Dramatic Changes (dramatic + change)

Distribution by Scientific Domains
Distribution within Life Sciences


Selected Abstracts


SHORT COMMUNICATION: History of Incidence of Autoimmune and Oncological Diseases in Identical Female Twins

AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 6 2009
Z. Ulcova-Gallova
Problem, The aim of study was to investigate identical female twins born in 1977 suffered from autoimmune diseases (twin A , Sjogren's syndrome, and twin B , systemic lupus erythematosus). Method of study, It was refer retrospective analysis of both sisters suffered beside autoimmune alterations (Sjogren's syndrome and systemic lupus erythematosus) also from gynecological diseases (twin A , praecancerosis of cervix uteri, twin B , carcinoma vaginae). Results, Relationships between disease activities and severities in the female twins were similar and the treatments were directed according to clinical symptoms and laboratory results. Dramatic change, unfortunately, occurred with twin B. The reason may be the association between SLE activity (lupus nephritis), hematological complication (leukopenia) and oncological vaginal recidivation. Conclusion, Association between autoimmune disease and gynecological cancer (or praecancerosis) is major risk than without immunology deviation. Twin A is periodically gynecologically observed. [source]


Modeling polycyclic aromatic hydrocarbon composition profiles of sources and receptors in the Pearl River Delta, China,

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2008
Chang Lang
Abstract Changes in concentration profiles of polycyclic aromatic hydrocarbons (PAHs) from emission sources to various environmental media in the Pearl River Delta, China were investigated using fugacity modeling under steady state assumption. Both assumed evenly and observed unevenly distributed PAH moles emission profiles were applied. Applicability of the fugacity model was validated against the observed media PAH concentrations and profiles. At equal emission rates, the differences of media concentrations among various PAHS were as high as three (air) to seven (soil and sediment) orders of magnitude. Dramatic changes of PAH profiles from emission sources to various bulk environmental media also were demonstrated by using the actual emission rates. In general, the fractions of higher molecular weight PAHs in air and water were much lower than those at the emission sources, although the PAH profiles in soil and sediment were characterized by a significant reduction of lower molecular weight PAHs. It is likely that the field-measured median concentration profiles cannot be adopted directly for source apportionment without rectification. The most influential parameters affecting PAH profiles in the study area were emission rates, degradation rates, adsorption coefficient, Henry's law constant, PAH concentrations in upstream surface water, fugacity ratio, vapor pressure, and diffusion coefficient in air. [source]


Sudden Worsening of Cluster Headache: A Signal of Aneurysmal Thrombosis and Enlargement

HEADACHE, Issue 8 2000
Juanita G. McBeath MD
We report a 55-year-old man presenting with symptoms of cluster headache, including throbbing pain behind the left eye, tearing, and rhinorrhea. Magnetic resonance imaging and magnetic resonance angiography revealed no abnormalities. Two days of intravenous dihydroergotamine resolved his pain. His headaches were somewhat relieved with a treatment regimen of 100 mg of imipramine each night, 40 mg of propranolol twice a day, 250 mg of divalproex three times a day, and dihydroergotamine nasal spray for breakthrough headaches. Two months later, the severity of his pain increased dramatically. Repeat imaging revealed a large thrombosed left posterior communicating artery aneurysm. Following obliterative surgery, his headaches are infrequent and mild and resemble tension headaches. Dramatic changes in headache characteristics can be an indicator of aneurysmal enlargement and thrombosis. This case illustrates the importance of repeat imaging when a patient's headache significantly worsens. [source]


Endocrine parameters of cystic fibrosis: Back to basics

JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2009
Michael S. Stalvey
Abstract Dramatic changes in the life expectancy of cystic fibrosis (CF) patients are occurring, creating a cohort of aging individuals experiencing long-term complications of this chronic disease. The two most common of these complications include CF-related diabetes and CF bone disease. The clinical implications of each have become better understood, as have potential therapies. However, data obtained from the basic science studies of both diseases have not been widely recognized. In this review, we focus on the known and hypothesized pathogenesis of these two disorders. Additionally, the molecular underpinnings of CF will be explained along with the potential interactions with endocrine disease phenotypes. J. Cell. Biochem. 108: 353,361, 2009. © 2009 Wiley-Liss, Inc. [source]


