliation. These challenges include lack of accessible ES valuation techniques; limited knowledge of the links between forests, food security, and human well‐being; weak demand and political will for the integration of ES in economic activities and environmental regulation; a disconnect between decision makers and ES valuation; and lack of transparent discussion platforms where stakeholders can work toward consensus on negotiated land‐use management decisions. Key research priorities to overcome these challenges are developing easy‐to‐use ES valuation techniques; quantifying links between forests and well‐being that go beyond economic values; understanding factors that prevent the incorporation of ES into markets, regulations, and environmental certification schemes; understanding how to integrate ES valuation into policy making processes, and determining how to reduce corruption and power plays in land‐use planning processes. 相似文献
475.
Emily B. Dennis Byron J.T. Morgan Tom M. Brereton David B. Roy Richard Fox 《Conservation biology》2017,31(6):1350-1361
Citizen scientists are increasingly engaged in gathering biodiversity information, but trade‐offs are often required between public engagement goals and reliable data collection. We compared population estimates for 18 widespread butterfly species derived from the first 4 years (2011–2014) of a short‐duration citizen science project (Big Butterfly Count [BBC]) with those from long‐running, standardized monitoring data collected by experienced observers (U.K. Butterfly Monitoring Scheme [UKBMS]). BBC data are gathered during an annual 3‐week period, whereas UKBMS sampling takes place over 6 months each year. An initial comparison with UKBMS data restricted to the 3‐week BBC period revealed that species population changes were significantly correlated between the 2 sources. The short‐duration sampling season rendered BBC counts susceptible to bias caused by interannual phenological variation in the timing of species’ flight periods. The BBC counts were positively related to butterfly phenology and sampling effort. Annual estimates of species abundance and population trends predicted from models including BBC data and weather covariates as a proxy for phenology correlated significantly with those derived from UKBMS data. Overall, citizen science data obtained using a simple sampling protocol produced comparable estimates of butterfly species abundance to data collected through standardized monitoring methods. Although caution is urged in extrapolating from this U.K. study of a small number of common, conspicuous insects, we found that mass‐participation citizen science can simultaneously contribute to public engagement and biodiversity monitoring. Mass‐participation citizen science is not an adequate replacement for standardized biodiversity monitoring but may extend and complement it (e.g., through sampling different land‐use types), as well as serving to reconnect an increasingly urban human population with nature. 相似文献
476.
Cocoon-spinning larvae of the codling moth, Cydia pomonella L. (Lepidoptera: Olethreutidae) employ a pheromone that attracts or arrests conspecifics seeking pupation sites. Such intraspecific communication signals are important cues for illicit receivers such as parasitoids to exploit. We tested the hypothesis that the prepupal C. pomonella parasitoid Mastrus ridibundus Gravenhorst (Hymenoptera: Ichneumonidae) exploits the larval aggregation pheromone to locate host prepupae. In laboratory olfactometer experiments, female M. ridibundus were attracted to 3-day-old cocoons containing C. pomonella larvae or prepupae. Older cocoons containing C. pomonella pupae, or larvae and prepupae excised from cocoons, were not attractive. In gas chromatographic-electroantennographic detection (GC-EAD) analyses of bioactive Porapak Q extract of cocoon-derived airborne semiochemicals, ten compounds elicited responses from female M. ridibundus antennae. Comparative GC-mass spectrometry of authentic standards and cocoon-volatiles determined that these compounds were 3-carene, myrcene, heptanal, octanal, nonanal, decanal, (E)-2-octenal, (E)-2-nonenal, sulcatone, and geranylacetone. A synthetic 11-component blend consisting of these ten EAD-active compounds plus EAD-inactive (+)-limonene (the most abundant cocoon-derived volatile) was as effective as Porapak Q cocoon extract in attracting both female M. ridibundus and C. pomonella larvae seeking pupation sites. Only three components could be deleted from the 11-component blend without diminishing its attractiveness to M. ridibundus, which underlines the complexity of information received and processed during foraging for hosts. Mastrus ridibundus obviously eavesdrop on the pheromonal communication signals of C. pomonella larvae that reliably indicate host presence.
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Gerhard GriesEmail: |
477.
Magnetic resonance (MR) imaging was performed on two women at the 33rd and 34th pregnancy week, respectively, after ultrasonographic detection of a brain malformation. Fetal neuromuscular blockade was induced by pancuronium bromide injected into the umbilical vein under continuous ultrasound (US) guidance. MR images supported the echotomographic diagnosis of holoprosencephaly, improving the image quality and offering additional information in such cases of difficult differential fetal diagnosis. Holoprosencephaly was finally confirmed by neonatal US and autopsy (case 1), US, CT and MR (case 2). 相似文献
478.
