Assessing the influence of organizational personality, applicants' need motivation, expectancy beliefs, and person-organization fit on applicant attraction

This research explored the thesis that organizational personality is related to applicants’ attraction to an organization through a process which involves need motivation, expectancy beliefs, and applicants’ perceptions of person-organization fit. Organizational personality may be defined as a collection of trait-like characteristics that individuals use to describe organizational practices, policies, values, and culture. Specifically, this research investigated the hypothesis that organizational personality information is useful to applicants because it helps individuals to determine their perceptions of fit. A sample of students (N = 198) and working adults (N = 198) participated in an online experiment. Findings indicated that individuals’ beliefs about the instrumentality of desirable work related outcomes are essential to determining their perceptions of fit and organizational attraction. Additionally, organizational personality perceptions interacted with need motivation to affect perceptions of fit and organizational attraction. For instance, perceptions of fit mediated the influence of the interaction between need for achievement and perceptions of innovativeness on organizational attraction. The interaction of need motivation and perceptions of organizational personality helped individuals to better determine their perceptions of fit and subsequent attraction toward organizations.^

Time orientation in organizations: Polychronicity and multitasking

This dissertation consists of four studies examining two constructs related to time orientation in organizations: polychronicity and multitasking. The first study investigates the internal structure of polychronicity and its external correlates in a sample of undergraduate students (N = 732). Results converge to support a one-factor model and finds measures of polychronicity to be significantly related to extraversion, agreeableness, and openness to experience. The second study quantitatively reviews the existing research examining the relationship between polychronicity and the Big Five factors of personality. Results reveal a significant relationship between extraversion and openness to experience across studies. Studies three and four examine the usefulness of multitasking ability in the prediction of work related criteria using two organizational samples (N = 175 and 119, respectively). Multitasking ability demonstrated predictive validity, however the incremental validity over that of traditional predictors (i.e., cognitive ability and the Big Five factors of personality) was minimal. The relationships between multitasking ability, polychronicity, and other individual differences were also investigated. Polychronicity and multitasking ability proved to be distinct constructs demonstrating differential relationships with cognitive ability, personality, and performance. Results provided support for multitasking performance as a mediator in the relationship between multitasking ability and overall job performance. Additionally, polychronicity moderated the relationship between multitasking ability and both ratings of multitasking performance and overall job performance in Study four. Clarification of the factor structure of polychronicity and its correlates will facilitate future research in the time orientation literature. Results from two organizational samples point to work related measures of multitasking ability as a worthwhile tool for predicting the performance of job applicants.

Wellness and Obesity: Implications for Health Care Costs Among Restaurant Managers

Overeating, inadequate exercise, work-related stress, and long working hours are accepted issues among restaurant managers. The underlying question was whether such life styles affect employers' health care cost and restaurant managers' health and ability to cope with imposed business requirements. The author discusses strategies to help employers reduce health care costs, increase employee productivity, and improve job satisfaction.

Glycemic Control: Risk Factors, Quality of Life, Workforce Participation, and Mortality Among US Adults with Type 2 Diabetes

Despite research showing the benefits of glycemic control, it remains suboptimal among adults with diabetes in the United States. Possible reasons include unaddressed risk factors as well as lack of awareness of its immediate and long term consequences. The objectives of this study were to, using cross-sectional data, 1) ascertain the association between suboptimal (Hemoglobin A1c (HbA1c) ≥7%), borderline (HbA1c 7-8.9%), and poor (HbA1c ≥9%) glycemic control and potentially new risk factors (e.g. work characteristics), and 2) assess whether aspects of poor health and well-being such as poor health related quality of life (HRQOL), unemployment, and missed-work are associated with glycemic control; and 3) using prospective data, assess the relationship between mortality risk and glycemic control in US adults with type 2 diabetes. Data from the 1988-1994 and 1999-2004 National Health and Nutrition Examination Surveys were used. HbA1c values were used to create dichotomous glycemic control indicators. Binary logistic regression models were used to assess relationships between risk factors, employment status and glycemic control. Multinomial logistic regression analyses were conducted to assess relationships between glycemic control and HRQOL variables. Zero-inflated Poisson regression models were used to assess relationships between missed work days and glycemic control. Cox-proportional hazard models were used to assess effects of glycemic control on mortality risk. Using STATA software, analyses were weighted to account for complex survey design and non-response. Multivariable models adjusted for socio-demographics, body mass index, among other variables. Results revealed that being a farm worker and working over 40 hours/week were risk factors for suboptimal glycemic control. Having greater days of poor mental was associated with suboptimal, borderline, and poor glycemic control. Having greater days of inactivity was associated with poor glycemic control while having greater days of poor physical health was associated with borderline glycemic control. There were no statistically significant relationships between glycemic control, self-reported general health, employment, and missed work. Finally, having an HbA1c value less than 6.5% was protective against mortality. The findings suggest that work-related factors are important in a person’s ability to reach optimal diabetes management levels. Poor glycemic control appears to have significant detrimental effects on HRQOL.

