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Unique Features (unique + feature)
Kinds of Unique Features Selected AbstractsSHARED AND UNIQUE FEATURES OF DIVERSIFICATION IN GREATER ANTILLEAN ANOLIS ECOMORPHSEVOLUTION, Issue 2 2006R. Brian Langerhans Abstract Examples of convergent evolution suggest that natural selection can often produce predictable evolutionary outcomes. However, unique histories among species can lead to divergent evolution regardless of their shared selective pressures,and some contend that such historical contingencies produce the dominant features of evolution. A classic example of convergent evolution is the set of Anolis lizard ecomorphs of the Greater Antilles. On each of four islands, anole species partition the structural habitat into at least four categories, exhibiting similar morphologies within each category. We assessed the relative importance of shared selection due to habitat similarity, unique island histories, and unique effects of similar habitats on different islands in the generation of morphological variation in anole ecomorphs. We found that shared features of diversification across habitats were of greatest importance, but island effects on morphology (reflecting either island effects per se or phylogenetic relationships) and unique aspects of habitat diversification on different islands were also important. There were three distinct cases of island-specific habitat diversification, and only one was confounded by phylogenetic relatedness. The other two unique aspects were not related to shared ancestry but might reflect as-yet-unmeasured environmental differences between islands in habitat characteristics. Quantifying the relative importance of shared and unique responses to similar selective regimes provides a more complete understanding of phenotypic diversification, even in this much-studied system [source] The National Survey of American Life: a study of racial, ethnic and cultural influences on mental disorders and mental healthINTERNATIONAL JOURNAL OF METHODS IN PSYCHIATRIC RESEARCH, Issue 4 2004James S. Jackson Abstract The objectives of the National Survey of American Life (NSAL) are to investigate the nature, severity, and impairment of mental disorders among national samples of the black and non-Hispanic white (n = 1,006) populations in the US. Special emphasis in the study is given to the nature of race and ethnicity within the black population by selecting and interviewing national samples of African-American (N = 3,570), and Afro-Caribbean (N = 1,623) immigrant and second and older generation populations. National multi-stage probability methods were used in generating the samples and race/ethnic matching of interviewers and respondents were used in the largely face-to-face interview, which lasted on average 2 hours and 20 minutes. The Diagnostic and Statistical Manual (DSM) IV World Mental Health Composite Interview (WHO-CIDI) was used to assess a wide range of serious mental disorders, potential risk and resilience factors, and help seeking and service use patterns. This paper provides an overview of the design of the NSAL, sample selection procedures, recruitment and training of the national interviewing team, and some of the special problems faced in interviewing ethnically and racially diverse national samples. Unique features of sample design, including special screening and listing procedures, interviewer training and supervision, and response rate outcomes are described. Copyright © 2004 Whurr Publishers Ltd. [source] Insulin pumps: from inception to the present and toward the futureJOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 2 2010F. M. Alsaleh BPharm MSc Summary As an alternative to the usual insulin injections, insulin pumps have been introduced as an advanced method of insulin delivery for managing type 1 diabetes mellitus patients. This review documents the history of insulin pump development and the production of ,smart pumps' that offer patients greater dosing accuracy, flexibility, and ease of use. This has resulted in an increase in the number of insulin pump users around the world. This paper also provides a comprehensive survey of the pumps currently available on the market and their specifications. Unique features of each product and the drawbacks are addressed in the review. The future direction of insulin pump development is targeted toward closing the loop, to allow feedback control between an insulin pump and a glucose sensor, and hence finer adjustment of insulin delivery rates as required. [source] The assessment of positivity and negativity in social networks: the reliability and validity of the social relationships index,JOURNAL OF COMMUNITY PSYCHOLOGY, Issue 4 2009Rebecca A. Campo The Social Relationships Index (SRI) was designed to examine positivity and negativity in social relationships. Unique features of this scale include its brevity and the ability to examine relationship positivity and negativity at the level of the specific individual and social network. The SRI's psychometric properties were examined in three studies. The SRI demonstrated good psychometric properties, including test,retest reliability for the assessment of positivity and negativity, and of relationship classifications across social networks. Additionally, discriminant and convergent validity was established with existing social relationship and personality scales. Finally, the SRI showed some generalizability across different contexts. These studies suggest that the SRI is a reliable and valid alternative measure for use in health studies that require a shorter assessment of relationships. © 2009 Wiley Periodicals, Inc. [source] Characterization of the Electroanatomic Substrate for Monomorphic Ventricular Tachycardia in Patients with Nonischemic CardiomyopathyPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 7 