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151.
The pucC genes of Rubrivivax gelatinosus strain 151 and Rhodopseudomonas acidophila strain 10050 have been identified, cloned and sequenced. In Rubrivivax gelatinosus the arrangement of the pucC gene with regard to the pucBA genes was shown to differ from that found in other species of photosynthetic bacteria. The Rhodopseudomonas acidophila pucC was found downstream of four new pucBA gene pairs, bringing the sequenced pucBA pairs to a total of eight in this strain. The predicted PucC protein sequences were compared to those of PucC from other
species and showed high similarity. Similarity was also seen to more distantly related proteins LhaA and orf428 of Rhodobacter capsulatus, orf G115 of Rhodospirillum rubrum and `orf428' from Synechocystis sp. PCC6803. An analysis of the predicted secondary structure of these proteins is given, and their structural similarity
to proteins in the Major Facilitator Superfamily is discussed with regard to their possible function.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
152.
Marlene Zuk John T. Rotenberry Leigh W. Simmons 《Evolution; international journal of organic evolution》1998,52(1):166-171
The field cricket Teleogryllus oceanicus has been introduced to Hawaii, where it is parasitized by an acoustically orienting parasitoid fly, Ormia ochracea. Previous work showed that call parameters from parasitized populations differ from those in unparasitized populations in a direction expected if selection by flies is occurring. Here we examined songs of males collected in the field and compare calling song characters of crickets later found to harbor parasitoid larvae with those of males free of parasitoids. The two groups differ significantly in several song characteristics, particularly the trill-like long chirp given at the beginning of each song. Males with longer long chirps containing shorter interpulse intervals are more likely to be parasitized, suggesting that the flies find such males more attractive. Depending on the traits females prefer, sexual selection may oppose natural selection in altering T. oceanicus song in parasitized populations. 相似文献
153.
A. Robertson A. M. Jarvis C. J. Brown R. E. Simmons 《Biodiversity and Conservation》1998,7(4):495-511
Namibia supports a highly diverse avifauna of 644 species, including over 90 species endemic to the southern African subregion and 13 species endemic to the country. Patterns of species diversity in relation to protected areas and habitat types were analysed using data from the Southern African Bird Atlas Project. A modified Shannon index appropriate for atlas data was used to derive an index of diversity for all species, wetland, terrestrial, threatened, and regional endemic species. Species richness for Namibian endemics was mapped. Overall species diversity is highest in the northeast of Namibia where wetland and riparian habitats coincide. Both wetland and terrestrial species show highest diversity in this area. The greatest diversity of southern African endemics falls within the Savanna-Karoo systems. Several key areas are identified for red data species, including the Caprivi Strip, Kunene and Orange Rivers, coastal wetlands and ephemeral river mouths and pans. This highlights the pressures operating on wetland and riparian habitats in arid environments. Concentrations of Namibian endemics are found in the northwestern (Kaoko) escarpment of the country. Although much of the area of high diversity of wetland, terrestrial and red data species falls within protected areas, national and regional endemics are poorly represented within national parks. 相似文献
154.
Phung Khanh Lam Dong Thi Hoai Tam Nguyen Minh Dung Nguyen Thi Hanh Tien Nguyen Tan Thanh Kieu Cameron Simmons Jeremy Farrar Bridget Wills Marcel Wolbers 《PloS one》2015,10(5)
PurposeTo identify risk factors and develop a prediction model for the development of profound and recurrent shock amongst children presenting with dengue shock syndrome (DSS)MethodsWe analyzed data from a prospective cohort of children with DSS recruited at the Paediatric Intensive Care Unit of the Hospital for Tropical Disease in Ho Chi Minh City, Vietnam. The primary endpoint was “profound DSS”, defined as ≥2 recurrent shock episodes (for subjects presenting in compensated shock), or ≥1 recurrent shock episodes (for subjects presenting initially with decompensated/hypotensive shock), and/or requirement for inotropic support. Recurrent shock was evaluated as a secondary endpoint. Risk factors were pre-defined clinical and laboratory variables collected at the time of presentation with shock. Prognostic model development was based on logistic regression and compared to several alternative approaches.ResultsThe analysis population included 1207 children of whom 222 (18%) progressed to “profound DSS” and 433 (36%) had recurrent shock. Independent risk factors for both endpoints included younger age, earlier presentation, higher pulse rate, higher temperature, higher haematocrit and, for females, worse hemodynamic status at presentation. The final prognostic model for “profound DSS” showed acceptable discrimination (AUC=0.69 for internal validation) and calibration and is presented as a simple score-chart.ConclusionsSeveral risk factors for development of profound or recurrent shock among children presenting with DSS were identified. The score-chart derived from the prognostic models should improve triage and management of children presenting with DSS in dengue-endemic areas. 相似文献
155.
Laurel R. Yohe Paúl M. Velazco Danny Rojas Beth E. Gerstner Nancy B. Simmons Liliana M. Dávalos 《Biology letters》2015,11(11)
The earliest record of plant visiting in bats dates to the Middle Miocene of La Venta, the world''s most diverse tropical palaeocommunity. Palynephyllum antimaster is known from molars that indicate nectarivory. Skull length, an important indicator of key traits such as body size, bite force and trophic specialization, remains unknown. We developed Bayesian models to infer skull length based on dental measurements. These models account for variation within and between species, variation between clades, and phylogenetic error structure. Models relating skull length to trophic level for nectarivorous bats were then used to infer the diet of the fossil. The skull length estimate for Palynephyllum places it among the larger lonchophylline bats. The inferred diet suggests Palynephyllum fed on nectar and insects, similar to its living relatives. Omnivory has persisted since the mid-Miocene. This is the first study to corroborate with fossil data that highly specialized nectarivory in bats requires an omnivorous transition. 相似文献
156.
