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Increasing Intensity (increasing + intensity)
Selected AbstractsDevelopmental expression and differential cellular localization of obscurin and obscurin-associated kinase in cardiac muscle cellsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 5 2008Andrei B. Borisov Abstract Obscurin and obscurin-associated kinase are two products of the obscurin transcriptional unit that encodes a recently identified giant muscle-specific protein obscurin. In this study, we characterized the developmental expression and cellular localization of obscurin and obscurin-associated kinase in cardiac muscle cells. We cloned murine obscurin-associated kinase and found that it is abundantly expressed in the heart as two isotypes encoded by 2.2 and 4.9 kb sequences. The 2.2 kb isotype of the kinase was more prominently expressed than the 4.9 kb isotype. Both obscurin and the kinase-like domains were progressively upregulated since the early stages of cardiac development. Obscurin-associated kinase was expressed at higher levels than obscurin at early stages of cardiomyogenesis. Increasing intensity of obscurin expression in the developing heart positively correlated with progressive cell differentiation and was higher in the ventricles compared to the atria. These data were supported by the results of experiments with primary cardiac cell cultures. Obscurin localization changed from a weakly immunopositive diffuse pattern in poorly differentiated cells to an intensely immunolabeled cross-striated distribution at the level of mid-A-bands and Z-disks during the assembly of the myofibrillar contractile apparatus. In dividing myocytes, unlike the interphase cells, obscurin translocated from disassembling myofibrils into a diffuse granulated pattern segregated separately from ,-actinin-immunopositive aggregates. Obscurin-associated kinase was localized mainly to cell nuclei with increasing incorporation into the Z-disks during differentiation. Our results suggest that these two novel proteins are involved in the progression of cardiac myogenesis during the transition to advanced stages of heart development. J. Cell. Biochem. 103: 1621,1635, 2008. © 2007 Wiley-Liss, Inc. [source] Crystallization Kinetics and X-ray Diffraction of Crystals Formed in Amorphous Lactose, Trehalose, and Lactose/Trehalose MixturesJOURNAL OF FOOD SCIENCE, Issue 5 2005Song Miao ABSTRACT: Effects of storage time and relative humidity on crystallization kinetics and crystal forms produced from freeze-dried amorphous lactose, trehalose, and a lactose/trehalose mixture were compared. Samples were exposed to 4 different relative water vapor pressure (RVP) (44.1%, 54.5%, 65.6%, 76.1%) environments at room temperature. Crystallization was observed from time-dependent loss of sorbed water and increasing intensities of peaks in X-ray diffraction patterns. The rate of crystallization increased with increasing storage humidity. Lactose crystallized as ,-lactose monohydrate, ,-anhydrous, and anhydrous forms of ,- and ,-lactose in molar ratios of 5:3 and 4:1 in lactose and lactose/trehalose systems. Trehalose seemed to crystallize as a mixture of trehalose dihydrate and anhydrate in trehalose and lactose/trehalose systems. The crystal forms in a mixture of lactose and trehalose did not seem to be affected by the component sugars, but crystallization of the component sugars was delayed. Time-dependent crystallization of lactose and trehalose in the lactose-trehalose mixture could be modeled using the Avrami equation. The results indicated that crystallization data are important in modeling of crystallization phenomena and predicting stability of lactose and trehalose-containing food and pharmaceutical materials. Keywords: crystallization, lactose, trehalose, crystal form, X-ray diffraction [source] Variability in responses to thermal stress in parasitoidsECOLOGICAL ENTOMOLOGY, Issue 6 2008GAËLLE AMICE Abstract 1.,To study phenotypic effects of stress, a stress is applied to cohorts of organisms with an increasing intensity. In the absence of mortality the response of traits will be a decreasing function of stress intensity because of increasing physiological costs. We call such decreasing functions type A responses. 2.,However, when stress caused mortality, some studies have found that for high stress intensities, survivors performed as well as control individuals (type B responses). We proposed that type A responses are caused by the physiological cost of stress whereas type B responses are caused by a mixture of physiological costs and selection. 