2002HENRY H. HSIA HSIA, H.H., et al.: Characterization of the Electroanatomic Substrate for Monomorphic Ventricular Tachycardia in Patients with Nonischemic Cardiomyopathy. Ventricular arrhythmias are common in the setting of nonischemic cardiomyopathy. The etiology for the cardiomyopathy is frequently not identified and the label of "idiopathic" is applied. Interstitial fibrosis with conduction system involvement and associated left bundle branch block characterizes the disease process in some patients and the mechanism for monomorphic ventricular tachycardia is commonly bundle branch reentry. However, most patients with nonischemic cardiomyopathy have VT due to myocardial reentry and demonstrate marked myocardial fibrosis and electrogram abnormalities. Although patient specific, the overall distribution of electroanatomic abnormalities appears to be equal on the endocardium and epicardium. The extent of electrogram abnormalities appears to parallel arrhythmia presentation and/or inducibility. Patients with sustained uniform morphology VT have the most extensive endocardial and epicardial electrogram abnormalities. Magnetic electroanatomic voltage mapping provides a powerful tool to characterize the location and extent of the arrhythmia substrate. Basal left ventricular myocardial involvement, as indexed by the location of contiguous electrogram abnormalities, is common in patients with sustained VT and left ventricular cardiomyopathy. The relatively equal distribution of electrogram abnormalities on the endocardium and epicardium, and the results of mapping and ablation attempts, suggest that critical parts of the reentrant circuit may be epicardial. Unique features of the electroanatomic substrate associated with cardiomyopathy due to Chagas' disease, sarcoidosis, and arrhythmogenic right ventricular dysplasia are also discussed. [source] Toilet training for a young boy with pervasive developmental disorderBEHAVIORAL INTERVENTIONS, Issue 1 2004A. Randi Post We employed a variation of the Azrin,Foxx (1971) procedure with a 3.5-year-old boy diagnosed with Pervasive Developmental Disability (PDD). Unique features of our design included tailoring to the in-home environment, training without systematically increasing fluid intake, introduction under circumstances that facilitated generalization and transfer without special procedures, the elimination of some specialized equipment, and use of social and activity reinforcers. Training was successful and was reported to have generalized to the inclusive school environment. Copyright © 2004 John Wiley & Sons, Ltd. [source] An in vitro model system for cytoskeletal confinementCYTOSKELETON, Issue 10 2009Sarah Köster Abstract The motility, shape, and functionality of the cell depend sensitively on cytoskeletal mechanics which in turn is governed by the properties of filamentous proteins - mainly actin, microtubules, and intermediate filaments. These biopolymers are confined in the dense cytoplasm and therefore experience strong geometric constraints on their equilibrium thermal fluctuations. To obtain a better understanding of the influence of confinement on cytoskeletal filaments we study the thermal fluctuations of individual actin filaments in a microfluidic in vitro system by fluorescence microscopy and determine the persistence length of the filaments by analyzing the radial distribution function. A unique feature of this method is that we obtain the persistence length without detailed knowledge of the complete contour of the filament which makes the technique applicable to a broad range of biological polymers, including those with a persistence length smaller than the optical resolution. Cell Motil. Cytoskeleton 2009. © 2009 Wiley-Liss, Inc. [source] Usefulness of Live/Real Time Three-Dimensional Transthoracic Echocardiography in Evaluation of Prosthetic Valve FunctionECHOCARDIOGRAPHY, Issue 10 2009Preeti Singh M.D. We studied 31 patients with prosthetic valves (PVs) using two-dimensional and three-dimensional transthorathic echocardiography (2DTTE and 3DTTE, respectively) in order to determine whether 3DTTE provides an incremental value on top of 2DTTE in the evaluation of these patients. With 3DTTE both leaflets of the St. Jude mechanical PV can be visualized simultaneously, thereby increasing the diagnostic confidence in excluding valvular abnormalities and overcoming the well-known limitations of 2DTTE in the examination of PVs, which heavily relies on Doppler. Three-dimensional transthorathic echocardiography provides a more comprehensive evaluation of PV regurgitation than 2DTTE with its ability to more precisely quantify PV regurgitation, in determining the mechanism causing regurgitation, and in localizing the regurgitant defect. Furthermore, 3DTTE is superior in identifying, quantifying, and localizing PV thrombi and vegetations, in addition to the unique feature of providing a look inside mass lesions by serial sectioning. These preliminary results suggest the superiority of 3DTTE over 2DTTE in the evaluation of PVs and that it provides incremental knowledge to the echocardiographer. [source] Treatment of congestive heart failure , current status of use of digitoxinEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue S2 2001G. G. Belz Digitalis glycosides exert a positive inotropic effect, i.e. an increase in myocardial contractility associated with a prolongation of relaxation period, and glycosides lower the heart rate (negative chronotropic), impede stimulus conduction (negative dromotropic) and promote myocardial excitability (positive bathmotropic). They seem to influence the activities of both the vagal and the sympathetic systems. Digitalis glycosides that belong to different substance classes are closely comparable concerning pharmacodynamics but differ substantially in regard to pharmacokinetics. Digoxin and its derivatives