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91.
A new species of Acritopappus, A. buiquensis, is described and illustrated from Pernambuco State, Brazil. This is the second record for the genus in the State. The position
of A. buiquensis in the genus is discussed. 相似文献
92.
F. Pérez-Pomares S. Díaz V. Bautista C. Pire G. Bravo J. Esclapez B. Zafrilla María-José Bonete 《Extremophiles : life under extreme conditions》2009,13(4):633-641
Three different amylolytic activities, designated AMY1, AMY2, and AMY3 were detected in the cytoplasm of the extreme halophilic
archaeon Haloferax mediterranei grown in a starch containing medium. This organism had also been reported to excrete an α-amylase into the external medium
in such conditions. The presence of these different enzymes which are also able to degrade starch may be related to the use
of the available carbohydrates and maltodextrins, including the products obtained by the action of the extracellular amylase
on starch that may be transported to the cytoplasm of the organism. The behavior of these intracellular hydrolytic enzymes
on starch is reported here and compared with their extracellular counterpart. Two of these glycosidic activities (AMY1, AMY3)
have also been purified and further characterized. As with other halophilic enzymes, they were salt dependent and displayed
maximal activity at 3 M NaCl, and 50°C. The purification steps and molecular masses have also been reported. The other activity
(AMY2) was also detected in extracts from cells grown in media with glycerol instead of starch and in a yeast extract medium.
This enzyme was able to degrade starch yielding small oligosaccharides and displayed similar halophilic behavior with salt
requirement in the range 1.5–3 M NaCl.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
93.
Ernest J. Harris Renato C. Bautista Roger I. Vargas Eric B. Jang Avraham Eitam Luc Leblanc 《BioControl》2010,55(5):593-599
Field experiments and surveys were conducted to evaluate the efficacy of releasing Fopius arisanus (Sonan) and Psyttalia fletcheri (Silvestri) parasitoids for suppression of Bactrocera cucurbitae (Coquillett) infesting wild Coccinia grandis L. In 2003 and 2004, P. fletcheri releases combined with natural emergence from wild fly populations resulted in better fly suppression, compared to the control site. While P. fletcheri developed freely on melon fly, F. arisanus was less successful at producing its own progeny, yet causing mortality and a twofold decrease in pupae recovered from ivy gourds. Concurrent releases of both parasitoids exerted a compounded suppressive effect on the melon fly population 2–3 times higher than during the pre-release phase. A similar, less obvious, pattern occurred in 2004, due to reduction of the ivy gourd fruit canopy. In 2005, only P. fletcheri was released, with greatly reduced impact, due to ivy gourd destruction and by growers leaving crop culls in fields, producing large numbers of melon flies unaffected by parasitoid releases. 相似文献
94.
95.
Background
Nepal is small in size but rich in bio-cultural diversity. The rugged terrain of the country is home to a number of unique assemblages of fauna, some of which are endemic. Not only faunal resources the country also harbors some very ancient populations whose interrelationship with these diverse faunal resources is very intimate and thus demands scientific study. Animals play important role in both material and spiritual spheres of their life. There are more than hundred groups of such populations in the country and the group Tamang is one of these. The present paper studies Tamang-animal relationships in central Nepal. There is a growing trend of scientific ethnozoological studies all across the globe, but this field is yet in its infancy in Nepal. The country is losing important fauna as well as ancient human cultures at the advent of development processes. As a result, ethnozoological knowledge is also teetering on the brink of extinction.Methods
Ethnozoological data were collected by applying different participatory approaches techniques such as semi-structured interviews, participatory rural appraisal, key informant interviews and focus group discussions. Quantitative data were obtained by employing a household level questionnaire survey. Data were collected from the period of September 2004 to August 2005. Most of the animals were identified up to the species level with the help of standard taxonomic keys.Results
The Tamang community treasures knowledge on various uses of 41 genera belonging to 28 families. Out of total number of animals, 14.6% belong to the Invertebrate group and the rest to the Vertebrate group. Of the total uses 58% fall in the food and medicinal use category, 16% in the magico-religious use category, 18% in the category of omen indication, and 2% each in the categories such as weather forecasting, trophy, ethnomusical and taboos.Conclusions
The Tamang maintain strong ties with animals both at a material as well as spiritual level. While some animals are the sources of important traditional medicines, others are omen indicators and weather forecasters. High priority should be given in conservation of those animals which are of high consensus value to the community. 相似文献96.
Simon van Mourik Aalt DJ van Dijk Maarten de Gee Richard GH Immink Kerstin Kaufmann Gerco C Angenent Roeland CHJ van Ham Jaap Molenaar 《BMC systems biology》2010,4(1):101
Background
The genetic control of floral organ specification is currently being investigated by various approaches, both experimentally and through modeling. Models and simulations have mostly involved boolean or related methods, and so far a quantitative, continuous-time approach has not been explored. 相似文献97.
