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61.
A procedure for the determination of proteolytic activity with dyed magnetic gelatine as an insoluble chromolytic substrate is described. The magnetic nature of the substrate enables magnetic separation of unhydrolysed substrate from the hydrolysed dyed peptide fragments. Such type of substrates could enable the development of new automated protease assays based on the principle of Flow Injection Analysis (FIA). 相似文献
62.
Sharon M B Joines Carolyn M Sommerich Gary A Mirka James R Wilson Samuel D Moon 《Journal of electromyography and kinesiology》2006,16(5):485-497
Musculoskeletal neck discomfort is prevalent in many occupations and has been the focus of much research employing surface electromyography (sEMG). Significant differences in experimental methods among researchers make comparisons across studies difficult. The goal of the current research was to use empirical methods to answer specific methodological questions concerning use of sEMG in evaluation of the neck extensor system. This was accomplished in two studies. In Experiment 1, ultrasound technology was used to: (a) determine accessibility of m. splenius and semispinalis capitis with surface electrodes, (b) identify appropriate electrode locations for these muscles/muscle groups, and (c) illustrate potential benefits of using ultrasound in locating muscles/placing electrodes. Experiment 2 sought to assess effects of posture when normalizing sEMG data. Results from Experiment 1 showed no direct access to semispinalis capitis for surface electrodes; their activity can only be sampled as part of a group of muscles. In most subjects, m. splenius was found to be accessible to surface electrodes. Electrode placement recommendations are provided. Results of Experiment 2 showed significant differences in normalized EMG data between a posture-specific technique and a reference posture technique. Posture-specific normalization is recommended for accurately assessing the relative intensity of contractions of these muscles. 相似文献
63.
The evolution of the diversity of plant secondary metabolites is still poorly understood. To determine whether natural enemies
could exert selection on plant secondary chemistry, pathogen infestation and invertebrate herbivory were measured on 10 genotypes
of Senecio jacobaea (Tansy Ragwort) at two experimental field sites during a 2-year period. The genotypes represented two chemotypes based on
the presence of the pyrrolizidine alkaloids (PA) jacobine and erucifoline. At one site, Heteren, mainly generalist herbivores
were present. Here, damage was limited and did not differ among genotypes or chemotypes. At the other site, Meijendel, several
specialists attacked the plants. Damage increased during the year, with a peak in July when most damage was caused by the
specialist moth Tyria jacobaeae. At this peak there was no difference in damage among chemotypes. In the months prior to T. jacobaeae damage, chemotypes with jacobine were more severely attacked by specialists than the chemotypes without jacobine. Total damage
during that period was positively correlated with both total PA concentration and jacobine concentration. Probably plant vigor
also played a role in host preference since damage per individual plant was positively correlated with plant size. Our results
suggest that total PA concentration and specifically jacobine had a positive effect on specialist feeding, indicating ecological
costs involved in the production of PAs. Ecological costs related to plant secondary compounds could explain why not all individuals
produce high levels of these compounds. In addition, differences in specialist herbivore pressures among sites may contribute
to the variation in secondary metabolites among populations. 相似文献
64.
Mirka?Jokela-M??tt?Email author Johan?Pahlberg Magnus?Lindstr?m Pavel?P.?Zak Megan?Porter Mikhail?A.?Ostrovsky Thomas?W.?Cronin Kristian?Donner 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2005,191(12):1087-1097
Visual-pigment absorbance spectra and eye spectral sensitivities were examined in eight populations of opossum shrimp from
different light environments. Four Finnish populations, two from the Baltic Sea and two from freshwater lakes, represent Mysis relicta, sensu stricto. The sibling species M. salemaai and M. diluviana are represented by, respectively, two Baltic Sea populations and two populations from freshwater lakes in Idaho, USA. In
M. relicta, the visual pigments of the two lake populations were similar (λmax=554.3±0.8 nm and 556.4±0.4 nm), but significantly red-shifted compared with the sea populations (at 529 and 535 nm) and with
M. salemaai (at 521 and 525 nm). All these pigments had only A2 chromophore and the lake/sea difference indicates adaptive evolution
of the opsin. In M. diluviana, λmax varied in the range 505–529 nm and the shapes of spectra suggested varying A1/A2 chromophore proportions, with pure A1 in
the 505 nm animals. Eye sensitivity spectra were flatter and peaked at longer wavelengths than the relevant visual-pigment
templates, but declined with the same slope beyond ca. 700 nm. The deviations from visual-pigment spectra can be explained
by ocular light filters based on three types of identified screening pigments. 相似文献
65.
Evaluation of stool antigen test, PCR on ORAL samples and serology for the noninvasive detection of Helicobacter pylori infection in children 总被引:3,自引:0,他引:3
Bonamico M Strappini PM Bonci E Ferri M Crisogianni M Guido M Thanasi E Nenna R Macchia S Luzzi I Magliocca FM Mastromarino P 《Helicobacter》2004,9(1):69-76
BACKGROUND: Endoscopy represents the gold standard for the diagnosis of Helicobacter pylori infection. We evaluated three noninvasive tests in a group of children: the immunoassay for detection of H. pylori stool antigen, the polimerase chain reaction for identification of bacterial DNA on the oral cavity and the serum specific antibodies. MATERIALS AND METHODS: One hundred and ninety children underwent endoscopy for various gastrointestinal symptoms. H. pylori stool antigen and anti-H. pylori antibodies were assayed by commercial kits. The bacterial DNA on saliva and oral plaque was detected by a seminested PCR. RESULTS: Based on the positivity of culture or urease rapid test and histology, infection was detected in 47 patients. The statistical analysis showed that, for the detection of the infection, stool antigen assay is more effective in sensitivity and negative predictive value (91.5% and 96.5%), whereas specificity and positive predictive values appear slightly better in serology (89.6% and 76.0%). Correlations between serum IgG both with patients' age (r = 0.21, p < .05) and H. pylori stool antigen (r = 0.47, p < .01) were found. The search for bacterial DNA on oral samples proved to be very specific (99.1% on saliva and 98.2% on plaque), but insensitive (22.2% and 25.7%). CONCLUSIONS. In children H. pylori stool antigen represents a sensitive test, suitable for detecting H. pylori infection. Serum IgG proved to be more specific; the PCR on the oral cavity resulted as being a very specific, but insensitive test. 相似文献
66.
