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Pattern Alone (pattern + alone)
Selected AbstractsObjective classification of atmospheric circulation over southern ScandinaviaINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 2 2001Maj-Lena Linderson Abstract A method for calculating circulation indices and weather types following the Lamb classification is applied to southern Scandinavia. The main objective is to test the ability of the method to describe the atmospheric circulation over the area, and to evaluate the extent to which the pressure patterns determine local precipitation and temperature in Scania, southernmost Sweden. The weather type classification method works well and produces distinct groups. However, the variability within the group is large with regard to the location of the low pressure centres, which may have implications for the precipitation over the area. The anticyclonic weather type dominates, together with the cyclonic and westerly types. This deviates partly from the general picture for Sweden and may be explained by the southerly location of the study area. The cyclonic type is most frequent in spring, although cloudiness and amount of rain are lowest during this season. This could be explained by the occurrence of weaker cyclones or low air humidity during this time of year. Local temperature and precipitation were modelled by stepwise regression for each season, designating weather types as independent variables. Only the winter season-modelled temperature and precipitation show a high and robust correspondence to the observed temperature and precipitation, even though <60% of the precipitation variance is explained. In the other seasons, the connection between atmospheric circulation and the local temperature and precipitation is low. Other meteorological parameters may need to be taken into account. The time and space resolution of the mean sea level pressure (MSLP) grid may affect the results, as many important features might not be covered by the classification. Local physiography may also influence the local climate in a way that cannot be described by the atmospheric circulation pattern alone, stressing the importance of using more than one observation series. Copyright © 2001 Royal Meteorological Society [source] Bridging the gap , structure determination of the red polymorph of tetrahexylsexithiophene by Monte Carlo simulated annealing, first-principles DFT calculations and Rietveld refinementJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 3 2002Marcus A. Neumann The crystal structure of the red polymorph of tetrahexylsexithiophene (THST) is solved from X-ray powder diffraction data by a direct-space Monte Carlo simulated-annealing approach. First-principles density functional theory (DFT) calculations are used to distinguish between three nearly identical solutions in the space groups C2/m, C2 and P and to improve the overall accuracy of the crystal structure. The correct space group is found to be C2/m. In all space groups, the thiophene backbone is planar and the hexyl side chains assume an all- trans conformation except for two terminal methyl residues, which adopt a gauche orientation. The ability of first-principles DFT calculations to provide atomic coordinates of single-crystal quality is demonstrated by lattice-energy minimization of the known crystal structure of the yellow polymorph of THST. The combination of Monte Carlo simulated annealing, first-principles DFT calculations and Rietveld refinement presented in this paper is generally applicable. It provides a powerful alternative to standard approaches in cases where the information content of the powder diffraction pattern alone is insufficient to distinguish between different structure solutions. DFT calculations can also provide invaluable guidance in Rietveld refinement. [source] Surface protein patterns govern morphology, proliferation, and expression of cellular markers but have no effect on physiological properties of cortical precursor cellsJOURNAL OF NEUROSCIENCE RESEARCH, Issue 11 2008Anna K. Magnusson Abstract The ability to differentiate and give rise to neurons, astrocytes, and oligodendrocytes is an inherent feature of neural stem cells, which raises hopes for cell-based therapies of neurodegenerative diseases. However, there are many hurdles to cross before such regimens can be applied clinically. A considerable challenge is to elucidate the factors that contribute to neural differentiation. In this study, we evaluated the possibility of steering neuronal maturation by growing cortical precursor cells on microscale surface patterns of extracellular matrix (ECM) proteins. When the cells were encouraged to extend processes along lines of ECM proteins, they displayed a much more mature morphology, less proliferation capacity, and greater expression of a neuronal marker in comparison with cells grown in clusters on ECM dots. This implied that the growth pattern alone could play a crucial role for neural differentiation. However, in spite of the strikingly different morphology, when