Mass and lifetime measurements of exotic nuclei in storage rings

MASS SPECTROMETRY REVIEWS, Issue 5 2008
Bernhard Franzke
Abstract Mass and lifetime measurements lead to the discovery and understanding of basic properties of matter. The isotopic nature of the chemical elements, nuclear binding, and the location and strength of nuclear shells are the most outstanding examples leading to the development of the first nuclear models. More recent are the discoveries of new structures of nuclides far from the valley of stability. A new generation of direct mass measurements which allows the exploration of extended areas of the nuclear mass surface with high accuracy has been opened up with the combination of the Experimental Storage Ring ESR and the FRragment Separator FRS at GSI Darmstadt. In-flight separated nuclei are stored in the ring. Their masses are directly determined from the revolution frequency. Dependent on the half-life two complementary methods are applied. Schottky Mass Spectrometry SMS relies on the measurement of the revolution frequency of electron cooled stored ions. The cooling time determines the lower half-life limit to the order of seconds. For Isochronous Mass Spectrometry IMS the ring is operated in an isochronous ion-optical mode. The revolution frequency of the individual ions coasting in the ring is measured using a time-of-flight method. Nuclides with lifetimes down to microseconds become accessible. With SMS masses of several hundreds nuclides have been measured simultaneously with an accuracy in the 2,×,10,7 -range. This high accuracy and the ability to study large areas of the mass surface are ideal tools to discover new nuclear structure properties and to guide improvements for theoretical mass models. In addition, nuclear half-lives of stored bare and highly charged ions have been measured. This new experimental development is a significant progress since nuclear decay characteristics are mostly known for neutral atoms. For bare and highly charged ions new nuclear decay modes become possible, such as bound-state beta decay. Dramatic changes in the nuclear lifetime have been observed in highly charged ions compared to neutral atoms due to blocking of nuclear decay channels caused by the modified atomic interaction. High ionization degrees prevail in hot stellar matter and thus these experiments have great relevance for the understanding of the synthesis of elements in the universe and astrophysical scenarios in general. © 2008 Wiley Periodicals, Inc., Mass Spec Rev 27: 428,469, 2008 [source]


Regulation of focal adhesion targeting and inhibitory functions of the FAK related protein FRNK using a novel estrogen receptor "switch"

CYTOSKELETON, Issue 2 2002
Karen H. Martin
Abstract Focal adhesion kinase (FAK) is a regulator of numerous adhesion-dependent processes including cell migration, cell proliferation, and cell survival. The C-terminal domain of FAK, FAK-related nonkinase (FRNK), is autonomously expressed and functions as an inhibitor of FAK signaling. Previous attempts to use FRNK as a tool to dissect FAK signaling have been limited because of an inability to temporally regulate the inhibitory functions of FRNK. In this report, we describe and characterize a conditionally targeted form of FRNK that was created by fusing the hormone-binding domain of the estrogen receptor (ER*) to the C-terminus of FRNK. In the absence of added hormone, FRNK-ER* was diffusely distributed throughout the cytoplasm of cells. Upon addition of hormone, the cytoplasmic pool of FRNK-ER* was rapidly redistributed to focal adhesions. We demonstrate that cells expressing FRNK-ER* show a hormone-dependent decrease in FAK tyrosine phosphorylation and cell migration. Furthermore, when cells expressing of FRNK-ER* were treated with hormone, the cells responded with a dramatic change in cell morphology, suggesting a role for FAK in the regulation of the adhesive properties of focal adhesions. Cell Motil. Cytoskeleton 51:76,88, 2002. © 2002 Wiley-Liss, Inc. [source]


SQUAMOUS CELL PAPILLOMA OF THE ESOPHAGUS: CLINICOPATHOLOGICAL STUDY OF 24 CASES

DIGESTIVE ENDOSCOPY, Issue 4 2004
Junya Oguma
Background:, Squamous cell papilloma of the esophagus is considered to be a rare condition; however, the number of cases with this condition reported in recent years has increased, perhaps due to advances in endoscopic diagnosis. Methods:, We reviewed the clinicopathological features of 26 lesions of squamous cell papilloma of the esophagus in 24 cases seen at our hospital from 1994 to 2003. There were nine men and 15 women, with a mean age of 60.5 years (range, 31,82 years). Six patients had a history of malignant disease in the past. With regard to the presence of other lesions in the esophagus, six patients had hiatal hernia and four had gastroesophageal re,ux disease. Results:, Two patients each had two lesions of squamous cell papilloma. There were seven lesions in which in,ammatory cell in,ltration was found on hisotological examination, of which four had underlying hiatal hernia; ,ve lesions were found to have mild dysplasia on histological examination of which three had gastroesophageal re,ux disease. The median duration of follow up of the cases was 8 months (range, 1,101 months). During the follow-up period, none of the lesions showed any dramatic change of appearance or malignant transformation. Conclusion:, In principle, while it may be suf,cient to keep patients with squamous cell papilloma of the esophagus under simple follow up, the patients must be investigated to rule out malignancy of other organs, and the small probability of malignant transformation of the tumor must always be borne in mind. [source]


Documenting the heroin shortage in New South Wales

DRUG AND ALCOHOL REVIEW, Issue 4 2006
CAROLYN DAY
Abstract Australian heroin markets have recently undergone dramatic change, sparking debate about the nature of such markets. This study aimed to determine the onset, peak and decline of the heroin shortage in New South Wales (NSW), using the most appropriate available methods to detect market level changes. The parameters of the heroin shortage were determined by reviewing: reports of heroin users about availability and price (derived from the existing literature and the Illicit Drug Reporting System); qualitative interviews with injecting drug users, and health and law enforcement professionals working in the illicit drug field; and examining data on heroin seizures over the past decade. There was a marked reduction in heroin supply in NSW in early 2001. An increase in the price of heroin occurred in 2001, whereas it had decreased steadily since 1996. A reduction in purity also occurred, as reported by drug users and heroin seizures. The peak period of the shortage appears to have been January to April 2001. The market appears to have stabilised since that time, although it has not returned to pre-2001 levels: heroin prices have decreased in NSW for street grams, but not to former levels, and the price of ,caps' (street deals) remain elevated. Heroin purity in NSW has remained low, with perhaps a 10% increase above the lowest recorded levels. These data support the notion that the heroin market in NSW underwent significant changes, which appear to have involved a lasting shift in the nature of the market. [source]


