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Several Previous Studies (several + previous_studies)
Selected AbstractsLinear and nonlinear measures of blood pressure variability: Increased chaos of blood pressure time series in patients with panic disorderDEPRESSION AND ANXIETY, Issue 2 2004Vikram K. Yeragani M.B.B.S. Abstract Arterial blood pressure (BP) variability increases progressively with the development of hypertension and an increase in BP variability is associated with end organ damage and cardiovascular morbidity. On the other hand, a decrease in heart rate (HR) variability is associated with significant cardiovascular mortality. There is a strong association between cardiovascular mortality and anxiety. Several previous studies have shown decreased HR variability in patients with anxiety. In this study, we investigated beat-to-beat variability of systolic and diastolic BP (SBP and DBP) in normal controls and patients with panic disorder during normal breathing and controlled breathing at 12, and 20 breaths per minute using linear as well as nonlinear techniques. Finger BP signal was obtained noninvasively using Finapres. Standing SBPvi and DBP BPvi (log value of BP variance corrected for mean BP divided by HR variance corrected for mean HR) were significantly higher in patients compared to controls. Largest Lyapunov exponent (LLE) of SBP and DBP, a measure of chaos, was significantly higher in patients in supine as well as standing postures. The ratios of LLE (SBP/HR) and LLE (DBP/HR) were also significantly higher (P < .001) in patients compared to controls. These findings further suggest dissociation between HR and BP variability and a possible relative increase in sympathetic function in anxiety. This increase in BP variability may partly explain the increase in cardiovascular mortality in this group of patients. Depression and Anxiety 19:85-95, 2004. © 2004 Wiley-Liss, Inc. [source] Time series analyses reveal transient relationships between abundance of larval anchovy and environmental variables in the coastal waters southwest of TaiwanFISHERIES OCEANOGRAPHY, Issue 2 2009CHIH-HAO HSIEH Abstract We investigated environmental effects on larval anchovy fluctuations (based on CPUE from 1980 to 2000) in the waters off southwestern Taiwan using advanced time series analyses, including the state-space approach to remove seasonality, wavelet analysis to investigate transient relationships, and stationary bootstrap to test correlation between time series. For large-scale environmental effects, we used the Southern Oscillation Index (SOI) to represent the El Niño Southern Oscillation (ENSO); for local hydrographic conditions, we used sea surface temperature (SST), river runoff, and mixing conditions. Whereas the anchovy catch consisted of a northern species (Engraulis japonicus) and two southern species (Encrasicholina heteroloba and Encrasicholina punctifer), the magnitude of the anchovy catch appeared to be mainly determined by the strength of Eng. japonicus (Japanese anchovy). The main factor that caused the interannual variation of anchovy CPUE might change through time. The CPUE showed a negative correlation with combination of water temperature and river runoff before 1987 and a positive correlation with river runoff after 1988. Whereas a significant negative correlation between CPUE and ENSOs existed, this correlation was driven completely by the low-frequency ENSO events and explained only 10% of the variance. Several previous studies on this population emphasized that the fluctuations of larval anchovy abundance were determined by local SST. Our analyses indicated that such a correlation was transient and simply reflected ENSO signals. Recent advances in physical oceanography around Taiwan showed that the ENSOs reduced the strength of the Asian monsoon and thus weakened the China Coastal Current toward Taiwan. The decline of larval anchovy during ENSO may be due to reduced China Coastal Current, which is important in facilitating the spawning migration of the Japanese anchovy. [source] ASARM-truncated MEPE and AC-100 enhance osteogenesis by promoting osteoprogenitor adhesionJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 9 2008Andrew P. Sprowson Abstract Matrix extracellular phosphoglycoprotein (MEPE) is a member of the SIBLING (Small Integrin-Binding Ligand, N-linked Glycoprotein) family of secreted glycophosphoproteins. Several previous studies have demonstrated that MEPE and its peptide motif, AC-100, may regulate bone mass and influence osteoblast activity, suggesting its potential for inclusion in novel therapeutic strategies aimed at increasing osteogenesis. Our study uses in vitro approaches to assess how adhesion of nonadherent cells is influenced by MEPE and whether response to MEPE is dependent on the maturity of osteoblastic cells. Truncated MEPE (ASARM removed) or AC-100 enhanced the adhesion, spreading, and focal complex formation of unadhered osteoblastic cells leading to increased differentiation and bone formation after 28 days of culture. Furthermore, addition of truncated MEPE or AC-100 to mature osteoblasts had no significant effect on bone formation. Our data supports an action for truncated MEPE and AC-100 in altering the physiology of immature poorly adherent cells which subsequently influences the way in which these cells interact with a substrate to facilitate their survival and/or commitment to the osteoblast lineage. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1256,1262, 2008 [source] Trabecular bone structure in the mandibular condyles of gouging and nongouging platyrrhine primatesAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2010Timothy M. Ryan Abstract The relationship between mandibular form and biomechanical function is a topic of significant interest to morphologists and paleontologists alike. Several previous studies have examined the morphology of the mandible in gouging and nongouging primates as a means of understanding the anatomical correlates of this feeding behavior. The goal of the current study was to quantify the trabecular bone structure of the mandibular condyle of gouging and nongouging primates to assess the functional morphology of the jaw in these animals. High-resolution computed tomography scan data were collected from the mandibles of five adult common marmosets (Callithrix jacchus), saddle-back tamarins (Saguinus fuscicollis), and squirrel monkeys (Saimiri sciureus), respectively, and various three-dimensional morphometric parameters were measured from the condylar trabecular bone. No significant differences were found among the taxa for most trabecular bone structural features. Importantly, no mechanically significant parameters, such as bone volume fraction and degree of anisotropy, were found to vary significantly between gouging and nongouging primates. The lack of significant differences in mechanically relevant structural parameters among these three platyrrhine taxa may suggest that gouging as a habitual dietary behavior does not involve significantly higher loads on the mandibular condyle than other masticatory behaviors. Alternatively, the similarities in trabecular architecture across these three taxa may indicate that trabecular bone is relatively unimportant mechanically in the condyle of these primates and therefore is functionally uninformative. Am J Phys Anthropol, 2010. © 2009 Wiley-Liss, Inc. [source] Virtual week and actual week: Age-related differences in prospective memoryAPPLIED COGNITIVE PSYCHOLOGY, Issue 7 2000Peter G. Rendell Several previous studies have shown that whereas young adults perform better than older adults on prospective memory (PM) tasks in the laboratory, this superiority is often reversed in real-life PM tasks. The present studies investigated this paradox by creating a laboratory task in the form of a board game (Virtual Week) that mimicked many features of daily living. It was hypothesized that older adults might use strategies derived from their more structured lives to outperform young adults on the board game. However, contrary to our prediction, it was found that younger adults were superior. In Experiment 2 we had participants perform very similar PM tasks in real life (Actual Week), and found that now the older adults were generally superior to their younger counterparts. Possible reasons are discussed for this striking age-related difference between laboratory-based and naturalistic PM tasks. Copyright © 2000 John Wiley & Sons, Ltd. [source] Using Penalized Splines to Model Age- and Season-of-Birth-Dependent Effects of Childhood Mortality Risk Factors in Rural Burkina FasoBIOMETRICAL JOURNAL, Issue 1 2009Heiko Becher Abstract Several previous studies have identified risk factors for childhood mortality in high risk areas, such as Sub-Saharan Africa. Among these are lifestyle factors related for example to nutrition or sanitation. Other factors are related to social class, ethnicity and poverty in general. Few studies have investigated a dependence of these factors by age and season of birth which is the focus in this study. We perform a survival analysis of 9121 children born between 1998 and 2001 in a rural area of western Burkina Faso. The whole population is under demographic surveillance since 1993. All cause mortality is used as the endpoint and follow-up information until the age of five years is available. Recently developed spline regression methods are used for the analysis. Ethnic group, religion, age of mother, twin status, sex, and distance to next health center are used as covariates all of which having a clear effect on survival in standard Cox regression analysis. With penalized spline regression, a more detailed risk pattern is observed. Ethnicity is more related to death at early age, as well as age of mother. The effect of the risk factors considered also appear to be related with season of birth (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Craniosynostosis and maternal smoking,BIRTH DEFECTS RESEARCH, Issue 2 2008Suzan L. Carmichael Abstract BACKGROUND: Several previous studies suggested increased risk of craniosynostosis among infants born to women who smoked. METHODS: This study used data from the National Birth Defects Prevention Study, a multi-state, population-based case-control study of infants delivered from 1997,2003. Nonmalformed, liveborn