3.,The present study exposed Aphidius picipes wasps to an increasing duration of cold storage (cold stress), and obtained variable responses as predicted when both physiological costs and selection of resistant individuals determine the outcome. 4.,When cold storage of parasitoids for biological control is desirable, research should be carried out to find (i) the temperature regime and duration of storage and (ii) the least sensitive stage for storage to minimise losses from mortality and reduction of fitness of survivors. 5.,Selection by cold stress as observed in the present study could result in rapid adaptation of populations exposed to such stress. [source] Quantitative solid-state 13C NMR spectroscopy of organic matter fractions in lowland rice soilsEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 2 2004R. J. Smernik Summary Spin counting on solid-state 13C cross-polarization (CP) nuclear magnetic resonance (NMR) spectra of two humic fractions isolated from tropical lowland soils showed that only 32,81% of potential 13C NMR signal was detected. The observability of 13C NMR signal (Cobs) was higher in the mobile humic acid (MHA) than in the calcium humate (CaHA) fraction, and increased with increasing intensity of irrigated rice cropping. NMR observability appeared to be related to the nature of the organic carbon, with phenol- and methoxyl-rich samples having the higher values of Cobs. The Bloch decay (BD) technique provided more quantitatively reliable 13C NMR spectra, as evidenced by values of Cobs in the range 91,100% for seven of the eight humic fractions studied. The BD spectra contained considerably more aryl and carbonyl signal, and less O,alkyl and alkyl signal, with the greatest differences between CP and BD spectra observed for the samples with low Cobs(CP). The causes of low CP observability were investigated using the spectral editing technique RESTORE ( REstoration of Spectra via TCH and T One Rho (T1,H) Editing). Rapid T1,H relaxation was found to be primarily responsible for the under-representation of carbonyl carbon, whereas inefficient cross-polarization was primarily responsible for the under-representation of aryl carbon in CP spectra. Proton NMR relaxation rates T1H and T1,H were found to correlate with other NMR properties and also with cropping management. Non-uniform rates of T1H relaxation in two of the CaHA fractions enabled the generation of proton spin relaxation editing subspectra. [source] Accumulation of heterocyclic nitrogen in humified organic matter: a 15N-NMR study of lowland rice soilsEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 3 2000N. Mahieu Summary Recent intensification of cropping and the attendant longer submergence of the soil for lowland rice in tropical Asia appear to have altered the nature of the soil organic matter, and perhaps also nutrient cycling. To identify the dominant forms of organic nitrogen in the soils we extracted the labile mobile humic acid (MHA) and the more recalcitrant calcium humate (CaHA) fractions from soils under several long-term field experiments in the Philippines and analysed them by 15N-nuclear magnetic resonance spectroscopy. Amide N dominated the spectra of all humic acid (HA) samples (60,80% of total peak area). Its proportion of total spectral area increased with increasing intensity of cropping and length of time during which the soil was flooded and was greater in the MHA fraction than in the CaHA fraction. Simultaneously the spectral proportion of free amino N and other chemical shift regions decreased slightly with increasing length of submergence. Heterocyclic N was detected at modest proportions (7,22%) and was more prevalent in more humified samples, especially in the CaHA of aerated soils. Correlations of spectral proportions of heterocyclic N with other properties of the HA, reported elsewhere, were highly significant. Correlations were positive with visible light absorption (r=,0.86) and concentration of free radicals (r=,0.85), both of which are indices of humification, and negative with concentration of H (r=,,0.86), a negative index of humification. Correlations of spectral proportions of amide N with these properties were also highly significant but in each case of opposite sign to that of heterocyclic N. Proportions of heterocyclic N declined with increasing duration of submergence. The results suggest that (i) 15N-NMR can reproducibly