Um estudo do gênero ata de audiência na esfera jurídico-trabalhista

The activities in labor judicial sphere are permeated by the use of diverse text genres, which are indispensable instruments to the accomplishment of actions that involve the jurisdictional realm. Among the genres that circulate in this domain, we selected the genre minutes of hearing as the object of study of this research, because it is a document supporting the actions, procedures and deliberations agreed, in hearings, by members involved in work-related litigation. In this study we aim to describe the elements that constitute the referred genre in what concerns its pragmatic, organizational and linguistic dimensions. Therefore, we use the postulations of Sociodiscursive Interactionism as theoretical framework, through the writings of Bronckart (2006; 2007; 2012), supported by Marcuschi studies (2008; 2010; 2011), Koch and Favero (1987), Elias Koch (2011; 2012) and Zanotto (2012). In methodological terms, it is characterized as a qualitative approach research (BOGDAN; BIKLEN, 1994; CHIZZOTTI, 2000; MOREIRA; CALEFFE, 2006) with aspects of an ethnographic work (ANDRÉ, 1995; CANÇADO, 1994). The discussion proposed inserts into the field of Applied Linguistics for it focalizes ―social issues and creates intelligibility about the social practices in which language plays the main role‖ (MOITA LOPES, 2006, p.14). The analyses indicate – regarding the pragmatic dimension – that the genre in focus constitutes artefact that enables the register of actions, deliberations, testimonials, procedures and occurrences established during the hearings and has as its interlocutors judges, litigants and their legal representatives. Concerning the organizational dimension, despite the genre in scope present a proposal of standardized writing, their examples contemplate variations and flexibility especially with regard to the development and outcome of the text. As for linguistic aspects, it is noticeable the presence of lexical choices inherent in the language used by labor law discourse community. Lastly, stand out the relevance of the research lies in the fact that it approaches, from the perspective of the Applied Linguistics, the forensic writing and, consequently, offers contributions to the understanding of such genre.

Análise das LER/DORT notificadas no Rio Grande do Norte de 2010 a 2014

The increasing prevalence of Repetitive Strain Injury / Work-Related Musculoskeletal Disorders (RSI / MSDs) has been explained by changes in the work that has been characterized by setting goals and productivity. This fact does not take into account the psycho-physiological characteristics of workers who become ill as a result of professional activities engaged in and also the adverse conditions in which his work was done. This study aimed to analyze the RSI / MSDs reported in the state of Rio Grande do Norte, Brazil, 2010-2014 compared to the profile of the population, epidemiological aspects and features of these diseases. It is a descriptive epidemiological cross-sectional study using secondary data obtained in the Notifiable Diseases Information System (SINAN) in May 2015 was used as the area covered by the Rio Grande do Norte. Data were collected regarding the grievances of work-related RSI / MSDs, assigned by the Worker's Health Reference Center (CEREST) of the State Health Department. Data were processed with the help of Microsoft Excel® 2013 and presented in tables in absolute frequency (n) and relative frequency (%). The results showed a total of 403 notifications of RSI / MSDs, where the vast majority 72% (290) was recorded in Natal. Regarding the profile of notified employees, 88.59% (357) have aged between 25 and 54 years, 62.78% (253) were female, and in relation to education, 31.51% (127) had high school complete. The most affected occupations were seamstresses (the clothing industry) with 24.97% (97), followed by masons, construction with 3.23% (13) and cashiers with 2.99% (12). About the work situation, 75.93% (306) had a formal contract, however, were sent to Communications Occupational accidents (CAT) only 67% (270) of the cases. Regarding the signs and symptoms, pain and limitation of movement were the most mentioned respectively with 98.01% (395) and 95.04% (383) of notifications. Notifications, 94.29% (380) showed exposure to repetitive movements in their workplace. The most frequent specific diagnoses were synovitis and tenosynovitis (CID F 65), with 30.02% (121) of notifications, followed by back pain (CID F 54) to 19.35% (78) and shoulder injuries (ICD M 75) with 15.88% (64). They were away from work 81.64% (329) of workers reported with RSI / MSDs. Evolution more prevalent among cases was temporary disability with 75.68% (305). It was concluded that the SINAN is a database of potential to characterize the profile of RSI / MSDs, requiring, however, an improvement in the coverage of records and data quality. In addition, this study reflects the need to implement protection strategies to workers by companies, signaling promotion, prevention and rehabilitation aimed at reducing these injuries and the improvement of occupational health indicators in Rio Grande do Norte.