performing whole-cell patch-clamp experiments, we never observed any differences in the functional properties between cells grown on the two patterns. These results clearly demonstrate that morphological appearances are not representative measures of the functional phenotype or grade of neuronal maturation, stressing the importance of complementary electrophysiological evidence. To develop successful transplantation therapies, increased cell survival is critical. Because process-bearing neurons are sensitive and break easily, it would be of clinical interest to explore further the differentiating capacity of the cells cultured on the ECM dot pattern, described in this article, which are devoid of processes but display the same functional properties as neurons with mature morphology. © 2008 Wiley-Liss, Inc. [source] Correlating sideband patterns with powder patterns for accurate determination of chemical shift parameters in solid-state NMRMAGNETIC RESONANCE IN CHEMISTRY, Issue 10 2008M. S. Ironside Abstract Powder patterns and sideband patterns have different strengths when it comes to using them to determine chemical shift parameters. Here, we show that chemical shift parameters can be determined with high accuracy by analysing the correlation pattern from a 2D experiment which correlates a powder pattern in the indirect dimension with a sideband pattern in the direct dimension. The chemical shift parameters so determined have greater accuracy than those obtained by analysing a sideband or powder pattern alone, for the same signal-to-noise ratio. This method can be applied for both resolved correlation patterns and to cases where two components share similar isotropic chemical shifts. The methodology is demonstrated in this paper, both theoretically and experimentally, on the 31P signals of the bis-phosphonate drug, pamidronate. Copyright © 2008 John Wiley & Sons, Ltd. [source] The impact of firm introductory strategies on consumers' perceptions of future product introductions and purchase decisionsTHE JOURNAL OF PRODUCT INNOVATION MANAGEMENT, Issue 2 2001Derrick S. Boonea In this research, we develop and test a model of the consumer's decision to immediately purchase a technologically advanced product or to delay such a purchase until a future generation of the product is released. We propose that for technologically advancing products, consumers consider both performance lag (how far behind am I now) and expected performance gain (how far ahead will I be if I wait to buy a future expected release) in their purchase decisions. Furthermore, we hypothesize that a firm's past product introductory strategy can significantly influence consumer perceptions of performance lag, performance gain, and the rate at which a product is advancing technologically. We also propose that these perceptions of lag, gain and rate of technological change influence purchase action and ultimately determine whether or not a consumer will delay or immediately purchase a firm's current technological offering. We investigate the above relationships by introducing a model of consumer purchase behavior that incorporates the effects of a firm's frequency and pattern of next generation product introduction, and test the impact of different introductory strategies on performance lag, gain, rate of change perceptions, and purchase action. In our first study we test our model in a monopolistic setting and show that, holding all else fixed, infrequent product upgrades and/or increasing intergenerational release times result in consumers perceiving larger performance lags and gains. We also show that, holding all else fixed, consumers with larger performance lags and/or gains are less likely to delay their purchases of the currently best available product. In our second study we test our model in a competitive setting and show that, holding all else fixed, a firm's past pattern of new product introduction can influence consumers' perceptions of the firm's product's rate of technological change. We also find that consumers are more likely to purchase products which they perceive to have higher rates of technological change. The key insight from this research is that firms have a strategic tool at their disposal that has been overlooked,the pattern of introduction of next generation products. Our findings suggest that a change in the frequency and/or pattern of introduction, in and of themselves, can influence consumers' perceptions of future product introductions, and ultimately influence their purchase actions. Specifically, we demonstrate that by better understanding consumers' purchase timing decisions, firms may be able to induce purchase on the basis of introductory frequency and pattern alone. Additionally, we demonstrate that by strategically managing consumer expectations of future product introductions, firms may be able to decrease the purchase likelihoods of competing products. Implications of our research and its application to the pattern and timing of preannouncements for new products are also explored. [source] Effects of spatially structured