are less lipophilic, show lower protein binding and shorter half-life, are mainly eliminated via the kidney and accumulate rather rapidly in cases of insufficient kidney function. Digitoxin is highly lipophilic and extensively bound to plasma proteins, has a longer half-life, is mainly eliminated in the metabolized state via urine and faeces and does not accumulate in kidney dysfunction. As a result of a more stable pharmacokinetic profile, the incidence of toxic side effects seems to be lower with digitoxin than with digoxin. Since the beginning of the 1990s, the antagonists of the RAAS qualified as the standard treatment for congestive heart failure, often in combination with diuretics, vasodilators or ,-antagonists. However, the important role of digitalis glycosides as therapeutic comedication or alternative was never denied, especially in atrial fibrillation with tachycardia. The PROVED and RADIANCE trials proved a detrimental effect of the withdrawal of digoxin therapy on exercise capacity, left-ventricular ejection fraction and clinical symptoms. The DIG trial revealed that digoxin comedication in sinus rhythm patients with congestive heart failure was associated with a lower morbidity (as taken from death or hospitalization because of worsening heart failure) and an unchanged overall mortality , being a unique feature among the available inotropic drugs. Comparable studies for digitoxin have not yet been performed but, because of its higher pharmacological stability, it might well be associated with even more advantages in this regard than digoxin. [source] Otx1 gene-controlled morphogenesis of the horizontal semicircular canal and the origin of the gnathostome characteristicsEVOLUTION AND DEVELOPMENT, Issue 4 2000Sylvie Mazan SUMMARY The horizontal semicircular canal of the inner ear is a unique feature of gnathostomes and is predated by the two vertical semicircular canals, which are already present in lampreys and some fossil, armored jawless vertebrates regarded as close relatives of gnathostomes. Inactivation in mice of the orthodenticle -related gene Otx1 results in the absence of this structure. In bony fishes and tetrapods (osteichthyans), this gene belongs to a small multigene family comprising at least two orthology classes, Otx1 and Otx2. We report that, as in the mouse, xenopus and zebrafish, Otx1- and Otx2 -related genes are present in a chondrichthyan, the dogfish Scyliorhinus canicula, with an Otx1 expression domain in the otocyst very similar to those observed in osteichthyans. A strong correlation is thus observed in extant vertebrates between the distribution of the horizontal semicircular canal and the presence of an Otx1 ortholog expressed in the inner ear, which supports the hypothesis that the absence of this characteristic in Otx1 -/- mice may correspond to an atavism. The same conclusion applies to two other gnathostome-specific characteristics also deleted in Otx1 -/- mice, the utriculosaccular duct and the ciliary process. Together with functional analyses of Otx1 and Otx2 genes in mice and comparative analyses of the Otx gene families characterized in chordates, these discoveries lead to the hypothesis that some of the anatomic characteristics of gnathostomes have appeared quite suddenly and almost simultaneously in vertebrate evolution, possibly as a consequence of gene functional diversifications following duplications of an ancestral chordate gene. [source] Specific Ser-Pro phosphorylation by the RNA-recognition motif containing kinase KISFEBS JOURNAL, Issue 14 2000Alexandre Maucuer We present here a first appraisal of the phosphorylation site specificity of KIS (for ,kinase interacting with stathmin'), a novel mammalian kinase that has the unique feature among kinases to possess an RNP type RNA-recognition motif (RRM). In vitro kinase assays using various standard substrates revealed that KIS has a narrow specificity, with myelin basic protein (MBP) and synapsin I being the best in vitro substrates among those tested. Mass spectrometry and peptide sequencing allowed us to identify serine 164 of MBP as the unique site phosphorylated by KIS. Phosphorylation of synthetic peptides indicated the importance of the proline residue at position +1. We also identified a tryptic peptide of synapsin I phosphorylated by KIS and containing a phosphorylatable Ser-Pro motif. Altogether, our results suggest that KIS preferentially phosphorylates proline directed residues but has a specificity different from that of MAP kinases and cdks. [source] The sedimentary structure of the Lomonosov Ridge between 88°N and 80°NGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 2 2005Wilfried Jokat SUMMARY While the origin of the 1800-km-long Lomonosov Ridge (LR) in the Central Arctic Ocean is believed to be well understood, details on the bathymetry and especially on the sediment and crustal structure of this unique feature are sparse. During two expeditions in 1991 and 1998 into the Central Arctic Ocean several high quality seismic lines were collected along the margin of the ridge and in the adjacent Makarov Basin (MB). The lines collected between 87°36,N and 80°N perpendicular to and along the LR show a sediment starved continental margin with a variety of geological structures. The different features may reflect the different geological histories of certain ridge segments and/or their different subsidence histories. The sediments in the deep MB have thicknesses up to 2.2 km (3 s TWT) close to the foot of the ridge. At least in part basement reflections characteristics suggest oceanic crust. The acoustically stratified layers are flat lying, except in areas close to the ridge. Seismic units on the LR can be divided into two units based on refraction velocity data and the internal geometry of the reflections. Velocities <3.0 km s,1 are considered to represent Cenozoic sediments