Adequar a ação pedagógica : explorando modos de organização diferenciada do trabalho educativo

Relatório final apresentado para a obtenção do grau de mestre em Educação pré-escolar e Ensino do 1º ciclo do ensino básico

Long-finned pilot whale population diversity and structure in Atlantic waters assessed through biogeochemical and genetic markers

Acknowledgements. Cetacean samples were collected under the auspices of stranding monitoring programs run by the Sociedade Portuguesa de Vida Selvagem, the Coordinadora para o Estudio dos Mamíferos Mariños (supported by the regional government Xunta de Galicia), the UK Cetacean Strandings Investigation Programme and the Scottish Agriculture College Veterinary Science Division (jointly funded by Defra and the Devolved Governments of Scotland and Wales), the Marine Mammals Research Group of the Institute of Marine Research (Norway), the Museum of Natural History of the Faroe Islands and the International Fund for Animal Welfare Marine Mammal Rescue and Research Program (USA). The authors thank all the members of these institutions and organizations for their assistance with data and sample collection. S.S.M., P.M.F. and M.F. were supported by PhD grants from the Fundação para a Ciência e Tecnologia (POPH/FSE ref SFRH/BD/ 38735/ 2007, SFRH/BD/36766/2007 and SFRH/BD/30240/ 2006, respectively). A.L. was supported by a postdoctoral grant from the Fundação para a Ciência e Tecnologia (ref SFRH/BPD/82407/2011). The work related to strandings and tissue collection in Portugal was partially supported by the SafeSea project EEAGrants PT 0039 (supported by Iceland, Liechtenstein and Norway through the EEA Financial Mechanism), the MarPro project Life09 NAT/PT/000038 (funded by the European Union program LIFE+) and the project CetSenti FCT RECI/AAG-GLO/0470/2012 (FCOMP- 01-0124-FEDER-027472) (funded by the program COMPETE and the Fundação para a Ciência e Tecnologia). G.J.P. thanks the University of Aveiro and Caixa Geral de Depósitos (Portugal) for financial support. The authors acknowledge the assistance of the chemical analysts at Marine Scotland Science with the fatty acid analysis.

Major Histocompatibility Complex (MHC) Class II sequence polymorphism in long-finned pilot whale (Globicephala melas) from the North Atlantic

Funding Silvia S. Monteiro and Marisa Ferreira were supported by a Ph.D. grant from Fundação para a Ciência e Tecnologia (ref SFRH/BD/38735/2007 and SFRH/BD/30240/2006, respectively). Alfredo López was supported by a postdoctoral grant from Fundação para a Ciência e Tecnologia (ref SFRH/BPD/82407/2011). Catarina Eira is supported by CESAM (UID/AMB/50017), from FCT/MEC through national funds and FEDER (PT2020, Compete 2020). The work related with strandings and tissue collection in Portugal was partially supported by the SafeSea Project EEAGrants PT 0039 (supported by Iceland, Liechtenstein and Norway through the EEA Financial Mechanism), by the Project MarPro–Life09 NAT/PT/000038 (funded by the European Union–Program Life+) and by the project CetSenti FCT RECI/AAG-GLO/0470/2012; FCOMP-01-0124-FEDER-027472 (Funded by the Program COMPETE and Fundação para a Ciência e Tecnologia).