vegetation patterns on hillslope erosion in a semiarid Mediterranean environment: a simulation studyEARTH SURFACE PROCESSES AND LANDFORMS, Issue 2 2005Matthias Boer Abstract A general trend of decreasing soil loss rates with increasing vegetation cover fraction is widely accepted. Field observations and experimental work, however, show that the form of the cover-erosion function can vary considerably, in particular for low cover conditions that prevail on arid and semiarid hillslopes. In this paper the structured spatial distribution of the vegetation cover and associated soil attributes is proposed as one of the possible causes of variation in cover,erosion relationships, in particular in dryland environments where patchy vegetation covers are common. A simulation approach was used to test the hypothesis that hillslope discharge and soil loss could be affected by variation in the spatial correlation structure of coupled vegetation cover and soil patterns alone. The Limburg Soil Erosion Model (LISEM) was parameterized and verified for a small catchment with discontinuous vegetation cover at Rambla Honda, SE Spain. Using the same parameter sets LISEM was subsequently used to simulate water and sediment fluxes on 1 ha hypothetical hillslopes with simulated spatial distributions of vegetation and soil parameters. Storms of constant rainfall intensity in the range of 30,70 mm h,1 and 10,30 min duration were applied. To quantify the effect of the spatial correlation structure of the vegetation and soil patterns, predicted discharge and soil loss rates from hillslopes with spatially structured distributions of vegetation and soil parameters were compared with those from hillslopes with spatially uniform distributions. The results showed that the spatial organization of bare and vegetated surfaces alone can have a substantial impact on predicted storm discharge and erosion. In general, water and sediment yields from hillslopes with spatially structured distributions of vegetation and soil parameters were greater than from identical hillslopes with spatially uniform distributions. Within a storm the effect of spatially structured vegetation and soil patterns was observed to be highly dynamic, and to depend on rainfall intensity and slope gradient. Copyright © 2005 John Wiley & Sons, Ltd. [source] Trace Element Fingerprinting of Australian Ocher Using Laser Ablation Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) for the Provenance Establishment and Authentication of Indigenous Art,JOURNAL OF FORENSIC SCIENCES, Issue 4 2007Rachel L. Green B.Sc. Abstract:, The expansion of indigenous art and the interest it has generated both at a domestic and international level means large monetary transactions are taking place between art galleries or centers and purchasers. As such, an accurate and conclusive method for provenance determination of traditional indigenous artistic materials must be established that can, if necessary, be used to assist in authentication of artworks. Laser ablation inductively coupled plasma mass spectrometry was utilized for elemental differentiation and provenance establishment of ocher samples. This research was used to develop a robust scientific protocol which facilitates definitive and accurate determination of provenance of Australian ochers and the artworks created using them. Analysis of the results obtained through this study show that the trace metal distribution patterns alone appear to be sufficient evidence to establish provenance of specific ochers, although additional differentiation between ocher samples, using major element distribution patterns, was achieved through the utilization of X-ray analytical techniques. [source] Energetic costs, underlying resource allocation patterns, and adaptive value of predator-induced life-history shiftsOIKOS, Issue 2 2008Karsten Rinke We studied costs and benefits of life history shifts of water fleas (genus Daphnia) in response to infochemicals from planktivorous fish. We applied a dynamic energy budget model to investigate the resource allocation patterns underlying the observed life history shifts and their adaptive value under size selective predation in one coherent analysis. Using a published data set of life history shifts in response to fish infochemicals we show that Daphnia invests less energy in somatic growth in the fish treatment. This observation complies with theoretical predictions on optimal resource allocation. However, the observed patterns of phenotypic plasticity cannot be explained by changes in resource allocation patterns alone because our model-based analysis of the empirical data clearly identified additional bioenergetic costs in the fish treatments. Consequently, the response to fish kairomone only becomes adaptive if the intensity of size selective predation surpasses a certain critical level. We believe that this is the first study that puts resource allocation, energetic costs, and adaptive value of predator induced life-history shifts , using empirical data , into one theoretical framework. [source] | ||||||||||||||||