Substantial Changes (substantial + change)

Distribution by Scientific Domains
Distribution within Life Sciences


Selected Abstracts


Substantial Change and Spatiotemporal Coincidence

RATIO, Issue 2 2003
E. J. Lowe
Substantial change occurs when a persisting object of some kind either begins or ceases to exist. Typically, this happens when one or more persisting objects of another kind or kinds are subjected to appropriate varieties of qualitative or relational change, as when the particles composing a lump of bronze are rearranged so as to create a statue. However, such transformations also seem to result, very often, in cases of spatiotemporal coincidence, in which two numerically distinct objects of different kinds exist in exactly the same place at the same time, such as a statue and a lump of bronze. Various attempts to resist this way of describing the results of such transformations are examined and found wanting and objections to the possibility of cases of spatiotemporal coincidence are rebutted. [source]


Practical nurses in elder care and changes in Finnish society , a biographical study

JOURNAL OF ADVANCED NURSING, Issue 2 2003
Leena Paasivaara MNSc
Background. ,Substantial changes in the socio-economic circumstances in Finnish society over the past century have resulted in major changes in the case of older people, and in the status of nursing staff who care for them. Aim. ,The purpose of this study was to describe and analyse the work of practical nurses in elder care through the experiences and life cycles of two practical nurses with a long working experience. Methods. ,The data consisted of oral biographical narratives produced by the two nurses in repeated interviews. The data were analysed using inductive content analysis. Findings. ,The following chronological stages and periods of the work of the informants emerged as the core themes of elder care: (1) Collective institutionalized care in the 1950s,1970s: The lowest caste in training, obedient subordinates, undemanding service and routine work; (2) Elderly orientated institutionalized care in the 1980s and 1990s: From subordination to co-operation as an experienced nurse, recognizing the specific qualities of the elderly; (3) Prospects of elder care from the 1990s onwards: Returning to custodial care? Conclusions. ,The themes are related to the more general changes that have taken place in Finnish society and health care. The future prospects of practical nurses seem challenging because the principles of social work and health care in Finnish society have shifted from institutionalization towards community care. As a consequence, practical nurses are required to have higher qualifications. [source]


Vascular alterations in the rabbit patellar tendon after surgical incision

JOURNAL OF ANATOMY, Issue 5 2001
M. R. DOSCHAK
Open incision of the patellar tendon (PT) is thought to promote acute vascular responses which ultimately result in an enhanced degree of tendon repair. Such a clinical procedure is commonly applied to patients with refractory tendinitis. The objective of this study was to quantify the vascular adaptations (both anatomical and physiological) to longitudinal incision of the PT, and the resultant effects on tendon organisation. Fifty-four New Zealand White rabbits were separated into 3 experimental groups and 2 control groups. Experimental groups underwent surgical incision of the right PT, and were assessed 3 d, 10 d and 42 d following injury; normal unoperated controls were evaluated at time zero, and sham-operated controls were evaluated at 3 d to control for the effects of incising the overlying skin. Quantitative measures of PT blood supply (blood flow, microvascular volume) and geometric properties of PT substance were obtained for each PT. Histomorphology was assessed to evaluate vascular remodelling and matrix organisation in the healing PT. Longitudinal open incision surgery of the PT led to rapid increases in both blood flow and vascular volume. The incision of overlying tissues alone (sham-operated) contributed to this measurable increase, and accounted for 36% and 42% of the elevated blood flow and vascular volume respectively at the 3 d interval. In the incised PT, blood flow significantly increased by 3 d compared with both time zero and sham-operated controls, and remained significantly elevated at the 10 d interval. Similarly, vascular volume of the incised PT increased at 3 d compared both with time zero and sham-operated controls. At the 10 d interval, the increase in vascular volume was greatest in the central PT substance. By 42 d both blood flow and vascular volume of the incised tendon had diminished, with only blood flow remaining significantly different from controls. In the contralateral limb, a significant neurogenically mediated vasodilation was measured in the contralateral PTs at both early time intervals, but was not seen by the later 42 d interval. With respect to PT geometric properties in the experimental animals, a larger PT results as the tendon matrix and blood vessels remodel. PT cross-sectional area increased rapidly by 3 d to 1·3 times control values, and remained significantly elevated at 42 d postinjury. Morphological assessments demonstrated the disruption of matrix organisation by vascular and soft tissue components associated with the longitudinal incisions. Substantial changes in matrix organisation persisted at 42 d after surgery. These findings suggest that open longitudinal incision of the PT increases the vascular supply to deep tendon early after injury. These changes probably arise through both vasomotor and angiogenic activity in the tissue. Since PT blood flow and vascular volume return towards control levels after 6 wk but structural features remain disorganised, we propose that vascular remodelling is more rapid and complete than matrix remodelling after surgical incision of the PT. [source]


Endothelin System in Human Persistent and Paroxysmal Atrial Fibrillation

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2001
BIANCA J.J.M. BRUNDEL Ph.D.
Endothelin System in Atrial Fibrillation. Introduction: Activation of the endothelin system is an important compensatory mechanism that is activated during left ventricular dysfunction. Whether this system plays a role at the atrial level during atrial fibrillation (AF) has not been examined in detail. The purpose of this study was to investigate mRNA and protein expression levels of the endothelin system in AF patients with and without concomitant underlying valve disease. Methods and Results: Right atrial appendages of 36 patients with either paroxysmal or persistent AF were compared with 36 controls in sinus rhythm. The mRNA amounts of pro-endothelin-1 (pro-ET-1), endothelin receptor A (ET-A), and endothelin receptor B (ET-B) were studied by semiquantitative polymerase chain reaction. Protein amounts of the receptors were investigated by slot-blot analysis. mRNA amounts of pro-ET-1 were increased (+ 40%; P = 0.002) only in AF patients with underlying valve disease. ET-A and ET-B receptor protein amounts were significantly reduced in patients with paroxysmal AF (,39% and ,47%, respectively) and persistent AF with underlying valve disease (, 28% and , 30%, respectively) and in persistent AF without valve disease (,20% and ,40%, respectively). ET-A mRNA expression was unaltered in paroxysmal and persistent AF, whereas ET-B mRNA was reduced by 30% in persistent AF with (P < 0.001) or without (P = 0.04) valve disease, but unchanged in paroxysmal AF. Conclusion: Substantial changes in gene expression of the endothelin system were observed in human atria during AF, especially in the presence of underlying valve disease. Alterations in endothelin expression associated with AF could play a role in the pathophysiology of AF and the progression of underlying heart disease. [source]