Long-finned pilot whale population diversity and structure in Atlantic waters assessed through biogeochemical and genetic markers

Acknowledgements. Cetacean samples were collected under the auspices of stranding monitoring programs run by the Sociedade Portuguesa de Vida Selvagem, the Coordinadora para o Estudio dos Mamíferos Mariños (supported by the regional government Xunta de Galicia), the UK Cetacean Strandings Investigation Programme and the Scottish Agriculture College Veterinary Science Division (jointly funded by Defra and the Devolved Governments of Scotland and Wales), the Marine Mammals Research Group of the Institute of Marine Research (Norway), the Museum of Natural History of the Faroe Islands and the International Fund for Animal Welfare Marine Mammal Rescue and Research Program (USA). The authors thank all the members of these institutions and organizations for their assistance with data and sample collection. S.S.M., P.M.F. and M.F. were supported by PhD grants from the Fundação para a Ciência e Tecnologia (POPH/FSE ref SFRH/BD/ 38735/ 2007, SFRH/BD/36766/2007 and SFRH/BD/30240/ 2006, respectively). A.L. was supported by a postdoctoral grant from the Fundação para a Ciência e Tecnologia (ref SFRH/BPD/82407/2011). The work related to strandings and tissue collection in Portugal was partially supported by the SafeSea project EEAGrants PT 0039 (supported by Iceland, Liechtenstein and Norway through the EEA Financial Mechanism), the MarPro project Life09 NAT/PT/000038 (funded by the European Union program LIFE+) and the project CetSenti FCT RECI/AAG-GLO/0470/2012 (FCOMP- 01-0124-FEDER-027472) (funded by the program COMPETE and the Fundação para a Ciência e Tecnologia). G.J.P. thanks the University of Aveiro and Caixa Geral de Depósitos (Portugal) for financial support. The authors acknowledge the assistance of the chemical analysts at Marine Scotland Science with the fatty acid analysis.

A recessionary debate: who suffered more? A study of sectoral well-being and economic insecurity in Ireland

The aim of this thesis is to identify the relationship between subjective well-being and economic insecurity for public and private sector workers in Ireland using the European Social Survey 2010-2012. Life satisfaction and job satisfaction are the indicators used to measure subjective well-being. Economic insecurity is approximated by regional unemployment rates and self-perceived job insecurity. Potential sample selection bias and endogeneity bias are accounted for. It is traditionally believed that public sector workers are relatively more protected against insecurity due to very institution of public sector employment. The institution of public sector employment is made up of stricter dismissal practices (Luechinger et al., 2010a) and less volatile employment (Freeman, 1987) where workers are subsequently less likely to be affected by business cycle downturns (Clark and Postal-Vinay, 2009). It is found in the literature that economic insecurity depresses the well-being of public sector workers to a lesser degree than private sector workers (Luechinger et al., 2010a; Artz and Kaya, 2014). These studies provide the rationale for this thesis in testing for similar relationships in an Irish context. Sample selection bias arises when a selection into a particular category is not random (Heckman, 1979). An example of this is non-random selection into public sector employment based on personal characteristics (Heckman, 1979; Luechinger et al., 2010b). If selection into public sector employment is not corrected for this can lead to biased and inconsistent estimators (Gujarati, 2009). Selection bias of public sector employment is corrected for by using a standard Two-Step Heckman Probit OLS estimation method. Following Luechinger et al. (2010b), the propensity for individuals to select into public sector employment is estimated by a binomial probit model with the inclusion of the additional regressor Irish citizenship. Job satisfaction is then estimated by Ordinary Least Squares (OLS) with the inclusion of a sample correction term similar as is done in Clark (1997). Endogeneity is where an independent variable included in the model is determined within in the context of the model (Chenhall and Moers, 2007). The econometric definition states that an endogenous independent variable is one that is correlated with the error term (Wooldridge, 2010). Endogeneity is expected to be present due to a simultaneous relationship between job insecurity and job satisfaction whereby both variables are jointly determined (Theodossiou and Vasileiou, 2007). Simultaneity, as an instigator of endogeneity, is corrected for using Instrumental Variables (IV) techniques. Limited Information Methods and Full Information Methods of estimation of simultaneous equations models are assed and compared. The general results show that job insecurity depresses the subjective well-being of all workers in both the public and private sectors in Ireland. The magnitude of this effect differs among sectoral workers. The subjective well-being of private sector workers is more adversely affected by job insecurity than the subjective well-being of public sector workers. This is observed in basic ordered probit estimations of both a life satisfaction equation and a job satisfaction equation. The marginal effects from the ordered probit estimation of a basic job satisfaction equation show that as job insecurity increases the probability of reporting a 9 on a 10-point job satisfaction scale significantly decreases by 3.4% for the whole sample of workers, 2.8% for public sector workers and 4.0% for private sector workers. Artz and Kaya (2014) explain that as a result of many austerity policies implemented to reduce government expenditure during the economic recession, workers in the public sector may for the first time face worsening perceptions of job security which can have significant implications for their well-being (Artz and Kaya, 2014). This can be observed in the marginal effects where job insecurity negatively impacts the well-being of public sector workers in Ireland. However, in accordance with Luechinger et al. (2010a) the results show that private sector workers are more adversely impacted by economic insecurity than public sector workers. This suggests that in a time of high economic volatility, the institution of public sector employment held and was able to protect workers against some of the well-being consequences of rising insecurity. In estimating the relationship between subjective well-being and economic insecurity advanced econometric issues arise. The results show that when selection bias is corrected for, any statistically significant relationship between job insecurity and job satisfaction disappears for public sector workers. Additionally, in order to correct for endogeneity bias the simultaneous equations model for job satisfaction and job insecurity is estimated by Limited Information and Full Information Methods. The results from two different estimators classified as Limited Information Methods support the general findings of this research. Moreover, the magnitude of the endogeneity-corrected estimates are twice as large as those not corrected for endogeneity bias which is similarly found in Geishecker (2010, 2012). As part of the analysis into the effect of economic insecurity on subjective well-being, the effects of other socioeconomic variables and work-related variables are examined for public and private sector workers in Ireland.

