Period Of Relative Stability Research Articles

Acute Exacerbations of Idiopathic Pulmonary Fibrosis

The natural history of idiopathic pulmonary fibrosis (IPF) has been characterized as a steady, predictable decline in lung function over time. Recent evidence suggests that some patients may experience a more precipitous course, with periods of relative stability followed by acute deteriorations in respiratory status. Many of these acute deteriorations are of unknown etiology and have been termed acute exacerbations of IPF. This perspective is the result of an international effort to summarize the current state of knowledge regarding acute exacerbations of IPF. Acute exacerbations of IPF are defined as acute, clinically significant deteriorations of unidentifiable cause in patients with underlying IPF. Proposed diagnostic criteria include subjective worsening over 30 days or less, new bilateral radiographic opacities, and the absence of infection or another identifiable etiology. The potential pathobiological roles of infection, disordered cell biology, coagulation, and genetics are discussed, and future research directions are proposed.

A Diagnostic Verification of the Precipitation Forecasts Produced by the Canadian Ensemble Prediction System.

A comparatively long period of relative stability in the evolution of the Canadian Ensemble Forecast System was exploited to compile a large homogeneous set of precipitation forecasts. The probability of exceedance of a given threshold was computed as the fraction of ensemble member forecasts surpassing that threshold, and verified directly against observations from 36 stations across the country. These forecasts were stratified into warm and cool seasons and assessed against the observations through attributes diagrams, Brier skill scores, and areas under receiver operating characteristic curves. These measures were deemed sufficient to illuminate the salient features of a forecast system. Particular attention was paid to forecasts of 24-h accumulation, especially the exceedance of thresholds in the upper decile of station climates. The ability of the system to forecast extended dry periods was also explored. Warm season forecasts for the 90th percentile threshold were found to be competitive with, even superior to, those for the cool season when verifying across the sample lumping together all of the stations. The relative skill of the forecasts in the two seasons depends strongly on station location, however. Moreover, the skill of the warm season forecasts rapidly drops below cool season values as the thresholds become more extreme. The verification, particularly of the cool season, is sensitive to the calibration of the gauge reports, which is complicated by the inclusion of snow events in the observational record.

Beyond Achievement: Entrepreneurship as Extreme Experience

How do entrepreneurs experience entrepreneurship, and what are the implications? The cognitive and emotional experiences of the entrepreneur as he/she performs the tasks associated with venture creation and high growth have received limited attention from researchers. The entrepreneurial context can be characterized in terms of peaks and valleys, or periods of relatively high pressure, stress, uncertainty, and ambiguity and periods of relative stability and predictability. Three inter-related psychological variables are investigated to determine their applicability in an entrepreneurial context: peak performance, peak experience, and flow. Results are reported of a series of in-depth, structured interviews conducted with two samples of entrepreneurs. Both qualitative and quantitative evidence is provided of the relevance of all three variables to entrepreneurs, with the highest scores for each variable demonstrated by entrepreneurs in high growth ventures. A number of implications are drawn for ongoing research and entrepreneurial practice, most notably in the area of entrepreneurial motivation. The findings suggest that entrepreneurship be approached as a vehicle for optimal human experiencing.

Bistability of atmospheric oxygen and the Great Oxidation

The history of the Earth has been characterized by a series of major transitions separated by long periods of relative stability. The largest chemical transition was the 'Great Oxidation', approximately 2.4 billion years ago, when atmospheric oxygen concentrations rose from less than 10(-5) of the present atmospheric level (PAL) to more than 0.01 PAL, and possibly to more than 0.1 PAL. This transition took place long after oxygenic photosynthesis is thought to have evolved, but the causes of this delay and of the Great Oxidation itself remain uncertain. Here we show that the origin of oxygenic photosynthesis gave rise to two simultaneously stable steady states for atmospheric oxygen. The existence of a low-oxygen (less than 10(-5) PAL) steady state explains how a reducing atmosphere persisted for at least 300 million years after the onset of oxygenic photosynthesis. The Great Oxidation can be understood as a switch to the high-oxygen (more than 5 x 10(-3) PAL) steady state. The bistability arises because ultraviolet shielding of the troposphere by ozone becomes effective once oxygen levels exceed 10(-5) PAL, causing a nonlinear increase in the lifetime of atmospheric oxygen. Our results indicate that the existence of oxygenic photosynthesis is not a sufficient condition for either an oxygen-rich atmosphere or the presence of an ozone layer, which has implications for detecting life on other planets using atmospheric analysis and for the evolution of multicellular life.

