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931.
To explore the role of the volatiles emitted from male labial gland (LG) of the bumblebee Bombus ardens ardens, we investigated the responses of virgin queens and males to volatiles using a gas chromatography–electroantennographic detector (GC–EAD) system and Y-tube olfactometer. GC–EAD analysis revealed that citronellol, the main compound detected in the male LG, caused clear electrophysiological responses in the antennae of B. a. ardens virgin queens and males although two minor compounds elicited antennal responses when applied in a high concentration. Behavioral tests using a Y-tube olfactometer showed that queens and males were significantly attracted to both LG extracts and citronellol more than to the solvent alone. This is the first study to demonstrate that citronellol as a major compound of male scent-marking pheromone in B. a. ardens functions as a sex attractant for queens. The results also suggest that this compound has another function as a trail marker used by males. 相似文献
932.
Hummingbird with modern feathering: an exceptionally well-preserved Oligocene fossil from southern France 总被引:1,自引:0,他引:1
Louchart A Tourment N Carrier J Roux T Mourer-Chauviré C 《Die Naturwissenschaften》2008,95(2):171-175
Hummingbirds (Trochilidae) today have an exclusively New World distribution, but their pre-Pleistocene fossil record comes from Europe only. In this study, we describe an exceptionally preserved fossil hummingbird from the early Oligocene of southeastern France. The specimen is articulated, with a completely preserved beak and feathering. Osteological characters allow to identify it as Eurotrochilus sp. This genus is a stem group representative of Trochilidae and was recently described from the early Oligocene of southern Germany. The new fossil reveals that these European Trochilidae were remarkably modern in size, skeletal proportions and the shape of the wing, tail and beak and hyoid bones. These features confirm the early acquisition of the abilities of hovering and nectarivory in hummingbirds, probably before the Oligocene. In several morphological characteristics, they resemble members of the 'true hummingbirds' (subfamily Trochilinae) and differ from hermits (Phaethornithinae). These features, which include a short and square tail and a moderately long, almost straight beak, appear to be primitive within the family Trochilidae. 相似文献
933.
Kevin Shirley Eric Marland Jenna Cantrell Gregg Marland 《Mitigation and Adaptation Strategies for Global Change》2011,16(3):325-346
We recognize that carbon-containing products do not decay and release CO2 to the atmosphere instantaneously, but release that carbon over extended periods of time. For an initial production of a
stock of carbon-containing product, we can treat the release as a probability distribution covering the time over which that
release occurs. The probability distribution that models the carbon release predicts the amount of carbon that is released
as a function of time. The use of a probability distribution in accounting for the release of carbon to the atmosphere realizes
a fundamental shift from the idea that all carbon-containing products contribute to a single pool that decays in proportion
to the size of the stock. Viewing the release of carbon as a continuous probabilistic process introduces some theoretical
opportunities not available in the former paradigm by taking advantage of other fields where the use of probability distributions
has been prevalent for many decades. In particular, theories developed in the life insurance industry can guide the development
of pricing and payment structures for dealing with the costs associated with the oxidation and release of carbon. These costs
can arise from a number of proposed policies (cap and trade, carbon tax, social cost of carbon, etc), but in the end they
all result in there being a cost to releasing carbon to the atmosphere. If there is a cost to the emitter for CO2 emissions, payment for that cost will depend on both when the emissions actually occur and how payment is made. Here we outline
some of the pricing and payment structures that are possible which result from analogous theories in the life insurance industry.
This development not only provides useful constructs for valuing sequestered carbon, but highlights additional motivations
for employing a probability distribution approach to unify accounting methodologies for stocks of carbon containing products. 相似文献
934.
