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31.
S. Maini  G. Nicoli 《BioControl》1990,35(2):185-193
Biological control of eggplant pests in general, and (CPB)Leptinotarsa decemlineata (Say) in particular, is highly problematic.Edovum puttleri Grissell, an exotic egg parasitoid which has been found potentially effective, is being reared to this end. Frozen CPB eggs (?18°C) proved to be accepted and suitable for parasitization byE. puttleri. However, when given a choice between 20 frozen and 20 normal eggs every 2 days, the females exhibited a significant preference for the latter. Parasitization and host predation patterns related to female age are described by 2 opposing fourth-order polynomial functions. Parasitization increased up to day 10, followed by progressive decline. Average life span per female was 31.10±.58, with a recorded maximum of 56 days. High predatory behaviour of older females, which showed a decrease in parasitization, was observed in these experimental conditions.  相似文献   
32.
Contaminated Syngonium clusters were multiplied in an air lift bioreactor in liquid medium containing sucrose with the medium being circulated through a sterilizing filter. After 30 days, the culture in filtered medium produced 19.5 shoot initials per gram fresh weight of inoculum compared to 8.7 shoot initials produced in unfiltered medium. Transfer to an elongation medium with 30 mg l-1 Rifampicin produced shoots on 67% of the clusters, while transfer to elongation medium without Rifampicin poduced shoots on 40% of the clusters. Clusters grown for three subcultures in a reactor without medium filtration had lost their multiplication ability. Clusters grown for three subcultures in a reactor with filtration, however, continued to show a two-three fold increase in fresh weight and shoot production.Abbreviations MS Murashige and Skoog  相似文献   
33.
Water, suspended particulate matter (SPM) and sediments were collected from the Esteiro de Estarreja (Ria de Aveiro, Portugal), which receives considerable quantities of waste mercury from a chlor-alkali plant. Dissolved and particulate Hg concentrations in the effluent ranged between 4 –167 g I–1 and 141–3144 g g–1, respectively, at pH values of >10. The effluent plume undergoes significant chemical changes during advection downestuary. The evidence suggested that adsorption of dissolved Hg onto organic-rich SPM was an important process. A maximum sediment Hg concentration of 500 g g–1 was found about 1.5 km from the discharge, as a result of the settling of Hg-rich SPM. Downestuary Hg concentrations in sediments decline to about 100 g g–1 at the mouth of the Esteiro. The particle-water interactions are discussed in terms of the transport of dissolved and particulate Hg into the Ria de Aveiro.  相似文献   
34.
Hidetoshi Kono  Junta Doi 《Proteins》1994,19(3):244-255
Globular proteins have high packing densities as a result of residue side chains in the core achieving a tight, complementary packing. The internal packing is considered the main determinant of native protein structure. From that point of view, we present here a method of energy minimization using an automata network to predict a set of amino acid sequences and their side-chain conformations from a desired backbone geometry for de novo design of proteins. Using discrete side-chain conformations, that is, rotamers, the sequence generation problem from a given backbone geometry becomes one of combinatorial problems. We focused on the residues composing the interior core region and predicted a set of amino acid Sequences and their side-chain conformations only from a given backbone geometry. The kinds of residues were restricted to six hydrophobic amino acids (Ala, Ile, Met, Leu, Phe, and Val) because the core regions are almost always composed of hydrophobic residues. The obtained sequences were well packed as was the native sequence. The method can be used for automated sequence generation in the de novo design of proteins. © 1994 Wiley-Liss, Inc.  相似文献   
35.
应用底物膜技术检测130例正常精液,精子顶体酶活性百分率的正常值下限为57%。459例不孕症病人精液分析,无精症25例,其余434例中75%精子顶体酶活性正常。实验表明精子密度对数值与顶体酶活性百分率之间有正相关,r=0.84(P<0.01),回归方程为顶体酶活性百分率y=48.43%+(8.9%)(log精子计数)。活动精子百分率与顶体酶活性之间有密切正相关,r=0.967,(P<0.01),顶体酶活性y=38.6%+0、36x%。前向活跃直线运动精子百分率与顶体酶活性之间也有密切相关.r=0.96,(P<0.01),顶体酶活性y=34.21%+0.61x%。  相似文献   
36.
Enzymes are potential catalysts for a wide range of large-scale chemical synthesis steps, particularly when the creation of a specific chiral center is desired. The efficient recycling of the enzyme catalyst and the removal of carryover impurities were crucial factors in the improvement of a stereoselective ester hydrolysis step used in the synthesis of a selective leukotriene antagonist. In this enzymatic reaction step, the substrate and product were both largely insoluble, while the enzyme was soluble in the aqueous reaction mixture. Microfiltration and ultrafiltration of the slurry reaction mother liquor indicated near 100% enzyme protein recovery, while activity recovery was about 70% to 80%. These activity losses might be accounted for by enzyme degradation (1 to 2 mg/L . h) during the 40-hour reaction period. Dissolved impurities, principally a diacid byproduct, in the enzyme recycling stream were reduced 60% to 70% by either lowering the solution pH to 4.0 or raising the solution ionic strength to 1 M. (c) 1993 John Wiley & Sons, Inc.  相似文献   
37.