Maximizing Organ Donation Opportunities Through Donation After Cardiac Death

John Edwards is the clinical administrator for Gift of Life Donor Program in Philadelphia, Pa, overseeing all clinical aspects of organ and tissue recovery, and a faculty member for the Gift of Life Institute, Philadelphia, providing training and mentoring for healthcare organizations nationally. Patti Mulvania oversees the clinical education program for the Gift of Life Donor Program in Philadelphia and is a faculty member of the Gift of Life Institute, specializing in consent and clinical communication. Virginia Robertson is the associate director of the Gift of Life Institute in Philadelphia. Formerly, she was the director of hospital services for the Gift of Life Donor Program. Gweneth George is the director of hospital services for the Gift of Life Donor Program in Philadelphia. She directs a team of nearly 20 hospital development staff accountable for donation performance in 150 acute care hospitals. Richard Hasz is vice president of clinical services for the Gift of Life Donor Program in Philadelphia. He oversees the day-to-day clinical operations, including transplant coordination, hospital development, organ preservation, and tissue recovery. Howard Nathan is president and chief executive officer of the Gift of Life Donor Program in Philadelphia. The program has been involved in coordinating more than 22 000 organ transplantations and tens of thousands of tissue transplantations since 1974.

Systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a clinically heterogeneous disease, which is autoimmune in origin and is characterized by the presence of autoantibodies directed against nuclear antigens. It is a multi-system disease, and patients can present in vastly different ways. Prevalence varies with ethnicity, but is estimated to be about 1 per 1000 overall with a female to male ratio of 10:1. The clinical heterogeneity of this disease mirrors its complex aetiopathogenesis, which highlights the importance of genetic factors and individual susceptibility to environmental factors. SLE can affect every organ in the body. The most common manifestations include rash, arthritis and fatigue. At the more severe end of the spectrum, SLE can cause nephritis, neurological problems, anaemia and thrombocytopaenia. Over 90% of patients with SLE have positive anti-nuclear antibodies (ANA). Significant titres are accepted to be of 1:80 or greater. SLE is a relapsing and remitting disease, and treatment aims are threefold: managing acute periods of potentially life-threatening ill health, minimizing the risk of flares during periods of relative stability, and controlling the less life-threatening, but often incapacitating day to day symptoms. Hydroxychloroquine and non-steroidal anti-inflammatory drugs are used for milder disease; corticosteroids and immunosuppressive therapies are generally reserved for major organ involvement; anti-CD20 monoclonal antibody is now used in patients with severe disease who has not responded to conventional treatments. Despite enormous improvements in prognosis since the introduction of corticosteroids and immunosuppressive drugs, SLE continues to have a significant impact on the mortality and morbidity of those affected.

A review of coal mining induced fault reactivation in Great Britain

Fault reactivation has been observed at several locations in almost every British coalfield. The movement of faults during mining subsidence has been known for at least 150 years, but the affects and consequences are not widely appreciated by other geologists, engineers, insurers, builders, lawyers and planners. This has lead to widespread damage to land, houses, roads, railways, engineered structures (bridges, tunnels, dams), utilities (sewers, pipelines, cables). Disputed cases of fault reactivation have resulted in lands tribunals and claims for compensation for damage to land and property, often incurring significant financial losses. These sources of data on fault reactivation includes anecdotal accounts, archive information and detailed case examples supported with surveying observations. The reactivation of a fault in an area undergoing mining subsidence may result in the generation of a fault scarp along the ground surface, accompanied by compression or fissuring. Ground deformation caused by reactivated faults varies from subtle flexures across the ground surface to steeply inclined scarps, 3–4 m high and at least 4 km long. In the latter, this may influence the morphology of an entire moorland plateaux and has a contributory role in groundwater flow and the drainage of the landscape, or the initiation (and reactivation) of landslides. Not all types of faults reactivate when subject to mining subsidence stresses. Furthermore, movement along faults does not continue indefinitely. It is usually the principal faults which cross the coalfields and define structural blocks and cells that are more prone to reactivation. Several phases of fault reactivation are possible, during multi-seam (3+) mining operations, separated by periods of relative stability. In some circumstances, such as minewater rebound or residual mining subsidence, further movements along a previously reactivated fault are possible. The objectives of this paper are to provide, for the first time, a comprehensive account of reported and recorded cases of mining-induced fault reactivation in Britain. These have been compiled over a 15 years period, from 1990 to 2005. There are 227 recorded cases of fault reactivation and this is thought to represents a large under estimation of the actual number. This may be attributed to a relatively poor understanding of geology and fault reactivation mechanisms by past investigators. There was a tendency to ignore fault reactivation cases to reduce mining subsidence compensation claims. Furthermore, relatively fewer investigations were undertaken compared to the more conventional widespread mining subsidence observations. Many cases of fault reactivation have been undocumented, not recorded or incorrectly interpreted. This paper also aims to draw attention to potential geotechnical hazards, liabilities, risks and consequences associated with faulted ground.