deposited after the ridge subsided below sea level. Velocities >4.0 km s,1 are associated with faulted sediments at deeper levels and may represent acoustic basement, which was affected by the Late Cretaceous/Early Cenozoic rift events. Along large parts of the ridge the transition of the two units is associated with an erosional unconformity. Close to the Laptev Sea such an erosional surface may not be present, because of the initial great depths of the rocks. Here, the deeper strata are affected by tectonism, which suggests some relative motion between the LR and the Laptev Shelf. Stratigraphic correlation with the Laptev Sea Shelf suggests that the ridge has not moved as a separate plate over the past 10 Myr. The seismic and regional gravity data indicate that the ridge broadens towards the Laptev Shelf. Although the deeper structure may be heavily intruded and altered, the LR appears to extend eastwards as far as 155°E, a consequence of a long-lived Late Cretaceous rift event. The seismic data across LR support the existence of iceberg scours in the central region of the ridge as far south as 81°N. However, no evidence for a large erosional events due to a more than 1000-m-thick sea ice cover is visible from the data. South of 85°N the seismic data indicate the presence of a bottom simulating reflector along all lines. [source] Effect of the plate thermal resistance on the heat transfer performance of a corrugated thin plate heat exchangerHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 3 2006Hiroshi Iwai Abstract Two-dimensional conjugate conduction/convection numerical simulations were carried out for flow and thermal fields in a unit model of a counter-flow-type corrugated thin plate heat exchanger core. The effects of the thermal resistance of the solid plate, namely the variation of the plate thickness and the difference of the plate material, on the heat exchanger performance were examined in the Reynolds number range of 100 Glutamate spillover augments GABA synthesis and release from axodendritic synapses in rat hippocampusHIPPOCAMPUS, Issue 1 2010Misty M. Stafford Abstract Tight coupling between gamma-aminobutyric acid (GABA) synthesis and vesicle filling suggests that the presynaptic supply of precursor glutamate could dynamically regulate inhibitory synapses. Although the neuronal glutamate transporter excitatory amino acid transporter 3 (EAAT3) has been proposed to mediate such a metabolic role, highly efficient astrocytic uptake of synaptically released glutamate normally maintains low-extracellular glutamate levels. We examined whether axodendritic inhibitory synapses in stratum radiatum of hippocampal area CA1, which are closely positioned among excitatory glutamatergic synapses, are regulated by synaptic glutamate release via presynaptic uptake. Under conditions of spatially and temporally coordinated release of glutamate and GABA within pyramidal cell dendrites, blocking glial glutamate uptake enhanced quantal release of GABA in a transporter-dependent manner. These physiological findings correlated with immunohistochemical studies revealing expression of EAAT3 by interneurons and uptake of D-asparate into putative axodendritic inhibitory terminals only when glial uptake was blocked. These results indicate that spillover of glutamate between adjacent excitatory and inhibitory synapses can occur under conditions when glial uptake incompletely clears synaptically released glutamate. Our anatomical studies also suggest that perisomatic inhibitory synapses, unlike synapses within dendritic layers of hippocampus, are not capable of glutamate uptake and therefore transporter-mediated dynamic regulation of inhibition is a unique feature of axodendritic synapses that may play a role in maintaining a homeostatic balance of inhibition and excitation. © 2009 Wiley-Liss, Inc. [source] Stepwise regulation of TH1 responses in autoimmunity: IL-12-related cytokines and their receptorsINFLAMMATORY BOWEL DISEASES, Issue 8 2005Christoph Becker PhD Abstract Interleukin (IL)-12 is a key cytokine of cell-mediated immune responses. Until recently, IL-12 was believed to be unique in its ability to induce the differentiation of naive T cells toward the TH1 phenotype and in its pathogenic activity, as shown in various disease models including inflammatory bowel disease. However, recently, 2 additional cytokines closely related to IL-12, IL-23 and IL-27, were discovered. Until then, the role of IL-12 was overestimated because it was believed that the p40 subunit was unique to IL-12. The discovery that IL-12 shares p40 with IL-23 and that IL-23 but not IL-12 is essential in models of chronic inflammation and autoimmunity led to a model in which IL-12 is essential to induce interferon-,-producing TH1 cells, whereas IL-23 mediates effector functions. The latest cytokine added to this cytokine family is IL-27. IL-27 has the unique feature to act on naive T cells, rendering them susceptible to IL-12 signaling. Thus, IL-27 may be essential for the early events of a cell-mediated immune response. This review focuses on these novel cytokines and their role in cell-mediated immune responses and discusses differences and common features within the family of IL-12-related cytokines. [source] Functional dissection of the hexamerin receptor and its ligand arylphorin in the blowfly Calliphora vicinaINSECT MOLECULAR BIOLOGY, Issue 5 2003I. A. Hansen Abstract The process of receptor-mediated uptake of hexamerin storage proteins from insect haemolymph by fat body cells is a unique feature of the class Insecta. We identified the binding domains of the hexamerin receptor and the hexamerin ligand arylphorin in the blowfly, by means of the yeast-two-hybrid-system. The receptor-binding domain of arylphorin was located within domain 3 of the arylphorin monomer. The ligand-binding domain of the hexamerin receptor was