Pseudo-dynamic seismic response of reinforced concrete frames infilled with non-structural brick masonry

EARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 10 2005
F. Colangelo
Abstract This paper presents pseudo-dynamic test results on the in-plane seismic behaviour of infilled frames. Thirteen single-storey, single-bay, half-size-scale, reinforced concrete-frame specimens, most of which infilled with non-structural masonry made of perforated bricks and cement mortar are tested. The infills are in contact with frames, without any connector; openings are not covered. The frames are different in their strength and details, reinforcement grade, and aspect ratio. Seismic input is the 1976 Tolmezzo (Friuli, Italy) ground acceleration, to which specimens are subjected two times: virgin and damaged by the previous test. The global seismic response of initially virgin infilled specimens considerably differs from that of bare specimens. This follows a dramatic change of properties: compared to a bare frame, the initial stiffness increases by one order of magnitude, and the peak strength more than doubles. The peak drift lessens; however, the displacement ductility demand does not. The energy demand is greater. Nevertheless, the influence of infill decreases as damage proceeds. Displacement time histories of damaged specimens are quite similar. At the local level, infill causes asymmetry and concentration of the frame deformation. Copyright © 2005 John Wiley & Sons, Ltd. [source]


Effects of Acer platanoides invasion on understory plant communities and tree regeneration in the northern Rocky Mountains

ECOGRAPHY, Issue 5 2005
Kurt O. Reinhart
Quantitative studies are necessary to determine whether invasive plant species displace natives and reduce local biodiversity, or if they increase local biodiversity. Here we describe the effects of invasion by Norway maple Acer platanoides on riparian plant communities and tree regeneration at two different scales (individual tree vs stand scales) in western Montana, USA, using both descriptive and experimental approaches. The three stands differed in community composition with the stand most dominated by A. platanoides invasion being more compositionally homogenous, and less species rich (,67%), species even (,40%), and diverse (,75%) than the two other stands. This sharp decrease in community richness and diversity of the highly invaded stand, relative to the other stands, corresponded with a 28-fold increase in A. platanoides seedlings and saplings. The dramatic difference between stand 1 vs 2 and 3 suggests that A. platanoides invasion is associated with a dramatic change in community composition and local loss of species diversity; however, other unaccounted for differences between stands may be the cause. These whole-stand correlations were corroborated by community patterns under individual A. platanoides trees in a stand with intermediate levels of patchy invasion. At the scale of individual A. platanoides canopies within a matrix of native trees, diversity and richness of species beneath solitary A. platanoides trees declined as the size of the trees increased. These decreases in native community properties corresponded with an increase in the density of A. platanoides seedlings. The effect of A. platanoides at the stand scale was more dramatic than at the individual canopy scale; however, at this smaller scale we only collected data from the stand with intermediate levels of invasion and not from the stand with high levels of invasion. Transplant experiments with tree seedlings demonstrated that A. platanoides seedlings performed better when grown beneath conspecific canopies than under natives, but Populus and Pinus seedlings performed better when grown beneath Populus canopies, the dominant native. Our results indicate that A. platanoides trees suppress most native species, including the regeneration of the natural canopy dominants, but facilitate conspecifics in their understories. [source]


Impact of basic FGF expression in astrocytes on dopamine neuron synaptic function and development

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2006
Caroline Forget
Abstract Behavioural sensitization to amphetamine (AMPH) requires action of the drug in the ventral midbrain where dopamine (DA) neurons are located. In vivo studies suggest that AMPH sensitization requires enhanced expression of basic fibroblast growth factor (bFGF) in the nucleus of midbrain astrocytes. One idea is that the AMPH-induced increase in bFGF expression in astrocytes leads to enhanced secretion of this peptide and to long-term plasticity in DA neurons. To study directly the effects of astrocytic expression of bFGF on DA neurons, we established a cell-culture model of mesencephalic astrocytes and DA neurons. Immunolabelling showed that even in the absence of a pharmacological stimulus, the majority of mesencephalic astrocytes in culture express bFGF at a nuclear level. Arguing against the idea that bFGF was secreted, bFGF was undetectable in the extracellular medium (below 10 pg/mL). However, supplementing culture medium with exogenous bFGF at standard concentrations (20 ng/mL) led to a dramatic change in the morphology of astrocytes, increased spontaneous DA release, and inhibited synapse formation by individual DA neurons. RNA interference (siRNA) against bFGF mRNA, caused a reduction in DA release but produced no change in synaptic development. Together these data demonstrate that under basal conditions (in the absence of a pharmacological stimulus such as amphetamine) bFGF is not secreted even though there is abundant nuclear expression in astrocytes. The effects of bFGF seen here on DA neurons are thus likely to be mediated through more indirect glial,neuronal interactions, leading to enhanced DA release without a necessary change in synapse number. [source]


