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91.
The West Indian fruit fly, Anastrepha obliqua, is one of seven species of quarantine importance of its genus and is one of the most economically important fruit fly pests in Colombia. The taxonomic status of this species is a key issue for further implementation of any pest management program. Several molecular studies have shown enough variability within Anastrepha obliqua to suggest its taxonomic status could be revised; however, there are no morphological studies supporting this hypothesis. The aim of this work was to describe the morphological variability of Colombian populations of Anastrepha obliqua, comparing this variability with that of other samples from the Neotropics. Measurements were performed on individuals from 11 populations collected from different geographic Colombian localities and were compared with populations from Mexico (2), Dominica Island (1), Peru (1) and Brazil (2). Linear morphometric analyses were performed using 23 female morphological traits, including seven variables of the aculeus, three of the thorax, and six of the wing; seven ratios among them were also considered. Discriminant function analyses showed significant morphological differentiation among the Colombian populations, separating them into two groups. Furthermore, in the comparisons between Colombian samples with those from other countries, three clusters were observed. The possibility of finding more than one species within the nominal Anastrepha obliqua population is discussed.  相似文献   
92.
We studied the phylogeography of the strict savannah pygmy mice Mus (Nannomys) minutoides in West Central Africa. A total of 846 base pairs of the cytochrome b sequence were obtained for 66 individuals collected in Gabon, Cameroon, Republic of Congo and Central African Republic. These sequences were compared to those of M. minutoides from other African countries and to eight other species of the genus Mus. We performed maximum likelihood, Bayesian and nested clade analyses, as well as neutrality tests and time estimates. We show that M. minutoides is a well‐differentiated monophyletic species that separated from other pygmy mice 1.17 Myr ago. A distinct West Central African M. minutoides clade diverged early from the other African populations of the species, with a more recent common ancestor dating 0.14 Myr. West Central African populations are globally homogeneous, despite the present fragmentation of savannahs by the rain forest. However, our analyses show an unexpected vicariance between geographically close savannahs, embedded in the rain forest in Central Gabon. One of these populations is genetically more similar to very distant peripheral populations than to three closely neighbouring populations situated on both sides of the Ogooué River. A non‐river geographical barrier probably persisted in this area, durably isolating these local populations. This hypothesis about the history of the savannah landscape should be testable through the biogeographical analysis of other strict savannah small mammal species.  相似文献   
93.
The 3-aryl-2-cyanoacrylamide scaffold was designed as core pharmacophore for inhibitors of the Dengue and West Nile virus serine proteases (NS2B-NS3). A total of 86 analogs was prepared to study the structure–activity relationships in detail. Thereby, it turned out that the electron density of the aryl moiety and the central double bond have a crucial influence on the activity of the compounds, whereas the influence of substituents of the amide residue is less relevant. The para-hydroxy substituted analog was found to be the most potent inhibitor in this series with a Ki-value of 35.7 μM at the Dengue and 44.6 μM at the West Nile virus protease. The aprotinin competition assay demonstrates a direct interaction of the inhibitor molecule with active centre of the Dengue virus protease. The target selectivity was studied in a counterscreen with thrombin and found to be 2.8:1 in favor of DEN protease and 2.3:1 in favor of WNV protease, respectively.  相似文献   
94.
刘井元  林文  陈辉 《蛛形学报》2011,20(2):115-118
自1989年以来,先后从湖北西部山地6个不同海拔、12个不同类型生境捕获的啮齿、食虫等小型哺乳动物体外采集到一大批革螨、恙螨和吸虱标本,经初步整理,鉴定有革螨l1科32属73种、恙螨有3亚科11属41种和亚种、吸虱3种,其中有中国新纪录1种,籁氏巨刺螨Macronyssus leucippe(Domrow)和湖北新纪录41种。  相似文献   
95.
Riverine tsetse flies such as Glossina palpalis gambiensis and G. tachinoides are the vectors of human and animal trypanosomoses in West Africa. Despite intimate links between tsetse and water, to our knowledge there has never been any attempt to design trapping devices that would catch tsetse on water. In mangrove (Guinea) one challenging issue is the tide, because height above the ground for a trap is a key factor affecting tsetse catches. The trap was mounted on the remains of an old wooden dugout, and attached with rope to nearby branches, thereby allowing it to rise and fall with the tide. Catches showed a very high density of 93.9 flies/"water-trap"/day, which was significantly higher (p < 0.05) than all the catches from other habitats where the classical trap had been used. In savannah, on the Comoe river of South Burkina Faso, the biconical trap was mounted on a small wooden raft anchored to a stone, and catches were compared with the classical biconical trap put on the shores. G. p. gambiensis and G. tachinoides densities were not significantly different from those from the classical biconical one. The adaptations described here have allowed to efficiently catch tsetse on the water, which to our knowledge is reported here for the first time. This represents a great progress and opens new opportunities to undertake studies on the vectors of trypanosomoses in mangrove areas of Guinea, which are currently the areas showing the highest prevalences of sleeping sickness in West Africa. It also has huge potential for tsetse control using insecticide impregnated traps in savannah areas where traps become less efficient in rainy season. The Guinean National control programme has already expressed its willingness to use such modified traps in its control campaigns in Guinea, as has the national PATTEC programme in Burkina Faso during rainy season.  相似文献   
96.
