Factors and mechanisms controlling soil organic carbon turnover in subsoils of agricultural sites

Two-third of the terrestrial C is stored in soils, and more than 50% of soil organic C (SOC) is stored in subsoils from 30 – 100 cm. Hence, subsoil is important as a source or sink for CO2 in the global carbon cycle. Especially the stable organic carbon (OC) is stored in subsoil, as several studies have shown that subsoil OC is of a higher average age than topsoil OC. However, there is still a lack of knowledge regarding the mechanisms of C sequestration and C turnover in subsoil. Three main factors are discussed, which possibly reduce carbon turnover rates in subsoil: Resource limitation, changes in the microbial community, and changes in gas conditions. The experiments conducted in this study, which aimed to elucidate the importance of the mentioned factors, focused on two neighbouring arable sites, with depth profiles differing in SOC stocks: One Colluvic Cambisol (Cam) with high SOC contents (8-12 g kg-1) throughout the profile and one Haplic Luvisol (Luv) with low SOC contents (3-4 g kg-1) below 30 cm depth. The first experiment was designed to gain more knowledge regarding the microbial community and its influence on carbon sequestration in subsoil. Soil samples were taken at four different depths on the two sites. Microbial biomass C (MBC) was determined to identify depth gradients in relation to the natural C availability. Bacterial and fungal residues as well as ergosterol were determined to quantify changes in the in the microbial community composition. Multi-substrate-induced-respiration (MSIR) was used to identify shifts in functional diversity of the microbial community. The MSIR revealed that substrate use in subsoil differed significantly from that in topsoil and also differed highly between the two subsoils, indicating a strong influence of resource limitations on microbial substrate use. Amino sugar analysis and the ratio of ergosterol to microbial biomass C showed that fungal dominance decreased with depth. The results clearly demonstrated that microbial parameters changed with depth according to substrate availability. The second experiment was an incubation experiment using subsoil gas conditions with and without the addition of C4 plant residues. Soil samples were taken from topsoil and subsoil of the two sites. SOC losses during the incubation, were not influenced by the subsoil gas conditions. Plant-derived C losses were generally stronger in the Cam (7.5 mg g-1), especially at subsoil gas conditions, than in the Luv (7.0 mg g-1). Subsoil gas conditions had no general effects on microbial measures with and without plant residue addition. However, the contribution of plant-derived MBC to total MBC was significantly reduced at subsoil gas conditions. This lead to the conclusion that subsoil gas conditions alter the metabolism of microorganisms but not the degradation of added plant residues is general. The third experiment was a field experiment carried out for two years. Mesh bags containing original soil material and maize root residues (C4 plant) were buried at three different depths at the two sites. The recovery of the soilbags took place 12, 18, and 24 months after burial. We determined the effects of these treatments on SOC, density fractions, and MBC. The mean residence time for maize-derived C was similar at all depths and both sites (403 d). MBC increased to a similar extent (2.5 fold) from the initial value to maximum value. This increase relied largely on the added maize root residues. However, there were clear differences visible in terms of the substrate use efficiency, which decreased with depth and was lower in the Luv than in the Cam. Hence freshly added plant material is highly accessible to microorganisms in subsoil and therefore equally degraded at both sites and depths, but its metabolic use was determined by the legacy of soil properties. These findings provide strong evidence that resource availability from autochthonous SOM as well as from added plant residues have a strong influence on the microbial community and its use of different substrates. However, under all of the applied conditions there was no evidence that complex substrates, i.e. plant residues, were less degraded in subsoil than in topsoil.