mapped to the extreme N-terminus of the receptor. The binding domains identified exhibit no similarity to any functional protein domains known to date. Additionally, we identified two previously unknown protein-interactors of the hexamerin receptor. The results of this study provide further insights regarding the mechanism of the receptor-mediated endocytosis of storage proteins in insects. [source] The immersed/fictitious element method for fluid,structure interaction: Volumetric consistency, compressibility and thin membersINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 1 2008Hongwu Wang Abstract A weak form and an implementation are given for fluid,structure interaction by the immersed/fictitious element method for compressible fluids. The weak form is applicable to models where the fluid is described by Eulerian coordinates while the solid is described by Lagrangian coordinates, which suits their intrinsic characteristics. A unique feature of the method is the treatment of the fictitious fluid by a Lagrangian description, which simplifies the interface conditions. Methods for enforcing volumetric consistency between the fluid and solid and treating thin members are given. Although a compressible viscous fluid is considered here, the new developments can be applied to incompressible fluids. Copyright © 2007 John Wiley & Sons, Ltd. [source] WTCP: an efficient mechanism for improving wireless access to TCP servicesINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 1 2003Karunaharan Ratnam Abstract The transmission control protocol (TCP) has been mainly designed assuming a relatively reliable wireline network. It is known to perform poorly in the presence of wireless links because of its basic assumption that any loss of a data segment is due to congestion and consequently it invokes congestion control measures. However, on wireless access links, a large number of segment losses will occur more often because of wireless link errors or host mobility. For this reason, many proposals have recently appeared to improve TCP performance in such environment. They usually rely on the wireless access points (base stations) to locally retransmit the data in order to hide wireless losses from TCP. In this paper, we present Wireless-TCP (WTCP), a new mechanism for improving wireless access to TCP services. We use extensive simulations to evaluate TCP performance in the presence of congestion and wireless losses when the base station employs WTCP, and the well-known Snoop proposal (A comparison of mechanisms for improving TCP performance in wireless networks. In ACM SIGCOMM Symposium on Communication, Architectures and Protocols, August 1996). Our results show that WTCP significantly improves the throughput of TCP connections due to its unique feature of hiding the time spent by the base station to locally recover from wireless link errors so that TCPs round trip time estimation at the source is not affected. This proved to be critical since otherwise the ability of the source to effectively detect congestion in the fixed wireline network is hindered. Copyright © 2003 John Wiley & Sons, Ltd. [source] Governance of social security regimes: Trends in SenegalINTERNATIONAL SOCIAL SECURITY REVIEW, Issue 3-4 2003Ahmadou Yéri Diop The main aim of this article is to analyse the Senegalese experience in the management of social security institutions. The keyword which occurs and reoccurs is autonomy. Except for Côte d'Ivoire, which has experimented with the same system since 2000, the Senegalese experience is unique in French-speaking sub-Saharan Africa. The article reviews the institutional pluralism which is another unique feature of the Senegalese situation, the genuine autonomy of management which exists and its results, illustrated by the example of the Social Security Fund. The results obtained in terms of financial stability, better quality of service and the installation of an efficient information system prove that this is the way of the future. Finally, the paper highlights the distribution of powers between the various bodies of the Fund. [source] TRANSFORMING ENRON: THE VALUE OF ACTIVE MANAGEMENTJOURNAL OF APPLIED CORPORATE FINANCE, Issue 4 2001Vince Kaminski Soon after Enron was formed as a regulated gas pipeline company in 1985, economic events forced a dramatic reorganization of the company. The result was the creation of an unregulated energy trading operation whose mission was to capitalize on opportunities arising from the deregulation of the natural gas market The initial form of the new business was that of a "gas bank" in which Enron became an intermediary between buyers and sellers of gas, locking in the spread as profit. Since there was no source of liquidity to the market, Enron had to develop its own risk management system. Furthermore, the need to respond quickly to rapidly changing market conditions required that Enron flatten its organizational structure and hire new people whose skills were better suited to the new decentralized organization. The focus of the new Enron accordingly became human and intellectual capital, not physical assets. Employees were encouraged to move about the firm to staff new business ventures. And in what may well be a unique feature in corporate America, Enron's top management today uses its human capital flows to guide its allocations of financial capital. Other aspects of the Enron model include attempts to capitalize on the option (as opposed to current DCF) value of assets, recognition of the value of networks in adding value to trading platforms, and the use of mark-to-market accounting for business transactions as a means of ensuring transparency and promoting timely decision-making. [source] Assessing the effects of measurement errors on the estimation of production functionsJOURNAL OF APPLIED ECONOMETRICS, Issue 6 2006Carmine Ornaghi This