Michal V. Marek Mirka
prtov Paulo De Angelis Giuseppe Scarascia-Mugnozza 《Plant science》2001,160(6):302-1136
During an open-top chamber experiment performed in evergreen ‘macchia’ ecosystem, which was represented by the clumps of natural vegetation dominated by Quercus ilex trees, the trees were exposed to one of two CO2 concentrations (ambient CO2, AC-variant and elevated CO2, i.e. ambient plus 350 μmol CO2 mol−1, EC-variant) continuously over 5 years. Clumps of natural vegetation were enclosed in open top chambers (OTCs). Within the crowns of investigated Quercus ilex trees in OTCs, two crown layers i.e. sunny (E-leaves) and shaded (S-leaves), were identified as differing in solar radiation environment. To evaluate the effect of elevated CO2, as well as the functional differentiation in assimilation activity of E- versus S-leaves, gas exchange and chlorophyll
fluorescence techniques were used. The stimulatory effect of the long-term elevated CO2 on the AN–PPFD relation was evident in E- and S-leaves of investigated Quercus trees. The ANmax sensitivity of AC-variant leaves to the sudden application of elevated CO2 was higher for S-leaves (42%) than for E-leaves (24%). The PPFD saturated rate of regulated thermal energy dissipation (ERD) confirmed the foliage differentiation caused by the long-term influence of elevated CO2. The ERD of E- and S-leaves in the AC-variant were 1.11 times of that in the EC-variant. However, the estimated rates of photochemistry (ERP) of E- and S-leaves in the EC-variant were 1.35 and 1.22 times of E- and S-leaves in the AC-variant. The achievement of the critical value of qP=0.4 in E- and S-leaves from the EC-variant under lower values of PPFD compared to the AC-variant indicates a higher degree of PSII over-reduction. Thus, elevated CO2 can be responsible for an increased susceptibility of photosynthetic apparatus to high irradiance. The obtained results support the hypothesis on the foliage vertical distribution effect on the whole canopy response to elevated CO2. The S-layers of the canopy can play an important role in providing storage space for photosynthesis under elevated CO2. 相似文献
67.
Polovina A Bobinac-Georgievski A Jaksić M Polovina-Prolosić T Grazio S 《Collegium antropologicum》2007,31(2):457-462
Community based rehabilitation program in people with musculoskeletal conditions was evaluated using Dartmouth COOP Functional Health Assessment Charts/WONCA (COOP/WONCA charts). The program consisted of educative and training protocol in a primary healthcare setting. It had two parts, both with six visits, in the first part three times a week and in the second part once a week. Clients with musculoskeletal conditions (N = 204) were included if they agreed to take active part in the rehabilitation process. The first part of the program was completed by 77 clients, and complete program by 52 subjects. Positive changes on the COOP/WONCA charts were achieved by more than 50% of the subjects that completed the program, in all categories but Social Activities. The program proved effective in terms of short-term evaluation with COOP/WONCA charts in those that complete the program. The high dropout rate and long-term efficiency have yet to be investigated. 相似文献
68.
Jeffrey A. Harvey Arjen Biere Taiadjana Fortuna Louise E. M. Vet Tim Engelkes Elly Morriën Rieta Gols Koen Verhoeven Heiko Vogel Mirka Macel Hanna M. Heidel-Fischer Katharina Schramm Wim H. van der Putten 《Biological invasions》2010,12(9):3045-3059
Exotic plants bring with them traits that evolved elsewhere into their new ranges. These traits may make them unattractive or even toxic to native herbivores, or vice versa. Here, interactions between two species of specialist (Pieris rapae and P. brassicae) and two species of generalist (Spodoptera exigua and Mamestra brassicae) insect herbivores were examined on two native crucifer species in the Netherlands, Brassica nigra and Sinapis arvensis, and an exotic, Bunias orientalis. Bu. orientalis originates in eastern Europe and western Asia but is now an invasive pest in many countries in central Europe. P. rapae, P. brassicae and S. exigua performed very poorly on Bu. orientalis, with close to 100% of larvae failing to pupate, whereas survival was much higher on the native plants. In choice experiments, the pierid butterflies preferred to oviposit on the native plants. Alternatively, M. brassicae developed very poorly on the native plants but thrived on Bu. orientalis. Further assays with a German Bu. orientalis population also showed that several specialist and generalist herbivores performed very poorly on this plant, with the exception of Spodoptera littoralis and M. brassicae. Bu. orientalis produced higher levels of secondary plant compounds (glucosinolates) than B. nigra but not S. arvensis but these do not appear to be important factors for herbivore development. Our results suggest that Bu. orientalis is a potential demographic ‘trap’ for some herbivores, such as pierid butterflies. However, through the effects of an evolutionary ‘lottery’, M. brassicae has found its way through the plant’s chemical ‘minefield’. 相似文献
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