Alkyne Hydroarylations with Chelating Dicarbene Palladium(II) Complex Catalysts: Improved and Unexpected Reactivity Patterns Disclosed Upon Additive Screening,

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 19 2009
Andrea Biffis
Abstract Palladium(II) complexes with a ligand set made from a chelating N-heterocyclic dicarbene ligand and two weakly coordinating anions (generally introduced in situ upon addition of 2 equiv. of a suitable silver salt) were found to be very active and selective catalysts for the room-temperature hydroarylation of alkynes at low catalyst loading (0.1 mol-%). Moreover, the screening of various strong acids as reaction promoters revealed that both the strength of the acid and the coordinating ability of its conjugated base influence the catalytic performance. Most remarkably, the use of HBF4 together with a dicarbene Pd complex catalyst provides a dramatic change in the selectivity of the reaction, with the prevalent formation of a product stemming from the insertion of two molecules of alkyne into the aromatic C,H bond. The results presented herein highlight the fact that the dicarbene ligand, apart from stabilising the catalyst, is also able to enhance catalytic activity and, most notably, to steer the reaction selectivity towards novel products. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]


Vestigial prototroch in a basal nemertean, Carinoma tremaphoros (Nemertea; Palaeonemertea)

EVOLUTION AND DEVELOPMENT, Issue 4 2004
S. A. Maslakova
Summary Nemerteans have been alleged to belong to a protostome clade called the Trochozoa that includes mollusks, annelids, sipunculids, echiurids, and kamptozoans and is characterized by, among other things, the trochophore larva. The trochophore possesses a prototroch, a preoral belt of specialized ciliary cells, derived from the trochoblast cells. Nemertea is the only trochozoan phylum for which presence of the trochophore larva possessing a prototroch had never been shown. However, so little is known about nemertean larval development that comparing it with development of other trochozoans is difficult. Development in the nemertean clade Pilidiophora is via a highly specialized planktonic larva, the pilidium, and most of the larval body is lost during a drastic metamorphosis. Other nemerteans (hoplonemerteans and palaeonemerteans) lack a pilidium, and their development is direct, forming either an encapsulated or planktonic "planuliform" larva, producing a juvenile without a dramatic change in body plan. We show that early in the development of a member of a basal nemertean assemblage, the palaeonemertean Carinoma tremaphoros, large squamous cells cover the entire larval surface except for the apical and posterior regions. Although apical and posterior cells continue to divide, the large surface cells cleavage arrest and form a contorted preoral belt. Based on its position, cell lineage, and fate, we suggest that this belt corresponds to the prototroch of other trochozoans. Lack of differential ciliation obscures the presence of the prototroch in Carinoma, but differentiation of the trochoblasts is clearly manifested in their permanent cleavage arrest and ultimate degenerative fate. Our results allow a meaningful comparison between the development of nemerteans and other trochozoans. We review previous hypotheses of the evolution of nemertean development and suggest that a trochophore-like larva is plesiomorphic for nemerteans while a pilidium type of development with drastic metamorphosis is derived. [source]


The withdrawal of antimicrobial treatment as a mechanism for defeating resistant microorganisms

FEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 3 2008
David J. Stokes
Abstract Antimicrobial resistance is a major concern in health care and farming settings throughout the world. The level of antimicrobial resistance continues to increase and the requirement for a novel and possibly dramatic change in therapy choices is required. One possible mechanism for overcoming resistance is the actual removal of antimicrobial treatment from the therapeutic armoury. This review examines the potential for success of a policy advocating the reduction of antimicrobial use and additionally the withdrawal of such treatments. Evidence from agriculture suggests that the removal of certain drugs from animal husbandry can result in concomitant falls in certain drug resistances in human patients. [source]


Short-term climatic trends affect the temporal variability of macroinvertebrates in California ,Mediterranean' streams

FRESHWATER BIOLOGY, Issue 12 2007
LEAH A. BÊCHE
Summary 1. Long-term studies in ecology are essential for understanding natural variability and in interpreting responses to disturbances and human perturbations. We assessed the long-term variability, stability and persistence of macroinvertebrate communities by analysing data from three regions in northern California with a mediterranean-climate. During the study period, precipitation either increased or decreased, and extreme drought events occurred in each region. 2. Temporal trends in precipitation resulted in shifts from ,dry-year' communities, dominated by taxa adapted to no or low flow, to ,wet-year' communities dominated by taxa adapted to high flows. The abundance of chironomid larvae was an important driver of community change. Directional change in community composition occurred at all sites and was correlated with precipitation patterns, with more dramatic change occurring in smaller streams. 3. All communities exhibited high to moderate persistence (defined by the presence/absence of a species) and moderate to low stability (defined by changes in abundance) over the study period. Stability and persistence were correlated with climatic variation (precipitation and El Niño Southern Oscillation) and stream size. Stability and persistence increased as a result of drought in small streams (first-order) but decreased in larger streams (second- and third-order). Communities from the dry season were less stable than those from the wet-season. 4. This study demonstrates the importance of long-term studies in capturing the effects of and recovery from rare events, such as the prolonged and extreme droughts considered here. [source]


