Showing papers by "University of Alberta published in 2001"

Forecasting agriculturally driven global environmental change

Abstract: During the next 50 years, which is likely to be the final period of rapid agricultural expansion, demand for food by a wealthier and 50% larger global population will be a major driver of global environmental change. Should past dependences of the global environmental impacts of agriculture on human population and consumption continue, 10(9) hectares of natural ecosystems would be converted to agriculture by 2050. This would be accompanied by 2.4- to 2.7-fold increases in nitrogen- and phosphorus-driven eutrophication of terrestrial, freshwater, and near-shore marine ecosystems, and comparable increases in pesticide use. This eutrophication and habitat destruction would cause unprecedented ecosystem simplification, loss of ecosystem services, and species extinctions. Significant scientific advances and regulatory, technological, and policy changes are needed to control the environmental impacts of agricultural expansion.

Critical thinking, cognitive presence, and computer conferencing in distance education

Abstract: This article describes a practical approach to judging the nature and quality of critical discourse in a computer conference. A model of a critical community of inquiry frames the research. A core concept in defining a community of inquiry is cognitive presence. In turn, the practical inquiry model operationalizes cognitive presence for the purpose of developing a tool to assess critical discourse and reflection. The authors present encouraging empirical findings related to an attempt to create an efficient and reliable instrument to assess the nature and quality of critical discourse and thinking in a text‐based educational context. Finally, the authors suggest that cognitive presence (i.e., critical, practical inquiry) can be created and supported in a computer‐conference environment with appropriate teaching and social presence.

Cultural Entrepreneurship: Stories, Legitimacy and the Acquisition of Resources

Abstract: We define cultural entrepreneurship as the process of storytelling that mediates between extant stocks of entrepreneurial resources and subsequent capital acquisition and wealth creation. We propose a framework that focuses on how entrepreneurial stories facilitate the crafting of a new venture identity that serves as a touchstone upon which legitimacy may be conferred by investors, competitors, and consumers, opening up access to new capital and market opportunities. Stories help create competitive advantage for entrepreneurs through focal content shaped by two key forms of entrepreneurial capital: firm-specific resource capital and industry-level institutional capital. We illustrate our ideas with anecdotal entrepreneurial stories that range from contemporary high technology accounts to the evolution of the mutual fund industry. Propositions are offered to guide future empirical research based on our framework. Theoretically, we aim to extend recent efforts to synthesize strategic and institutional perspectives by incorporating insights from contemporary approaches to culture and organizational identity.

Nurses’ Reports On Hospital Care In Five Countries

Abstract: The current nursing shortage, high hospital nurse job dissatisfaction, and reports of uneven quality of hospital care are not uniquely American phenomena. This paper presents reports from 43,000 nurses from more than 700 hospitals in the United States, Canada, England, Scotland, and Germany in 1998-1999. Nurses in countries with distinctly different health care systems report similar shortcomings in their work environments and the quality of hospital care. While the competence of and relation between nurses and physicians appear satisfactory, core problems in work design and workforce management threaten the provision of care. Resolving these issues, which are amenable to managerial intervention, is essential to preserving patient safety and care of consistently high quality.

Internal Monitoring Mechanisms and CEO Turnover: A Long‐Term Perspective

Abstract: We report evidence on chief executive officer (CEO) turnover during the 1971 to 1994 period. We find that the nature of CEO turnover activity has changed over time. The frequencies of forced CEO turnover and outside succession both increased. However, the relation between the likelihood of forced CEO turnover and firm performance did not change significantly from the beginning to the end of the period we examine, despite substantial changes in internal governance mechanisms. The evidence also indicates that changes in the intensity of the takeover market are not associated with changes in the sensitivity of CEO turnover to firm performance. STOCKHOLDERS RELY ON INTERNAL AND EXTERNAL monitoring mechanisms to help resolve agency problems that arise from the separation of ownership and control in modern corporations. Boards of directors and blockholders are important internal control mechanisms whereas the takeover market is a major source of external control. Both academicians and practitioners have speculated that improvements in corporate governance structures would enhance the internal control mechanisms. For example, Jensen (1993) argues that the corporate governance structures of LBO associations and venture capital funds should be models for corporations that desire more efficient control systems. Among the desirable features Jensen points to are smaller, outsider-dominated boards, and substantial equity ownership by managers and board members. Similarly, Blair (1995) discusses corporate governance reformers who advocate changes like those cited by Jensen as well as greater institutional investor involvement in corporate decisions. In addition to pro