Het Effect van de Kanker Nazorg Wijzer* op Werkgerelateerde Problematiek en Kwaliteit van Leven bij Werkende Ex-Kankerpatiënten

Doordat kanker vaker in een vroeg stadium wordt ontdekt en de behandelingen effectiever zijn, is de kans om te overleven toegenomen. Om ex-kankerpatiënten te kunnen begeleiden na hun ziekte is de Kanker Nazorg Wijzer (KNW) ontwikkeld: een online interventie voor ex-kankerpatiënten ter ondersteuning van ervaren problemen op diverse gebieden waaronder werkhervatting. De KNW bestaat uit modules met informatie, advies, training en feedback-op-maat voor die betreffende probleemgebieden. In het huidige onderzoek stond het effect van de KNW op werkgerelateerde problematiek bij werkende ex-kankerpatiënten centraal en werd ook het effect op kwaliteit van leven gemeten. Verwacht werd dat na zes maanden gebruik van de KNW het aantal werkzame uren (werkhervatting), de werktevredenheid en kwaliteit van leven bij de gebruikers (interventiegroep) meer is toegenomen dan bij de niet-gebruikers (controlegroep) en dat de problemen op het werk en de onvervulde behoefte aan werkgerelateerde informatie meer is afgenomen. Additief werd verondersteld dat, binnen de interventiegroep, de respondenten die specifiek de werkmodule hadden gebruikt een groter verschil laten zien tussen de voor- en nameting met betrekking tot de werkgerelateerde problematiek. Op basis van voorgaand onderzoek zijn sekse, leeftijd, opleiding en actieve coping meegenomen als confounders evenals de voormetingscores van de afhankelijke variabelen. Het betreft een gerandomiseerd experiment naar de effecten van de KNW. Respondenten zijn geworven bij 22 Nederlandse ziekenhuizen en werden random toegewezen aan de interventiegroep of controlegroep. Voor de effectmeting is alleen de data van werkende ex-kankerpatiënten gebruikt. Effecten werden getoetst met multiple regressie analyses waarbij werd gecorrigeerd voor de genoemde confouders. In de interventiegroep (N = 245) waren 156 werkende ex-kankerpatiënten (85.3% vrouw, leeftijd M = 50.7) en in de controlegroep (N = 236) waren dit er 134 (85.1% vrouw, leeftijd M = 51.2). De MRA gaf na correctie van de voormetingscores en confounders aan dat het gebruik van de KNW zorgde voor een significante verbetering van kwaliteit van leven op de subschalen fysiek functioneren (p = 0.005), emotioneel functioneren (p = 0.026), sociaal functioneren (p = 0.002) en vermoeidheid (p = 0.021). De MRA gaf geen significant effect van het gebruik van de KNW op de werkgerelateerde problematiek. Additief gaf een vergelijking binnen de interventiegroep tussen de gebruikers van de werkmodule (N = 25) en de niet gebruikers (N = 131) aan dat het aantal gewerkte uren significant meer was toegenomen onder de gebruikers (t (68) = 1.680, p = 0.049).