controls were selected randomly from birth certificates or birth hospitals. Data from maternal telephone interviews were available for 531 cases and 5008 controls. RESULTS: Smoking during the first month of pregnancy was not associated with craniosynostosis. Smoking later in pregnancy was associated with increased risk, but only among mothers who smoked at least one pack/day. For example, during the second trimester, the odds ratio for smoking <5 cigarettes/day was 1.0 (95% confidence interval [CI] 0.6, 1.8), but the odds ratio (OR) for smoking 15 or more cigarettes/day was 1.6 (95% CI 0.9, 2.8), after adjustment for maternal age, education, race-ethnicity, sub-fertility, parity, folic acid supplement intake, body mass index, and study center. Among women who did not smoke, adjusted odds ratios suggested that secondhand smoke exposure at home, but not at work/school, was associated with modestly increased risk; the OR for home exposure was 1.3 (95% CI 0.9, 1.9). Results followed a similar pattern for some, but not all, specific suture types, but numbers for some groupings were small. CONCLUSIONS: The results suggest moderately increased risk of craniosynostosis among mothers who were the heaviest smokers and who continued to smoke after the first trimester. Results are somewhat equivocal, given that most confidence intervals included one. Birth Defects Research (Part A), 2008. © 2007 Wiley-Liss, Inc. [source] Genome-wide amplification and allelotyping of sporadic pituitary adenomas identify novel regions of genetic lossGENES, CHROMOSOMES AND CANCER, Issue 3 2003D. J. Simpson Through the use of a candidate gene approach, several previous studies have identified loss of heterozygosity (LOH) at putative tumor-suppressor gene (TSG) loci in sporadic pituitary tumors. This study reports a genome-wide allelotyping by use of 122 microsatellite markers in a large cohort of tumors, consisting of somatotrophinomas and non-functioning adenomas. Samples were first subject to prior whole genome amplification by primer extension pre-amplification (PEP) to circumvent limitations imposed by insufficient DNA for whole-genome analysis with this number of microsatellite markers. The overall mean frequency of loss in invasive tumors was significantly higher than that in their non-invasive counterparts (7 vs. 3% somatotrophinomas; 6 vs. 3% non-functioning adenomas, respectively). Analysis of the mean frequency of LOH, across all markers to individual chromosomal arms, identified 13 chromosomal arms in somatotrophinomas and 10 in non-functioning tumors, with LOH greater than the 99% upper confidence interval calculated for the rate of overall random allelic loss. In the majority of cases, these losses were more frequent in invasive tumors than in their non-invasive counterparts, suggesting these to be markers of tumor progression. Other regions showed similar frequencies of LOH in both invasive and non-invasive tumors, implying these to be early changes in pituitary tumorigenesis. This genome-wide study also revealed chromosomal regions where losses were frequently associated with an individual marker, for example, chromosome arm 1q (LOH > 30%). In some cases, these losses were subtype-specific and were found at a higher frequency in invasive tumors than in their non-invasive counterparts. Identification of these regions of loss provides the first preliminary evidence for the location of novel putative TSGs involved in pituitary tumorigenesis that are, in some cases, subtype-specific. This investigation provides an unbiased estimate of global aberrations in sporadic pituitary tumors as assessed by LOH analysis. The identification of multiple "hotspots" throughout the genome may be a reflection of an unstable chromatin structure that is susceptible to a deletion or epigenetic-mediated gene-silencing events. © 2003 Wiley-Liss, Inc. [source] Variability and trends in the directional wave climate of the Southern HemisphereINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 4 2010Mark A. Hemer Abstract The effect of interannual climate variability and change on the historic, directional wave climate of the Southern Hemisphere is presented. Owing to a lack of in situ wave observations, wave climate in the Southern Hemisphere is determined from satellite altimetry and global ocean wave models. Altimeter data span the period 1985 to present, with the exception of a 2-year gap in 1989,1991. Interannual variability and trends in the significant wave height are determined from the satellite altimeter record (1991 to present), and the dominant modes of variability are identified using an empirical orthogonal function (EOF) analysis. Significant wave heights in the Southern Ocean are observed to show a strong positive correlation with the Southern Annular Mode (SAM), particularly during Austral autumn and winter months. Correlation between altimeter derived significant wave heights and the Southern Oscillation Index is observed in the Pacific basin, which is consistent with several previous studies. Variability and trends of the directional wave climate are determined using the ERA-40 Waves Re-analysis for the period 