Hepatitis C virus replication in mice with chimeric human livers

Abstract: Lack of a small animal model of the human hepatitis C virus (HCV) has impeded development of antiviral therapies against this epidemic infection. By transplanting normal human hepatocytes into SCID mice carrying a plasminogen activator transgene (Alb-uPA), we generated mice with chimeric human livers. Homozygosity of Alb-uPA was associated with significantly higher levels of human hepatocyte engraftment, and these mice developed prolonged HCV infections with high viral titers after inoculation with infected human serum. Initial increases in total viral load were up to 1950-fold, with replication confirmed by detection of negative-strand viral RNA in transplanted livers. HCV viral proteins were localized to human hepatocyte nodules, and infection was serially passaged through three generations of mice confirming both synthesis and release of infectious viral particles. These chimeric mice represent the first murine model suitable for studying the human hepatitis C virus in vivo.

Clinical Outcomes and Insulin Secretion After Islet Transplantation With the Edmonton Protocol

Abstract: Islet transplantation offers the prospect of good glycemic control without major surgical risks. After our initial report of successful islet transplantation, we now provide further data on 12 type 1 diabetic patients with brittle diabetes or problems with hypoglycemia previous to 1 November 2000. Details of metabolic control, acute complications associated with islet transplantation, and long-term complications related to immunosuppression therapy and diabetes were noted. Insulin secretion, both acute and over 30 min, was determined after intravenous glucose tolerance tests (IVGTTs). The median follow-up was 10.2 months (CI 6.5-17.4), and the longest was 20 months. Glucose control was stable, with pretransplant fasting and meal tolerance-stimulated glucose levels of 12.5+/-1.9 and 20.0+/-2.7 mmol/l, respectively, but decreased significantly, with posttransplant levels of 6.3+/-0.3 and 7.5+/-0.6 mmol/l, respectively (P < 0.006). All patients have sustained insulin production, as evidenced by the most current baseline C-peptide levels 0.66+/-0.06 nmol/l, increasing to 1.29+/-0.25 nmol/l 90 min after the meal-tolerance test. The mean HbA1c level decreased from 8.3+/-0.5% to the current level of 5.8+/-0.1% (P < 0.001). Presently, four patients have normal glucose tolerance, five have impaired glucose tolerance, and three have post-islet transplant diabetes (two of whom need oral hypoglycemic agents and low-dose insulin (<10 U/day). Three patients had a temporary increase in their liver-function tests. One patient had a thrombosis of a peripheral branch of the right portal vein, and two of the early patients had bleeding from the hepatic needle puncture site; but these technical problems were resolved. Two patients had transient vitreous hemorrhages. The two patients with elevated creatinine levels pretransplant had a significant increase in serum creatinine in the long term, although the mean serum creatinine of the group was unchanged. The cholesterol increased in five patients, and lipid-lowering therapy was required for three patients. No patient has developed cytomegalovirus infection or disease, posttransplant lymphoproliferative disorder, malignancies, or serious infection to date. None of the patients have been sensitized to donor antigen. In 11 of the 12 patients, insulin independence was achieved after 9,000 islet equivalents (IEs) per kilogram were transplanted. The acute insulin response and the insulin area under the curve (AUC) after IVGTT were consistently maintained over time. The insulin AUC from the IVGTT correlated to the number of islets transplanted, but more closely correlated when the cold ischemia time was taken into consideration (r = 0.83, P < 0.001). Islet transplantation has successfully corrected labile type 1 diabetes and problems with hypoglycemia, and our results show persistent insulin secretion. After a minimum of 9,000 IEs per kilogram are provided, insulin independence is usually attained. An elevation of creatinine appears to be a contraindication to this immunosuppressive regimen. For the subjects who had labile type 1 diabetes that was difficult to control, the risk-to-benefit ratio is in favor of islet transplantation.

