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1.
The biomass of three desert plants, Amsonia kearneyana, A. grandiflora and A. palmeri, was used for the production of glucose and ethanol by simultaneous saccharification and fermentation techniques. Ethanol yields were 0.46 g g-1 for A. keurneyana, 0.51 g g-1 for A. grandiflora and 0.51 g g-1 for A. palmeri. When the plant materials were saccharified into glucose only, the yields obtained were 0.35 g g-1 for A. kearneyana, 0.39 g g-1 for A. grandiflora and 0.22 g g-1 for A. palmeri.H. Punnapayak is with the Department of Botany, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand; J.J. Hoffmann is with the Bioresources Research Facility, University of Arizona, Tuscon, AZ 85706, USA.  相似文献   
2.
Infection with endophytic fungi (Acremonium spp.) was detected in wild populations of Lolium spp. from 15 of 20 European countries. Of 523 populations examined, 38% contained no infection, 48% contained 1–50% infection and 14% contained 51–100% infection. Level of infection was slightly but significantly associated with abundance of Lolium in the sward. For data from France, significant correlations were obtained between level of infection and five climate variables; the highest correlations were with evapotranspiration (0.66, P < 0.001) and water supply deficit (-0.66, P < 0.001). A model established using multiple regression analysis and incorporating five climatic variables, accounted for 56% of total variation; water supply deficit alone accounted for 43%. These climatic variables were shown by geostatistical analysis to account for a spatial structure in infection level. Groups of Lolium populations with a high level of infection were located mostly in Mediterranean regions, where stress from summer drought is common.  相似文献   
3.
Nest defence intensity and nestling provisioning effort of female willow tits (Parus montanus) were significantly correlated at the end of nestling period: well-fed young were defended most intensely. Increased effort was rewarded, since broods with the highest female per-offspring provisioning rates were the most likely to produce local recruits. This suggests that the feeding ability is an important cue for parental investment decisions, at least in a species like the willow tit which has adopted the clutch adjustment strategy. Thus, the most valuable broods would not necessarily be the largest ones, but the ones in which the original number of young could be fed most adequately. However, no associations were found between the level of parental effort and offspring weight, size or condition, nor did the broods producing recruits differ from other broods in timing of breeding or number and size of offspring. The female behaviour may suggest that they invest the most time, energy and risk in the young whose chances of joining the winter flock are the best. The first well-fed young also gain an advantage of prior residency in joining the flock. The first to join normally obtain higher social status, and hence better winter survival, than latecomers. The corresponding patterns in male parental investment behaviour were weak or absent, which suggested that the male effort was affected by the female behaviour. Males seemed to invest in nestling provisioning in such a way as to supplement the female effort. During nest defence action males also seemed to invest in protection of females against predation.  相似文献   
4.
Morphologically intermediate plants between Weigela hortensis (Siebold & Zucc.) K.Koch and W. maximowiczii (S.Moore) Rehder have been found in Miyagi and Yamagata Pref., northern Japan. Quantitative character analyses of flowers, pollen stainability and molecular analyses indicated that the intermediate plants were hybrids of those two species. This is the first record of an intersectional hybrid with W. maximowiczii (sect. Weigelastrum ) as one of the parent species. The morphological differences among hybrid individuals imply the possibility of backcrosses or formation of second or later generations of hybrids, although those may be quite rare because of a low frequency of viable pollen grains. Causes of hybridization between two distantly-related species in Weigela are discussed. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 138 , 369–380.  相似文献   
5.
1. We assessed sex‐specific seasonal changes in major energy storage compounds (triglycerides, glycogen) in Gammarus fossarum and Gammarus pulex collected from the field, with respect to their reproductive activity. 2. The dynamics of stored energy followed a seasonal pattern in both species and sexes. Moreover, over a 4‐year period, these changes were independent of the year in which they were investigated. Stored energy reached a peak in late winter, but was depleted in late summer and early autumn, coinciding with the reproductive periods. 3. Triglyceride (annual mean ± SD) accounted for 79.7 ± 11.9% of the total stored energy and was responsible for the seasonal pattern. In contrast, glycogen contributed a lesser percentage (20.3 ± 11.9%). Over the study period, the amount of stored energy ranged between 0.39 and 4.08 kJ g?1 dry mass (triglyceride: 0.19–3.69 kJ g?1 dry mass; glycogen: 0.14–0.80 kJ g?1 dry mass). 4. In both species, the energy reserves of males were drastically depleted shortly before the cessation of precopulatory mate guarding in the field, thus offering a bioenergetic explanation for the reproductive period in these two widespread species.  相似文献   
6.