1980,2001. Significant wave height, mean wave period and mean wave direction data are used to describe the climate of the wave energy flux vector. An EOF analysis of the wave energy flux vector is carried out to determine the dominant modes of variability of the directional seasonal wave energy flux climate. The dominant mode of variability during autumn and winter months is strongly correlated to the SAM. There is an anti-clockwise rotation of wave direction with the southward intensification of the Southern Ocean storm belt associated with the SAM. Clockwise rotation of flux vectors is observed in the Western Pacific Ocean during El-Nino events. Directional variability of the wave energy flux in the Western Pacific Ocean has previously been shown to be of importance to sand transport along the south-eastern Australian margin, and the New Zealand region. The directional variability of the wave energy flux of the Southern Ocean associated with the SAM is expected to be of importance to the wave-driven currents responsible for the transport of sand along coastal margins in the Southern Hemisphere, in particular those on the Southern and Western coastal margins of the Australian continent. Copyright © 2009 Royal Meteorological Society [source] Preference for green packaging in consumer product choices , Do consumers care?INTERNATIONAL JOURNAL OF CONSUMER STUDIES, Issue 5 2008Joonas Rokka Abstract In this paper, consumer environmental choice is studied by analysing the relative importance of green packaging when compared with other relevant product attributes. The empirical study is based on a choice-based conjoint analysis of preferences for functional drink products of a sample of 330 consumers using these products. Our choice-based approach on environmental behaviour brings new insights to previous research, which predominantly relies on attitude models. Results indicate that consumers differ in their preferences for packaging, brand, price and convenience of use of daily products. In addition, various distinctive consumer segments can be identified on the market. Contrary to several previous studies, we found that the largest consumer segment, one-third of consumers, favoured environmentally labelled packaging as the most important criteria in their choice. The findings emphasize the increasing importance of ethical and environmental dimension in product choices. We also propose that the attention in environmental consumer research should be shifted from general attitude studies towards the study of actual product choices. [source] The net barter terms of trade: A smooth transition approachINTERNATIONAL JOURNAL OF FINANCE & ECONOMICS, Issue 1 2003Anna Persson Abstract This paper analyses the net barter terms of trade measured by the primary commodity price index relative to the indexes of unit values of export of manufactures from industrial countries. The starting point is that the series is stationary but possibly non-linear. Statistical tests indicate that the logarithmed series is non-linear and we estimate a Smooth Transition Autoregressive model to describe the process. The dynamics of the model are illustrated by use of parametrically estimated local spectra and generalized impulse response functions. Our model encompasses models from several previous studies, and our conclusion is that the starting point very much decides the outcome. Copyright © 2003 John Wiley & Sons, Ltd. [source] Fifteen years of Env C2V3C3 evolution in six individuals infected clonally with human immunodeficiency virus type 1JOURNAL OF MEDICAL VIROLOGY, Issue 11 2007Bernd Kupfer Abstract The study of the evolution of human immunodeficiency virus type 1 (HIV-1) requires blood samples collected longitudinally and data on the approximate time point of infection. Although these requirements were fulfilled in several previous studies, the infectious sources were either unknown or heterogeneous genetically. In the present study, HIV-1 env C2V3C3 (nt 7029-7315) evolution was examined retrospectively in a cohort of hemophiliacs. Compared to other cohorts, the area of interest here was the infection of six hemophiliacs by the same virus strain, that is, the infecting viruses shared an identical genome. As expected, divergence from the founder sequence as well as interpatient divergence of the predominant virus strains increased significantly over time. Based on the V3 nucleotide sequences, CCR5 usage was predicted exclusively throughout the whole period of infection in all patients. Interestingly, common patterns of viral evolution were detected in the patients of the cohort. Four amino acid substitutions within the V3 loop emerged and persisted subsequently in five (positions 305 and 308 of the HXB2 gp120 reference sequence) and six patients (positions 325 and 328 in HXB2 gp120), respectively. These common changes within the V3 loop are likely to be enforced by HIV-1 specific immune response. J. Med. Virol. 