Granular computing: an introduction

Abstract: The study is concerned with the fundamentals of granular computing. Granular computing, as the name itself stipulates, deals with representing information in the form of some aggregates (that embrace a number of individual entities) and their ensuing processing. We elaborate on the rationale behind granular computing. Next, a number of formal frameworks of information granulation are discussed including several alternatives such as fuzzy sets, interval analysis, rough sets, and probability. The notion of granularity itself is defined and quantified. A design agenda of granular computing is formulated and the key design problems are raised. A number of granular architectures are also discussed with an objective of delineating the fundamental algorithmic, and conceptual challenges. It is shown that the use of information granules of different size (granularity) lends itself to general pyramid architectures of information processing. The role of encoding and decoding mechanisms visible in this setting is also discussed in detail, along with some particular solutions. We raise an issue of interoperability of granular environments. The intent of the paper is to elaborate on the fundamentals and put the entire area in a certain perspective while not moving into specific algorithmic details.

Quinolone and Macrolide Resistance in Campylobacter jejuni and C. coli: Resistance Mechanisms and Trends in Human Isolates

Abstract: The incidence of human Campylobacter jejuni and C. coli infections has increased markedly in many parts of the world in the last decade as has the number of quinolone-resistant and, to a lesser extent, macrolide-resistant Campylobacter strains causing infections. We review macrolide and quinolone resistance in Campylobacter and track resistance trends in human clinical isolates in relation to use of these agents in food animals. Susceptibility data suggest that erythromycin and other macrolides should remain the drugs of choice in most regions, with systematic surveillance and control measures maintained, but fluoroquinolones may now be of limited use in the empiric treatment of Campylobacter infections in many regions.

Does Greater Firm-Specific Return Variation Mean More or Less Informed Stock Pricing?

Abstract: Roll (1988) observes low R2 statistics for common asset pricing models due to vigorousfirms-specific returns variation not associated with public information. He concludes (p. 56) that this implies â¬Seither private information or else occasional frenzy unrelated to concrete information.â¬?We show that firms and industries with lower market model R2 statistics exhibit higher association between current returns and future earnings, indicating more information about future earnings in current stock returns. This supports Rollâ¬"s first interpretation ⬠higher firms-specific returns variation as a fraction of total variation signals more information-laden stock prices and, therefore, more efficient stock markets.

The cumulative effects of climate warming and other human stresses on Canadian freshwaters in the new millennium

Abstract: Climate warming will adversely affect Canadian water quality and water quantity. The magnitude and timing of river flows and lake levels and water renewal times will change. In many regions, wetlands will disappear and water tables will decline. Habitats for cold stenothermic organisms will be reduced in small lakes. Warmer temperatures will affect fish migrations in some regions. Climate will interact with Overexploitation, dams and diversions, habitat destruction, non-native species, and pollution to destroy native freshwater fisheries. Acute water problems in the United States and other parts of the world will threaten Canadian water security. Aquatic communities will be restructured as the result of changes to competition, changing life cycles of many organisms, and the invasions of many non-native species. Decreased water renewal will increase eutrophication and enhance many biogeochemical processes. In poorly buffered lakes and streams, climate warming will exacerbate the effects of acid precipitation. Decreases in dissolved organic carbon caused by climate warming and acidification will cause increased penetration of ultraviolet radiation in freshwaters. Increasing industrial agriculture and human populations will require more sophisticated and costly water and sewage treatment.