Community-level changes in Australian subalpine vegetation following invasion by the non-native shrub Cytisus scoparius

JOURNAL OF VEGETATION SCIENCE, Issue 5 2004
Lynise J. Wearne
Abstract: Question: What are the changes associated with the recent invasion by the non-native legume, Cytisus scoparius? Location: Subalpine vegetation (1500 m a.s.l.) in Australia. Methods: We used multivariate techniques and regression analyses to assess vegetation and environmental changes across six study sites. Vegetation and environmental variables were investigated at three different stages of invasion: (1) recent invasion (8,10 yr), (2) mature invasion (15,16 yr) and (3) long-term invasion (25 yr). Results: Substantial changes in floristic composition and species richness were evident after 15 yr and these changes became more pronounced after 25 yr. Changes due to invasion were associated with a dramatic loss of native species or a reduction in their abundance. No ,new species' were evident under invaded stands. Forbs were most affected by the establishment of C. scoparius, although all growth forms responded negatively. Dense canopy shading and an increasingly dense, homogeneous litter layer in the understorey as a result of C. scoparius were strong environmental drivers of vegetation change. Greenhouse studies confirmed the importance of these processes on the germination and growth of two native species. Conclusions: This study highlights the potential for C. scoparius to alter both vegetation and environmental processes in the subalpine region. [source]


Molecular physiology of adventitious root formation in Petunia hybrida cuttings: involvement of wound response and primary metabolism

NEW PHYTOLOGIST, Issue 3 2009
Amir H. Ahkami
Summary ,,Adventitious root formation (ARF) in the model plant Petunia hybrida cv. Mitchell has been analysed in terms of anatomy, gene expression, enzymatic activities and levels of metabolites. This study focuses on the involvement of wound response and primary metabolism. ,,Microscopic techniques were complemented with targeted transcript, enzyme and metabolite profiling using real time polymerase chain reaction (PCR), Northern blot, enzymatic assays, chromatography and mass spectrometry. ,,Three days after severance from the stock plants, first meristematic cells appeared which further developed into root primordia and finally adventitious roots. Excision of cuttings led to a fast and transient increase in the wound-hormone jasmonic acid, followed by the expression of jasmonate-regulated genes such as cell wall invertase. Analysis of soluble and insoluble carbohydrates showed a continuous accumulation during ARF. A broad metabolite profiling revealed a strong increase in organic acids and resynthesis of essential amino acids. ,,Substantial changes in enzyme activities and metabolite levels indicate that specific enzymes and metabolites might play a crucial role during ARF. Three metabolic phases could be defined: (i) sink establishment phase characterized by apoplastic unloading of sucrose and being probably mediated by jasmonates; (ii) recovery phase; and (iii) maintenance phase, in which a symplastic unloading occurs. [source]


Light source inner surface changes depending on treatment

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 4 2008
A. Skudra
Abstract Our work is connected with the preparation of different type of electrodeless discharge lamps. In this work we investigate the influence of the SiO2 glass wall treatment procedures on the inner surface of the electrodeless lamps. Three different treatment procedures were applied: vacuum cleaning, vacuum-thermal cleaning and training in the high frequency discharge. The surface modification has been investigated by means of atomic force microscopy. Substantial changes of the SiO2 glass surface have been observed. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Coarse sediment transport in mountain streams in Colorado and Wyoming, USA

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 3 2005
Sandra E. Ryan
Abstract Since the early 1990s, US Forest Service researchers have made thousands of bedload measurements in steep, coarse-grained channels in Colorado and Wyoming, USA. In this paper we use data from 19 of those sites to characterize patterns and rates of coarse sediment transport for a range of channel types and sizes, including step,pool, plane-bed, pool,riffle, and near-braided channels. This effort builds upon previous work where we applied a piecewise regression model to (1) relate flow to rates of bedload transport and (2) define phases of transport in coarse-grained channels. Earlier, the model was tested using bedload data from eight sites on the Fraser Experimental Forest near Fraser, Colorado. The analysis showed good application to those data and to data from four supplementary channels to which the procedure was applied. The earlier results were, however, derived from data collected at sites that, for the most part, have quite similar geology and runoff regimes. In this paper we evaluate further the application of piecewise regression to data from channels with a wider range of geomorphic conditions. The results corroborate with those from the earlier work in that there is a relatively narrow range of discharges at which a substantial change in the nature of bedload transport occurs. The transition from primarily low rates of sand transport (phase I) to higher rates of sand and coarse gravel transport (phase II) occurs, on average, at about 80 per cent of the bankfull (1·5-year return interval) discharge. A comparison of grain sizes moved during the two phases showed that coarse gravel is rarely trapped in the samplers during phase I transport. Moreover, the movement and capture of the D16 to D25 grain size of the bed surface seems to correspond with the onset of phase II transport, particularly in systems with largely static channel surfaces. However, while there were many similarities in observed patterns of bedload transport at the 19 studied sites, each had its own ,bedload signal' in that the rate and size of materials transported largely reflected the nature of flow and sediment particular to that system. Published in 2005 by John Wiley & Sons, Ltd. [source]