Andrew J. M. Cooper Rebecca K. Simmons Diana Kuh Soren Brage Rachel Cooper NSHD scientific data collection team 《PloS one》2015,10(5)
PurposeTo investigate the associations of time spent sedentary, in moderate-to-vigorous-intensity physical activity (MVPA) and physical activity energy expenditure (PAEE) with physical capability measures at age 60-64 years.MethodsTime spent sedentary and in MVPA and, PAEE were assessed using individually calibrated combined heart rate and movement sensing among 1727 participants from the MRC National Survey of Health and Development in England, Scotland and Wales as part of a detailed clinical assessment undertaken in 2006-2010. Multivariable linear regression models were used to examine the cross-sectional associations between standardised measures of each of these behavioural variables with grip strength, chair rise and timed up-&-go (TUG) speed and standing balance time.ResultsGreater time spent in MVPA was associated with higher levels of physical capability; adjusted mean differences in each capability measure per 1standard deviation increase in MVPA time were: grip strength (0.477 kg, 95% confidence interval (CI): 0.015 to 0.939), chair rise speed (0.429 stands/min, 95% CI: 0.093 to 0.764), standing balance time (0.028 s, 95% CI: 0.003 to 0.053) and TUG speed (0.019 m/s, 95% CI: 0.011 to 0.026). In contrast, time spent sedentary was associated with lower grip strength (-0.540 kg, 95% CI: -1.013 to -0.066) and TUG speed (-0.011 m/s, 95% CI: -0.019 to -0.004). Associations for PAEE were similar to those for MVPA.ConclusionHigher levels of MVPA and overall physical activity (PAEE) are associated with greater levels of physical capability whereas time spent sedentary is associated with lower levels of capability. Future intervention studies in older adults should focus on both the promotion of physical activity and reduction in time spent sedentary. 相似文献
157.
158.
Mechanisms enabling men to identify women likely to engage in extra-pair copulations (EPCs) would be advantageous in avoiding cuckoldry. Men’s judgments of female sexual faithfulness often show high consensus, but accuracy appears poor. We examined whether accuracy of these judgments made to images of women could be improved through i) employing a forced choice task, in which men were asked to select the more faithful of two women and/or ii) providing men with full person images. In Experiment 1, men rated 34 women, for whom we had self-reported EPC behavior, on faithfulness, trustworthiness or attractiveness from either face or full person photographs. They then completed a forced choice task, selecting the more faithful of two woman from 17 pairs of images, each containing one woman who had reported no EPCs and one who had reported two or more EPCs. Men were unable to rate faithfulness with any accuracy, replicating previous findings. However, when asked to choose the more faithful of two women, they performed significantly above chance, although the ability to judge faithfulness at above-chance levels did not generalize to all pairs of women. Although there was no significant difference in accuracy for face and full person image pairs, only judgments from faces were significantly above chance. In Experiment 2, we showed that this accuracy for faces was repeatable in a new sample of men. We also showed that individual variation in accuracy was unrelated to variation in preferences for faithfulness in a long-term partner. Overall, these results show that men’s judgments of faithfulness made from faces of unfamiliar women may contain a kernel of truth. 相似文献
159.
Yixin H. Ye Alison M. Carrasco Francesca D. Frentiu Stephen F. Chenoweth Nigel W. Beebe Andrew F. van den Hurk Cameron P. Simmons Scott L. O’Neill Elizabeth A. McGraw 《PLoS neglected tropical diseases》2015,9(6)
BackgroundDengue viruses (DENV) are the causative agents of dengue, the world’s most prevalent arthropod-borne disease with around 40% of the world’s population at risk of infection annually. Wolbachia pipientis, an obligate intracellular bacterium, is being developed as a biocontrol strategy against dengue because it limits replication of the virus in the mosquito. The Wolbachia strain wMel, which has been introduced into the mosquito vector, Aedes aegypti, has been shown to invade and spread to near fixation in field releases. Standard measures of Wolbachia’s efficacy for blocking virus replication focus on the detection and quantification of virus in mosquito tissues. Examining the saliva provides a more accurate measure of transmission potential and can reveal the extrinsic incubation period (EIP), that is, the time it takes virus to arrive in the saliva following the consumption of DENV viremic blood. EIP is a key determinant of a mosquito’s ability to transmit DENVs, as the earlier the virus appears in the saliva the more opportunities the mosquito will have to infect humans on subsequent bites.Conclusions/SignificanceThe saliva-based traits reported here offer more disease-relevant measures of Wolbachia’s effects on the vector and the virus. The lengthening of EIP highlights another means, in addition to the reduction of infection frequencies and DENV titers in mosquitoes, by which Wolbachia should operate to reduce DENV transmission in the field. 相似文献
160.
David Simmons A. Toby Prevost Chris Bunn Daniel Holman Richard A. Parker Simon Cohn Sarah Donald Charlotte A. M. Paddison Candice Ward Peter Robins Jonathan Graffy 《PloS one》2015,10(3)