Institutional Sources of Practice Variation: Staffing College and University Recycling Programs

Abstract: In this paper, I examine how variation arises in the staffing of recycling programs at colleges and universities. Through initial fieldwork, I identified two basic recycling program forms. Some schools adopted recycling programs that entailed the creation of new, full-time recycling manager positions that were filled by ecological activists. Other schools adopted more minimalist programs that were staffed by current employees who were more ecologically ambivalent and assumed recycling management responsibilities as a part-time, additional duty. Results of a subsequent survey of a population of colleges and universities show that this variation in staffing was importantly shaped by the Student Environmental Action Coalition, a national social movement organization that provided resources and support to student environmental groups at particular schools. Implications for the study of how field-level organizations shape the content of organizational practices are discussed.

DIRT @SBT@discovery of inference rules from text

Abstract: In this paper, we propose an unsupervised method for discovering inference rules from text, such as "X is author of Y a X wrote Y", "X solved Y a X found a solution to Y", and "X caused Y a Y is triggered by X". Inference rules are extremely important in many fields such as natural language processing, information retrieval, and artificial intelligence in general. Our algorithm is based on an extended version of Harris' Distributional Hypothesis, which states that words that occurred in the same contexts tend to be similar. Instead of using this hypothesis on words, we apply it to paths in the dependency trees of a parsed corpus.

Non-parametric Productivity Analysis with Undesirable Outputs: An Application to the Canadian Pulp and Paper Industry

Abstract: This article extends the Chavas-Cox approach to non-parametric analysis by incorporating undesirable outputs to provide a more complete representation of the production technology. Inner and outer non-parametric technology bounds are constructed. The methods are illustrated with application to time series data for the Canadian pulp and paper industry. Conventional measures that ignore changes in pollutant outputs underestimate true productivity growth. Further, there is a large gap between estimates generated with reference to inner and outer bounds to the technology, suggesting that researchers need to be aware of the limitations of results derived from analyses relying only on DEA methods. Copyright 2001, Oxford University Press.

Discovery of inference rules for question-answering

Abstract: One of the main challenges in question-answering is the potential mismatch between the expressions in questions and the expressions in texts. While humans appear to use inference rules such as ‘X writes Y’ implies ‘X is the author of Y’ in answering questions, such rules are generally unavailable to question-answering systems due to the inherent difficulty in constructing them. In this paper, we present an unsupervised algorithm for discovering inference rules from text. Our algorithm is based on an extended version of Harris’ Distributional Hypothesis, which states that words that occurred in the same contexts tend to be similar. Instead of using this hypothesis on words, we apply it to paths in the dependency trees of a parsed corpus. Essentially, if two paths tend to link the same set of words, we hypothesize that their meanings are similar. We use examples to show that our system discovers many inference rules easily missed by humans.

Theories of musculoskeletal injury causation.

Abstract: Based on the scientific evidence in published literature about precipitation of musculoskeletal injuries in the workplace, four theories have been proposed to explain these afflictions. Central to all theories is the presupposition that all occupational musculoskeletal injuries are biomechanical in nature. Disruption of mechanical order of a biological system is dependent on the individual components and their mechanical properties. These common denominators will be causally affected by the individual's genetic endowment, morphological characteristics and psychosocial makeup, and by the occupational biomechanical hazards. This phenomenon is explained by the Multivariate Interaction Theory. Differential Fatigue Theory accounts for unbalanced and asymmetric occupational activities creating differential fatigue and thereby a kinetic and kinematic imbalance resulting in injury precipitation. Cumulative Load Theory suggests a threshold range of load and repetition product beyond which injury precipitates, as all material substances have a finite life. Finally, Overexertion Theory claims that exertion exceeding the tolerance limit precipitates occupational musculoskeletal injury. It is also suggested that while these theories may explain the immediate mechanism of precipitation of injuries, they all operate simultaneously and interact to modulate injuries to varying degrees in different cases.