Using a conditioning paradigm, the olfactory sensitivity of four spider monkeys and four pigtail macaques for a homologous series of carboxylic acids (n-propionic acid to n-heptanoic acid) was investigated. With only few exceptions, the animals of both species significantly discriminated concentrations <1 p.p.m. from the odorless solvent and in several cases individual monkeys even demonstrated thresholds <1 p.p.b. The results showed (i). both primate species to have a well-developed olfactory sensitivity for carboxylic acids, which for some substances matches or even is markedly better than that of species such as the rat or the dog and (ii). a significant correlation between perceptibility in terms of olfactory detection thresholds and carbon chain length of the carboxylic acids in both species tested. These findings lend further support to the growing body of evidence suggesting that between-species comparisons of the number of functional olfactory receptor genes or of neuroanatomical features are poor predictors of olfactory performance, and that general labels such as 'microsmat' or 'macrosmat'-which usually are based on allometric comparisons of olfactory brain structures-are inadequate to describe a species' olfactory capabilities. 相似文献
98.
99.
Bautista James A. Chynwat Veeradej Cua Agnes Jansen Frans Jos Lugtenburg Johan Gosztola David Wasielewski Michael R. Frank Harry A. 《Photosynthesis research》1998,55(1):49-65
The spectroscopic and photochemical properties of the synthetic carotenoid, locked-15,15-cis-spheroidene, were studied by absorption, fluorescence, circular dichroism, fast transient absorption and electron spin resonance spectroscopies in solution and after incorporation into the reaction center of Rhodobacter (Rb.) sphaeroides R-26.1. HPLC purification of the synthetic molecule reveals the presence of several di-cis geometric isomers in addition to the mono-cis isomer of locked-15,15-cis-spheroidene. In solution, the absorption spectrum of the purified mono-cis sample was red-shifted and showed a large cis-peak at 351 nm compared to unlocked all-trans spheroidene. Molecular modeling and semi-empirical calculations reveal how geometric isomerization and structural factors affect the room temperature spectra. The spectroscopic studies of the purified locked-15,15-mono-cis molecule in solution reveal a more stable manifold of excited states compared to the unlocked spheroidene. Reaction centers of Rb. sphaeroides R-26.1 in which the locked-15,15-cis-spheroidene was incorporated show no difference in either the spectroscopic properties or photochemistry compared to reaction centers in which unlocked spheroidene was incorporated or to Rb. sphaeroides wild type strain 2.4.1 reaction centers which naturally contain spheroidene. The data suggest that the natural selection of a cis-isomer of spheroidene for incorporation into native reaction centers of Rb. sphaeroides wild type strain 2.4.1 is more determined by the structure or assembly of the reaction center protein than by any special quality of the cis-isomer of the carotenoid that would affect its ability to participate in triplet energy transfer or carry out photoprotection. 相似文献
100.
Foraging adaptations include behavioral and physiological responses, but most optimal foraging models deal exclusively with behavioral decision variables, taking other dimensions as constraints. To overcome this limitation, we measured behavioral and physiological responses of European starlings Sturnus vulgaris to changes in food availability in a laboratory environment. The birds lived in a closed economy with a choice of two foraging modes (flying and walking) and were observed under two treatments (hard and easy) that differed in the work required to obtain food. Comparing the hard with the easy treatment, we found the following differences. In the hard treatment, daily amount of work was higher, but daily intake was lower. Even though work was greater, total daily expenditure was smaller, partly because overnight metabolism was lower. Body mass was lower, but daily oscillation in body mass did not differ. Feces' caloric density was lower, indicating greater food utilization. Energy expenditure rate expressed as multiples of basal metabolic rate (BMR) increased during the working period from 3.5 x BMR (easy) to 5.2 x BMR (hard), but over the 24-h period, it was close to 2.4 x BMR in both treatments. We also found that rate of expenditure during flight was very high in both treatments (52.3 W in easy and 45.5 W in hard), as expected for short (as opposed to cruising) flights. The relative preferences between walking and flying were incompatible with maximizing the ratio of energy gains per unit of expenditure (efficiency) but compatible with maximizing net gain per unit of time during the foraging cycle (net rate). Neither currency explained the results when nonforaging time was included. Time was not a direct constraint: the birds rested more than 90% of the time in both treatments. Understanding this complex picture requires reasoning with ecological, physiological, and cognitive arguments. We defend the role of optimality as an appropriate tool to guide this integrative perspective. 相似文献