Southern Mali mainly belongs to the Sudanian savanna bioclimatic zone, but forest patches showing botanical affinities with Guinean humid forest remain as gallery forests or ravine forests. To characterize the rodent diversity of this area and check for the presence of some species of Guinean affinities in this group, rodent assemblages were sampled in four regions of southern Mali, using trapping and observational data in forest and surrounding habitats. Twenty-four species were recorded, comprising a representative sample of the expected overall diversity in this group according to rarefaction curves. Praomys rostratus was the dominant species in the most humid, closed lowland forest. Praomys daltoni was also present in this habitat type, being all the more abundant as habitat degradation was apparent. It became the dominant species in ravine forest on rocky substrate where P. rostratus was completely absent. In Sudanian savanna habitats and in herbaceous and cultivated areas, Mastomys erythroleucus dominated a diverse rodent community. A few species were found that testified for Guinean affinities of the most humid forest patches, especially in the extreme southeast of the country (region of Sikasso). Rodent assemblages of the Bafing and Mts Mandingues areas, in the western part of the study area, showed the highest similarity, in relation with environmental characteristics of this region representing an extension of the Fouta Djallon plateau in Guinea. The results obtained highlight the high biodiversity value of this forest-savanna mosaic, and provide new arguments in favour of the preservation of West African forest patches and their surrounding habitats.  相似文献   
97.
Following an outbreak of Rift Valley fever (RVF) in south-eastern Mauritania during 1998, entomological investigations were conducted for 2 years in the affected parts of Senegal and Mauritania, spanning the Sénégal River basin. A total of 92 787 mosquitoes (Diptera: Culicidae), belonging to 10 genera and 41 species, were captured in light traps. In Senegal, Culex poicilipes (41%) and Mansonia uniformis (39%) were the most abundant species caught, whereas Aedes vexans (77%) and Cx. poicilipes (15%) predominated in Mauritania. RVF virus was isolated from 63 pools of Cx. poicilipes: 36 from Senegal in 1998 and 27 from Mauritania in 1999. These results are the first field evidence of Cx. poicilipes naturally infected with RVFV, and the first isolations of this virus from mosquitoes in Mauritania - the main West African epidemic and epizootic area. Additional arbovirus isolates comprised 25 strains of Bagaza (BAG) from Aedes fowleri, Culex neavei and Cx. poicilipes; 67 Sanar (ArD 66707) from Cx. poicilipes; 51 Wesselsbron (WSL) from Ae. vexans and 30 strains of West Nile (WN) from Ma. uniformis, showing differential specific virus-vector associations in the circulation activity of these five arboviruses.  相似文献   
98.
Cognitive abilities and techno-economic behaviours of hominids in the time period between 2.6-2.3 Myr have become increasingly well-documented. This time period corresponds to the oldest evidence for stone tools at Gona (Kada Gona, West Gona, EG 10-12, OGS 6-7), Hadar (AL 666), lower Omo valley (Ftji1, 2 & 5, Omo 57, Omo 123) in Ethiopia, and West Turkana (Lokalalei sites -LA1 & LA2C-) in Kenya. In 2002 a new palaeoanthropological site (LA1alpha), 100 meters south of the LA1 archaeological site, produced a first right lower molar of a juvenile hominid (KNM-WT 42718). The relative small size of the crown, its marked MD elongation and BL reduction, the relative position of the cusps, the lack of a C6 and the mild expression of a protostylid, reinforced by metrical analyses, demonstrate the distinctiveness of this tooth compared with Australopithecus afarensis, A. anamensis, A. africanus and Paranthropus boisei, and its similarity to early Homo. The LA1alpha site lies 2.2 m above the Ekalalei Tuff which is slightly younger than Tuff F dated to 2.34+/-0.04 Myr. This juvenile specimen represents the oldest occurrence of the genus Homo in West Turkana.  相似文献   
99.
A new bothid flounder, Engyprosopon vanuatuensis, is described on the basis of 15 specimens (9 males and 6 females, 41.1–55.8mm in standard length) collected from deep waters (163–165m) off Vanuatu Island in 1994 during the French exploratory cruise MUSORSTOM 8. The new species clearly differs from its congeners in having a short body, big eyes, large scales, and many gill rakers without serrations. Remarkable sexual dimorphism appears in interorbital width, anterior curve of head profile, rostral and orbital spines, length of ocular-side pectoral fin, small dots on eyes, and pigmentation of blind-side body.  相似文献   
100.
West Nile virus (WNV) has made considerable impact as an emerging infectious disease, spreading from coast to coast across North America since 1999. The disease has exhibited great spatial variability in North America, making an ecosystems approach to understanding the local human and vector ecology critical to prevention and control. This study underscores the importance of employing both personal prevention and community participatory approaches to create messages that have been adapted to the local ecology and are designed to reduce the risk of human infection with this mosquito-borne virus. As the virus spreads into new areas, underlying attitudes toward mosquitoes and the local perception of environment/ecology can affect the success of control and prevention measures. This work presents results from focus group discussions conducted in two Colorado counties in 2003, a year of significant WNV activity in the state. Issues addressed include residents’ assessment of risk and how this perception varied by age group and location, use or nonuse of repellents, and community attitudes toward mosquito control in areas with different ecologies and histories of mosquito-borne disease. The need to address individual components of personal prevention, to target prevention to specific audiences, and to disseminate prevention messages through local channels is discussed. The authors propose including aspects of ecology and disease proximity in understanding risk perception and addressing emerging diseases with a prominent ecological component.  相似文献   
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