Negotiating Compliance in Heart Failure: Remaining Issues and Questions

Living with heart failure (HF) means living with a chronic illness characterized by periods of acute decompensation alternating with periods of relative stability. Improved medical care for patients with cardiovascular diseases, coupled with the aging of the populations in the developed world, has resulted in a steadily increasing prevalence of HF. Rehospitalization rates are high for this patient population. In 20-64% of the cases, poor compliance by patients with the prescribed HF treatment is a contributing factor to hospitalization. This article uses a review of the literature on HF non-compliance, including the prevalence, barriers, consequences, and the long-term outcomes of non-compliance with HF therapy, to illustrate remaining issues and questions. Original studies published in English or German between 1966 and June 2004 identified by combining patient compliance, non-compliance, adherence, self-care, rehospitalization, patient education, and management programs, with heart failure in the search strategy are included. Creative approaches to achieving a true partnership between providers and patients are needed if clinical outcomes are to improve.

Urinary Incontinence in Japanese Women with Chronic Obstructive Pulmonary Disease: Review

The relationship between urinary incontinence and chronic obstructive pulmonary disease (COPD) among Japanese women is reviewed. The prevalence of COPD is increasing because of the aging population and the high rate of cigarette consumption. The prevalence of COPD in Japan was 16.4% for males and 5% for females aged 40 years and above in 2000. COPD is a progressive disease, which can have periods of relative stability but readily regresses. Its characteristic symptoms include cough, sputum production, dyspnoea and frequently urinary incontinence. The persistent cough of COPD increases intra-abdominal pressure and results in increased rates of urinary incontinence especially for female patients. The prevalence of urinary incontinence among Japanese women with chronic lung disease varies between 30.4% and 68%, which is higher than those of the general population (25-56.9%) and outpatient clients attending gynaecology clinics (27-31%). However, there is no published report specifically on the prevalence of urinary incontinence among Japanese women with COPD. As COPD is one of the causes of urinary incontinence, the obvious prevention strategy is tobacco control and early detection using screening tests. Urinary incontinence should be identified and dealt with in order to improve the quality of life for COPD patients.

Cindy Forster,The Time of Freedom: Campesino Workers in Guatemala's October Revolution. Pittsburgh: University of Pittsburgh Press, 2001. xi + 287 pp. $32.95 cloth; 19.95 paper.

Forster's work in The Time of Freedom is a worthy contribution to scholarship on collective behavior in Latin America. The work appears largely intended to provide a narrative account of peasant organizing in a specific locale; however, the work implicitly incorporates a more comprehensive theory about bottom-up collective action. The account of bottom-up collective action given by the author is really one of contentious politics involving the simultaneous dynamics of four key groups: rural indigenous, rural ladinos, large landowners, and politicians. The movement is contentious for two reasons. First, the social movement arises from a previous period of relative stability, although under a dictatorship, and it incurs a significant change in elite political ideology. Second, the time frame spans about ten years, from the fall of Ubico in 1944 to the fall of Arbenz in 1954. The author leads the reader through the three stages of initial formation, mass action, and demobilization. The author's account of the 1944 Guatemalan Revolution challenges the traditional interpretation of hierarchical initiation. Historical accounts of the 1944 Revolution portray it as urban in its locale and middle-class in its support. Ignoring the rural indigenous and ladinos leaves a chasm in the understanding of contemporary Guatemalan history and politics. This is of particular importance in understanding the movement towards violence that followed from the failure to institutionalize the hard-earned gains of the collective movement.