Dynamic changes in the epigenomic state and nuclear organization of differentiating mouse embryonic stem cells

GENES TO CELLS, Issue 4 2007
Satoru Kobayakawa
Changes in nuclear organization and the epigenetic state of the genome are important driving forces for developmental gene expression. However, a strategy that allows simultaneous visualization of the dynamics of the epigenomic state and nuclear structure has been lacking to date. We established an experimental system to observe global DNA methylation in living mouse embryonic stem (ES) cells. The methylated DNA binding domain (MBD) and the nuclear localization signal (nls) sequence coding for human methyl CpG-binding domain protein 1 (MBD1) were fused to the enhanced green fluorescent protein (EGFP) reporter gene, and ES cell lines carrying the construct (EGFP-MBD-nls) were established. The EGFP-MBD-nls protein was used to follow DNA methylation in situ under physiological conditions. We also monitored the formation and rearrangement of methylated heterochromatin using EGFP-MBD-nls. Pluripotent mouse ES cells showed unique nuclear organization in that methylated centromeric heterochromatin coalesced to form large clusters around the nucleoli. Upon differentiation, the organization of these heterochromatin clusters changed dramatically. Time-lapse microscopy successfully captured a moment of dramatic change in chromosome positioning during the transition between two differentiation stages. Thus, this experimental system should facilitate studies focusing on relationships between nuclear organization, epigenetic status and cell differentiation. [source]


Adaptive AQM controllers for IP routers with a heuristic monitor on TCP flows

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 1 2006
Yang Hong
Abstract We propose adaptive proportional (P) and proportional-integral (PI) controllers for Active Queue Management (AQM) in the Internet. We apply the classical control theory in the controller design and choose a proper phase margin to achieve good performance of AQM. We have identified a simple heuristic parameter that can monitor the changes of network environment. Our adaptive controllers would self-tune only when the dramatic change in the network parameters drift the monitoring parameter outside its specified interval. When compared to P controller, a PI controller has the advantage of regulating the TCP source window size by adjusting the packet drop probability based on the knowledge of instantaneous queue size, thus steadying the queue size around a target buffer occupancy. We have verified our controllers by OPNET simulation, and shown that with an adaptive PI controller applied, the network is asymptotically stable with good robustness. Copyright © 2005 John Wiley & Sons, Ltd. [source]


Optimization of parabolic trough solar collector system

INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 4 2006
Saad D. Odeh
Abstract Process heat produced by solar collectors can contribute significantly in the conservation of conventional energy resources, reducing CO2 emission, and delaying global warming. One of the major problems associated with solar process heat application is fluctuation in system temperature during unsteady state radiation conditions which may cause significant thermal and operation problems. In this paper a transient simulation model is developed for analysing the performance of industrial water heating systems using parabolic trough solar collectors. The results showed that to prevent dramatic change and instability in process heat during transient radiation periods thermal storage tank size should not be lower than 14.5 l m,2 of collector area. Small periods of radiation instability lower than 30 min do not have significant effect on system operation. During these periods when water flow rate of collector loop is doubled the time required to restore system normal operating condition increased by a ratio of 1.5. Copyright © 2005 John Wiley & Sons, Ltd. [source]


FINANCIAL STRATEGY FOR MIDDLE MARKET COMPANIES: a ROUNDTABLE DISCUSSION

JOURNAL OF APPLIED CORPORATE FINANCE, Issue 4 2000
Article first published online: 5 APR 200
Dennis Soter begins with the provocative observation that "U.S. companies, private as well as public, are systematically underleveraged," and goes on to suggest that debt-financed stock repurchases may help address the current valuation problems faced by many middle market companies (and by many larger firms in basic industries as well). Soter makes his case by presenting two case histories. In the first, Equifax, the Atlanta-based provider of credit information services, combined a leveraged Dutch auction stock repurchase with a multi-year series of open market repurchase programs and an EVA incentive plan to produce large increases in operating efficiency and shareholder value. In the second, FPL Group (the parent of Florida Power and Light) became the first profitable utility to cut its dividend, substituting a policy of ongoing stock repurchase for its 33% reduction in dividend payments. Following Soter, John Brehm, the CFO of IPALCO Enterprises (the parent of Indianapolis Power and Light), explains the rationale for his company's decision to become the first utility to do a leveraged recap (while also cutting its dividend by a third). As in the case of Equifax, IPALCO's dramatic change in capital structure (also combined with an EVA incentive plan) was associated with major operating improvements and a positive stock market response. But, of course, high leverage is not right for all companies. And, to reinforce that point, James Perry, CEO of Argosy Gaming, recounts his harrowing experience of having to raise new equity shortly after taking charge of his overleveraged company. By arranging an infusion of convertible preferred, Argosy was able not only to stave off bankruptcy, but to fund major new investment and engineer a remarkable turnaround of its operations. Finally, William Dutmers, Chairman of Knape & Vogt, a small midwestern manufacturing company, discusses the role of debt-financed stock repurchases and an EVA management approach in his company's recent operating improvements. [source]