A fractal model for the characterization of mycelial morphology   总被引:1,自引:0,他引:1  
A new technique based on a fractal model has been developed for the quantification of the macroscopic morophology of mycelia. The morphological structuring is treated as a fractal object, and the fractal dimension, determined by an ultrasonic scattering procedure developed for the purpose, serves as a quantitative morphological index. Experimental observations reported earlier and simulations of mycelial growth, carried out using a probabilistic-geometric growth model developed for the purpose, both validate the applicability of the fractal model. In experiments with three different species, the fractal dimensions of pelletous structures were found to be in the range 1.45-2.0 and those of filamentous structures were in the range 1.9-2.7, with values around 2.0 representing mixed morphologies. Fractal dimensions calculated from simulated mycelia are in rough agreement with these ranges. The fractal dimension is also found to be relatively insensitive to the biomass concentration, as seen by dilution of the original broths. The relation between morphology and filtration properties of the broths has also been studied. The fractal dimension shows a strong correlation with the index of cake compressibility and with the Kozeny constant, two filtration parameters that are known to be morphology dependent. This technique could thus be used to develop correlations between the morphology, represented by the fractal dimension, and important morphology-dependent process variables. (c) 1993 John Wiley & Sons, Inc.  相似文献   
38.
《L'Anthropologie》2023,127(2):103134
The most abundant evidence of Pampean Pleistocene human presence are modified bones, as lithic procurement sites located farther than 300 km away. Therefore, we focused on the study of bone modifications, in particular cut and percussion marks. We studied Pampean paleontological collections of Argentine and European museums as an alternative resource of previously unnoticed human modification evidences. We compared marks characteristics with those of archaeological collections from diverse climatic and cultural adaptations, from middle Pleistocene sites (Vallonet, Atapuerca, Lazaret, Arago and Terra Amata) to terminal Pleistocene ones (Abri Pataud, Isturiz and La Vache). Marks typologies were defined, leading to the identification of a particular cutmark that we named double parallel considered as highly diagnostic of anthropic use of lithic artifacts. We also propose that hafted artifacts were used on carcass processing. Perimortem bone modifications are classified in relation with mark morphology (e.g., percussion striae), inferred gesture or action (e.g., breakage of diaphysis), and inferred objective of that action (e.g., marrow extraction). The megafauna specimens analyzed from the historical collections (d’Angelis-Vilardebó, 1847, Muñiz-Dupotet, 1842 and Breton-Bonnement, 1881) present modifications compatible with dismemberment, defleshing, tongue and masseter extraction, and utilization as anvils. The lack of contextual data (location, stratigraphy) and the loss due to museum selection/collecting of accompanying material prevent paleoenvironmental and paleoecological inferences. Regional geology indicates that most of the historical collections were exhumed in riverbank cuts with ages between 70 and 13 ky BP. Preliminary direct dating presents evidence of a Pampean human occupation, at least, since OIS 2.  相似文献   
39.
Introduction and objectivesThere is a considerable lack of structure in training health professionals in geriatrics. The narratives can promote a collaborative reflection on different topics and might be used as a pedagogic strategy for undergraduate health students. This study aimed to explore the adoption of new perspectives on ageing after the implementation of dynamic narratives in the first graduate year for physiotherapy students.Materials and methodsAn exploratory qualitative study was performed. Participants were included if they were: ≥18 years old, physiotherapy students and agreed to participate. Physiotherapy students (n = 44) were recruited from the School of Health Sciences, Polytechnic Institute of Leiria. Two gaming sessions were performed to help students, as narrators, express their visions and ways to deal with the geriatrics field. Students’ perspectives about ageing at baseline (T1) and after the narratives experience (T2) were collected by answering the following question: What is your perception regarding ageing? Two evaluators were involved in qualitative data analysis by performing: (i) an individual analysis of themes/subthemes and a discussion meeting to evaluate discrepancies and to reach a consensus.ResultsNegative perceptions about ageing were referred 39 times at T1 (most of them related to restriction; deterioration subthemes). There were no negative perceptions registered at T2. Positive perceptions increased at T2, from n = 39 to n = 52, and three new subthemes emerged (beginning of something, fighting ageism, challenge).ConclusionThis study demonstrated the potential of narrative-based experiences as a desirable pedagogic methodology (board games-oriented) for geriatric education in undergraduate health students.  相似文献   
40.
IntroductionBNT162b2 (BioNTech and Pfizer) is a nucleoside-modified mRNA vaccine that provides protection against SARS-CoV-2 infection and is generally well tolerated. However, data about its efficacy, immunogenicity and safety in people of old age or with underlying chronic conditions are scarce.PurposeTo describe BNT162b2 (BioNTech and Pfizer) COVID-19 vaccine immunogenicity, effectiveness and reactogenicity after complete vaccination (two doses), and immunogenicity and reactogenicity after one booster, in elders residing in nursing homes (NH) and healthy NH workers in real-life conditions.MethodsObservational, ambispective, multicenter study. Older adults and health workers were recruited from three nursing homes of a private hospital corporation located in three Spanish cities. The primary vaccination was carried out between January and March 2021. The follow-up was 13 months. Humoral immunity, adverse events, SARS-CoV-2 infections, hospitalizations and deaths were evaluated. Cellular immunity was assessed in a participant subset.ResultsA total of 181 residents (mean age 84.1 years; 89.9% females, Charlson index ≥2: 45%) and 148 members of staff (mean age 45.2 years; 70.2% females) were surveyed (n:329). After primary vaccination of 327 participants, vaccine response in both groups was similar; ≈70% of participants, regardless of the group, had an antibody titer above the cut-off considered currently protective (260 BAU/ml). This proportion increased significantly to ≈ 98% after the booster (p < 0.0001 in both groups). Immunogenicity was largely determined by a prior history of COVID-19 infection. Twenty residents and 3 workers were tested for cellular immunity. There was evidence of cellular immunity after primary vaccination and after booster. During the study, one resident was hospitalized for SARS-CoV-2. No SARS-CoV-2-related deaths were reported and most adverse events were mild.ConclusionsOur results suggest that the BNT162b2 mRNA COVID-19 vaccine is immunogenic, effective and safe in elderly NH residents with underlying chronic conditions.  相似文献   
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