Freight rates and productivity gains in British tramp shipping 1869–1950

The standard source for pre-WWII global freight rate trends is the Isserliss index. We think it is time for a new look at his British tramp shipping index, especially given his sources offer vastly more information than Isserliss used. Our new estimates confirm the precipitous decline in real freight rates before World War I, but we also extend them to 1997, a long period of relative stability. In an effort to identify the contribution of transport revolutions to global commodity price convergence, we create route-specific deflators, rather than relying on the Sauerbeck index. Finally, using the price-dual and new factor price indices, we calculate total factor productivity growth for five global routes, and then identify the sources of productivity growth along them.

Volatility in World Equity Markets

Past research suggests that US stock market volatility was greater during the 1930s than in any other 10-year time period and the post-WWII era is a period of relative stability, despite slightly higher volatility levels during the 1970s and 1980s. More recent evidence suggests that volatility levels from 1998 to 2001 have more in common with 1930s levels than with any other time period. We extend this body of research to include the volatility experiences of seven equity markets in the US, Europe, and Asia. For each market, we compare the average monthly volatility of each five-year period, beginning with January 1923, with that for the most recent period in the study, January 1998 to August 2001. We find that when there are statistical differences between current and past levels of volatility, recent volatility is usually significantly greater than past volatility. In only a small number of cases do we find current volatility to be less than past volatility. This suggests that the 1998–2001 period was unusually volatile for most markets examined. We also find that volatility behavior tends to be country-specific and cannot be generalized on an aggregate basis.

Lake sediments record large-scale shifts in moisture regimes across the northern prairies of North America during the past two millennia.

Six high-resolution climatic reconstructions, based on diatom analyses from lake sediment cores from the northern prairies of North America, show that shifts in drought conditions on decadal through multicentennial scales have prevailed in this region for at least the last two millennia. The predominant broad-scale pattern seen at all sites is a major shift in moisture regimes from wet to dry, or vice versa (depending on location), that occurred after a period of relative stability. These large-scale shifts at the different sites exhibit spatial coherence at regional scales. The three Canadian sites record this abrupt shift between anno Domini 500 and 800, and subsequently conditions become increasingly variable. All three U.S. sites underwent a pronounced change, but the timing of this change is between anno Domini 1000 and 1300, thus later than in all of the Canadian sites. The mechanisms behind these patterns are poorly understood, but they are likely related to changes in the shape and location of the jet stream and associated storm tracks. If the patterns seen at these sites are representative of the region, this observed pattern can have huge implications for future water availability in this region.

On nystagmus, saccades, and fixations.

Investigations of the ways in which the eyes move came to prominence in the 19th century, but techniques for measuring them more precisely emerged in the 20th century. When scanning a scene or text the eyes engage in periods of relative stability (fixations) interspersed with ballistic rotations (saccades). The saccade-and-fixate strategy, associated with voluntary eye movements, was first uncovered in the context of involuntary eye movements following body rotation. This pattern of eye movements is now referred to as nystagmus, and involves periods of slow eye movements, during which objects are visible, and rapid returns, when they are not; it is based on a vestibular reflex which attempts to achieve image stabilisation. Post-rotational nystagmus was reported in the late 18th century (by Wells), with afterimages used as a means of retinal stabilisation to distinguish between movement of the eyes and of the environment. Nystagmus was linked to vestibular stimulation in the 19th century, and Mach, Breuer, and Crum Brown all described its fast and slow phases. Wells and Breuer proposed that there was no visual awareness during the ballistic phase (saccadic suppression). The saccade-and-fixate strategy highlighted by studies of nystagmus was shown to apply to tasks like reading by Dodge, who used more sophisticated photographic techniques to examine oculomotor kinematics. The relationship between eye movements and perception, following earlier intuitions by Wells and Breuer, was explored by Dodge, and has been of fundamental importance in the direction of vision research over the last century.

Joined-up Government in Practice: A Case Study of Children's Needs in Sheffield

'Joined-up government' has been a policy thrust characterising much of the first term of the Labour government. The last four years have seen a flourish of area-based and local partnership initiatives. Information and IT are seen as crucial to facilitate joined-up government and improved service delivery at both central and local level. Ambitious targets are thus set to make all dealings with government deliverable electronically by 2005. This article examines data sharing in a local partnership, using as an example the preparation of the Children's Service Plan 2000-2003 in the city of Sheffield, setting out the national policy background, with particular reference to children's services plans; introducing the project; discussing the results obtained in the data collection exercise, and concluding that the organisational and cultural change necessary to share information effectively require time, and above all a period of relative stability to mature and take hold.

One­hundred­year code déjà vu?