article explores to what extent the poor results that are often found when estimating parameters of production functions can be attributed to measurement errors, due to the use of common price deflators across firms. Because of the lack of detailed micro-economic data, econometricians have to rely on industry-wide deflators when computing outputs and intermediate inputs. A unique feature of the longitudinal data used in this paper is that it reports firm-level prices. This allows for a comparative assessment of production function parameters where the outputs and intermediate inputs are computed using both firm-specific prices and industry-wide deflators. The empirical results presented in this paper show that the use of common deflators across firms leads to lower scale estimates, mainly because of a large downward bias in the estimated coefficients for labour. Copyright © 2006 John Wiley & Sons, Ltd. [source] A New Look at Husbands' and Wives' Time AllocationJOURNAL OF CONSUMER AFFAIRS, Issue 1 2004MOHAMMAD ALENEZI The impacts of economic and non-economic factors on husbands' and wives' market work time and housework time are estimated using 13 years of data from the Panel Survey of Income Dynamics. Several limitations in earlier studies are addressed, and a unique feature of the study is the direct estimation of effects on time allocation from changes in the prices of market-produced goods and input goods in household production. Many of the findings of earlier studies are reconfirmed, but new insights are also explored. Husbands and wives respond similarly in their time allocations to changes in input goods prices, but their responses are different to changes in market goods prices. [source] Fluorescence background suppression in Raman spectroscopy using combined Kerr gated and shifted excitation Raman difference techniquesJOURNAL OF RAMAN SPECTROSCOPY, Issue 4 2002P. Matousek An exceptionally high level of fluorescence rejection from resonance Raman spectra was achieved using a combination of two techniques, namely Kerr gated temporal rejection with shifted excitation Raman difference spectroscopy. The method was able to recover the resonance Raman spectrum from the intense fluorescence background with a signal-to-noise ratio at least 10 times higher than that achievable with either of the two approaches used individually. To demonstrate the effectiveness of the technique we obtained the resonance Raman spectrum of the laser dye rhodamine 6G (1 × 10,3 mol dm,3) in methanol by excitation at 532 nm and measuring under the maximum of fluorescence emission at 560,590 nm. The method reached the photon shot noise limit of the residual fluorescence providing a detection limit for Raman spectra 106 times lower than the original fluorescence intensity in an accumulation time of 800 s. A unique feature of the experiment was the way in which the optical parametric amplifier light source was configured to alternate automatically between the two excitation wavelengths using an optogalvanic mirror arrangement. The ultra-high sensitivity of the combined approach holds great promise for selective probing of complex biological systems using resonance Raman spectroscopy. Copyright © 2002 John Wiley & Sons, Ltd. [source] Molecular phylogeny of Enchytraeidae (Oligochaeta) indicates separate invasions of the terrestrial environmentJOURNAL OF ZOOLOGICAL SYSTEMATICS AND EVOLUTIONARY RESEARCH, Issue 3 2010Bent Christensen Abstract Enchytraeidae is a family of soil inhabiting small- to medium-sized oligochaete worms using degradable plant material as a food source and primarily adapted to terrestrial or semi-terrestrial environments. The molecular phylogeny based upon both mitochondrial and nuclear genes indicates early segregations of the two genera Enchytraeus and Lumbricillus leaving the remaining genera included in this study as a later segregated major monophyletic branch. Extant members of the two former genera dominate in decaying seaweed in the littoral zone along the sea although members of in particular the genus Enchytraeus have also invaded other habitats. Historically the littoral zone of the sea is undoubtedly the first terrestrial or semi-terrestrial habitat where dead plant material accumulates to any greater extent and Enchytraeus and Lumbricillus may represent early successful attempts to exploit this resource. Inland soils probably had to await the emergence of land plants in order to provide a similar food resource and here the major branch of enchytraeid genera diversified into a high number of species in the numerous decomposer networks of this varied environment. A subdivision into the genera Enchytraeus and Lumbricillus on the one hand and a branch of mainly inland genera on the other is supported by differences in two somewhat neglected morphological features. Firstly, in Enchytraeus and Lumbricillus the testes are enclosed in a testis sac within which the male cells mature, by one possible exception a unique feature among Oligochaeta, The other enchytraeid genera studied and Oligochaeta in general lack this sac and the male cells mature directly in the cavity of the testicular segment. Secondly, species of Enchytraeus and Lumbricillus generally have a higher reproductive output than species of the inland terrestrial branch and this may represent an adaptation to the unpredictable littoral zone compared to the more stable nature of inland habitats. In the older literature the genus Mesenchytraeus is considered to have a basic position within the entire family but our molecular data do not support this expectation. In Enchytraeidae the nephridia are elaborate organs of a characteristic and constant shape covering species from different genera in a pattern following the molecular phylogeny. Other much used morphological features such as shape of setae, anteclitellar origin of the dorsal vessel