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Many Attempts (many + attempt)
Selected AbstractsCombating deceptive advertisements and labelling on food products , an exploratory study on the perceptions of teachersINTERNATIONAL JOURNAL OF CONSUMER STUDIES, Issue 3 2003Wai-ling Theresa Lai Yeung People are becoming more health conscious nowadays, but most of them are not able to adopt a lifestyle with adequate physical exercise and a healthier eating pattern. Many attempt to compensate by taking ,health foods'. Despite the recent economic recession, the functional food market expands rapidly in Asian countries. Recent statistics indicate a huge increase in weight loss and functional food product advertising expenditure in Hong Kong and other Asian countries. In a massive survey conducted by the Hong Kong Consumer Council, it was found that 85% of the medicines, health food and therapies sampled contain questionable claims and misleading messages (Consumer Council, 1999). In fact, young people do not understand much about modern food processing, in particular those present in low energy and functional foods, and they know very little about the modern food marketing strategies. The situation is detrimental to consumer welfare especially to the younger generation. This study attempts to reflect critically on the implications of these issues for the health and well-being of young people in Hong Kong. It explores directions for designing relevant and effective education programmes to empower young people in understanding food advertising strategies and making informed decisions on food choice. The paper will begin with a critical review on the current situation in Hong Kong. An interview survey on preservice and in-service teachers' perception towards misleading food advertising and labelling will then be reported. The situations at schools will be defined and problems faced by teachers in providing relevant consumer education programmes to students will be identified. Finally, the study will look to the future, with a view to developing students' critical skills in evaluating claims offered in food advertisements. [source] Climate change causes rapid changes in the distribution and site abundance of birds in winterGLOBAL CHANGE BIOLOGY, Issue 11 2008ILYA M. D. MACLEAN Abstract Detecting coherent signals of climate change is best achieved by conducting expansive, long-term studies. Here, using counts of waders (Charadrii) collected from ca. 3500 sites over 30 years and covering a major portion of western Europe, we present the largest-scale study to show that faunal abundance is influenced by climate in winter. We demonstrate that the ,weighted centroids' of populations of seven species of wader occurring in internationally important numbers have undergone substantial shifts of up to 115 km, generally in a northeasterly direction. To our knowledge, this shift is greater than that recorded in any other study, but closer to what would be expected as a result of the spatial distribution of ecological zones. We establish that year-to-year changes in site abundance have been positively correlated with concurrent changes in temperature, but that this relationship is most marked towards the colder extremities of the birds' range, suggesting that shifts have occurred as a result of range expansion and that responses to climate change are temperature dependent. Many attempts to model the future impacts of climate change on the distribution of organisms, assume uniform responses or shifts throughout a species' range or with temperature, but our results suggest that this may not be a valid approach. We propose that, with warming temperatures, hitherto unsuitable sites in northeastern Europe will host increasingly important wader numbers, but that this may not be matched by declines elsewhere within the study area. The need to establish that such changes are occurring is accentuated by the statutory importance of this taxon in the designation of protected areas. [source] Reform in a Cold Climate: Change in US Campaign Finance LawGOVERNMENT AND OPPOSITION, Issue 4 2005Dean McSweeney The Bipartisan Campaign Reform Act (BCRA) of 2002 was the first major change in US federal campaign finance law in a quarter of a century. Many attempts at reform had failed in that period. Few members of Congress were enthusiasts for reform, the two parties and two chambers had conflicting interests to protect, successive presidents did not promote the issue and public pressure for reform was weak. When reform was achieved in 2002, many of these formidable obstacles remained in place. This paper draws on the literature of public interest reform and policy innovation to attribute the change to a policy entrepreneur whose resources had undergone a sharp increase, the neutralization of opposition, the impact of an event (the bankruptcy of the Enron Corporation) and membership turnover in Congress. The substantial support for the bill in Congress from Democrats, the party with most to lose from reform, is attributed to the inescapability of past commitments. [source] On identifying marker genes from gene expression data in a neural framework through online feature analysisINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 4 2006Nikhil Ranjan Pal Many attempts have been made to analyze gene expression data. Typical goals of such analysis include discovery of subclasses, designing predictors/classifiers for diseases, identifying marker genes, and trying to get a deeper understanding of underlying biological process. Success of each of these tasks strongly depends on the features used to solve the problem. The high dimensional nature of expression profiles makes the task very difficult. Consequently, many researchers have used some feature selection criteria to reduce the dimensionality of the problem. These approaches are off-line in nature, as feature selection is done in a separate phase from the system design phase. These approaches ignore the fact that utility of features depends on both the problem that is solved and the tool that is used to solve the problem. We here propose to use a novel neural scheme that picks up the necessary features on-line when the system learns the classification task. Because it considers all the features at one go, it does not miss any subtle combination of these features. We demonstrate the effectiveness of our on-line feature selection (OFS) scheme to distinguish between acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) cancer expression data set. Our scheme could identify only five genes that can produce results as good as or even better than what is reported in the literature on this data set. It identifies an important marker gene that alone has a very good discriminating power. This analysis method is quite general in nature and can be effectively used in other areas of bioinformatics. © 2006 Wiley Periodicals, Inc. Int J Int Syst 21: 453,467, 2006. [source] Ordinary people, extraordinary voices: The emotional labour of lay people caring for and about people with a mental health problemINTERNATIONAL JOURNAL OF MENTAL HEALTH NURSING, Issue 5 2010Christine Hogg ABSTRACT Many attempts to reduce the stigmatization of people with mental illness have often been predicated, based on the desire to persuade the public that people with mental illness are ,ill' in the same way as people with medical conditions. This paper presents one aspect from the findings of a study that examined the ways in which lay people perceived mental health and illness. Data are drawn from the discussion of the roles and experiences of different non-mental health professionals who cared for and about people they met in their everyday employment. In this paper, we argue that central to these roles is the importance of listening to people in an arena which is non-statutory and without judgment. We demonstrate that people use popular sectors when they are unsure of the problem they have, or they are reluctant to refer themselves to the professional sector. The paper presents narrative extracts illustrating the emotional labour operating in each participant's role and the extent to which they provide support for their client's emotional and psychological well-being. The implications for mental health nursing are discussed in relation to working with and alongside people experiencing mental distress, in relation to ,ordinary human qualities'. [source] Model-based uncertainty in species range predictionJOURNAL OF BIOGEOGRAPHY, Issue 10 2006Richard G. Pearson Abstract Aim, Many attempts to predict the potential range of species rely on environmental niche (or ,bioclimate envelope') modelling, yet the effects of using different niche-based methodologies require further investigation. Here we investigate the impact that the choice of model can have on predictions, identify key reasons why model output may differ and discuss the implications that model uncertainty has for policy-guiding applications. Location, The Western Cape of South Africa. Methods, We applied nine of the most widely used modelling techniques to model potential distributions under current and predicted future climate for four species (including two subspecies) of Proteaceae. Each model was built using an identical set of five input variables and distribution data for 3996 sampled sites. We compare model predictions by testing agreement between observed and simulated distributions for the present day (using the area under the receiver operating characteristic curve (AUC) and kappa statistics) and by assessing consistency in predictions of range size changes under future climate (using cluster analysis). Results, Our analyses show significant differences between predictions from different models, with predicted changes in range size by 2030 differing in both magnitude and direction (e.g. from 92% loss to 322% gain). We explain differences with reference to two characteristics of the modelling techniques: data input requirements (presence/absence vs. presence-only approaches) and assumptions made by each algorithm when extrapolating beyond the range of data used to build the model. The effects of these factors should be carefully considered when using this modelling approach to predict species ranges. Main conclusions, We highlight an important source of uncertainty in assessments of the impacts of climate change on