The approach to next international botanical congress, to be held in Vienna in 2005, is curiously similar to that (100 years earlier) leading into Vienna Congress of 1905. Entering 1905 Vienna Congress, four competing codes were in use--the De Candollean, Kew, Berlin, and (Weatherby, 1949). A strong presence in background at 1905 congress was Otto Kuntze, with his penchant for changes (Smith, 1957), potentially impacting nomenclatural stability. Issues considered at 1905 congress were: type method; use of descriptive Latin; how strict priority should be, and relatedly, a proposal to conserve certain names. From 1905 congress, first set of internationally codified rules was established, which included acceptance of a list of conserved generic names (Nicolson, 2000). Competing codes were not eliminated as a result of 1905 congress, however, but were reduced to two (Weatherby, 1949)-the International Rules (arising basically out of Candollean system) and American Code. Most European taxonomists were unwilling to accept type method, rigid views on priority, or laxity toward use of Latin, supported by American contingent. Through conciliatory efforts, e.g., Hitchcock (1925), agreement on adopting type method for application of names, and on requiring Latin diagnoses for new taxa, was achieved in Cambridge Congress in 1930; Latin requirement did not actually take effect until 1 January, 1935. Botanical congresses since Cambridge, 1930, have not produced such major substantive changes in pursuant editions of botanical code. In spite of rumblings after Yokohama Congress, 1993, regarding adoption of lists and like, deliberations of St. Louis Congress, 1999, led to little significant change in document. There has, thus, been a more than 70year period of relative stability. However, as we approach Vienna Congress, 2005, it appears that taxonomists will again be facing (much as in Vienna Congress of 1905) real possibility of intrusion of several, potentially competitive codes and/or strongly conflicting ideas, each with respective advocates. The codes or putative codes which could significantly affect botanical nomenclature are: International Code of Botanical Nomenclature (ICBN); International Code of Nomenclature for Cultivated Plants (ICNCP; Trehane & al., 1995), this cultivated code not being competitive against ICBN; PhyloCode; and BioCode. And, now waiting in background is, not Otto Kuntze, but seemingly ever-present urgings for adoption of vetted lists (Hawksworth, 2000; McNeill, 2000). The specter of major alterations of rules, looming again in 2005, as in 1905, pointedly reifies popular expression, the more things change, more they stay same. Of particular concern at this time are implications of implementation of a PhyloCode. The work of de Queiroz & Gauthier (1990, 1994), de Queiroz (1997) and Cantino & al. (1997) led to perception of a need to translate phylogenetic principles directly into nomenclatural practice. Their methodology would apply names to clades, not ranks, and would provide phylogenetic definitions of such names (Stuessy, 2000, 2001, has questioned name definition). Concepts of phylogenetic nomenclature have been merged with, or melded into, present push for rank-free classification and PhyloCode (cf. Hibbett & Donoghue, 1998; Mishler, 2000; Langer, 2001); all of this is based on belief that attempting to prosecute phylogenetic work under Linnaean (and Hennigian) classification proliferate a cumbersome list of names according to rank, putatively anathema to phylogenetic progress; many such names, it is felt, would later have to be disbanded or changed. Though some workers are possibly loath to admit it, unwanted changes now relate to differing results obtained, on same group of organisms, using different types of molecular data and/or different computational methodologies (cf. Daugbjerg & Andersen, 1997; Marshall, 1997; Maley & Marshall, 1998; Waddell & al., 1999). Precepts of phylogenetic nomenclature and rankless systems are embodied in current internet posting of developing PhyloCode (http://www.ohiou.edu/phylocode/). Text accompanying PhyloCode states that it may be used concurrently with existing codes based on Linnaean nomenclature, implication being that PhyloCode is a document which offer taxonomists additional nomenclatural benefit. However, also stated is

Interpretation of trends in acidic deposition and surface water chemistry in Scotland during the past three decades