7.
Plasmids were found in strains representing all four species of the genus Deinococcus viz. D. radiodurans, D. radiopugnans, D. radiophilus and D. proteolyticus but were not found in the most intensively-investigated strain of the genus, D. radiodurans R1. Their sizes were calculated from electron micrographs. D. radiophilus yielded three size classes of plasmid while D. radiodurans Sark, D. proteolyticus and D. radiopugnans each yielded two. Attempts to cure D. radiophilus and D. radiodurans Sark of any of their plasmids, using a variety of methods, were unsuccessful. A 10.8 kbase pair (kb) plasmid from D. radiophilus, pUE1, was cloned into the PstI site of pAT153 and propagated in Escherichia coli HB101. The recombinant plasmid, pUE109 was subjected to single and double digestion with various restriction endonucleases and its restriction map constructed. The resistance of E. coli HB101 to ultraviolet radiation was not increased when pUE109 was introduced into it. Attempts to transform D. radiodurans with pUE109 failed to detect tetracycline-resistant transformants.  相似文献   
8.
Conservation forage (17 hay and 18 grass silage samples) from 15 farms with different intensities of grassland management in the Federal State of Brandenburg were examined for contamination with fusaria and their mycotoxins. The numbers of culturable filamentous fungi in hay were determined by plate counting andFusarium isolates were classified taxonomically. The mycotoxins Zearalenone (ZEA) and Deoxynivalenol (DON) were extracted from hay as well as silage by different procedures and detected chromatographically (HPLC). The numbers of filamentous fungi in the hay samples were 102 and 106 CFU/g FM independently of intensive or extensive management. Only fourFusarium species were identified.Fusarium culmorum, a potential toxin producing species, was most frequently detected (52% of all isolates). ZEA was found in two hay and four silage samples (6-66 μg/kg), DON in three hay and seven silage samples (63–1290 μg/kg). There were no differences between forage samples of extensive and intensive cultivated grassland of the year 2003 regarding numbers of fusaria and the content of their mycotoxins.
Presented at the 26th Mykotoxin-Workshop in Herrsching, Germany, May 17–19, 2004.  相似文献   
9.
Methicillin-resistant Staphylococcus spp. (MRSS) are causing numerous forms of illness in humans ranging from mild to fatal infections. We need to investigate the resistant pattern for different clinical isolates to control the resistance phenomena. This study was designed to provide the resistance pattern of isolated Staphylococcus spp. from various clinical samples in Khartoum State and to elucidate the frequencies of Multidrug-resistant (MDR), Extensively drug-resistant (XDR) and pan-drug resistant (PDR). Two hundred and ten bacterial isolates were from different sources (catheter tip, sputum, vaginal swab, urine, tracheal aspirate, blood, pus, nasal swab, stool, throat swab, pleural fluid, and ear swab). Isolates were identified based on their morphological characters and biochemical reaction. Antibiotics susceptibility screening was performed using twenty-three antibiotics from eighteen classes against all isolated Staphylococcus spp. following the Clinical and Laboratory Standards Institute (CLSI) guideline. The result revealed that out of 63 Gram-positive isolated bacteria, 52 (82.5%) were Staphylococcus spp. with a high incidence of S. aureus 37(71.2%). Out of all Staphylococcus spp., 38 (73.1%) were Methicillin-resistant (MR). The prevalence of MDR was higher in S. aureus (89.2%) than in S. epidermidis (75%). All Staphylococcus spp. displayed resistance to ampicillin and penicillin, while all S. aureus were sensitive to daptomycin and fosfomycin. One isolate was XDR possible PDR, while no PDR was reported in all isolated bacteria. This study provided evidence for the antimicrobial-resistant (AMR) burden in Sudan and highlighted the need for a practical and functional stewardship program to reduce the unreasonable costs of antibiotics.  相似文献   
10.
The large plaquing (24 mm2) soilborne bacteriophage, Fo-l, did not affect the colonization ability on sugarbeet roots of its host, fluorescent Pseudomonas sp. strain B26. Phage Fo-l did not increase in numbers on sugarbeet roots when seeds were coated with less than 106 CFU (colony forming units) of B26 and when less than 300 PFU (plaque forming units) of phage Fo-l was added per g of soil (dry weight). Above these threshold values, phage replication occurred and up to 2 × 106 PFU per root system could be recovered.  相似文献   
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