GeoChip-based analysis of functional microbial communities during the reoxidation of a bioreduced uranium-contaminated aquifer

ENVIRONMENTAL MICROBIOLOGY, Issue 10 2009
Joy D. Van Nostrand
Summary A pilot-scale system was established for in situ biostimulation of U(VI) reduction by ethanol addition at the US Department of Energy's (DOE's) Field Research Center (Oak Ridge, TN). After achieving U(VI) reduction, stability of the bioreduced U(IV) was evaluated under conditions of (i) resting (no ethanol injection), (ii) reoxidation by introducing dissolved oxygen (DO), and (iii) reinjection of ethanol. GeoChip, a functional gene array with probes for N, S and C cycling, metal resistance and contaminant degradation genes, was used for monitoring groundwater microbial communities. High diversity of all major functional groups was observed during all experimental phases. The microbial community was extremely responsive to ethanol, showing a substantial change in community structure with increased gene number and diversity after ethanol injections resumed. While gene numbers showed considerable variations, the relative abundance (i.e. percentage of each gene category) of most gene groups changed little. During the reoxidation period, U(VI) increased, suggesting reoxidation of reduced U(IV). However, when introduction of DO was stopped, U(VI) reduction resumed and returned to pre-reoxidation levels. These findings suggest that the community in this system can be stimulated and that the ability to reduce U(VI) can be maintained by the addition of electron donors. This biostimulation approach may potentially offer an effective means for the bioremediation of U(VI)-contaminated sites. [source]


Analysis of a Leptospira interrogans locus containing DNA replication genes and a new IS, IS1502

FEMS MICROBIOLOGY LETTERS, Issue 2 2002
R.L. Zuerner
Abstract A region of the Leptospira interrogans serovar pomona genome encoding DNA replication genes was characterized. This region, designated the ppa-ntrC locus, includes 19 open reading frames and a new insertion sequence, IS1502. Although this locus resembles replication origins from many eubacteria, it lacks several genes common to homologous loci. Some replication-related genes were previously located near rrf, and may have been moved to that location by homologous recombination between short sequence elements common to both loci. Further analysis showed that the ppa-ntrC region has undergone substantial change during spirochete evolution. Transcription analysis using RT-PCR revealed uniquely organized polycistronic mRNAs in the ppa-ntrC locus. The dnaN and recF intergenic region of serovar pomona was different from the homologous sites of 41 L. interrogans serovars by the presence of IS1502. The distribution of IS1502 throughout pathogenic Leptospira species varies. This result suggests that IS1502 may have been recently introduced into Leptospira. [source]


Recognition of Indigenous Interests in Australian Water Resource Management, with Particular Reference to Environmental Flow Assessment

GEOGRAPHY COMPASS (ELECTRONIC), Issue 3 2008
Sue Jackson
Australia's new national water policy represents a substantial change from the previous approach, because it recognises a potential need for allocations to meet particular indigenous requirements, which will have to be quantitatively defined in water allocation plans. However, indigenous values associated with rivers and water are presently poorly understood by decision-makers, and some are difficult to quantify or otherwise articulate in allocation decisions. This article describes the range of Australian indigenous values associated with water, and the way they have been defined in contemporary water resource policy and discourse. It argues that the heavy reliance of indigenous values on healthy river systems indicates that, theoretically at least, they are logically suited for consideration in environmental flow assessments. However, where indigenous interests have been considered for assessment planning purposes indigenous values have tended to be overlooked in a scientific process that leaves little room for different world views relating to nature, intangible environmental qualities and human relationships with river systems that are not readily amenable to quantification. There is often an implicit but untested assumption that indigenous interests will be protected through the provision of environmental flows to meet aquatic ecosystem requirements, but the South African and New Zealand approaches to environmental flow assessment, for example, demonstrate different riverine uses potentially can be accommodated. Debate with indigenous land-holders and experimentation will show how suited different environment flow assessment techniques are to addressing indigenous environmental philosophies and values. [source]


Contribution of N2O to the greenhouse gas balance of first-generation biofuels

GLOBAL CHANGE BIOLOGY, Issue 1 2009
EDWARD M. W. SMEETS
Abstract In this study, we analyze the impact of fertilizer- and manure-induced N2O emissions due to energy crop production on the reduction of greenhouse gas (GHG) emissions when conventional transportation fuels are replaced by first-generation biofuels (also taking account of other GHG emissions during the entire life cycle). We calculate the nitrous oxide (N2O) emissions by applying a statistical model that uses spatial data on climate and soil. For the land use that is assumed to be replaced by energy crop production (the ,reference land-use system'), we explore a variety of options, the most important of which are cropland for food production, grassland, and natural vegetation. Calculations are also done in the case that emissions due to energy crop production are fully additional and thus no reference is considered. The results are combined with data on other emissions due to biofuels production that are derived from existing studies, resulting in total GHG emission reduction potentials for major biofuels compared with conventional fuels. The results show that N2O emissions can have an important impact on the overall GHG balance of biofuels, though there are large uncertainties. The most important ones are those in the statistical model and the GHG emissions not related to land use. Ethanol produced from sugar cane and sugar beet are relatively robust GHG savers: these biofuels change the GHG emissions by ,103% to ,60% (sugar cane) and ,58% to ,17% (sugar beet), compared with conventional transportation fuels and depending on the reference land-use system that is considered. The use of diesel from palm fruit also results in a relatively constant and substantial change of the GHG emissions by ,75% to ,39%. For corn and wheat ethanol, the figures are ,38% to 11% and ,107% to 53%, respectively. Rapeseed diesel changes the GHG emissions by ,81% to 72% and soybean diesel by ,111% to 44%. Optimized crop management, which involves the use of state-of-the-art agricultural technologies combined with an optimized fertilization regime and the use of nitrification inhibitors, can reduce N2O emissions substantially and change the GHG emissions by up to ,135 percent points (pp) compared with conventional management. However, the uncertainties in the statistical N2O emission model and in the data on non-land-use GHG emissions due to biofuels production are large; they can change the GHG emission reduction by between ,152 and 87 pp. [source]