Groundwater is the main source of drinking water and water for agricultural and industrial usage. Therefore, groundwater contamination is prevented and contaminated groundwater is remediated to protect public health and the environment. Methods to remediate groundwater contamination have been recently developed. The use of redox processes in water remediation technologies has not been properly reviewed. Numerous water remediation technologies, such as ultrasonication, bioremediation, electrokinetics and nanotechnology, are closely related to redox processes. Redox processes control the chemical speciation, bioavailability, toxicity, mobility and adsorption of water pollutants in environment. Here, we review (1) general introduction of redox processes, (2) applicability of redox processes in water remediation, and (3) catalytic enhancement of redox potentials to explore its wide applicability in environmental remediation. 相似文献
935.
Adult Vinciguerria nimbaria are the main prey of tuna during the tuna fishing season (late autumn and winter) in the equatorial Atlantic (0–4°N, and
~15°W). V. nimbaria trophic behavior in the fishing grounds was studied in relation to hydrobiological factors to determine its role in the trophic
food web. Sampling stations spaced by 20 nautical miles were set up along a 15°W north–south transect from 4°N to 0°40S. At
each station, the temperature and vertical fluorescence profiles were recorded. Nitrate and chlorophyll a analyses were performed on water sampled at different levels in the euphotic zone. Vertical plankton hauls were carried out
at depths of 0–100 and 0–200 m using a standard WP2 net fitted with a 200-μm mesh gauze. Vinciguerria nimbaria adults were collected using a young-fish mid-water trawl net (10 × 15 m opening mouth, 10 mm cod end mesh). The weight of
the stomach contents, the stomach fullness index, the number of prey, the frequency of occurrence and the prey preponderance
were recorded for 20 fish from each haul. An oligotrophic typical tropical structure (TTS) was found between 1° and 4°N where
small zooplankton was relatively abundant above or near the thermocline. In the TTS, V. nimbaria behaved as an epipelagic fish, feeding on the dominant small prey during the daytime. In turn, it was a prey for tuna. In
the equatorial zone, where zooplankton was more abundant than in the north equatorial zone, V. nimbaria behaved as a mesopelagic fish and as an opportunistic mesozooplankton feeder. It consumed a wide range of sizes of food,
feeding on the most abundant species of zooplankton as well as the largest zooplankton species, possibly while migrating towards
the surface in the late afternoon or in the deep layer. 相似文献
936.
Background, aim, and scope
Ever since the discovery of the mutagenic properties of ionizing radiation, the possibility of birth sex odds shifts in exposed human populations was considered in the scientific community. Positive evidence, however weak, was obtained after the atomic bombing of Japan. We previously investigated trends in the sex odds before and after the Chernobyl Nuclear Power Plant accident. In a pilot study, combined data from the Czech Republic, Denmark, Finland, Germany, Hungary, Norway, Poland, and Sweden between 1982 and 1992 showed a downward trend in the sex odds and a significant jump in 1987, the year immediately after Chernobyl. Moreover, a significant positive association of the sex odds between 1986 and 1991 with Chernobyl fallout at the district level in Germany was observed. Both of these findings, temporality (effect after exposure) and dose response association, yield evidence of causality. The primary aim of this study was to investigate longer time periods (1950–2007) in all of Europe and in the USA with emphasis on the global atmospheric atomic bomb test fallout and on the Chernobyl accident. To obtain further evidence, we also analyze sex odds data near nuclear facilities in Germany and Switzerland. 相似文献937.
The photovoltaic conversion efficiency for near-infrared (NIR) sunlight is improved successfully by dye sensitization of bulk heterojunction polymer solar cells, in which the active layer was prepared by a ternary blend of poly(3-hexylthiophene), a fullerene derivative (1-(3-methoxycarbonyl)propyl-1-phenyl-[6,6]-methanofullerene), and an NIR dye, silicon phthalocyanine bis(trihexylsilyl oxide). The mechanism of the NIR-dye sensitization is studied by femtosecond transient absorption spectroscopy. 相似文献
938.