The Influence of Task Complexity on Consumer Choice: A Latent Class Model of Decision Strategy Switching

Abstract: The literature indicating that person‐, context‐, and task‐specific factors cause consumers to utilize different decision strategies has generally failed to affect the specification of choice models used by practitioners and academics alike, who still tend to assume an utility maximizing, omniscient, indefatigable consumer. This article (1) introduces decision strategy selection, within a maintained compensatory framework, into aggregate choice models via latent classes, which arise because of task complexity; (2) it demonstrates that within an experimental choice task, the model reflects changing aggregate preferences as choice complexity changes and as the task progresses. The import of these findings for current practice, model interpretation, and future research needs is examined.

Pervasive negative effects of rewards on intrinsic motivation: The myth continues.

Abstract: A major concern in psychology and education is that rewards decrease intrinsic motivation to perform activities. Over the past 30 years, more than 100 experimental studies have been conducted on this topic. In 1994, Cameron and Pierce conducted a meta-analysis of this literature and concluded that negative effects of reward were limited and could be easily prevented in applied settings. A more recent meta-analysis of the literature by Deci, Koestner, and Ryan (1999) shows pervasive negative effects of reward. The purpose of the present article is to resolve differences in previous meta-analytic findings and to provide a meta-analysis of rewards and intrinsic motivation that permits tests of competing theoretical explanations. Our results suggest that in general, rewards are not harmful to motivation to perform a task. Rewards given for low-interest tasks enhance free-choice intrinsic motivation. On high-interest tasks, verbal rewards produce positive effects on free-choice motivation and self-reported task interest. Negative effects are found on high-interest tasks when the rewards are tangible, expected (offered beforehand), and loosely tied to level of performance. When rewards are linked to level of performance, measures of intrinsic motivation increase or do not differ from a nonrewarded control group. Overall, the pattern of results indicates that reward contingencies do not have pervasive negative effects on intrinsic motivation. Theoretical and practical implications of the findings are addressed.

Mutual compensation of mobility and threshold voltage temperature effects with applications in CMOS circuits

Abstract: Mutual compensation of mobility and threshold voltage temperature variations may result in a zero temperature coefficient bias point of a MOS transistor. The conditions under which this effect occurs, and stability of this bias point are investigated. Possible applications of this effect include voltage reference circuits and temperature sensors with linear dependence of voltage versus temperature. The theory is verified experimentally investigating the temperature behavior of a simple voltage reference circuit realized in 0.35 /spl mu/m CMOS process.

Ltap, a mammalian homolog of Drosophila Strabismus/Van Gogh, is altered in the mouse neural tube mutant Loop-tail.

Abstract: Neural tube defects (NTDs) such as spina bifida and anencephaly are common congenital malformations in humans (1/1,000 births) that result from failure of the neural tube to close during embryogenesis The etiology of NTDs is complex, with both genetic and environmental contributions; the genetic component has been extensively studied with mouse models Loop-tail (Lp) is a semidominant mutation on mouse chromosome 1 (ref 4) In the two known Lp alleles (Lp, Lpm1Jus), heterozygous mice exhibit a characteristic looped tail, and homozygous embryos show a completely open neural tube in the hindbrain and spinal region, a condition similar to the severe craniorachischisis defect in humans Morphological and neural patterning studies indicate a role for the Lp gene product in controlling early morphogenesis and patterning of both axial midline structures and the developing neural plate The 06-cM/07-megabase (Mb) Lp interval is delineated proximally by D1Mit113/Apoa2/Fcer1g and distally by Fcer1a/D1Mit149/Spna1 and contains a minimum of 17 transcription units One of these genes, Ltap, encodes a homolog of Drosophila Strabismus/Van Gogh (Stbm/Vang), a component of the frizzled/dishevelled tissue polarity pathway Ltap is expressed broadly in the neuroectoderm throughout early neurogenesis and is altered in two independent Lp alleles, identifying this gene as a strong candidate for Lp