Simultaneous light and small-angle neutron scattering on aggregating concentrated colloidal suspensions

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 1 2003
Sara Romer
A new sample environment has been developed in order to perform light and small-angle neutron scattering (SANS) simultaneously on colloidal systems. The combination of SANS and diffusing wave spectroscopy (DWS) is of particular use in the high-concentration regime. DWS provides information on the local dynamic properties of the individual particles, whereas SANS gives access to the structural properties on similar length scales. The combination of both methods thus allows one to obtain structural and dynamic information over a very large range of length and time scales. Using this new setup, the onset of aggregation and the sol,gel transition in concentrated destabilized polystyrene sphere suspensions have been investigated. At the gel point, a dramatic change of the particle dynamics from diffusion to a subdiffusive arrested motion is observed. However, while the DWS measurements indicate that dramatic changes in the local dynamics occur over a long period, the SANS pattern quickly reaches its final appearance. The SANS experiments thus indicate that a fluid-like structure is arrested in the course of the gel formation. The data are found to be in good qualitative agreement with computer simulations. [source]


New approaches to understanding late Quaternary climate fluctuations and refugial dynamics in Australian wet tropical rain forests

JOURNAL OF BIOGEOGRAPHY, Issue 2 2009
Jeremy VanDerWal
Abstract Aim, We created spatially explicit models of palaeovegetation stability for the rain forests of the Australia Wet Tropics. We accounted for the climatic fluctuations of the late Quaternary, improving upon previous palaeovegetation modelling for the region in terms of data, approach and coverage of predictions. Location, Australian Wet Tropics. Methods, We generated climate-based distribution models for broad rain forest vegetation types using contemporary and reconstructed ,pre-clearing' vegetation data. Models were projected onto previously published palaeoclimate scenarios dating to c. 18 kyr bp. Vegetation stability was estimated as the average likelihood that a location was suitable for rain forest through all climate scenarios. Uncertainty associated with model projections onto novel environmental conditions was also tracked. Results, Upland rain forest was found to be the most stable of the wet forest vegetation types examined. We provide evidence that the lowland rain forests were largely extirpated from the region during the last glacial maximum, with only small, marginally suitable fragments persisting in two areas. Models generated using contemporary vegetation data underestimated the area of environmental space suitable for rain forest in historical time periods. Model uncertainty resulting from projection onto novel environmental conditions was low, but generally increased with the number of years before present being modelled. Main conclusions, Climate fluctuations of the late Quaternary probably resulted in dramatic change in the extent of rain forest in the region. Pockets of high-stability upland rain forest were identified, but extreme bottlenecks of area were predicted for lowland rain forest. These factors are expected to have had a dramatic impact on the historical dynamics of population connectivity and patterns of extinction and recolonization of dependent fauna. Finally, we found that models trained on contemporary vegetation data can be problematic for reconstructing vegetation patterns under novel environmental conditions. Climatic tolerances and the historical extent of vegetation may be underestimated when artificial vegetation boundaries imposed by land clearing are not taken into account. [source]


Cloud computing: Retro revival or the new paradigm?

JOURNAL OF CORPORATE ACCOUNTING & FINANCE, Issue 5 2010
LuAnn Bean
"Cloud computing" is one of the most recently hyped concepts in information technology (IT). While some argue that it is just the old "time-sharing" mainframe model transformed, others contend that it is a dramatic change in how we will expand computing possibilities. Which is correct? Is it something that your company should consider? The author explains what cloud computing is and examines its advantages and disadvantages. © 2010 Wiley Periodicals, Inc. [source]


Two contrasted P,T,time paths of coronitic metanorites of the French Massif Central: are reaction textures reliable guides to metamorphic histories?

JOURNAL OF METAMORPHIC GEOLOGY, Issue 2 2005
C. NICOLLET
Abstract Metanorites from two eclogitized metagabbros of the Hercynian French Massif Central preserve coronitic textures of hornblende, garnet, quartz and/or kyanite produced at the expense of the primary magmatic assemblage orthopyroxene and plagioclase. Using a petrogenetic grid in the CFMASH system, two possible P,T evolutions for the origin of the coronas are evaluated. The sequence of reactions involving the formation of Hbl (,Ky) ± Grt and Qtz coronitic assemblages is consistent with an isobaric cooling at high pressure (c. 1,2 GPa) under hydrated conditions. However, this P,T path, inferred by using only petrographical observations, is inconsistent with the geochronological constraints: emplacement of the gabbro at 490 Ma and high-pressure metamorphism at 410 Ma. In order to reconcile petrographical observations with geochronological constraints, we propose a discontinuous two-stage evolution involving a change in water activity with time. (1) Emplacement and cooling of the norite at low pressure under anhydrous conditions, at 490 Ma. (2) During the Hercynian orogeny, the norite experienced an increase in pressure and temperature under fluid-present conditions. Adding water to the system implies a dramatic change in the petrogenetic grid topology, restricting the orthopyroxene,plagioclase assemblage only to high temperatures. Therefore, the breakdown of the unstable magmatic assemblage, through apparent retrograde reactions, occurred along the prograde P,T path which never crossed the equilibrium boundaries of these reactions. [source]


Critical appraisal of the management of severe malnutrition: 1.

JOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 10 2006
Epidemiology, treatment guidelines
Abstract: Hospital case-fatality rates for severe malnutrition in the developing world remain high, particularly in Africa where they have not changed much over recent decades. In an effort to improve case management, WHO has developed treatment guidelines. The aim of this review is to critically appraise the evidence for the guidelines and review important recent advances in the management of severe malnutrition. We conclude that not only is the evidence base deficient, but also the external generalisability of even good-quality studies is seriously compromised by the great variability in clinical practice between regions and types of health facilities in the developing world, which is much greater than between developed countries. The diagnosis of severe wasting is complicated by the dramatic change in reference standards (from CDC/WHO 1978 to CDC 2000 in EpiNut) and also by difficulties in accurate measurement of length. Although following treatment guidelines has resulted in improved outcomes, there is evidence against the statement that case-fatality rates (particularly in African hospitals) can be reduced below 5% and that higher rates are proof of poor practice, because there is wide variation in severity of illness factors. The practice of prolonged hospital treatment of severe malnutrition until wasting and/or oedema has resolved is being replaced by shorter hospital stays combined with outpatient or community follow-up because of advances in dietary management outside of hospital. [source]


Freeze-dry microscopy of protein/sugar mixtures: Drying behavior, interpretation of collapse temperatures and a comparison to corresponding glass transition Data

JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 9 2009
Eva Meister
Abstract The purpose of this study is to investigate the change in collapse appearance and temperature of protein/sugar mixtures as a function of nucleation temperature (Tn), sublimation velocity (Vsub) and the sugar/protein mole ratio when performing freeze-dry microscopy experiments. BSA and HSA were used as sample proteins and mixed with either sucrose or trehalose. Differential scanning calorimetry was used to determine the corresponding glass transition temperatures . To allow a more representative comparison between these analytical methods, a collapse midpoint temperature (Tc-50) was introduced. While there was no distinct correlation between Tn and the onset of collapse (Toc) for either mixture, Vsub was found to correlate with the measured collapse temperature which is important for comparability of experiments. Furthermore, Vsub could be used to qualitatively investigate the product resistance to water vapor flow. A dramatic change in the appearance of collapse was found for high sugar/protein mole ratios (,362:1) which needs to be considered to avoid a misinterpretation of Toc data. At low protein concentrations midpoint data showed good agreement with Toc values but were found significantly lower at higher protein concentrations. Application of the Gordon,Taylor equation failed to predict the critical temperature for any of the protein/sugar mixtures studied. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:3072,3087, 2009 [source]


Investigation of a New Approach to Measuring Contact Angles for Hydrophilic Impression Materials

JOURNAL OF PROSTHODONTICS, Issue 2 2007
Gerard Kugel DMD
Purpose: The purpose of this investigation was to examine the initial water contact angles of seven unset impression materials using commercially available equipment, in an effort to determine whether polyether impression materials (Impregum) have lower contact angles and are, therefore, more hydrophilic than VPS impression materials. Materials and Methods: The hydrophilic properties of unset polyether and VPS impression materials were analyzed with respect to their water contact angle measurements using the commercially available Drop Shape Analysis System DSA 10. Twenty-five data points per second were collected via video analysis. There was no delay from start of measurement and data collection. Data was collected for approximately 12 s. Droplet size was determined on the thickness of canula. If the droplets became too small in volume, the water that evaporated during the measurement was large in comparison to the volume of the droplet. Therefore, 5 ,l was chosen as the lowest volume. Five trials were conducted per series for each featured material. Contact angles were calculated using the circle fitting method. Three tests using this technique were designed to control the variables of contact angle measurement with regard to time, the varying amount of fluid in contact with impression material during clinical use, and material thickness. Sample thickness of impression material was controlled by stripping the paste flat on a glass plate using a marking template to ensure a constant film thickness. Tests were conducted in a climatized room at 24°C ± 1°C. Deionized water was used as the fluid. The device was calibrated according to manufacturer's instruction for Young,Laplace fitting prior to the measurements. Results were analyzed using One-Way ANOVA, Tukey test, and t -test, as appropriate. Results: Comparing the fast setting impression materials by One-Way ANOVA and Tukey tests (p < .05) revealed the initial contact angles to range from 66.2 ± 1.5° to 127.5 ± 4.4°, of which the polyether material was the lowest after 45 s (66.2 ± 1.5°), 120 s (70.3 ± 2.8°), and 24 h (80.3 ± 1.0°) after start of the mix. The selected times represent the different stages of unset material, ranging from 45 s as the earliest practical data collection time to 24 h, at which a stone model would be poured. The polyether materials tested exhibited lower contact angles and, thus, significantly higher initial hydrophilicity than all measured VPS materials. Additionally, Impregum impression materials are more hydrophilic in the unset stage than in the set stage. VPS may show a stepwise development of hydrophilicity in the set stage that was not observed in the unset stage. Conclusions: The polyether impression materials tested were significantly more hydrophilic before, during, and after setting than that of VPS impression materials. Regardless of the amount of water in contact with the impression material, the polyether impression materials showed a significantly higher hydrophilicity in the unset stage than the VPS materials. The initial contact angle was not dependent on the thickness of the material. All parameters, including variation of time, volume of water droplet, and thickness of material, resulted in different absolute contact angles, but did not lead to a dramatic change in the ranking of the materials with regard to their hydrophilic behavior. [source]