Perceived Work-related Factors and Turnover Intention : - A Case Study of a South Korean Construction Company

Purpose – Employee turnover entails considerable costs and is a major problem for the construction industry. By creating an extensive framework, this study aims to examine whether perceived work-related factors affect turnover intention in South Korean construction companies. Research design – The paper is based on the results of a questionnaire of 136 employees that was conducted and provided by a Korean construction company. Research hypotheses were tested via correlation analyses. The most influencing work-related factors, as well as differences among job levels, were determined by multiple regression analyses. Findings – Communication, immediate leaders, organizational commitment, and organizational pride substantially affect turnover intentions. All of these factors can be considered as relational factors. The most influencing factors differ among job levels. Discussion/practical implications – Immediate leaders should be aware of their role in retaining employees and enhance communication, organizational commitment and pride. This study shows how the importance of certain variables differs for groups of employees. Theoretical implications/limitations– This study is based on a sample of employees from a Korean construction company. Therefore, the generalizability of the findings has to be tested. Future research should test the proposed framework with other factors or resources. Originality/value – This study shed light on the turnover subject in the South Korean construction industry. It shows that different factors can influence turnover intention among job levels. A framework was created, which is based on 16 work-related factors including organizational factors, HRM practices and job attitudes.

IT Adoption and Usage in Non-Profit Organizations: a Cross-generational Case Study

A gulf has tended to develop between the adoption and usage of information technology by different generations, at the heart of which is different ways of experiencing and relating to the world around us. This research idea is currently being developed following data collection and feedback is sought on ways forward to enable impact. The research focuses on information technology in the form of multimedia. Multimedia meaning ‘media’ and ‘content’ that uses a combination of different content forms; or electronically integrated communication engaging all or most of the senses (e.g. graphic art, sound, animation and full-motion video presented by way of computer or other electronic means) mainly through presentational technologies. Although multimedia is not new, some organization’s particularly those in the non-profit sector do not always have the technical or financial resources to support such systems and consequently may struggle to adopt and support its usage amongst different generations. However non-profit organizations are being forced to pay more attention to the way they communicate with markets and the public due to the professionalism of communication everywhere in society. The case study used for this study is a church circuit comprising of 15 churches in the Midlands region of the United Kingdom which was selected due to the diverse age groups catered for within this type of non-profit organization. Participants in the study also had a range of skills, experiences and backgrounds which adds to the diversity of the population studied. Data gathered focused on the attitudes and opinions of the adoption and use of multimedia amongst different age groups. 395 questionnaires were distributed, comprising of 11 opinion questions and 4 demographic questions. 83% of the questionnaires were returned, representing 35% of the total circuit membership. Three people from each of the following age categories were also interviewed: 1920 – 1946 (Matures); 1947-1964 (Baby Boomers); 1965-1982 (Generation X); 1983-2004 (Net Generation). Results of the questionnaire and comments from the interviews were found not to tally with the widespread assumption that the younger generation is attracted by the use of multimedia in comparison to the older generation. The highest proportion of those who said that they gain more from a service enhanced by multimedia was from the Baby Boomers. Comments from interviews suggested that: ‘we need to embrace multimedia if we are to attract and retain the younger generation’; ‘multimedia often helps children to remain focused and clarifies the objective of the service’. However, because the younger generations’ world tends to be dominated by computer technology the questionnaire showed that they are more likely to have higher standards when it comes to the use of multimedia, such as identifying higher levels of equipment failing to work and annoying use of sounds compared to older age groups. In comparison problems experienced with multimedia for the Matures age group had the highest percentage of difficulty with the size of letters; the colour of letters and background and the sound not loud enough which is to be expected. Since every organization is unique any type of multimedia adopted and used should be specific to their needs, its stakeholders and the physical building in order to enhance that uniqueness and its needs. Giving thought to whether the type of multimedia is the best method for communicating the message to the particular audience alongside how technical and financial resources are best used can assist in accommodating different age groups that need to be catered for.