Cholinergic suppression of excitatory synaptic responses in layer II of the medial entorhinal cortex

HIPPOCAMPUS, Issue 2 2007
Bassam N. Hamam
Abstract Theta-frequency (4,12 Hz) electroencephalographic activity is thought to play a role in mechanisms mediating sensory and mnemonic processing in the entorhinal cortex and hippocampus, but the effects of acetylcholine on excitatory synaptic inputs to the entorhinal cortex are not well understood. Field excitatory postsynaptic potentials (fEPSPs) evoked by stimulation of the piriform (olfactory) cortex were recorded in the medial entorhinal cortex during behaviors associated with theta activity (active mobility) and were compared with those recorded during nontheta behaviors (awake immobility and slow wave sleep). Synaptic responses were smaller during behavioral activity than during awake immobility and sleep, and responses recorded during movement were largest during the negative phase of the theta rhythm. Systemic administration of cholinergic agonists reduced the amplitude of fEPSPs, and the muscarinic receptor blocker scopolamine strongly enhanced fEPSPs, suggesting that the theta-related suppression of fEPSPs is mediated in part by cholinergic inputs. The reduction in fEPSPs was investigated using in vitro intracellular recordings of EPSPs in Layer II neurons evoked by stimulation of Layer I afferents. Constant bath application of the muscarinic agonist carbachol depolarized membrane potential and suppressed EPSP amplitude in Layer II neurons. The suppression of EPSPs was not associated with a substantial change in input resistance, and could not be accounted for by a depolarization-induced reduction in driving force on the EPSP. The GABAA receptor-blocker bicuculline (50 ,M) did not prevent the cholinergic suppression of EPSPs, suggesting that the suppression is not dependent on inhibitory mechanisms. Paired-pulse facilitation of field and intracellular EPSPs were enhanced by carbachol, indicating that the suppression is likely due to inhibition of presynaptic glutamate release. These results indicate that, in addition to well known effects on postsynaptic conductances that increase cellular excitability, cholinergic activation in the entorhinal cortex results in a strong reduction in strength of excitatory synaptic inputs from the piriform cortex. © 2006 Wiley-Liss, Inc. [source]


Decadal-scale changes in the tails of probability distribution functions of climate variables in Switzerland

INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 10 2009
Martin Beniston
Abstract An analysis of several Swiss climatological sites reveals that a substantial change in the behaviour of pressure, minimum and maximum temperature extremes has occurred in the past two decades. Extreme cold tails defined by the 10% quantiles of temperature drop by a factor of 2 or 3, while the upper tails (beyond the 90% quantile) exhibit a four- or five-fold increase in all seasons. Pressure shows contrasting behaviour, with increases in wintertime highs and summertime lows, while precipitation shows little change. On the basis of the observed datasets, temperature biases related to extremes of pressure or precipitation have been computed, as well as for joint combinations of precipitation and pressure extremes. The most dominant bias is associated with periods without rainfall, during which temperatures are at least 1 °C warmer than otherwise. Changes in the behaviour of joint combinations of extreme pressure and precipitation regimes also have a discernible influence on temperatures. Copyright © 2008 Royal Meteorological Society [source]


Effect of manufacturing treatments on the rheological character of Mozzarella cheese made from microfiltration retentate depleted of whey proteins,

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 6 2001
Randall L. Brandsma
Low-moisture, part-skim (LMPS) Mozzarella cheeses were made from highly concentrated skim milk microfiltration (MF) retentate and butteroil. Differing combinations of rennet concentration, coagulation temperature and post-coagulation curd cutting time were used, with comparisons made of the rheological and functional characteristics of cheeses during ageing. Lubricated squeezing flow, stress relaxation, melt and stretch measurements demonstrated that commercial LMPS Mozzarella had substantial textural and functional change between 7 and 30 days of age, while the rheological and functional behaviour of LMPS MF Mozzarella (MFM) exhibited substantial change between 30 and 60 days of age. Rennet concentration was the only experimental factor to significantly affect MFM rheological and functional development. The delayed development of MFM was partially attributed to inhibition of normal cheese proteolysis via whey protein (WP) incorporation, lack of starter culture protease, and homogenization of MF cheesemilk. Use of starter culture in MFM led to improved rheological and functional behaviour. [source]


Aging stability of complete blood count and white blood cell differential parameters analyzed by Abbott CELL-DYN Sapphire hematology analyzer

INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 1 2009
P. HEDBERG
Summary This study presents the results of an aging stability study of complete blood count (CBC) and leukocyte differential parameters using the Abbott CELL-DYN Sapphire hematology analyzer. Stability studies showed no substantial change in CBC parameters up to 24,48 h at +23 ± 2 °C (room temperature), except for optical platelet count (PLTo). For specimens aged over 24, the value of impedance platelet count yielded more reliable results than the routine PLTo. White blood cell (WBC) differential parameters, except eosinophils, were stable for up to 48 h at +23 ± 2 °C. CBC parameters were stable for 72 h, except mean platelet volume, which slightly increased between 48 and 72 h, at +4 °C. WBC differentials were stable 48,72 h, with a slight decrease observed in absolute neutrophils and lymphocytes at +4 °C. [source]


Continuity and change in the southern European social model

INTERNATIONAL LABOUR REVIEW, Issue 1 2008
Maria KARAMESSINI
Abstract. Over the past 20 years or so, the southern European model has undergone substantial change in every way. The changes in industrial relations, wage-setting and employment protection legislation have tended to increase wage and labour flexibility and restrict labour market segmentation. Changes within the welfare state have sought to improve labour force skills, fill gaps in social protection, reduce inequalities in social security and contain social expenditure growth. Yet institutional change has not eliminated the main features of this model: pronounced labour market segmentation and familialism; however, extremely low fertility rates are indicative of the limits of familialism in the near future. [source]