An Assessment of Psychological Need in Emergency Medical Staff in the Northern Health and Social Care Trust Area

Setting: Psychological stress is increasingly recognised within emergency medicine, given the environmental and clinical stressors associated with the specialism. The current study assessed whether psychological distress is experienced by emergency medical staff and if so, what is the expressed need within this population? Participants: Participants included ambulance personnel, nursing staff, doctors and ancillary support staff within two Accident and Emergency (A&E) departments and twelve ambulance bases within one Trust locality in NI (N = 107). Primary and secondary outcome measures: The General Health Questionnaire (GHQ-12, Goldberg, 1972, 1978), Secondary Traumatic Stress Scale (STSS, Bride, 2004) and an assessment of need questionnaire were completed and explored using mixed method analysis. Results: Results showed elevated levels of psychological distress within each profession except ambulance service clinical support officers (CSOs). Elevated levels of secondary trauma symptomatology were also found; the highest were within some nursing grades and junior doctors. Decreased enjoyment in job over time was significantly associated with higher scores. Analysis of qualitative data identified sources of stress to include low morale. A total of 65% of participants thought that work related stressors had negatively affected their mental health. Participants explored what they felt could decrease psychological distress including improved resources and psychoeducation. Conclusion: There were elevated levels of distress and secondary traumatic stress within this population as well as an expressed level of need, on both systemic and support levels.

Generations and intention to leave current job : Belgian nurses in the workplace

This master thesis aims to identify work-related factors making Belgian nurses consider leaving their job voluntary and to compare the work-related factors across different generations. The purpose of this master thesis has a descriptive nature of research. The research approach chosen is a deductive approach and the research design chosen is a quantitative research design. Cluster sampling in combination with simple random sampling was used as sampling technique. 128 nurses were surveyed from April to May 2016. Nurses who reported to leave the organization due to retirement reasons, temporary employment contract or maternity leave were excluded from the study as this study investigates the voluntary turnover intention. A total of 68 nurses were included in the study which indicates an overall response rate of 53 %. Numerous of the findings in this master thesis are consistent with previous studies on turnover intention of different generations in other western-countries than Belgium. The work-related factor workload was most often reported by Belgian nurses with no intention to leave their job. Belgian nurses with an intention to leave their job indicated most often the work-related factor (non-)financial benefits. The generation-specific findings indicated both similarities and differences between the work-related factors selected. It was observed that Baby Boomers with an intention to leave their job selected most often variables related to the work-related factors (non-)financial benefits, supportive organization and workload. The variable lack of recognition appeared among Baby Boomers with an intention and no intention to leave their job. Surprisingly was the often selected variables lack of direct and/clear feedback on performances and unsupportive supervisor among Baby Boomers with professional turnover intention. Further, it was observed that Generation Xers with an intention to leave their job selected most often variables related to the work-related factors supportive organization, communication, (non-)financial benefits, work content and workload. The variables inadequate opportunity for advancement/professional growth and imbalance work-life appeared among Generation Xers with an intention and no intention to leave their job. Generation Yers with an intention to leave their job selected most frequently variables related to the work-related factors (non-)financial benefits, workload and commitment. The variables inadequate salary and opportunities elsewhere appeared among nurses with an intention and no intention to leave their job. Surprisingly was the often selected variable inadequate salary among Generation Yers with professional turnover intention.

Prevalence of musculoskeletal disorders among dentists from Mumbai, India

The world health organization defines musculoskeletal disorder (MSD) as “a disorder of muscles, tendons, peripheral vascular system not directly resulting from an acute or instantaneous event.1 Work related MSDs are one of the most important occupational hazards.1 Among many other occupations, dentistry is a highly demanding profession that requires good visual acuity, hearing, depth perception, psychomotor skills, manual dexterity, and ability to maintain occupational postures over long periods.