Causes of teachers’ turnover intentions in Swedish schools : A qualitative research

Purpose – The purpose of this paper is to explore the causes of teachers' turnover intentions in selected Swedish schools. Research methodology – This research took the form of a qualitative research. Semi-structured interviews were used to explore the causes of teachers' turnover intentions within the schools selected for this study. The sample was composed by 9 teachers that work in Säter. In order to provide a different yet meaningful perspective, a further interview with the Säter school department has been conducted. Results – Several of the results were coherent with the literature: elements such as motivations to teach, administrative support, workload, class size and collaboration were found to be related to teachers’ turnover intentions and therefore confirmed the previous studies. However, factors like salary, mentoring, autonomy, physical conditions and orderly environment were not found to have a connection with the respondents’ turnover intentions, hence constituting a result that did not confirm the literature. Originality – This thesis extended the previous research related to the causes of teachers’ turnover intentions by focusing on Sweden, which had not been investigated yet to that matter. The Swedish context appears particularly worth researching because of both the particularity of its decentralized educational system and the widespread turnover intentions of teachers.

Changing times, changing stories: generational differences in climate change perspectives from four remote indigenous communities in Subarctic Alaska

Indigenous Arctic and Subarctic communities currently are facing a myriad of social and environmental changes. In response to these changes, studies concerning indigenous knowledge (IK) and climate change vulnerability, resiliency, and adaptation have increased dramatically in recent years. Risks to lives and livelihoods are often the focus of adaptation research; however, the cultural dimensions of climate change are equally important because cultural dimensions inform perceptions of risk. Furthermore, many Arctic and Subarctic IK climate change studies document observations of change and knowledge of the elders and older generations in a community, but few include the perspectives of the younger population. These observations by elders and older generations form a historical baseline record of weather and climate observations in these regions. However, many indigenous Arctic and Subarctic communities are composed of primarily younger residents. We focused on the differences in the cultural dimensions of climate change found between young adults and elders. We outlined the findings from interviews conducted in four indigenous communities in Subarctic Alaska. The findings revealed that (1) intergenerational observations of change were common among interview participants in all four communities, (2) older generations observed more overall change than younger generations interviewed by us, and (3) how change was perceived varied between generations. We defined “observations” as the specific examples of environmental and weather change that were described, whereas “perceptions” referred to the manner in which these observations of change were understood and contextualized by the interview participants. Understanding the differences in generational observations and perceptions of change are key issues in the development of climate change adaptation strategies.

Burnout and turnover intentions in Australian coaches as related to organisational support and perceived control

Eficácia de um programa de formulação de objectivos no basquetebol, efeitos no rendimento e nas competências psicológicas. Turnover, uma consequência presente, uma realidade inalterável?

Dissertação de Mestrado apresentada no Instituto Superior de Psicologia Aplicada para obtenção de grau de Mestre na especialidade de Psicologia Social e das Organizações

Knowing What to Do: School Focus, Teacher Morale, and Teacher Turnover

This study explored how schools’ focus – the collective perception among teachers of clarity and consistency regarding school goals, expectations, and priorities – related to schoolwide morale and school turnover rates. I examined the hypothesis that focus attenuates the deleterious effects of student misconduct on teacher morale and the contributory role of student misconduct leading to teacher turnover. In addition, I examined climate strength regarding perceptions school focus as an indicator of focus itself, as well a potential moderating effect of climate strength on the magnitude of school focus-school morale and school focus-turnover relationships. Data from a national sample of middle and high schools (N schools = 348, N teachers = 11,376) were analyzed using school-level multiple regression models. Schools with higher focus had significantly higher morale, independent of related perceptions of administrative leadership. No significant relationship was found between school focus and school turnover rates. The hypothesized moderating effect of focus on student misconduct and morale was not supported, though there was a significant indication that focus attenuated the positive relationship between student misconduct and turnover. Climate strength of school focus ratings significantly correlated with focus scores, but did not moderate relationships between focus and predicted outcomes. Findings suggest that school-level focus does represent a characteristic of schools that has a meaningful positive relationship with teacher morale but do not necessarily clarify how that relationship manifests in schools or if that relationship presents an avenue for intervention.