biodiversity and emphasize that model predictions should be interpreted in policy-guiding applications along with a full appreciation of uncertainty. [source] A new human catalytic antibody Se-scFv-2D8 and its selenium-containing single domains with high GPX activityJOURNAL OF MOLECULAR RECOGNITION, Issue 4 2010Junjie Xu Abstract Glutathione peroxidase (GPX) is a well-known antioxidant selenoenzyme, which can catalyze the reduction of a variety of hydroperoxides and consequently protect cells and other biological tissues against oxidative damage. Many attempts have been made to mimic its function, and a human catalytic antibody Se-scFv-B3 with GPX activity has been prepared in our previous study. This time, a new clone 2D8 that bound specifically to the glutathione analog GSH-S-DNPBu was selected again by using the technology of phage display antibody library, and then scFv-2D8 was successfully expressed in soluble form and purified using Ni2+ -immobilized metal affinity chromatography. After being converted into selenium-containing scFv by chemically modification, it showed higher GPX activity than previous abzyme Se-scFv-B3. The heavy chain variable fragment of scFv-2D8 was also prepared and converted into selenium-containing protein using the same method. This selenium-containing single-domain antibody showed some GPX activity and, to the best of our knowledge, is the first human single-domain abzyme with GPX activity, which lays a foundation for preparing GPX abzyme with human origin, lower molecular weight and higher activity. Copyright © 2009 John Wiley & Sons, Ltd. [source] SpamED: A spam E-mail detection approach based on phrase similarityJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 2 2009Maria Soledad Pera E-mail messages are unquestionably one of the most popular communication media these days. Not only are they fast and reliable but also free in general. Unfortunately, a significant number of e-mail messages received by e-mail users on a daily basis are spam. This fact is annoying since spam messages translate into a waste of the user's time in reviewing and deleting them. In addition, spam messages consume resources such as storage, bandwidth, and computer-processing time. Many attempts have been made in the past to eradicate spam; however, none has proven highly effective. In this article, we propose a spam e-mail detection approach, called SpamED, which uses the similarity of phrases in messages to detect spam. Conducted experiments not only verify that SpamED using trigrams in e-mail messages is capable of minimizing false positives and false negatives in spam detection but it also outperforms a number of existing e-mail filtering approaches with a 96% accuracy rate. [source] Synthesis and characterization of novel thermoplastic poly(oligophosphazene-urethane)sPOLYMER INTERNATIONAL, Issue 6 2009Yubo Zhou Abstract BACKGROUND: Polyurethanes are some of the most popular polymers used in a variety of products, such as coatings, adhesives, flexible and rigid foams, elastomers, etc. Despite the possibility of tailoring their properties, polyurethanes suffer a serious disadvantage of poor thermal stability. Many attempts have been made in order to improve the thermal stability of polyurethanes. RESULTS: A new hydroxyl-terminated oligomer containing sulfone groups, 2,2-bis(4-hydroxy-4,4-sulfonyldiphoneloxy)tetraphenoxyoligocyclotriphosphazene (HSPPZ), was synthesized. HSPPZ was characterized using Fourier transform infrared (FTIR), NMR and gel permeation chromatography analyses. A series of novel thermoplastic poly(oligophosphazene-urethane)s were then synthesized via the reaction of NCO-terminated polyurethane prepolymer with HSPPZ containing chain-extender diols. Their structure and properties were investigated using FTIR spectroscopy, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, water contact angle measurement and tensile measurements. CONCLUSION: Compared to conventional thermoplastic polyurethanes, poly(oligophosphazene-urethane)s exhibit better thermal stability, low-temperature resistance and hydrophobicity, but their mechanical properties are slightly poorer. Copyright © 2009 Society of Chemical Industry [source] Reduction of GAG storage in MPS II mouse model following implantation of encapsulated recombinant myoblastsTHE JOURNAL OF GENE MEDICINE, Issue 11 2005Adelaide Friso Abstract Background Hunter syndrome, mucopolysaccharidosis type II (MPS II), is a X-linked inherited disorder caused by the deficiency of the enzyme iduronate-2-sulfatase (IDS), involved in the lysosomal catabolism of the glycosaminoglycans (GAG) dermatan and heparan sulfate. Such a deficiency leads to the intracellular accumulation of undegraded GAG and eventually to a progressive severe clinical pattern. Many attempts have been made in the last two to three decades to identify possible therapeutic strategies for the disorder, including gene therapy and somatic cell therapy. Methods In this study we evaluated the intraperitoneal implantation of allogeneic myoblasts over-expressing IDS, enclosed in alginate microcapsules, in the MPS II mouse model. Animals were monitored for 8 weeks post-implantation, during which plasma and tissue