Meaningful Change and Responsiveness in Common Physical Performance Measures in Older Adults

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 5 2006
Subashan Perera PhD
OBJECTIVES: To estimate the magnitude of small meaningful and substantial individual change in physical performance measures and evaluate their responsiveness. DESIGN: Secondary data analyses using distribution- and anchor-based methods to determine meaningful change. SETTING: Secondary analysis of data from an observational study and clinical trials of community-dwelling older people and subacute stroke survivors. PARTICIPANTS: Older adults with mobility disabilities in a strength training trial (n=100), subacute stroke survivors in an intervention trial (n=100), and a prospective cohort of community-dwelling older people (n=492). MEASUREMENTS: Gait speed, Short Physical Performance Battery (SPPB), 6-minute-walk distance (6MWD), and self-reported mobility. RESULTS: Most small meaningful change estimates ranged from 0.04 to 0.06 m/s for gait speed, 0.27 to 0.55 points for SPPB, and 19 to 22 m for 6MWD. Most substantial change estimates ranged from 0.08 to 0.14 m/s for gait speed, 0.99 to 1.34 points for SPPB, and 47 to 49 m for 6MWD. Based on responsiveness indices, per-group sample sizes for clinical trials ranged from 13 to 42 for substantial change and 71 to 161 for small meaningful change. CONCLUSION: Best initial estimates of small meaningful change are near 0.05 m/s for gait speed, 0.5 points for SPPB, and 20 m for 6MWD and of substantial change are near 0.10 m/s for gait speed, 1.0 point for SPPB, and 50 m for 6MWD. For clinical use, substantial change in these measures and small change in gait speed and 6MWD, but not SPPB, are detectable. For research use, these measures yield feasible sample sizes for detecting meaningful change. [source]


A post Keynesian critique of privatization policies in transition economies

JOURNAL OF INTERNATIONAL DEVELOPMENT, Issue 5 2002
John Marangos
The privatization policies implemented in transition economies were based on the neoclassical principles of economic thought. The neoclassical privatization policies contributed to the well-known results of a large reduction in output, high unemployment and inflation and a breakdown of institutional norms resulting in corruption and illegal activities. For the post Keynesians, there could have been a transition to a market economy without a substantial change in property ownership. This was because ownership, as such, was less important than competition, the incentive structure and the nature of regulatory policies. Consequently, post Keynesian policies of privatization would had resulted in a substantially smaller social cost of transition. Copyright © 2002 John Wiley & Sons, Ltd. [source]


Adverse reactions to immunization with newer vaccines in the very preterm infant

JOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 8 2005
Vanessa J Ellison
Objective: To study the frequency and types of adverse reactions to currently available vaccines in very preterm infants. Methods: Case notes were obtained for very preterm infants ,30 weeks' gestational age who received their first immunization at the Royal Women's Hospital, Melbourne, during 1999,2003. Data were extracted for the time periods 48 h before and 48 h after immunizations, with the data extraction blinded as to whether the period being evaluated was pre- or post-immunization. Data collected focused on the frequency and severity of apnoea, respiratory support, fever and clinical consequences of adverse reactions. Results: A total of 48 very preterm infants were immunized during the period; 37 infants had Comvax (Haemophilus influenzae type B and hepatitis B vaccine), Infanrix (diphtheria, tetanus and acellular pertussis vaccine) and inactivated poliomyelitis vaccine, and 11 infants had Comvax and Infanrix only. Their mean (SD) gestational age at birth was 26.4 (1.7) weeks with mean birthweight of 872 (235) g. The mean postnatal age at immunization was 76 (20) days. Low-grade fever (>37.5°C per axilla) occurred in 16 (33%) infants after immunization, but none before immunization (P < 0.001). There was no substantial change in recorded apnoea. No serious adverse events were noted. Four (8%) infants underwent a septic work up post-immunization. The C-reactive protein was increased in all four infants, but other tests for sepsis were negative. Conclusion: Fever remains a common adverse event following immunization of the preterm infant in spite of the development of a new generation of vaccines. [source]


A case study of one school system's adoption and implementation of an elementary science program

JOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 1 2005
Michael P. Kelly
In this investigation we employed a case study approach with qualitative and quantitative data sources to examine and discover the characteristics of the processes used by a midwestern U.S. school system to adopt and implement a new K,6 science curriculum. Analysis of data yielded several results. Elementary teachers received what they requested, a hands-on science program with texts and kits. Teachers as a group remained in the early stages of the Concerns-Based Adoption Model profile of concerns. Many K,6 teachers remained uncomfortable with teaching science. Teachers' attitudes regarding the new program were positive, and they taught more science. Teachers struggled with science-as-inquiry, with a science program they believe contained too many concepts and too much vocabulary, and with their beliefs that students learned more and loved the new hands-on program. Traditional science teaching remained the norm. Administrative support was positive but insufficient to facilitate full implementation of the new program and more substantial change in teaching. Standardized science achievement test scores did not show an observable pattern of growth. It is concluded that a systematic, ongoing program of professional development is necessary to address teachers' concerns and help the district realize its goal of standards-based K,6 science instruction. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 42: 25,52, 2005 [source]


Assemblage structure, but not diversity or density, change with depth on a northeast Pacific seamount

MARINE ECOLOGY, Issue 2010
Craig R. McClain
Abstract Although depth-related patterns in assemblage structure are documented in several deep-sea systems, variation in diversity, assemblage structure, and abundance with depth on individual seamounts remains unexplored. Knowledge of alpha- and beta-diversity on single seamounts is needed for any robust generalization about large-scale biodiversity patterns on seamounts. Here, we explore bathymetric variation in benthic megafauna, based on ROV video transects, on Davidson seamount (1246,3656 m) in the Northeast Pacific Ocean. We found that substantial change in assemblage structure can occur over vertical scales on an individual seamount. Changes of 50% in assemblage composition (beta-diversity, faunal turnover) were observed over as little as a ,1500 m depth interval down the flanks of the seamount, although bathymetric clines in composition were not uniform across major taxa. Diversity and density exhibit no consistent bathymetric pattern and can vary greatly on a single isobath. Our findings suggest that ecological and evolutionary processes may vary considerably on a single seamount. As such, seamounts should be viewed as patchworks of habitats where high beta-diversity may ultimately increase total biodiversity. [source]


A Second Republic for Italy?