measure some portion of heterocyclic N, (ii) formation of heterocyclic N is associated solely with gradual humification occurring over many years, and (iii) the abundant phenols in the submerged rice soils did not promote formation of heterocyclic N, and hence some other process is responsible for a substantial decrease in the availability of native N associated with intensive rice cropping. [source] Analysis of phosphorus in two humic acid fractions of intensively cropped lowland rice soils by 31P-NMREUROPEAN JOURNAL OF SOIL SCIENCE, Issue 3 2000N. Mahieu Summary The organic forms of phosphorus in the soil appear to be changing as rice growing intensifies and the soil is flooded for longer in tropical Asia. To examine these changes, we extracted the labile mobile humic acid (MHA) and more recalcitrant calcium humate (CaHA) fractions from soils supporting long-term field trials in the Philippines and analysed them by solution 31P-nuclear magnetic resonance (NMR) spectroscopy. Diester P and sugar-diester P accumulated moderately with increasing intensity of irrigated rice cropping, reaching a combined 42% of all MHA-P for a triple-cropped irrigated field compared with 28% for fully aerated fields growing dryland crops. The mono- to diester P ratio decreased by 43% for the MHA and CaHA from the aerated fields to the triple-cropped field. Smaller effects on forms of P were noted for the rates and type of N, P and K fertilizer and site effects. The effects of treatment and site were more noticeable in the MHA than in the CaHA. The proportions in the NMR spectra were tightly correlated with visible light absorption, concentrations of organic free radicals and H, and 15N-NMR spectral proportions, which indicate the degree of humification. The MHA and CaHA accounted for only 0.6,8.3% and 0.9,5.7%, respectively, of total P; most of the P is inorganic. [source] Balances of phosphorus and nitrogen in carp pondsFISHERIES MANAGEMENT & ECOLOGY, Issue 1-2 2000R. Knösche The impact of carp pond effluents on natural waters was investigated in the German federal states of Brandenburg, Saxony and Bavaria, and in Hungary. Data from 38 ponds (size = 0.25,122 ha) were available for the calculation of inlet,outlet differences. An average difference of 0.51 kg phosphorus (P) ha,1 year,1 was obtained. This means that every hectare of pond surface releases 510 g P less than it receives from the incoming water. This result was independent of the amount of fish harvested (, 1500 ha,1 year,1). The average retention of P (P-balance) was 5.71 kg P ha,1 year,1. Phosphorus retention increased with increasing intensity of production. Nitrogen (N) retention increased with production intensity from 78.5 kg ha,1 year,1 in German standard ponds to >,290 kg N ha,1 year,1in pig-cum-fish ponds in Hungary. A predominantly mineralized sludge suspension is released during harvesting at loads below 1% of the retention capacity of the pond. Under usual pond management regimes, the sludge load during harvesting ranged from 50 to 200 L ha,1, equivalent to 0.3,9.3 g dry matter ha,1. The present study suggests that ponds are not a burden on the environment. By contrast, these water bodies improve water quality. Therefore, pressures to reduce the intensity of pond production cannot be justified on the basis of supposed impacts on water quality. However, even if loads during harvesting are low compared with the retention capacity of the pond, more effort should be carried out to reduce the pollution of streams by pond outlets downstream. This can be done by limiting pond drainage to periods when the suspended material has settled or by short-term sedimentation of the sludge in a settling pond downstream of the rearing facility. [source] Wild coffee management and plant diversity in the montane rainforest of southwestern EthiopiaAFRICAN JOURNAL OF ECOLOGY, Issue 1 2010Christine B. Schmitt Abstract Coffea arabica occurs naturally in the montane rainforests of Ethiopia, but large areas of these unique forests have been converted to other land-uses. In the remaining forest, wild coffee is managed and harvested with increasing intensity because of rising coffee prices in the world market. This study evaluated the impact of coffee management on wild coffee populations and the forest vegetation as a basis for conservation planning in southwestern Ethiopia. Vegetation surveys and yield assessments were carried out in unmanaged natural forest and in managed semi-forest coffee (SFC) systems. Analyses