IDS levels, as well as tissue and urinary GAG contents, were measured. Results and conclusions Induced enzyme activity occurred both in the plasma and in the different tissues analyzed. A significant decrease in urinary undegraded GAG between the fourth and the sixth week of treatment was observed. Moreover, a biochemical reduction of GAG deposits was measured 8 weeks after treatment in the liver and kidney, on average 30 and 38%, respectively, while in the spleen GAG levels were almost normalized. Finally, the therapeutic effect was confirmed by histolochemical examination of the same tissues. Such effects were obtained following implantation of about 1.5 × 106 recombinant cells/animal. Taken together, these results represent a clear evidence of the therapeutic efficacy of this strategy in the MPS II mouse model, and encourage further evaluation of this approach for potential treatment of human beings. Copyright © 2005 John Wiley & Sons, Ltd. [source] The carbon,nutrient balance hypothesis: its rise and fallECOLOGY LETTERS, Issue 1 2001J.G. Hamilton The idea that the concentration of secondary metabolites in plant tissues is controlled by the availability of carbon and nitrogen in the environment has been termed the carbon,nutrient balance hypothesis (CNB). This hypothesis has been invoked both for prediction and for post hoc explanation of the results of hundreds of studies. Although it successfully predicts outcomes in some cases, it fails to such an extent that it cannot any longer be considered useful as a predictive tool. As information from studies has accumulated, many attempts have been made to save CNB, but these have been largely unsuccessful and have managed only to limit its utility. The failure of CNB is rooted in assumptions that are now known to be incorrect and it is time to abandon CNB because continued use of the hypothesis is now hindering understanding of plant,consumer interactions. In its place we propose development of theory with a firm evolutionary basis that is mechanistically sophisticated in terms of plant and herbivore physiology and genetics. [source] Don't Leave Me Hanging on the Anglophone: The Potential for Online Distance Higher Education in the Asia-Pacific RegionHIGHER EDUCATION QUARTERLY, Issue 2-3 2004Simon MarginsonArticle first published online: 9 DEC 200 Abstract In the last decade there have been many attempts to mount online distance higher education programs on a global scale, led by the e-learning industry and university companies and consortia, some with government support: e.g. Universitas21 Global, Cardean University, Fathom, NYUOnline and the UKe-University. A primary commercial objective has been student markets in the Asia-Pacific nations, especially China, given unmet domestic demand and the growth of cross-border education. However while for-profit providers such as the University of Phoenix Online have shown mass online programs are viable in targeted markets, albeit more expensive than face-to-face programs, would-be global ventures have faltered or collapsed. The paper reviews the failure of English language global e-learning in the light of industry marketing strategies, the economics of online education, and the specifics of Asia-Pacific nations including unmet demand for education. It argues that for exporter universities, the potential of cross-border online education can only be realised if communications capacity in the Asia-Pacific nations is enhanced; and online programs are teaching-intensive, and customised for cultural and linguistic variations. Long-term equal partnerships with local and system providers are essential. For policy makers, the implosion of global e-learning points to the need to use expert judgment in relation to the different options for enhancing the capacity of higher education at home and abroad. It also suggests the need for greater scepticism about commercially driven scenarios and claims of company prospectuses, and about the viability of market-controlled paths of development. [source] Isolation of epithelial stem cells from dermis by a three-dimensional culture system,JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 1 2006Reinhold J. Medina Abstract Skin is a representative self-renewing tissue containing stem cells. Although many attempts have been made to define and isolate skin-derived stem cells, establishment of a simple and reliable isolation procedure remains a goal to be achieved. Here, we report the isolation of cells having stem cell properties from mouse embryonic skin using a simple selection method based on an assumption that stem cells may grow in an anchorage-independent manner. We inoculated single cell suspensions prepared from mouse embryonic dermis into a temperature-sensitive gel and propagated the resulting colonies in a monolayer culture. The cells named dermis-derived epithelial progenitor-1 (DEEP) showed epithelial morphology and grew rapidly to a more than 200 population doubling level over a period of 250 days. When the cells were kept confluent, they spontaneously formed spheroids and continuously grew even in spheroids. Immunostaining revealed that all of the clones were positive for the expression of cytokeratin-8, ,18, ,19, and E-cadherin and negative for the expression of cytokeratin-1, ,5, ,6, ,14, ,20, vimentin, nestin, a ckit. Furthermore, they expressed epithelial stem cell markers such as p63, integrin ,1, and S100A6. On exposure to TGF, in culture, some of DEEP-1 cells expressed ,-smooth muscle actin. When the cells were transplanted into various organs of adult SCID mice, a part of the inoculated cell population acquired neural, hepatic, and renal cell properties. These results indicate that the cells we isolated were of epithelial stem cell origin and that our new approach is useful for isolation of multipotent stem cells from skin tissues. J. Cell. Biochem. 