Welfare Reform in America: A Clash of Politics and Research

JOURNAL OF SOCIAL ISSUES, Issue 4 2000
Diana M. Zuckerman
The 1996 welfare reform law radically changed welfare as we knew it, after many years of debate and concerns across the ideological spectrum. Research should have provided essential information to revise the program, but instead, research was used as an ideological weapon to support conflicting points of view. President Clinton promised to end welfare as we know it but his welfare reform plan was superceded by the election of a Republican majority of the House and Senate in 1994. The resulting welfare bill included key elements from the Republican Contract with America. The purpose of this article is to describe how political pressures resulted in a dramatic change in law, despite doomsday predictions and almost no solid information about the law's likely impact. [source]


Photomechanical transdermal delivery of insulin in vivo

LASERS IN SURGERY AND MEDICINE, Issue 3 2001
Shun Lee PhD
Abstract Background and Objective Previous studies have shown that photomechanical waves transiently permeabilize the stratum corneum in vivo. The aim of the present work was to investigate the potential of photomechanical waves for systemic drug delivery. Study Design/Materials and Methods Photomechanical waves were generated by ablation of a polystyrene target by a Q-switched ruby laser. Systemic insulin delivery in a streptozotocin-diabetic rat model was monitored by measuring the blood glucose level. Results After photomechanical insulin delivery, the blood glucose decreased 80 ,±, 3% and remained below 200 mg/dl for more than 3 hours. Whereas in control experiments (for which insulin was applied without photomechanical waves), there was no dramatic change in the blood glucose (standard deviation of measurements over 4 hours was 7%). Conclusion The application of the photomechanical waves allowed ,6-kDa protein molecules (insulin) to pass through the stratum corneum and into the systemic circulation. Lasers Surg. Med. 28:282,285, 2001. © 2001 Wiley-Liss, Inc. [source]


Macromolecular helicity inversion of poly(phenylacetylene) derivatives induced by various external stimuli

MACROMOLECULAR SYMPOSIA, Issue 1 2003
Katsuhiro Maeda
Abstract Unique macromolecular helicity inversion of stereoregular, optically active poly(phenylacetylene) derivatives induced by external achiral and chiral stimuli is briefly reviewed. Stereoregular, cis-transoidal poly(phenylacetylene)s bearing an optically active substituent, such as (1R,2S)-norephedrine (poly- 1) and , -cyclodextrin residues (poly- 2), show an induced circular dichroism (ICD) in the UV-visible region of the polymer backbone in solution due to a predominantly one-handed helical conformation of the polymers. However, poly- 1 undergoes a helix-helix transition upon complexation with chiral acids having an R configuration, and the complexes exhibit a dramatic change in the ICD of poly- 1. Poly- 2 also shows the inversion of macromolecular helicity responding to molecular and chiral recognition events that occurred at the remote cyclodextrin residues from the polymer backbone; the helicity inversion is accompanied by a visible color change. A similar helix-helix transition of poly((R)- or (S)-(4-((1-(1-naphthyl)ethyl)carbamoyl)phenyl)acetylene) is also briefly described. [source]


Reflectance spectra of iron meteorites: Implications for spectral identification of their parent bodies

METEORITICS & PLANETARY SCIENCE, Issue 2 2010
Edward A. CLOUTIS
Powder spectra are invariably red-sloped over this wavelength interval and have a narrow range of visible albedos (approximately 10,15% at 0.56 ,m). Metal (Fe:Ni) compositional variations have no systematic effect on the powder spectra, increasing grain size results in more red-sloped spectra, and changes in viewing geometry have variable effects on overall reflectance and spectral slope. Roughened metal slab spectra have a wider, and higher, range of visible albedos than powders (22,74% at 0.56 ,m), and are also red-sloped. Smoother slabs exhibit greater differences from iron meteorite powder spectra, exhibiting wider variations in overall reflectance, spectral slopes, and spectral shapes. No unique spectral parameters exist that allow for powder and slab spectra to be fully separated in all cases. Spectral differences between slabs and powders can be used to constrain possible surface properties, and causes of rotational spectral variations, of M-asteroids. The magnitude of spectral variations between M-asteroids and rotational and spectral variability does not necessarily imply a dramatic change in surface properties, as the differences in albedo and/or spectral slope can be accommodated by modest changes in grain size (for powders), small changes in surface roughness (for slabs), or variations in viewing geometry. Since metal powders exhibit much less spectral variability than slabs, M-asteroid spectral variability requires larger changes in either powder properties or viewing geometry than for slabs for a given degree of spectral variation. [source]