show that wild coffee density and coffee yields were low in natural forest (max. 15 kg ha,1 year,1). In SFC systems, 30% of the canopy trees and most undergrowth vegetation were removed. This stimulated wild coffee growth and strongly enhanced yields (max. 54 kg ha,1 year,1), but severely disturbed forest structure. Species richness increased by 26% because of an increase in species of ruderal and secondary vegetation; however, species richness and abundance of typical forest species declined. Conservation of the natural forest therefore requires the control of wild coffee management. Wild coffee certification is discussed as one tool to reconcile conservation measures and the interests of local farmers. Résumé Coffea arabica pousse naturellement dans les forêts pluviales de montagne en Ethiopie, mais de grandes superficies de ces forêts uniques ont été transformées pour d'autres usages. Dans la forêt restante, le café sauvage est géré et récolté de façon de plus en plus intense en raison de l'augmentation du prix du café au niveau mondial. Cette étude a évalué l'impact de la gestion des populations sauvages de café, ainsi que la végétation forestière, afin d'établir une base pour la planification de la conservation dans le sud-ouest de l'Ethiopie. Des études de végétation et des évaluations des récoltes ont été réalisées dans une forêt naturelle non gérée et dans des systèmes semi forestiers où les caféiers sont gérés. Les analyses révèlent que la densité des caféiers sauvages et les récoltes de café sont faibles dans la forêt naturelle (max 15 kg ha,1an,1). Dans les systèmes semi forestiers, 30% des arbres de la canopée et la plus grande partie de la végétation en sous-bois ont été enlevés. Cela stimule la croissance des caféiers et augmente fortement les récoltes (max 54 kg ha,1an,1), mais cela perturbe gravement la structure forestière. La richesse en espèces a augmenté de 26%à cause de l'augmentation des espèces dans la végétation rudérale et secondaire; cependant, la richesse et l'abondance des espèces typiquement forestières ont décliné. La conservation de la forêt naturelle exige dès lors le contrôle de la gestion du café sauvage. On discute de la certification du café sauvage comme moyen de réconcilier les mesures de conservation et les intérêts des fermiers locaux. [source] Evolutionary significance of cranial variation in Asian Homo erectusAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2002Susan C. Antón Abstract Homo erectus inhabited a wide geographic area of Asia, ranging from 40° north latitude in China to 8° south latitude in island Southeast Asia. Yet variation within Asian H. erectus and its relation to ecological and temporal parameters have been little studied. I synthesize the revised radiometric chronologies for hominid sites in Asia and their relation to new oxygen isotope curves (proxies for climatic fluctuations and landbridge connections). These data suggest substantial opportunities in the later Pleistocene for both regional isolation and gene flow between hominids in mainland and Southeast Asia. They also suggest that the most northerly located Chinese sites (Zhoukoudian and Nanjing) may have been occupied during sequential, interglacial periods. Probably reflecting these periods of isolation, nonmetric features and principal components analysis (PCA) of calvarial shape suggest regional differentiation between northern Asian and Southeast Asian H. erectus. The most recent Southeast Asian fossils (e.g., Ngandong) conform to the Southeast Asian pattern. Except perhaps in brain size, there is no evidence that the temporally intermediate Chinese fossils are intermediate in morphology between older and younger Indonesian fossils. In fact, northern Chinese calvaria are easier to exclude from the larger Asian H. erectus hypodigm than are the Ngandong fossils. The Chinese specimens differ from the others based on their narrower occipitals and frontals for their cranial size. The Chinese sample from Zhoukoudian alone is thus not a good proxy for the morphology and variation seen within Asian H. erectus. Both the Chinese and late Indonesian samples exhibit less variation than does the early Indonesian sample; this along with their shared morphological bauplan suggests a common origin and no more than subspecific differentiation. This shared morphology, despite regional differences, was likely maintained by the increasing intensity of multiple glaciations (and longer-lasting land bridge connections) between mainland