98: 174,184, 2006. © 2006 Wiley-Liss, Inc. [source] Modernizing UK health services: ,short-sharp-shock' reform, the NHS subsistence economy, and the spectre of health care famineJOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 2 2005Bruce G. Charlton MD Abstract Modernization is the trend for societies to grow functionally more complex, efficient and productive. Modernization usually occurs by increased specialization of function (e.g. division of labour, such as the proliferation of specialists, in, medicine),, combined, with, increased, organization, in, order to co-ordinate the numerous specialized functions (e.g. the increased size of hospitals and specialist teams, including the management of these large groups). There have been many attempts to modernize the National Health Service (NHS) over recent decades, but it seems that none have significantly enhanced either the efficiency or output of the health care system. The reason may be that reforms have been applied as a ,drip-drip' of central regulation, with the consequence that health care has become increasingly dominated by the political system. In contrast, a ,short-sharp-shock' of radical and rapid modernization seems to be a more successful strategy for reforming social systems , in-between waves of structural change the system is left to re-orientate towards its client group. An example was the Flexner-initiated reform of US medical education which resulted in the closure of nearly half the medical colleges, an immediate enhancement in quality and efficiency of the system and future growth based on best institutional practices. However, short-sharp-shock reforms would probably initiate an NHS ,health care famine' with acute shortages and a health care crisis, because the NHS constitutes a ,subsistence economy' without any significant surplus of health services. The UK health care system must grow to generate a surplus before it can adequately be modernized. Efficient and rapid growth in health services could most easily be generated by stimulating provision outside the NHS, using mainly staff trained abroad and needs-subsidized ,item-of-service'-type payment schemes. Once there is a surplus of critically vital health services (e.g. acute and emergency provision), then radical modernization should rapidly improve the health service by a cull of low-quality and inefficient health care providers. [source] Contrasting effects of long distance seed dispersal on genetic diversity during range expansionJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 1 2006R. BIALOZYT Abstract Currently many attempts are made to reconstruct the colonization history of plant species after the last ice age. A surprising finding is that during the colonization phase genetic diversity did not decrease as much as expected. In this paper we examine whether long distance seed dispersal events could play a role in the unexpected maintenance of genetic diversity during range expansion. This study is based on simulations carried out with a maternally inherited haploid locus using a cellular automaton. The simulations reveal a close relationship between the frequency of long distance seed dispersal events and the amount of genetic diversity preserved during colonization. In particular, when the colonized region is narrow, a complete loss of genetic diversity results from the occurrence of very rare long distance dispersal (LDD) events. We call this phenomenon the ,embolism effect'. However, slightly higher rates of LDD events reverse this effect, up to the point that diversity is better preserved than in a pure diffusion model. This phenomenon is linked to the reorganization of the genetic structure during colonization and is called the ,reshuffling effect'. [source] Comparative analysis of webometric measurements in thematic environmentsJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 8 2005Cristina Faba-Pérez There have been many attempts to evaluate Web spaces on the basis of the information that they provide, their form or functionality, or even the importance given to each of them by the Web itself. The indicators that have been developed for this purpose fall into two groups: those based on the study of a Web space's formal characteristics, and those related to its link structure. In this study we examine most of the webometric indicators that have been proposed in the literature together with others of our own design by applying them to a set of thematically related Web spaces and analyzing the relationships between