79:1729,1739, 2007. © 2007 Wiley-Liss, Inc. [source] Bone mass is preserved in a critical-sized osteotomy by low energy pulsed electromagnetic fields as quantitated by in vivo micro-computed tomographyJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2004Michael O. Ibiwoye Abstract The effectiveness of non-invasive pulsed electromagnetic fields (PEMF) on stimulating bone formation in vivo to augment fracture healing is still controversial, largely because of technical ambiguities in data interpretation within several previous studies. To address this uncertainty, we implemented a rigorously controlled, blinded protocol using a bilateral, mid-diaphyseal fibular osteotomy model in aged rats that achieved a non-union status within 3,4 weeks post-surgery. Bilateral osteotomies allowed delivery of a PEMF treatment protocol on one hind limb, with the contralateral limb representing a within-animal sham-treatment. Bone volumes in both PEMF-treated and sham-treated fibulae were assessed simultaneously in vivo using highly sensitive, high-resolution micro-computed tomography (,CT) over the course of treatment. We found a significant reduction in the amount of time-dependent bone volume loss in PEMF-treated, distal fibular segments as compared to their contralateral sham-treated bones. Osteotomy gap size was significantly smaller in hind limbs exposed to PEMF over sham-treatment. Therefore, our data demonstrate measurable biological consequences of PEMF exposure on in vivo bone tissue. © 2004 Orthopaedic Research Society. Published y Elsevier Ltd. All rights reserved. [source] The alignment between the distribution of satellites and the orientation of their central galaxyMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2006Xiaohu Yang ABSTRACT We use galaxy groups selected from the Sloan Digital Sky Survey to examine the alignment between the orientation of the central galaxy (defined as the brightest group member) and the distribution of satellite galaxies. By construction, we therefore only address the alignment on scales smaller than the halo virial radius. We find a highly significant alignment of satellites with the major axis of their central galaxy. This is in qualitative agreement with the recent study of Brainerd, but inconsistent with several previous studies who detected a preferential minor-axis alignment. The alignment strength in our sample is strongest between red central galaxies and red satellites. On the contrary, the satellite distribution in systems with a blue central galaxy is consistent with isotropic. We also find that the alignment strength is stronger in more massive haloes and at smaller projected radii from the central galaxy. In addition, there is a weak indication that fainter (relative to the central galaxy) satellites are more strongly aligned. We present a detailed comparison with previous studies, and discuss the implications of our findings for galaxy formation. [source] Clinical response of patients with sickle cell anemia to cromolyn sodium nasal sprayAMERICAN JOURNAL OF HEMATOLOGY, Issue 11 2006Mehran Karimi Abstract Sickle cell anemia is the most common heritable hematological disease affecting humans. Although hydroxyurea is the most commonly used antisickling agent, several previous studies suggest that cromolyn sodium also prevents sickling when administered acutely. However, no previous studies have evaluated the safety or efficacy of prolonged administration of cromolyn to patients with sickle cell anemia. The purpose of this study, therefore, was to test the hypothesis that prolonged administration of cromolyn alone or in combination with hydroxyurea would decrease the incidence of pain crises and/or alter the chronic pain seen in patients with this disease. In this crossover, single-blind, in vivo and in vitro study, 17 patients with sickle cell disease were studied. Each patient had to fill out a standard pain chart. Every 3 months the patients' medications changed in the following manner: The first 3 months the patients used cromolyn sodium nasal spray; the second 3 months they received placebo nasal spray; the third 3 months they received cromolyn sodium nasal spray and hydroxyurea capsule; and the last 3 months they received hydroxyurea capsule and placebo nasal spray. The least pain was felt with the mixture of hydroxyurea capsule and cromolyn sodium nasal inhaler. Furthermore, with the other combinations of medications, there were no significant statistical changes in the number of sickled red blood cells. Every combination used in this survey had positive effects on decreasing the pain. cromolyn sodium nasal spray is significantly efficient in decreasing sickle cell crisis as well as pain intensity in patients with sickle cell anemia. Am. J. Hematol., 2006. © 2006 Wiley-Liss, Inc. [source] An Improved Algorithm for Satellite-derived UV Radiation,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 1 2003Sigrid Wuttke ABSTRACT The improved algorithm surface irradiance derived from a range of satellite-based sensors (SIDES) is presented in this article. It calculates various types of surface UV intensities, such as biologically weighted or unweighted UV spectra, integrated doses or irradiance at specific wavelengths, using data from satellite instruments. These surface UV data are mainly useful for environmental impact or process studies where high accuracy or a high temporal resolution is