The trophic status of herbivorous fishes on coral reefs 总被引:1,自引:0,他引:1
Dietary analyses of 17 species of nominally herbivorous fishes on the northern Great Barrier Reef were carried out to resolve the questions to what extent diet in nominally herbivorous reef fishes is dominated by living plant material and whether short-chain fatty acid profiles in the alimentary tract predict diet. The fishes included members of the families Acanthuridae, Scaridae and Kyphosidae. The analyses revealed consumption of a wide range of food resources including macroscopic algae, turfing algae, pelagic and planktonic animal matter, organic detritus and sediments. In only 7 of the 17 species was living algae the dominant dietary item. Gastrointestinal short-chain fatty acids (SCFA) profiles reflecting the fermentative activities of gut symbionts were used as a framework for the initial analysis of dietary patterns. The feeding patterns implied by the SCFA profiles were validated by direct observation of food material through gut content analysis. We identified four main trophic groupings differentiated by fermentation profiles and diet. These were: (1) species with low levels of SCFA in gut samples (mean mM 9.2ǂ.8) but a high proportion of isovalerate (mean 15.4%dž.7): Acanthurus nigricauda, A. olivaceus, Ctenochaetus striatus, Chlorurus microrhinos, C.sordidus, Scarus schlegeli; (2) species that fed on turfing, filamentous and small thallate algae and displayed moderate levels of SCFA (mean mM 21.9DŽ.9): Acanthurus nigricans, A.lineatus, Naso tuberosus; (3) species that fed on large thallate (macroscopic) algae with high levels of SCFA (mean mM 41.2Dž.5) with very low proportions of isovalerate (mean 0.5%ǂ.1): Kyphosus cinerascens, K.vaigiensis, Naso unicornis, Zebrasoma scopas; and (4) species with diets dominated by planktonic animal material with moderate levels of SCFA (mean mM 21.3ǃ.5): Naso annulatus, N. brevirostris, N. hexacanthus, N. vlamingii. We conclude that a wide range of dietary items are taken by the 17 nominal herbivores, and that dietary groupings do not reflect taxonomic relationships. There was evidence of convergence in feeding modes and diet between phylogenetically distinct taxa and divergence within particular lineages. 相似文献
479.
We re-evaluated the "diel feeding hypothesis" by measuring diel variation in starch, protein, and floridoside in three algal "types" collected from a fringing coral reef at Lizard Island, Great Barrier Reef, Australia. Samples of two species of rhodophyte algae, Gracilaria arcuata and Acanthophora spicifera, and the turf assemblage from the territories of the herbivorous pomacentrid Stegastes nigricans were collected at four time periods through the day: 0630-0730, 1000-1100, 1330-1430, and 1630-1730 hours. We also measured the ability of several species of marine fish (the herbivores Acanthurus nigricans, A. lineatus, A. olivaceus, and Parma alboscapularis and the detritivore Ctenochaetus striatus) to hydrolyse floridoside by estimating !-galactosidase activity in tissue from the anterior intestine. We detected no diel pattern in protein content of the algae but found a significant steady increase in starch content throughout the day. Floridoside content increased in the morning and decreased in the afternoon, a pattern that may be driven by midday photoinhibition of the algae. All the fishes tested could utilise floridoside. Our results support the diel feeding hypothesis. Although floridoside content decreased in the afternoon, our results suggest floridoside was used during the day by the algae to synthesise starch. Thus the algae increased in nutritional value until photoinhibition occurred at midday then subsequently maintained their nutritional value during the afternoon. This pattern of algal nutrients increasing to a midday peak and remaining relatively constant throughout the afternoon correlates well with the diel feeding pattern in many species of marine herbivorous fish. 相似文献
480.
Louis V. Verchot Meine Van Noordwijk Serigne Kandji Tom Tomich Chin Ong Alain Albrecht Jens Mackensen Cynthia Bantilan K. V. Anupama Cheryl Palm 《Mitigation and Adaptation Strategies for Global Change》2007,12(5):901-918
Agriculture is the human enterprise that is most vulnerable to climate change. Tropical agriculture, particularly subsistence
agriculture is particularly vulnerable, as smallholder farmers do not have adequate resources to adapt to climate change.
While agroforestry may play a significant role in mitigating the atmospheric accumulation of greenhouse gases (GHG), it also
has a role to play in helping smallholder farmers adapt to climate change. In this paper, we examine data on the mitigation
potential of agroforestry in the humid and sub-humid tropics. We then present the scientific evidence that leads to the expectation
that agroforestry also has an important role in climate change adaptation, particularly for small holder farmers. We conclude
with priority research questions that need to be answered concerning the role of agroforestry in both mitigation and adaptation
to climate change. 相似文献