the different indicators. [source] Schema Theory and Knowledge-Based Processes in Second Language Reading Comprehension: A Need for Alternative PerspectivesLANGUAGE LEARNING, Issue 2007Hossein Nassaji How is knowledge represented and organized in the mind? What role does it play in discourse comprehension and interpretation? What are the exact mechanisms whereby knowledge-based processes are utilised in comprehension? These are questions that have puzzled psycholinguists and cognitive psychologists for years. Despite major developments in the field of second language (L2) reading over the last two decades, many attempts at explaining the role of knowledge in L2 comprehension have been made almost exclusively in the context of schema theory, a perspective that provides an expectation-driven conception of the role of knowledge and considers that preexisting knowledge provides the main guiding context through which information is processed and interpreted. In this article, I first review and critically analyze the major assumptions underlying schema theory and the processes that it postulates underlie knowledge representation and comprehension. Then I consider an alternative perspective, a construction-integration model of discourse comprehension, and discuss how this perspective, when applied to L2 reading comprehension, offers a fundamentally different and more detailed account of the role of knowledge and knowledge-based processes that L2 researchers had previously tried to explain within schema-theoretic principles. [source] Bayesian optimal reconstruction of the primordial power spectrumMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2009M. Bridges ABSTRACT The form of the primordial power spectrum has the potential to differentiate strongly between competing models of perturbation generation in the early universe and so is of considerable importance. The recent release of five years of Wilkinson Microwave Anisotropy Probe observations have confirmed the general picture of the primordial power spectrum as deviating slightly from scale invariance with a spectral tilt parameter of ns, 0.96. None the less, many attempts have been made to isolate further features such as breaks and cut-offs using a variety of methods, some employing more than ,10 varying parameters. In this paper, we apply the robust technique of the Bayesian model selection to reconstruct the optimal degree of structure in the spectrum. We model the spectrum simply and generically as piecewise linear in ln k between ,nodes' in k space whose amplitudes are allowed to vary. The number of nodes and their k -space positions are chosen by the Bayesian evidence so that we can identify both the complexity and location of any detected features. Our optimal reconstruction contains, perhaps, surprisingly few features, the data preferring just three nodes. This reconstruction allows for a degree of scale dependence of the tilt with the ,turn-over' scale occurring around k, 0.016 Mpc,1. More structure is penalized by the evidence as overfitting the data, so there is currently little point in attempting reconstructions that are more complex. [source] Historical Review of Penile Prosthesis Design and Surgical Techniques: Part 1 of a Three-Part Review Series on Penile Prosthetic SurgeryTHE JOURNAL OF SEXUAL MEDICINE, Issue 3 2009Gerard D. Henry MD ABSTRACT Introduction., Throughout history, many attempts to cure complete impotence have been recorded. Early attempts at a surgical approach involved the placement of rigid devices to support the natural process of erection formation. However, these early attempts placed the devices outside of the corpora cavernosa, with high rates of erosion and infection. Today, most urologists in the United States now place an inflatable penile prosthesis (IPP) with an antibiotic coating inside the tunica albuginea. Aim., The article describes the key historical landmarks in penile prosthesis design and surgical techniques. Methods., The article reviews and evaluates the published literature for important contributions to penile prosthesis design and surgical techniques. Main Outcome Measures., The article reviews and evaluates the historical landmarks in penile prosthesis design and surgical techniques that appear to improve outcomes and advance the field of prosthetic urology for the treatment of erectile dysfunction. Results., The current review demonstrates the stepwise progression starting with the use of stenting for achieving rigidity in the impotent patient. Modern advances were first used in war-injured patients which led to early implantation with foreign material. The design and techniques of penile prostheses placement have advanced such that now, more complications are linked to medical issues than failure of the implant. Conclusions., Today's IPPs have high patient satisfaction rates with low mechanical failure rates. Gerard D. Henry. Historical review of penile prosthesis design and surgical techniques: Part 1 of a three-part review series on penile prosthetic surgery. J Sex Med 2009;6:675,681. [source] Reconsideration of the physical and empirical origins of Z,R relations in radar meteorologyTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 