Haber W 《Environmental science and pollution research international》2007,14(6):359-365
Humans’ superiority over all other organisms on earth rests on five main foundations: command of fire requiring fuel; controlled
production of food and other biotic substances; utilization of metals and other non-living materials for construction and
appliances; technically determined, urban-oriented living standard; economically and culturally regulated societal organization.
The young discipline of ecology has revealed that the progress of civilization and technology attained, and being further
pursued by humankind, and generally taken for granted and permanent, is leading into ecological traps. This metaphor circumscribes
ecological situations where finite resources are being exhausted or rendered non-utilizable without a realistic prospect of
restitution. Energy, food and land are the principal, closely interrelated traps; but the absolutely decisive resource in
question is land whose increasing scarcity is totally underrated. Land is needed for fulfilling growing food demands, for
producing renewable energy in the post-fossil and post-nuclear era, for maintaining other ecosystem services, for urban-industrial
uses, transport, material extraction, refuse deposition, but also for leisure, recreation, and nature conservation. All these
needs compete for land, food and non-food biomass production moreover for good soils that are scarcer than ever. We are preoccupied
with fighting climate change and loss of biodiversity; but these are minor problems we could adapt to, albeit painfully, and
their solution will fail if we are caught in the interrelated traps of energy, food, and land scarcity. Land and soils, finite
and irreproducible resources, are the key issues we have to devote our work to, based on careful ecological information, planning
and design for proper uses and purposes. The article concludes with a short reflection on economy and competition as general
driving forces, and on the role and reputation of today’s ecology.
Updated version of the keynote lecture presented at the EcoSummit 2007 in Beijing, China, May 24. The article is gratefully
dedicated to the memory of my late colleague and friend Frank B. Golley. 相似文献
939.
Shah Ghulam Mustafa Tufail Nadia Bakhat Hafiz Faiq Ahmad Iftikhar Shahid Muhammad Hammad Hafiz Mohkum Nasim Wajid Waqar Atika Rizwan Muhammad Dong Renjie 《Environmental science and pollution research international》2019,26(6):5463-5474
Environmental Science and Pollution Research - Reutilization of putrescible municipal solid wastes (MSW) in agriculture can provide valuable plant nutrients. However, it may pose serious... 相似文献
940.
Bruna Matturro Carla Ubaldi Paola Grenni Anna Barra Caracciolo Simona Rossetti 《Environmental science and pollution research international》2016,23(13):12613-12623
Polychlorobiphenyl (PCB) biodegradation was followed for 1 year in microcosms containing marine sediments collected from Mar Piccolo (Taranto, Italy) chronically contaminated by this class of hazardous compounds. The microcosms were performed under strictly anaerobic conditions with or without the addition of Dehalococcoides mccartyi, the main microorganism known to degrade PCBs through the anaerobic reductive dechlorination process. Thirty PCB congeners were monitored during the experiments revealing that the biodegradation occurred in all microcosms with a decrease in hepta-, hexa-, and penta-chlorobiphenyls (CBs) and a parallel increase in low chlorinated PCBs (tri-CBs and tetra-CBs). The concentrations of the most representative congeners detected in the original sediment, such as 245-245-CB and 2345-245-CB, and of the mixture 2356-34-CB+234-245-CB, decreased by 32.5, 23.8, and 46.7 %, respectively, after only 70 days of anaerobic incubation without any bioaugmentation treatment. Additionally, the structure and population dynamics of the microbial key players involved in the biodegradative process and of the entire mixed microbial community were accurately defined by Catalyzed Reporter Deposition Fluorescence In Situ Hybridization (CARD-FISH) in both the original sediment and during the operation of the microcosm. The reductive dehalogenase genes of D. mccartyi, specifically involved in PCB dechlorination, were also quantified using real-time PCR (qPCR). Our results demonstrated that the autochthonous microbial community living in the marine sediment, including D. mccartyi (6.32E+06 16S rRNA gene copy numbers g?1 sediment), was able to efficiently sustain the biodegradation of PCBs when controlled anaerobic conditions were imposed. 相似文献