required. In contrast to several previous studies, SIDES has been validated with spectral measurements. By this method an averaging of positive or negative deviations over the complete wavelength range is avoided. This is especially important for UV wavelengths around 300 nm where biological effectiveness is highest. The results of SIDES deviate less than 7% from ground-based observations for wavelengths between 295 and 400 nm. In contrast, the corresponding deviations of the joint research center algorithm escalate for shorter wavelengths, reaching 35% at 295 nm. This large deviation is due to an inaccurate interpolation procedure that has been detected by spectral analysis. Thus, spectral validation is demonstrated to be an appropriate tool to detect weaknesses in such an algorithm and provides information essential for improvement. [source] Occupation and multiple myeloma: An occupation and industry analysisAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 8 2010Laura S. Gold PhD Abstract Background Multiple myeloma (MM) is an incurable plasma cell malignancy with a poorly understood etiology. The purpose of our research was to examine the relationships between lifetime occupations and MM in a relatively large case,control study. Methods MM cases (n,=,180) were identified through cancer registries in the Seattle-Puget Sound area and Detroit. Population-based controls (n,=,481) were identified using random digit dialing and Medicare and Medicaid Services files. In-person interviews were conducted to ascertain occupational histories. Standard occupational classification (SOC) and standard industrial classification (SIC) codes were assigned to each job held by each participant. Unconditional logistic regression was used to generate odds ratios (ORs) and 95% confidence intervals (CIs) for associations between MM and having ever worked in each occupation/industry and according to duration of employment in an occupation/industry. Results The risk of MM was associated with several manufacturing occupations and industries, including machine operators and tenders, not elsewhere classified (SOC 76) (OR,=,1.8, CI,=,1.0,3.3); textile, apparel, and furnishing machine operators and tenders (SOC 765) (OR,=,6.0, CI,=,1.7,21); and machinery manufacturing, except electrical (SIC 35) (OR,=,3.3, CI,=,1.7,6.7). Several service occupations and industries, such as food and beverage preparation (SOC 521) (OR,=,2.0, CI,=,1.1,3.8), were also associated with MM. One occupation that has been associated with MM in several previous studies, painters, paperhangers, and plasterers (SOC 644) was associated with a non-significantly elevated risk (OR,=,3.6, CI,=,0.7,19). Conclusions We found associations between the risk of MM and employment in several manufacturing and service-related occupations and industries. Am. J. Ind. Med. 53:768,779, 2010. © 2010 Wiley-Liss, Inc. [source] The Sensitivity of Canadian Corporate Investment to LiquidityCANADIAN JOURNAL OF ADMINISTRATIVE SCIENCES, Issue 3 2000Sean Cleary This study examines the investment behaviour of 201 Canadian firms over the 1987-94 period and confirms that liquidity is a significant determinant of Canadian corporate investment. Contrary to recent US evidence, the investment-liquidity sensitivity of financially constrained firms is not found to be significantly different from that of unconstrained firms. Surprisingly, partially constrained firms exhibit higher investment-liquidity sensitivity than both constrained and unconstrained firms. The difference from the US results is attributed to the industry structure and closely held nature of Canadian firms. Finally, this study highlights the importance of sample size by demonstrating how sensitive the results can be to the behaviour of a small number of firms. This represents an important observation, since the conclusions of several previous studies are based on small sample results. Résumé Cette étude passe en revue la gestion des investissements de 201 sociétés canadiennes durant les années 1987-94 et confirme que, en ce qui concerne le milieu d'affaires canadien, la liquidité est un facteur important dans la mise de fonds. Contrairement aux données récentes provenant des EU, l'importance de la liquidité des placements chez les maisons de commerce sous con-traintes fiscales ne s'avère pas ,tre très différente de celle chez les maisons sans pareilles contraintes. De façon surprenante, les maisons sous contraintes fiscales partielles démontrent une sensibilité plus accrue à la liquidité des placements que les maisons davantage contraintes, ou encore sans aucune contrainte. L'écart entre ces données et celles provenant des EU s'explique en fonction de l'organisation industrielle et de la plus haute concentration des actionnaires dans les maisons de commerce canadiennes. Enfin, cette étude souligne l'importance de l'ampleur de l'échantillonage en démontrant à quel point les données peuvent varier en fonction d'un nombre restraint de maisons de commerce. Etant donné que les conclusions de plusieurs études précédentes étaient tirées d'échantillonages plus restreints, cette observation gagne en portée. [source] | |||||||||||||||||||