POLITICAL STUDIES REVIEW, Issue 1 2003
Mark Donovan
Radical change in the representative dimension of Italy's political system was expected to bring a transition to a ,Second Republic' in Italy. That has not happened. Nevertheless, after three consultations using the new parliamentary electoral system, studies focusing on the ,input' side of Italian politics are beginning to agree that substantial change has occurred. It is, however, too early to identify the extent of change in public administration and centre,local government relations, whilst even in parliament it is argued that consensual decision-making continued at least into the late 1990s. The impact of party system change on policy-making has thus been shown to be less direct than many expected, providing rich material for research into the relationship between institutional and policy change. Nevertheless, institutional change continues, particularly with regard to the decentralisation of government, and some studies suggest that this is the key to Italy's political transformation, rather than electoral reform or even change in the form of government. Still, the election of Italy's first right-wing majority government in 2001 may yet bring change in parliamentary practice and policy-making more generally. [source]


Reliability of the anaerobic threshold in cardiopulmonary exercise testing of patients with abdominal aortic aneurysms,

ANAESTHESIA, Issue 1 2009
E. Kothmann
Summary Anaerobic threshold (AT), determined by cardiopulmonary exercise testing (CPET), is a well-documented measure of pre-operative fitness, although its reliability in patient populations is uncertain. Our aim was to assess the reliability of AT measurement in patients with abdominal aortic aneurysms. Eighteen patients were recruited. CPET was performed four times over a 6-week period. We examined shifts in the mean AT to evaluate systematic bias with random measurement error assessed using typical within-patient error and intraclass correlation coefficient (ICC, 3,1) statistics. There was no significant or clinically substantial change in mean AT across the tests (p = 0.68). The typical within-patient error expressed as a percentage coefficient of variation was 10% (95% CI, 8,13%), with an ICC of 0.74 (95% CI, 0.55,0.89). We consider the reliability of the AT to be acceptable, supporting its clinical validity and utility as an objective marker of pre-operative fitness in this population. [source]


Managing the complexity of change in postgraduate surgical education and training

ANZ JOURNAL OF SURGERY, Issue 3 2009
David J. Hillis
Abstract Pressure of workforce shortages, educational reform, heightened regulatory requirements and increased community expectations and scrutiny, has led to demand for substantial change in the provision of surgical education and training. The Royal Australasian College of Surgeons has responded positively to these external factors through an extensive review of local and worldwide practice and opinion, providing ongoing realignment of its governance and committee structure, substantially adjusting the structure of its educational program and increasing the educational support to trainees and supervisors. The College looks to the Council and its senior Fellows to create the direction and drive, but these changes need to be supported and implemented with care by the management and administrative staff of the College and specialist societies. This is in an opinion-rich zone with substantial regulatory scrutiny. [source]


STUDIES ON THE EXPRESSION LEVELS OF STEROL-METABOLIZING ENZYMES IN THE OBESE MODEL SHR/NDmcr- cp RATS

CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 2004
Makiko Kudo
SUMMARY 1.,Expression levels of four key enzymes of cholesterol metabolism, namely 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, lanosterol 14-demethylase (CYP51), cholesterol 7,-hydroxylase (CYP7A1) and sterol 12,-hydroxylase (CYP8B1), in metabolic syndrome model rats (SHR/NDmcr-cp) were examined. 2.,Decreased expression of CYP51, which may be linked to the development of obesity, was found in the rats. 3.,Expression of CYP8B1 was significantly higher in young rats. 4.,No substantial change was observed in the mRNA levels of the dominant rate-limiting enzymes of sterol metabolism, namely HMG-CoA reductase and CYP7A1, in the rats. 5.,These findings suggest that the expression levels of two key enzymes managing the downstream parts of the cholesterol-metabolizing pathways are altered in the rats, although little change was observed in the expression levels of the dominant rate-limiting enzymes of cholesterol metabolism. [source]


One-year follow-up of patients with acromegaly treated with fixed or titrated doses of lanreotide Autogel®