Qualidade de vida no trabalho nos serviços de maior turnover do Hospital Nossa Senhora do Rosário, E.P.E.

O desempenho de uma atividade laboral prende-se, de um modo geral, com a necessidade de realização pessoal e profissional e a necessidade de subsistência. A qualidade de vida no trabalho envolve fatores fundamentais, desde as condições físicas do local de trabalho à progressão na carreira que, por sua vez vão influenciar a produtividade, a motivação e os custos associados à falta de qualidade dos cuidados. Cabe a cada Organização ser responsável pela manutenção e melhoria qualidade de vida dos seus colaboradores e, deste modo, com o desenvolvimento de pessoal especializado e motivado, a Organização consegue diminuir os custos e aumentar a produtividade. Esta investigação pretende identificar quais os fatores que influenciam a qualidade de vida no trabalho dos enfermeiros que desenvolvem os seus cuidados nos Serviços com maior turnover do Hospital Nossa Senhora do Rosário, E.P.E. (HNSR, E.P.E.), que são: o Serviço de Cirurgia, Medicina e a Urgência Geral. Foi elaborado um questionário dirigido aos enfermeiros prestadores de cuidados com o intuito de recolher dados relativos aos fatores que influenciam a qualidade de vida e as suas consequências (turnover, acidentes de trabalho e stress ocupacional). Os enfermeiros destacaram como principais fatores influenciadores da qualidade de vida no trabalho a sobrecarga de trabalho e a motivação para a realização do trabalho e como consequências da falta de qualidade de vida no trabalho a desmotivação e o desgaste físico e psicológico. ABSTRACT: The requirement of an employment is closely related to personal and professional fulfilments, and also to subsistence matters. The quality of life of the employee depends upon factors like physical labor conditions to range from career development. These factors will affect the performance and motivation of the employee. Each institution should be responsible for the maintenance and improvement of the quality of life of their employees. This will allow for the development of specialized staff which in turn may lead to a reduction on costs and to higher productivity. The aim of this research project is to identify the factors that have a great influence on the quality of life of nurses working on HNSR, E.P.E. departments with higher turnover. The departments with higher turnover are: surgery, medicine and emergency. ln order to collect information about the different factors influencing quality of life and their ultimate consequences, such as turnover, labor accidents and occupational stress, a questionnaire was set up. Afterwards, this questionnaire was sent to nursing care staff of HNSR, E.P.E. The nurses mention as major indicators influencing their quality of life at their job: the overload of work and motivation to care. The main stated consequences of the lack of quality life at work were: demotivation and burnout.

Human resources management, citizenship behavior, and turnover intention in the portuguese public administration

Framed by a social exchange perspective, this study address the issue of whether positive employees’ perceptions about human resource management practices influence positive attitudes and behaviour. We hypothesize that human resource management practices (HRMP) have a significant negative effect on intention to voluntary leave the organization and a positive effect on organizational citizenship behaviour (OCB), and that OCB could mediate the relationship between HRMP and turnover intention. A sample of 165 employees from the Portuguese public administration participated in the study. Data was analysed through descriptive statistics, confirmatory factor analysis and hypotheses were tested using single and multiple linear regressions. Results indicate that HRMP is positively associated with OCB, but only internal communication practice is highly valued by Portuguese public employees and successfully predicts OCB. HRMP also show a positive association with turnover intention but only celebration and recognition practices are predictors of turnover intention. Contrary to our hypothesis OCB did not acted as mediator between HRMP and turnover intention. Some suggestions on managerial human resource practices were proposed as well as some main questions raised in the Portuguese public administration context.