Abstract. Trends in major ionic components of bulk precipitation were analysed for two sites, Faskally and Loch Ard forest in Scotland, for the period 1972-2000. The pattern of change was not linear. Large reductions in sulphur deposition occurred in the early 1980s and, to a lesser extent, during 1995-2000, with a period of relative stability between 1988-95. pH increased significantly at both sites but nitrate and ammonia only increased significantly at Loch Ard forest. Long-term chemical data from a total of 37 streams and lochs in four selected regions of Scotland were analysed over three time periods (all available data (mostly 1978-2000), 1988-98 and 1995-2000) to match the deposition patterns. For the whole study period a significant decline in non-marine sulphate was found at all sites while the most consistent increases in pH and alkalinity were recorded at all the high elevation loch sites in the Galloway area. Significant reductions in toxic forms of aluminium were also recorded, mostly at sites where pH had increased. Nitrate trends were equivocal except for catchments with clear-felling operations. For these sites, negative trends were found where felling occurred in the 1980s, while positive trends were found at sites with felling in the 1990s. With the exception of one site, dissolved organic carbon concentrations increased significantly with moorland sites showing smaller increases than forested sites. Associated with this change was a significant increase in complexed forms of aluminium. Trends for the 1988-98 period were much smaller than those for the whole study period and in many cases were insignificant. This contrasts with the 1995-2000 period when large and significant reductions in sulphate and nitrate were recorded along with increases in marine salts, probably as a result of climatically related events. Qualitative, experimental and monitoring data from lochs in the Galloway area revealed evidence of recovery of fish populations. Interpretation of chemical and biological trends was clearly influenced by the choice of the time series, especially in relation to deposition and climatic changes. Nevertheless, all the fresh waters included in this study are currently in the best ecological condition since the 1970s in the context of recovery from acidification. Keywords: deposition, trends, acidification, forestry, recovery, fish, climate

The impact of margins in futures markets: evidence from the gold and silver markets

This paper investigates the impact of margin requirements on the trading activity in the gold and silver futures markets. We extend prior research in at least two ways. First, we examine the role of time to contract-expiration in the relationship between margin levels and trading activity. We make the case that such an examination will reveal the nature of the costs that margins impose on futures traders. Second, we examine the impact margins have on the makeup of traders in futures markets. The evidence indicates that trading activity becomes more sensitive to margin changes as one gets closer to contract maturity, consistent with the notion that margins impose important transaction (rather than opportunity) costs on futures traders. Further to this evidence, we find that speculators and small traders, typically illiquid, are especially sensitive to margins. The data also indicate that margins are likely to be hiked following periods of increased volatility, and reduced following periods of relative stability, suggesting that margin alterations primarily serve as insurance to the futures exchanges.

Tectonic and mining induced fault reactivation around Barlaston on the Midlands Microcraton, North Staffordshire, UK

The North Staffordshire Coalfield occupies the northern apex of a triangular area of late Proterozoic continental crust, the Midlands Microcraton. Most faults identified at surface in the late Carboniferous rocks originated either as a result of reactivation of structure during the Variscan orogen in the late Carboniferous, or its collapse in the early Permian. The coalfield has been extensively undermined and many examples of mining-induced fault movement have been recorded in the Barlaston area between 1960–2000. The style of ground deformation observed in the area is described. Most movements have resulted in a series of distinct, extensive, fault scarps and fissures on the ground surface, causing widespread damage to structures, property, underground utilities and land. Several phases of fault movement have occurred, separated by periods of relative stability. Fault scarps may occasionally reach 2 m high, being indicative of multi-seam (3+) mining operations. These are restricted to a few metres in width but reach several hundreds of metres in length. The reasons why so many faults have been reactivated around Barlaston, why the surface expression of the faults are different in Carboniferous and Triassic outcrops, and why some faults appear to have reactivated since the cessation of mining are discussed.

The Dynamics of Alignment: Insights from a Punctuated Equilibrium Model

Several prior articles have emphasized the importance of alignment between business and information system (IS) strategies, and between business and IS structures. Seeking to advance our understanding of alignment, we examine the dynamics of changes in alignment through strategy/structure interactions in the business and IS domains. More specifically, we address the following question: In what ways does alignment evolve over time? Changes in the strategic IS management profile (which includes business strategy, IS strategy, business structure, and IS structure) over time are examined using a punctuated equilibrium model, involving long periods of relative stability, or evolutionary change, interrupted by short periods of quick and extensive, or revolutionary, change. Case studies of changes in business and IS strategies and structure over long time periods in three organizations suggest that the punctuated equilibrium model provides a valuable perspective for viewing these dynamics. The cases suggest that a pattern of alignment may continue over a long period, because either the level of alignment is high or the managers do not recognize the low alignment as a problem. Revolutions, involving changes in most or all dimensions of the strategic IS management profile, interrupt the evolutionary changes. However, organizations hesitate to make such revolutionary changes in strategic IS management profiles. Complete revolutions apparently require a combination of strong triggers. Finally, post-revolution adjustments to one dimension of the strategic IS management profile seem to follow revolutionary changes.