CLINICAL ENDOCRINOLOGY, Issue 6 2004
Ph. Caron
Summary objective, Somatostatin analogue treatment is first-line medical therapy for acromegaly. This study compared the efficacy and tolerability of titrated doses of the long-acting somatostatin analogue preparation lanreotide Autogel® with fixed doses and with lanreotide prolonged release (PR) 30 mg microparticles. patients, Patients entering the initial study had received a diagnosis of active acromegaly within the previous 5 years. design, This open, comparative, multicentre study was a 1-year extension of a previous trial during which patients with acromegaly had switched from lanreotide PR 30 mg microparticles injected intramuscularly every 7, 10 or 14 days, for at least 3 months, to one of three fixed doses of lanreotide Autogel® (120, 90, or 60 mg every 28 days, respectively). In this extension study, patients continued to receive 60, 90, or 120 mg of lanreotide Autogel® by deep subcutaneous injection every 28 days for 1 year. Doses could be titrated at entry or after four or eight injections, according to the GH/IGF-I response (dose increased if GH > 2·5 µg/l, or decreased if GH < 1 µg/l with normal IGF-I). measurements, Mean ± SEM GH and IGF-I concentrations were analysed and gallbladder echography performed at weeks 0, 16, 32, and 48. Acromegaly symptoms were recorded monthly and tolerance and side-effects were monitored throughout the study. results, In total, 130 patients entered this extension phase. After 1 year of treatment with titrated doses of lanreotide Autogel®, mean GH (2·4 ± 0·2 µg/l) and IGF-I (287 ± 12 µg/l) concentrations were significantly lower than with lanreotide microparticles (GH, 2·8 ± 0·2 µg/l, P < 0·001; IGF-I, 332 ± 15 µg/l, P < 0·01) or with fixed-dose lanreotide Autogel® (GH, 3·0 ± 0·2 µg/l, P < 0·001; IGF-I, 310 ± 14 µg/l, P = 0·02). GH hypersecretion was reduced to , 2·5 µg/l in 68% of patients with titrated-dose lanreotide Autogel® compared with 49% with microparticles (P < 0·001) and 56% with fixed-dose lanreotide Autogel® (P , 0·005). In the 65 patients who did not require any dose titration, there was no substantial change in serum lanreotide concentration, GH or IGF-I levels over the 12-month study duration. Acromegaly was effectively controlled (GH , 2·5 µg/l and normalized IGF-I) in significantly more patients (43%) compared with microparticles (32%; P < 0·05). There was a trend for improved control of acromegalic symptoms with dose titration, whereas the incidence of gastrointestinal symptoms and local tolerance was similar with lanreotide Autogel® and lanreotide microparticles. Gallbladder echographies showed new lithiasis in 8% of lanreotide Autogel® patients. conclusion, Dose titration of lanreotide Autogel® improved GH and IGF-I control in patients with acromegaly beyond that achieved using fixed doses of lanreotide Autogel® or lanreotide microparticles. Titrated long-term lanreotide Autogel® treatment is well tolerated. [source]


Matrix Models as a Tool for Understanding Invasive Plant and Native Plant Interactions

CONSERVATION BIOLOGY, Issue 3 2005
DIANE M. THOMSON
competencia; invasión biológica; plantas invasoras; modelo matricial; perturbación Abstract:,Demographic matrix models are an increasingly standard way to evaluate the effects of different impacts and management approaches on species of concern. Although invasive species are now considered among the greatest threats to biodiversity, matrix methods have been little used to explore and integrate the potentially complicated effects of invasions on native species. I developed stage-structured models to assess the impacts of invasive grasses on population growth and persistence of a federally listed (U.S.A.) endemic plant, the Antioch Dunes evening primrose (Oenothera deltoides subsp. howellii [Munz] W. Klein). I used these models to evaluate two frequently made assumptions: (1) when rare plant populations decline in invaded habitats, invasive species are the cause and (2) invasive plants suppress rare plants primarily through direct resource competition. I compared two control and two removal matrices based on previous experimental work that showed variable effects of invasive grasses on different life-history stages of O. deltoides. Matrix analysis showed that these effects translated into substantial changes in population growth rates and persistence, with control matrices predicting a mean stochastic population growth rate (,) of 0.86 and removal matrices predicting growth rates from 0.92 to 0.93. Yet even the most optimistic invasive removal scenarios predicted rapid decline and a probability of extinction near one in the next 100 years. Competitive suppression of seedlings had much smaller effects on growth rates than did lowered germination, which probably resulted from thatch accumulation and reduced soil disturbance. These results indicate that although invasive grasses have important effects on the population growth of this rare plant, invasion impacts are not solely responsible for observed declines and are likely to be interacting with other factors such as habitat degradation. Further, changes in the disturbance regime may be as important a mechanism creating these impacts as direct resource competition. My results highlight the value of demographic modeling approaches in creating an integrated assessment of the threats posed by invasive species and the need for more mechanistic studies of invasive plant interactions with native plants. Resumen:,Los modelos demográficos matriciales son una forma cada vez más utilizada para evaluar los efectos de diferentes impactos y métodos de gestión sobre las especies en cuestión. Aunque actualmente se considera a las plantas invasoras entre las mayores amenazas a la biodiversidad, los modelos matriciales han sido poco utilizados para explorar e integrar los efectos potencialmente complicados de las invasiones sobre las especies nativas. Desarrollé modelos estructurados por etapas para evaluar los impactos de pastos invasores sobre el crecimiento poblacional y la persistencia de una especie de planta endémica, enlistada federalmente (E.U.A.), Oenothera deltoides ssp. howellii [Munz] W. Klein. Utilicé estos modelos para evaluar dos suposiciones frecuentes: (1) cuando las poblaciones de plantas raras declinan en hábitats invadidos, las especies invasoras son la causa y (2) las plantas invasoras suprimen a las plantas raras principalmente mediante la competencia directa por recursos. Comparé dos matrices de control y dos de remoción con base en trabajo experimental previo que mostró efectos variables de los pastos invasores sobre las diferentes etapas de la historia de vida de O. deltoides. El análisis de la matriz mostró que estos efectos se tradujeron en cambios sustanciales en las tasas de crecimiento y persistencia de la población, las matrices de control predijeron una tasa media de crecimiento poblacional estocástica (,) de 0.86 y las matrices de remoción predijeron tasas de crecimiento de 0.92-0.93. Aun los escenarios más optimistas de remoción de invasores predijeron una rápida declinación y una probabilidad de extinción en 100 años cerca de uno. La supresión competitiva de plántulas tuvo mucho menor efecto sobre las tasas de crecimiento que la disminución en la germinación, que probablemente resultó de la acumulación de paja y reducción en la perturbación del suelo. Estos resultados indican que, aunque los pastos invasores tienen efectos importantes sobre el crecimiento poblacional de esta planta rara, los impactos de la invasión no son los únicos responsables de las declinaciones observadas y probablemente están interactuando con otros factores como la degradación del hábitat. Más aun, los cambios en el régimen de perturbación pueden ser un mecanismo tan importante en la creación de estos impactos como la competencia directa por recursos. Mis resultados resaltan el valor del enfoque de los modelos demográficos para la evaluación integral de las amenazas de especies invasoras y la necesidad de estudios más mecanicistas de las interacciones de plantas invasoras con plantas nativas. [source]