Progress in understanding of the molecular basis underlying functional diversification of cyclic di-nucleotide turnover proteins

Cyclic di-GMP was the first cyclic di-nucleotide second messenger described, presaging the discovery of additional cyclic di-nucleotide messengers in bacteria and eukaryotes. The GGDEF diguanylate cyclase (DGC) and EAL and HD-GYP phosphodiesterase (PDE) domains conduct the turnover of cyclic di-GMP. These three unrelated domains belong to superfamilies that exhibit significant variations in function, to include both enzymatically active and inactive members with a subset involved in synthesis and degradation of other cyclic di-nucleotides. Here we summarize current knowledge of sequence and structural varitions that underpin the functional diversification of cyclic di-GMP turnover proteins. Moreover, we highlight that superfamily diversification is not restricted to cyclic di-GMP signaling domains, as particular DHH/DHHA1 domain and HD domain proteins have been shown to act as cyclic di-AMP phosphodiesterases. We conclude with a consideration of the current limitations that such diversity of action places on bioinformatic prediction of the roles of GGDEF, EAL and HD-GYP domain proteins.

Overexpression Of Ucp1 In Tobacco Induces Mitochondrial Biogenesis And Amplifies A Broad Stress Response.

Uncoupling protein one (UCP1) is a mitochondrial inner membrane protein capable of uncoupling the electrochemical gradient from adenosine-5'-triphosphate (ATP) synthesis, dissipating energy as heat. UCP1 plays a central role in nonshivering thermogenesis in the brown adipose tissue (BAT) of hibernating animals and small rodents. A UCP1 ortholog also occurs in plants, and aside from its role in uncoupling respiration from ATP synthesis, thereby wasting energy, it plays a beneficial role in the plant response to several abiotic stresses, possibly by decreasing the production of reactive oxygen species (ROS) and regulating cellular redox homeostasis. However, the molecular mechanisms by which UCP1 is associated with stress tolerance remain unknown. Here, we report that the overexpression of UCP1 increases mitochondrial biogenesis, increases the uncoupled respiration of isolated mitochondria, and decreases cellular ATP concentration. We observed that the overexpression of UCP1 alters mitochondrial bioenergetics and modulates mitochondrial-nuclear communication, inducing the upregulation of hundreds of nuclear- and mitochondrial-encoded mitochondrial proteins. Electron microscopy analysis showed that these metabolic changes were associated with alterations in mitochondrial number, area and morphology. Surprisingly, UCP1 overexpression also induces the upregulation of hundreds of stress-responsive genes, including some involved in the antioxidant defense system, such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and glutathione-S-transferase (GST). As a consequence of the increased UCP1 activity and increased expression of oxidative stress-responsive genes, the UCP1-overexpressing plants showed reduced ROS accumulation. These beneficial metabolic effects may be responsible for the better performance of UCP1-overexpressing lines in low pH, high salt, high osmolarity, low temperature, and oxidative stress conditions. Overexpression of UCP1 in the mitochondrial inner membrane induced increased uncoupling respiration, decreased ROS accumulation under abiotic stresses, and diminished cellular ATP content. These events may have triggered the expression of mitochondrial and stress-responsive genes in a coordinated manner. Because these metabolic alterations did not impair plant growth and development, UCP1 overexpression can potentially be used to create crops better adapted to abiotic stress conditions.

Extraction, purification and biochemical characterization of a peroxidase from Copaifera langsdorffii leaves

The aim of this work is to obtain, purify and characterize biochemically a peroxidase from Copaifera langsdorffii leaves (COP). COP was obtained by acetone precipitation followed by ion-exchange chromatography. Purification yielded 3.5% of peroxidase with the purification factor of 46.86. The COP optimum pH is 6.0 and the temperature is 35 ºC. COP was stable in the pH range of 4.5 to 9.3 and at temperatures below 50.0 ºC. The apparent Michaelis-Menten constants (Km) for guaiacol and H2O2 were 0.04 mM and 0.39 mM respectively. Enzyme turnover was 0.075 s-1 for guaiacol and 0.28 s-1 for hydrogen peroxide. Copaifera langsdorffii leaves showed to be a rich source of active peroxidase (COP) during the whole year. COP could replace HRP, the most used peroxidase, in analytical determinations and treatment of industrial effluents at low cost.