Phenology is a major determinant of tree species range

Abstract: Global warming is expected to have a major impact on plant distributions, an issue of key importance in biological conservation. However, very few models are able to predict species distribution accurately, although we know species respond individually to climate change. Here we show, using a process-based model (PHENOFIT), that tree species distributions can be predicted precisely if the biological processes of survival and reproductive success only are incorporated as a function of phenology. These predictions showed great predictive power when tested against present distributions of two North American species – quaking aspen and sugar maple – indicating that on a broad scale, the fundamental niche of trees coincides with their realized niche. Phenology is shown here to be a major determinant of plant species range and should therefore be used to assess the consequences of global warming on plant distributions, and the spread of alien plant species.

Nucleoside analogues: mechanisms of drug resistance and reversal strategies

Abstract: Nucleoside analogues (NA) are essential components of AML induction therapy (cytosine arabinoside), effective treatments of lymphoproliferative disorders (fludarabine, cladribine) and are also used in the treatment of some solid tumors (gemcitabine). These important compounds share some general common characteristics, namely in terms of requiring transport by specific membrane transporters, metabolism and interaction with intracellular targets. However, these compounds differ in regard to the types of transporters that most efficiently transport a given compound, and their preferential interaction with certain targets which may explain why some compounds are more effective against rapidly proliferating tumors and others on neoplasia with a more protracted evolution. In this review, we analyze the available data concerning mechanisms of action of and resistance to NA, with particular emphasis on recent advances in the characterization of nucleoside transporters and on the potential role of activating or inactivating enzymes in the induction of clinical resistance to these compounds. We performed an extensive search of published in vitro and clinical data in which the levels of expression of nucleoside-activating or inactivating enzymes have been correlated with tumor response or patient outcome. Strategies aiming to increase the intracellular concentrations of active compounds are presented.

Affect Monitoring and the Primacy of Feelings in Judgment

Abstract: Multidisciplinary evidence suggests that people often make evaluative judgments by monitoring their feelings toward the target. This article examines, in the context of moderately complex and consciously accessible stimuli, the judgmental properties of consciously monitored feelings. Results from four studies show that, compared to cold, reason-based assessments of the target, the conscious monitoring of feelings provides judgmental responses that are (a) potentially faster, (b) more stable and consistent across individuals, and importantly (c) more predictive of the number and valence of people’s thoughts. These findings help explain why the monitoring of feelings is an often diagnostic pathway to evaluation in judgment and decision making.

Global change and arctic ecosystems: is lichen decline a function of increases in vascular plant biomass?

Abstract: Cornelissen, J. H. C., Callaghan, T. V., Alatalo, J. M., Michelsen, A., Graglia, E., Hartley, A. E., Hik, D. S., Hobbie, S. E., Press, M. C., Robinson, C. H., Henry, G. H. R. (2001). Global change and arctic ecosystems: is lichen decline a function of increases in vascular plant biomass. Journal of Ecology, 89, (6), 984-994. Sponsorship: Swedish Natural Science Research Council (NFR)/Swedish Environmental Protection Agency (two grants)/ US National Science Foundation (four grants)/ the Danish Natural Science Research Council (two grants)/ NASA (Global Change Fellowship), NSERC (Canada, two grants)/the Natural Environment Research Council (UJ, two grants)/ the 'Stiftelse for Oscar & Lilli Lamms Minne' (Sweden) / ESRC (Global Change Research Council).

