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941.
942.
对松材线虫与其在葡萄牙和欧洲的媒介昆虫樟子松墨天牛(Monochamus galloprovincialis)进行了首次研究。在病死木中发现,松材线虫在天牛刚羽化时聚集在蛹室中,线虫主要集中在天牛的后胸部。天牛羽化后6周内,松材线虫主要在天牛成虫补充营养时进入新寄主树,其次在天牛产卵时也会进入寄主树。总的看来,松材线虫在欧洲与其携带天牛之间互作与其在亚洲与松墨天牛及在北美与卡来罗纳墨天牛之间的关系十分相似。经研究,影响线虫与天牛携带关系的因子有内源和外源两类因子,如化学气味和各种信号。但是,其他多数因子尚未了解。研究影响线虫与天牛携带关系的因子将有助于了解两种生物密切关系的内在机制,并有助于研发出新的防控方法。 相似文献
943.
Spherical Ag nanoparticles (AgNPs) with a diameter of 20 nm or smaller were biologically synthesized using algae Parachlorella kessleri. The effect of storage conditions on the long-term stability of AgNPs was investigated. UV/Vis spectrophotometry, transmission electron microscopy, and dynamic light scattering measurements revealed that the long-term stability of AgNPs was influenced by light and temperature conditions. The most significant loss of stability was observed for the AgNPs stored in daylight at room temperature. The AgNPs stored under these conditions began to lose their stability after approximately 30 d; after 100 d, a substantial amount of agglomerated particles settled to the bottom of the Erlenmeyer flask. The AgNPs stored in the dark at room temperature exhibited better long-term stability. Weak particle agglomeration began at approximately the 100th day. The AgNPs stored in the dark at about 5℃ exhibited the best long-term stability; the AgNPs stored under such conditions remained spherical, with a narrow size distribution, and stable (no agglomeration) even after 6 months. Zeta-potential measurements confirmed better dispersity and stability of AgNPs stored under these conditions. 相似文献
944.
945.
María Catalina Ramírez Jaime Plazas Camilo Torres Juan Camilo Silva Luis Camilo Caicedo Miguel Angel González 《Systemic Practice and Action Research》2012,25(2):95-116
In several rural areas in Colombia there is a serious lack of water quality supply. Thereby the problematic situation is understood
as complex one that involves stakeholders with pluralistic interests, multiple variables and requires the development of sustainable
and suitable solutions. In order to address this issue, this paper proposes an integration of engineering design framework
(CDIO) with a systemic approach. Particularly the approach emphasizes on systemic elements such as autonomy, systems within
systems, cooperation between stakeholders and cause effect relations; it also proposes a previous observing phase for engineering
design framework. Thus the proposed systemic framework aims to generate projects that improve living conditions in rural communities
and promote the production of knowledge between the stakeholders to ensure sustainability in the long term. To illustrate
the proposal, this work contains a case study that discusses a project carried out by a research team—Ingenieros Sin Fronteras Colombia—in a rural district near to Colombia’s capital. The experience, which involved and benefited 16 families in the community,
provided strong evidence to support the proposed framework. The paper concludes with a discussion about the replication of
this proposal in other contexts. 相似文献
946.
Bráulio de Freitas Marçal 《Journal of Natural History》2019,53(39-40):2479-2488
ABSTRACTManakins (Pipridae) are a group of Neotropical birds well known for their spectacular lekking displays and non-monogamous mating system. Nevertheless, the two species of Antilophia have been traditionally considered monogamous and, therefore, an exception to this rule. In this paper, we studied the home range and the mating system of a colour-ringed population of the Helmeted Manakin Antilophia galeata in southeastern Brazil. We propose that it is a non-monogamous species that ranges widely during the breeding season, presenting a lekking behaviour in the form of unspectacular but aggressive chasing courtship displays. 相似文献
947.