and various modifications of the intestine have arisen more than once. Zusammenfassung Enchytraeidae sind eine Familie kleiner bis mittelgroßer edaphischer Oligochaeten, welche abbaubares Pflanzenmaterial als Nahrungsquelle nutzen und primär an terrestrische oder semiterrestrische Lebensräume angepaßt sind. Die hier vorgestellte, auf mitochondrialen und nukleären Genen beruhende molekulare Phylogenie indiziert eine frühe Abtrennung der beiden Gattungen Enchytraeus und Lumbricillus und beläßt die übrigen der in dieser Studie untersuchten Gattungen als eine später abgezweigte monophyletische Großgruppe. Rezente Glieder der beiden erwähnten Gattungen dominieren in verrottendem Strandanwurf des Meereslitorals, obwohl Arten insbesondere der Gattung Enchytraeus auch andere Lebensräume erobert haben. Historisch gesehen ist das Meereslitoral zweifelsohne das erste terrestrische oder semiterrestrische Habitat, in dem totes Pflanzenmaterial in größerem Ausmaß akkumulierte, und Enchytraeus und Lumbricillus könnten frühe erfolgreiche Versuche der Nutzung dieser Ressource darstellen. Festlandsböden dagegen bedurften wahrscheinlich der Entwicklung von Landpflanzen, um eine vergleichbare Nahrungsquelle zur Verfügung zu stellen, und hier diversifizierte sich der Hauptzweig der Enchytraeidengattungen in viele Arten in den diversen Zersetzernetzen dieses vielgestaltigen Lebensraums. Eine Unterteilung in die Gattungen Enchytraeus und Lumbricillus auf der einen Seite und einen Zweig mit vorwiegend terrestrischen Gattungen auf der anderen wird durch zwei bislang eher vernachlässigte morphologische Merkmale gestützt. Erstens, bei Enchytraeus und Lumbricillus wird der Hoden von einem Testis-Sack, in dem die männlichen Zellen reifen, umschlossen. Dies ist mit einer möglichen Ausnahme einzigartig bei Oligochaeten. Bei den übrigen untersuchten Enchytraeidengattungen und bei Oligochaeten generell fehlt dieser Sack, und die männlichen Zellen reifen unmittelbar in der Körperhöhle des Hodensegmentes. Zweitens, die Reproduktionsrate von Enchytraeus und Lumbricillus ist generell höher als die der Arten des Festlandszweigs. Dies könnte eine Anpassung an die im Vergleich zu Festlandsböden instabileren Bedingungen des Meereslitorals bedeuten. In der älteren Literatur wird der Gattung Mesenchytraeus eine basale Position innerhalb der gesamten Familie zugewiesen, aber unsere molekularen Daten stützen diese Annahme nicht. Die Nephridien der Enchytraeiden sind komplexe Organe mit einer charakteristischen und artübergreifend konstanten Form, deren gattungsmäßige Abwandlungen der molekularen Phylogenie entsprechen. Andere oft verwendete morphologische Merkmale wie Borstenform, anteclitellarer Ursprung des Dorsalgefäßes und verschiedene Darmmodifikationen sind mehr als einmal entstanden. [source] In Situ Coacervated Microcapsules with Filled Polyelectrolytes and Charge-Controlled Permeation for Dye MoleculesMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 9 2008Feng Wang Abstract Microcapsules with charge-controlled permeation for electrolytes were fabricated by an in situ coacervation method in the presence of polyelectrolyte during core removal. A layer of PAH was adsorbed onto PSS-doped CaCO3 microparticles, followed by crosslinking of the PAH layer with GA and core removal in a solution of EDTA with or without PAH. In the presence of PAH, microcapsules with a larger size, weight and PSS content than with PAH were obtained. Microcapsules produces without PAH showed a unique feature of charge-controlled permeation for electrolytes: negatively charged probes were completely rejected, but positively charged ones were attracted. [source] Genetic analysis of the strong gyrase site (SGS) of bacteriophage Mu: localization of determinants required for promoting Mu replicationMOLECULAR MICROBIOLOGY, Issue 4 2000M. L. Pato The Mu strong gyrase site (SGS), located in the centre of the Mu genome, is required for efficient Mu replication, as it promotes synapsis of the prophage termini. Other gyrase sites tested, even very strong ones, were unable to substitute for the SGS in Mu replication. To determine the features required for its unique properties, a deletion analysis was performed on the SGS. For this analysis, we defined the 20 bp centred on the midpoint of the 4 bp staggered cleavage made by gyrase to be the ,core' and the flanking sequences to be the ,arms'. The deletion analysis showed that (i) ,,40 bp of the right arm is required, in addition to core sequences, for both efficient Mu replication and gyrase cleavage; and (ii) the left arm was not required for efficient Mu replication, although it was required for efficient gyrase cleavage. These observations implicated the right arm as the unique feature of the SGS. The second observation showed that strong gyrase cleavage and Mu replication could be dissociated and suggested that even weak gyrase sites, if supplied with the right arm of the SGS, could promote Mu replication. Hybrid sites were constructed with gyrase sites that could not support efficient Mu replication. The SGS right arm was used to replace one arm of the strong pSC101 gyrase site or the weaker pBR322 site. The pSC101 hybrid site allowed efficient Mu replication, whereas the pBR322 hybrid site allowed substantial, but reduced, replication. Hence, it appears that optimal Mu replication requires a central strong gyrase site with the properties imparted by the right arm sequences. Possible roles for the SGS right arm in Mu replication are addressed. [source] Delaunay Tessellation Field Estimator analysis of the PSCz local Universe: density field and cosmic flowMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2007Emilio Romano-Díaz ABSTRACT We apply the Delaunay Tessellation Field Estimator (DTFE) to reconstruct and analyse the matter distribution and cosmic velocity flows in the local Universe on the basis of