and island Southeast Asia during the last million years. Am J Phys Anthropol 118:301,323, 2002. © 2002 Wiley-Liss, Inc. [source] Effects of fire intensity on plant species composition of sandstone communities in the Sydney regionAUSTRAL ECOLOGY, Issue 4 2002DAVID A. MORRISON Abstract Fire intensity measures the heat output of a fire, and variation in fire intensity has been shown to have many effects on the demography of plant species, although the consequent effects on the floristic composition of communities have rarely been quantified. The effects of variation in fire intensity on the floristic composition of dry sclerophyll vegetation with different fire histories near Sydney was estimated. In particular, differences in species abundance of woodland and shrubland communities subjected to four fire-intensity classes: unburnt, low intensity (<500 kW m -1), medium intensity (500-2500 kW m -1) and high intensity (>2500 kW m -1) were examined. The samples had a standardized previous fire frequency and season, thus minimizing the effects of other aspects of the fire regime. There was a clear effect of fire intensity on the relative abundances of the vascular plant species, with increasing intensity of the fire producing vegetation that was increasingly different from the unburnt vegetation. This pattern was repeated in both the woodland and shrubland vegetation types, suggesting that it was not an artefact of the experimental conditions. However, the effects of fire intensity on floristic composition were no greater than were the differences between these two similar vegetation types, with variation in fire intensity accounting for only approximately 10% of the floristic variation. Nevertheless, the effects of fire intensity on the abundance of individual species were consistent across taxonomic groups, with the monocotyledon and Fabaceae species being more abundant at higher than lower intensities, the Proteaceae and Rutaceae more abundant at intermediate intensities, and the Epacridaceae more abundant at lower rather than higher intensities. The number of fire-tolerant species increased with increasing fire intensity, and those fire-tolerant species present were most abundant in the areas burnt with medium intensity. The number of fire-sensitive species did not respond to fire intensity, and those species present were most abundant in the areas burnt with low intensity. This suggests that either fire-sensitive species respond poorly to higher fire intensities or fire-tolerant species respond poorly to lower fire intensities, perhaps because of differences in seed germination, seedling survival or competition among adults. [source] Age dependence of cataract induced by ultraviolet radiation-B in miceACTA OPHTHALMOLOGICA, Issue 2007Y ZHANG Purpose: To investigate for the C57BL/6 mouse if there is an age dependence of the dose-response function for in vivo UVR-300 nm induced forward light scattering in the lens. Methods: Each of four age groups of 25 mice aged 3, 6, 12, or 24 weeks were randomly distributed on five age group specific UVR-B dose levels. The dose levels selected for each age group were derived from the expected maximum tolerable dose (MTD). Expected MTDs were set to 1.9, 3.2, 4.8, and 6.0 kJ/m^2 for the 3, 12, and 24 weeks mice, respectively, based on published data for the albino Sprague Dawley rat. Each animal was unilaterally exposed to UVR-B to the pre-determined dose, delivered during 15 minutes. All mice were sacrificed two days after exposure and both lenses were extracted for; macroscopic imaging in incident illumination against a grid and in dark-field illumination, and measurement of intensity of forward light scattering. The difference of intensity of forward light scattering between the exposed and the contralateral not exposed lens was fitted against dose received using regression based on a second order polynomial model. Results: Two days after exposure, subcapsular opacities were observed in the exposed lenses from all dose groups except at 0 kJ/m^2. In all age groups, the difference of intensity of forward light scattering increased with increasing UVR-B dose. The increase was age dependent. Conclusions: In the pigmented C57BL/6 mouse, an increasing in vivo dose of UVR-300 nm induces an increasing intensity of forward light scattering that is age dependent in the age interval 3-24 weeks. This finding should be considered in future design of experiments on UVR-effects to the mouse lens. [source] | |||||||||||||