Early emergency department treatment of acute asthma with systemic corticosteroids

Abstract: Background The airway edema and secretions associated with acute asthma are most effectively treated with anti-inflammatories such as corticosteroids delivered by inhaled, oral, intravenous or intra-muscular routes. There is an unresolved debate about the use of systemic corticosteroids in the early treatment of acute asthma for emergency department patients. Objectives To determine the benefit of treating patients with acute asthma with systemic corticosteroids within an hour of presenting to the emergency department (ED). Search methods Randomised controlled trials were identified from the Cochrane Airways Group Asthma Register. Primary authors and content experts were contacted to identify eligible studies. Bibliographies from included studies and known reviews were searched. Selection criteria Only randomised controlled trials (RCTs) or quasi-randomised trials were eligible for inclusion. Studies were included if patients presenting to the ED with acute asthma were treated with IV/IM or oral corticosteroids (CS) versus placebo within 1 hour of arrival and either admission rate or pulmonary function results were reported. Data collection and analysis Trial selection, data extraction and quality assessment were carried out independently by two reviewers, and confirmed with corresponding authors. Main results Twelve studies involving 863 patients (435 corticosteroids; 428 placebo) were included. Early use of CS for acute asthma in the ED significantly reduced admission rates (N = 11; pooled OR: 0.40, 95% CI: 0.21 to 0.78). This would correspond with a number needed to treat of 8 (95% CI: 5 to 21). This benefit was more pronounced for those not receiving systemic CS prior to ED presentation (N = 7; OR: 0.37, 95% CI: 0.19 to 0.70) and those with more severe asthma (N = 7; OR: 0.35, 95% CI: 0.21 to 0.59). Oral CS therapy in children was particularly effective (N = 3; OR: 0.24, 95% CI: 0.11 to 0.53); no trials in adults used the oral route. Side effects were not significantly different between corticosteroid treatments and placebo. An update search conducted in September 2002 did not yield any further trials. Authors' conclusions Use of corticosteroids within 1 hour of presentation to an ED significantly reduces the need for hospital admission in patients with acute asthma. Benefits appear greatest in patients with more severe asthma, and those not currently receiving steroids. Children appear to respond well to oral steroids.

Countryside biogeography: use of human-dominated habitats by the avifauna of southern costa rica

Abstract: Understanding the multifaceted relationship between biodiversity and land- use intensity is key to conservation policy. To begin to characterize this relationship in a tropical region, we investigated the bird fauna in an agricultural landscape in southern Costa Rica. Landsat Thematic Mapper (TM) data show that about 27% of the land remains forested in the 15 km radius study region encompassing our sites. The rest was cleared about 40 yr ago for relatively small-scale coffee and cattle production, intermixed with other crops. Our goals were to: (1) compare the composition of the avifauna found in forest- fragment and open habitats of the countryside; (2) assess the faunal change that has occurred since deforestation; and (3) provide a baseline for future comparisons. We surveyed the avifauna of eight forest fragments (0.3-25 ha) and 13 open-habitat sites (1.0 ha each) in the agricultural landscape. The pre-deforestation avifauna was ap- proximated by the long-term bird list for the largest forest fragment (Las Cruces, LC; 227 ha) in the study region. We assumed conservatively that a species recorded in LC but not detected elsewhere occurred only in LC. Of the 272 locally extant bird species considered in this study, 149 (55%) occurred in forest habitats only. There was a significant positive correlation between forest fragment size and species richness for these forest birds. Of the remaining 123 species, 60 (22% of the total) occurred both in forest and open habitats. Sixty-three species (23%) occurred in open habitats only; the three nonnative species (1%) are in this group. Based on comparisons with larger forest tracts outside of the study region, it appeared that between 4 and 28 species (1-9% of the possible original totals) have gone locally extinct since deforestation began. The avifauna of open habitats was similar through- out the study region and did not vary with proximity to extensive forest. A substantial proportion of the native bird fauna occurs in a densely (human) populated, agricultural landscape almost a half-century after extensive clearance. There are, however, cautionary messages: (1) the common occurrence of forest birds in human-dominated coun- tryside (including both forest-fragment and open habitats) does not necessarily imply that these species maintain sustainable populations there; (2) about half of the species have little prospect of surviving outside of the forest; and (3) ongoing intensification of land use may greatly reduce avian diversity in countryside habitats. Nonetheless, countryside habitats may buy time for the conservation of some species; at best, they may even sustain a moderate fraction of the native biota.