Alvar González-Christen Christian Alejandro Delfín-Alfonso Alberto González-Romero 《西北部美国博物学家》2011,69(3)
Mearn’s grasshopper mouse ( Onychomys arenicola ) in Mexico is found primarily in the central and northern states. This is the first report of the genus Onychomys in the state of Veracruz, based on 7 captured specimens (3 collected). This finding extends the species’ known distribution by approximately 470 km east-southeast. In addition, this record increases the alpha diversity of terrestrial mammals for the state of Veracruz to 192 species. 相似文献
948.
An extant, indigenous desert tortoise population is reported from the cape region of Baja California Sur, Mexico. This population is described and figured as a new species, Xerobates lepidocephalus , distinct from all other North American tortoises including Xerobates agassizii , X. berlandieri , Gopherus flavomarginatus , and G. polyphemus . Xerobates lepidocephalus , or the scaly-headed tortoise, whose range is known only from an extremely small area in the gulf-drainage mountains just south of La Paz, appears to be a peninsular relict whose closest living relative is probably X. agassizii . However, carpal bone affinities connote a close relationship between X. lepidocephalus and the Oligoeene species X. laticunea from Wyoming and Colorado, suggesting that the former species may be one of the more primitive contemporary tortoises of the Xerobates lineage. Such evidence indicates that X. lepidocephalus is not of vicariant origin resulting from the formation of the cape of Baja California. Scaly-headed tortoises likely ranged, and may yet be discovered, in other medium-elevation mountain ranges of the cape. 相似文献
949.
The diversification of Mediterranean Phlebotomus species occurred during the Neogene and Quaternary periods. The climatic and geographical history of the Mediterranean area plausibly influenced the climatic requirements of recent sand fly species. Our aim was to investigate the European zoogeography and the climate-based ecological groups of eight Phlebotomus species considering the phylogeography of the studied taxa. Jaccard index calculation, hierarchical cluster and principal component analyses were performed. The results of Jaccard-coefficient calculations may indirectly refer to the former existence of three possible glacial refuges of sand fly populations in Europe: an Iberian, an Apennine and a Balkan Peninsula–Asia Minor refuge. Three main climatic groups of the studied sand fly species were distinguished, namely the so-called ‘Trans-Mediterranean’, ‘East Mediterranean’ and ‘West Mediterranean’ groups. Our results suggest that the ancestor of Phlebotomus similis and Phlebotomus sergenti was adapted to the hot, dry summer Mediterranean climate during the late Neogene. The third member of this climate group, Phlebotomus papatasi because of co-adaptation shows similar climatic requirements as P. similis and P. sergenti. The five Larroussius species studied should have evolved under moister climatic conditions. Species of the ‘West Mediterranean’ group were adapted to the milder and wetter oceanic climate of Atlantic coasts. The species of the ‘East Mediterranean’ group diversified under the less balanced climate of the East Mediterranean. The recent climatic requirements and the European distribution of the studied species is the consequence of the complex Quaternary–Neogene geographical and climatic history of their former habitats in the Old continent. The adaptation of the ancestors of the studied sand fly species to the changing geographical and climatic factors of Europe are discussed. 相似文献
950.
Natalie Villar Freret-Meurer Amanda Vaccani do Carmo Nayara Brandão Okada Tatiane Fernández do Carmo 《Journal of Natural History》2018,52(23-24):1571-1580
Seahorses are fishes that suffer high trading pressure in the international market. Three species have been recorded in Brazil, Hippocampus reidi, Hippocampus erectus and Hippocampus patagonicus, already classified as threatened or data deficient. Guaíba Island is an ecologically relevant site due to its position between two bays in Rio de Janeiro state. The present study aimed to survey the seahorse population of Guaíba Island, verifying several population structure parameters. Eight diving sites were selected around the island. Only the longsnout seahorse H. reidi was recorded. The population showed the largest density ever recorded in the world for the species. Sex ratio was 1:1 and seahorses were reproductively active. We observed three juveniles. The mean length recorded was 8.9 ± 1.64 cm. The population structure was similar to others populations studied throughout the Brazilian coast. 相似文献