Prescribing Flood Regimes to Sustain Riparian Ecosystems along Meandering Rivers

CONSERVATION BIOLOGY, Issue 5 2000
Brian D. Richter
By managing river flows for water supplies and power generation, water management agencies have inadvertently caused considerable degradation of riverine ecosystems and associated biodiversity. New approaches for meeting human needs for water while conserving the ecological integrity of riverine ecosystems are greatly needed. We describe an approach for identifying the natural flooding characteristics that must be protected or restored to maintain riparian ( floodplain) ecosystems along meandering rivers. We developed a computer model to simulate flood-driven changes in the relative abundance of riparian patch types along the Yampa River in Colorado ( U.S.A.). The model is based on research suggesting that the duration of flooding at or above 209 m3 per second (125% of bankfull discharge) is particularly important in driving lateral channel migration, which is responsible for initiating ecological succession in the Yampa's riparian forest. Other hydrologic variables, such as the magnitude of annual peak flows, were not as strongly correlated with lateral channel migration rates. Model simulations enabled us to tentatively identify a threshold of alteration of flood duration that could lead to substantial changes in the abundance of forest patch types over time should river flows be regulated by future water projects. Based on this analysis, we suggest an ecologically compatible water management approach that avoids crossing flood alteration thresholds and provides opportunity to use a portion of flood waters for human purposes. Recommended improvements to the Yampa model include obtaining additional low-elevation aerial photographs of the river corridor to enable better estimation of channel migration rates and vegetation changes. These additional data should greatly improve the model's accuracy and predictive capabilities and therefore its management value. Resumen: La composición y estructura de ecosistemas ribereños están fuertemente ligadas a la variabilidad hidrológica natural. Al manejar el flujo de ríos para abastecer agua y generar energía, las agencias de manejo de agua han causado inadvertidamente una degradación considerable de los ecosistemas ribereños y la biodiversidad asociada a ellos. Se necesitan nuevas estrategias para satisfacer las necesidades humanas de agua al mismo tiempo que se conserva la integridad de los ecosistemas ribereños. Describimos una estrategia para identificar las características de inundaciones naturales que deben ser protegidas o restauradas para mantener ecosistemas riparios ( planicies de inundación) a lo largo de ríos sinuosos. Desarrollamos un modelo de computadora para simular los cambios causados por inundaciones en la abundancia relativa de tipos de parche ripario a lo largo del río Yampa, en Colorado ( Estados Unidos de Norteamérica). Este modelo se basa en investigación que sugiere que la duración de la inundación a, o mayor a, 209 m3 por segundo (125% de descarga del banco lleno a su capacidad) es particularmente importante en la conducción de la migración de canales laterales, lo cual es responsable de la iniciación de la sucesión ecológica en el bosque ripario del río Yampa. Otras variables hidrológicas, como lo es la magnitud del pico de los flujos anuales no estuvieron tan fuertemente correlacionadas con las tasas de migración lateral de canales. Las simulaciones del modelo nos permitieron identificar límites tentativos de alteración de la duración de la inundación que podrían conducir a cambios sustanciales en la abundancia de tipos de parches forestales en el tiempo si los flujos de los ríos son regulados en proyectos de agua futuros. En base a este análisis, sugerimos una estrategia de manejo de agua ecológicamente compatible que evita sobrepasar los límites de alteración de las inundaciones y provee la oportunidad de usar una porción del agua de las inundaciones para fines humanos. Las recomendaciones de mejoras al modelo del río Yampa incluyen la necesidad de obtener fotografías aéreas de baja elevación adicionales del corredor del río, que permitan una mejor estimación de las tasas de migración de los canales y los cambios en la vegetación. Estos datos adicionales deberán mejorar en gran medida la precisión del modelo y sus capacidades predictivas y, por lo tanto, su valor de manejo. [source]


Computational fluid dynamics modelling of boundary roughness in gravel-bed rivers: an investigation of the effects of random variability in bed elevation

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 4 2001
A.P. Nicholas
Abstract Results from a series of numerical simulations of two-dimensional open-channel flow, conducted using the computational fluid dynamics (CFD) code FLUENT, are compared with data quantifying the mean and turbulent characteristics of open-channel flow over two contrasting gravel beds. Boundary roughness effects are represented using both the conventional wall function approach and a random elevation model that simulates the effects of supra-grid-scale roughness elements (e.g. particle clusters and small bedforms). Results obtained using the random elevation model are characterized by a peak in turbulent kinetic energy located well above the bed (typically at y/h,=,0·1,0·3). This is consistent with the field data and in contrast to the results obtained using the wall function approach for which maximum turbulent kinetic energy levels occur at the bed. Use of the random elevation model to represent supra-grid-scale roughness also allows a reduction in the height of the near-bed mesh cell and therefore offers some potential to overcome problems experienced by the wall function approach in flows characterized by high relative roughness. Despite these benefits, the results of simulations conducted using the random elevation model are sensitive to the horizontal and vertical mesh resolution. Increasing the horizontal mesh resolution results in an increase in the near-bed velocity gradient and turbulent kinetic energy, effectively roughening the bed. Varying the vertical resolution of the mesh has little effect on simulated mean velocity profiles, but results in substantial changes to the shape of the turbulent kinetic energy profile. These findings have significant implications for the application of CFD within natural gravel-bed channels, particularly with regard to issues of topographic data collection, roughness parameterization and the derivation of mesh-independent solutions. Copyright © 2001 John Wiley & Sons, Ltd. [source]