the PSCz galaxy survey. The prime objective of this study is the production of optimal resolution 3D maps of the volume-weighted velocity and density fields throughout the nearby universe, the basis for a detailed study of the structure and dynamics of the cosmic web at each level probed by underlying galaxy sample. Fully volume-covering 3D maps of the density and (volume-weighted) velocity fields in the cosmic vicinity, out to a distance of 150 h,1 Mpc, are presented. Based on the Voronoi and Delaunay tessellation defined by the spatial galaxy sample, DTFE involves the estimate of density values on the basis of the volume of the related Delaunay tetrahedra and the subsequent use of the Delaunay tessellation as natural multidimensional (linear) interpolation grid for the corresponding density and velocity fields throughout the sample volume. The linearized model of the spatial galaxy distribution and the corresponding peculiar velocities of the PSCz galaxy sample, produced by Branchini et al., forms the input sample for the DTFE study. The DTFE maps reproduce the high-density supercluster regions in optimal detail, both their internal structure as well as their elongated or flattened shape. The corresponding velocity flows trace the bulk and shear flows marking the region extending from the Pisces,Perseus supercluster, via the Local Superclusters, towards the Hydra,Centaurus and the Shapley concentration. The most outstanding and unique feature of the DTFE maps is the sharply defined radial outflow regions in and around underdense voids, marking the dynamical importance of voids in the local Universe. The maximum expansion rate of voids defines a sharp cut-off in the DTFE velocity divergence probability distribution function. We found that on the basis of this cut-off DTFE manages to consistently reproduce the value of ,m, 0.35 underlying the linearized velocity data set. [source] Viral infections in the mouthORAL DISEASES, Issue 2002CG Teo Oral hairy leukoplakia (OHL) and Kaposi's sarcoma (KS) are commonly encountered in the HIV-infected patient. A unique feature of OHL is non-cytolytic high level of replication of Epstein,Barr virus (EBV) in the glossal epithelium. The expression of viral-encoded anti-apoptotic proteins concomitant to replicative proteins probably underlies this phenomenon. The question of whether OHL arises from activation of EBV latent in the tongue, or from superinfection by endogenous EBV shed via non-glossal sites or by exogenous EBV remains unresolved. Human herpesvirus 8 (HHV8) is now seen as necessary but not sufficient cause of KS. Expression of HHV8-encoded oncogenic proteins in endothelial cells probably explains the aberrant proliferation of these cells in KS lesions. Studies into why KS is so commonly observed at the palate in HIV-infected patients may provide important clues to its pathogenesis. [source] A population-based birth defects surveillance system in the People's Republic of ChinaPAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 3 2003Song Li Summary We describe a unique birth defects surveillance system in the People's Republic of China. The system was instituted in March 1992 as a component of an evaluation of the effectiveness of a public health campaign using periconceptional folic acid supplementation to prevent neural tube defects, and currently surveys birth cohorts of , 150 000 infants per year. Local health care providers collect information in the form of detailed written descriptions and photographs of affected infants. The system allows for detection of birth defects at the local level with later definitive classification and coding; however, information is limited to structural anomalies that are visible on physical examination. This birth defects surveillance system provides an extensive database of infants with major and minor external structural anomalies, including the unique feature of a photographic record for most cases. These data can be used for aetiological studies, descriptive epidemiology and identification of unusual trends. [source] Chromophore Interaction in Xanthorhodopsin,Retinal Dependence of Salinixanthin Binding,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2008Eleonora S. Imasheva Xanthorhodopsin is a light-driven proton pump in the extremely halophilic bacterium Salinibacter ruber. Its unique feature is that besides retinal it has a carotenoid, salinixanthin, with a light harvesting function. Tight and specific binding of the carotenoid antenna is controlled by binding of the retinal. Addition of all- trans retinal to xanthorhodopsin bleached with hydroxylamine restores not only the retinal chromophore absorption band, but causes sharpening of the salinixanthin bands reflecting its rigid binding by the protein. In this report we examine the correlation of the changes in the two chromophores during bleaching and reconstitution with native all- trans retinal, artificial retinal analogs and retinol. Bleaching and reconstitution both appear to be multistage processes. The carotenoid absorption changes during bleaching occurred not only upon hydrolysis of the Schiff base but continued while the retinal was leaving its binding site. In the case of reconstitution, the 13-desmethyl analog formed the protonated Schiff base slower than retinal, and provided the opportunity to observe changes in carotenoid binding at various stages. The characteristic sharpening of the carotenoid bands, indicative of its reduced conformational heterogeneity in the binding site, occurs when the retinal occupies the binding site but the covalent bond to Lys-240 via a Schiff base is not yet formed. This is confirmed by the results for retinol reconstitution, where the Schiff base does not form but the carotenoid exhibits its characteristic spectral change from the binding. [source]
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