572 2001A. R. Jameson Abstract The rainfall rate, R, and the radar reflectivity factor, Z, are represented by a sum over a finite number of raindrops. It is shown here and in past work that these variables should be linearly related. Yet observations show that correlations between R and Z are often more appropriately described by nonlinear power laws. In the absence of measurement effects, why should this be so? In order to justify this observation, there have been many attempts to create physical ,explanations' for power laws. However, the present work argues that, because correlations do not prove causation (an accepted fact in the statistical sciences), such explanations are suspect, particularly since the parametric fits are not unique and because they exhibit fundamental physical inconsistencies. So why, then, do so many correlations fit power laws when physical arguments show that Z and R should be related linearly? It is shown in the present work that physically based, linear, relations between Z and R apply in statistically homogeneous rain. (Note that statistical homogeneity does not mean that the rain is spatially uniform.) In contrast, nonlinear power laws are empirical fits to correlated, but statistically inhomogeneous data. This conclusion is proven theoretically after developing a ,generalized' Z,R relation based upon physical consideration of R and Z as random variables. This relation explicitly incorporates details of the drop microphysics as well as the variability in measurements of Z and R. In statistically homogeneous rain, this generalized expression shows that the coefficient relating Z and R is a constant resulting in a linear Z,R relation. In statistically inhomogeneous rain, however, the coefficient varies in an unknown fashion so that one must resort to statistical fits, often power laws, in order to relate the two quantities empirically over widely varying conditions. This conclusion is independently verified using Monte Carlo simulations of rain from earlier work and is also corroborated using disdrometer observations. Thus, the justification for nonlinear power-law Z,R relations is not physical, but rather statistical, in that they provide convenient parametric fits for estimating mean R from measured mean Z in statistically inhomogeneous rain. Finally, examples based upon disdrometer data suggest that such generalized relations between two variables defined by such sums are potentially useful over a wide range of remote-sensing problems and over a wide range of scales. The examples also offer hope that data collected over disparate sampling-volumes and sampling-frequencies can still be combined to yield meaningful estimates. Although additional testing is required, this allows us to write programs which combine estimates of R using remote-sensing techniques with sparse but direct rainfall observations. [source] HemoCD as an Artificial Oxygen Carrier: Oxygen Binding and AutoxidationARTIFICIAL ORGANS, Issue 2 2009Koji Kano Abstract Despite many attempts to construct completely artificial systems for carrying oxygen (O2) in aqueous solution, no successful example had been reported until quite recently except for picket fence porphinatoiron(II) embedded in liposomal membrane. We newly prepared a 1:1 complex (hemoCD) of 5,10,15,20-tetrakis(4-sulfonatophenyl)porphinatoiron(II) (Fe[II]TPPS) and a per- O -methylated ,-cyclodextrin dimer having a pyridine linker (Py3CD). HemoCD binds O2 reversibly in aqueous solution. The oxygen affinity corresponding to the partial O2 pressure, at which half of the hemoCD molecules are oxygenated, was 16.9 torr in phosphate buffer at pH 7.0 and 25°C. Oxy-hemoCD was gradually autoxidized (t1/2 = 30.1 h) due to nucleophilic attack of a water molecule to the O2,Fe bond. Encapsulation of the iron center of Fe(II)TPPS by two cyclodextrin truncated cones is essential for binding of O2 to the ferrous center of the porphyrin. This manuscript reports the basic characteristics of hemoCD and the possible future utility of a totally artificial O2 carrier. [source] Implications of an interpretive understanding of LCA practiceBUSINESS STRATEGY AND THE ENVIRONMENT, Issue 7 2008Emma Rex Abstract Despite the desirability of a life cycle perspective and many attempts to facilitate life cycle assessment (LCA), industry has been relatively slow to adopt LCA. In this research, we thus set out to investigate the underpinnings of LCA practice in industry. A literature review shows that the present understanding is that ,structural' conditions such as location and sector determine the use of LCA in industry. However, a field study of two companies in the Swedish forest product industry (thus in the same sector and country) indicates that LCA practice is shaped more by individual preferences and chance events. Our results imply a more interpretive understanding of LCA practice than has been put forward by previous research. The two types of understanding are discussed and their implications for practitioners in industry, organizations promoting the use of LCA and further research are presented. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment. [source] | ||||||||||||||||||||||