scholarly journals Plant Response to Mechanically-Induced Stress: A Case Study on Specialized Metabolites of Leafy Vegetables

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2650
Author(s):  
Jana Šic Žlabur ◽  
Sanja Radman ◽  
Sanja Fabek Uher ◽  
Nevena Opačić ◽  
Božidar Benko ◽  
...  

Plants have evolved various adaptive mechanisms to environmental stresses, such as sensory mechanisms to detect mechanical stimuli. This plant adaptation has been successfully used in the production practice of leafy vegetables, called mechanical conditioning, for many years, but there is still a lack of research on the effects of mechanically-induced stress on the content of specialized metabolites, or phytochemicals with significant antioxidant activity. Therefore, the aim of this study was to determine the content of specialized metabolites and antioxidant capacity of lettuce and green chicory under the influence of mechanical stimulation by brushing. Mechanically-induced stress had a positive effect on the content of major antioxidants in plant cells, specifically vitamin C, total phenols, and flavonoids. In contrast, no effect of mechanical stimulation was found on the content of pigments, total chlorophylls, and carotenoids. Based on the obtained results, it can be concluded that induced mechanical stress is a good practice in the cultivation of leafy vegetables, the application of which provides high quality plant material with high nutritional potential and significantly higher content of antioxidants and phytochemicals important for human health.

1994 ◽  
Vol 6 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Charles Anderson ◽  
Robert J. Morris

A case study ofa third year course in the Department of Economic and Social History in the University of Edinburgh isusedto considerandhighlightaspects of good practice in the teaching of computer-assisted historical data analysis.


Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 474
Author(s):  
Silvia Todros ◽  
Silvia Spadoni ◽  
Edoardo Maghin ◽  
Martina Piccoli ◽  
Piero G. Pavan

Muscular tissue regeneration may be enhanced in vitro by means of mechanical stimulation, inducing cellular alignment and the growth of functional fibers. In this work, a novel bioreactor is designed for the radial stimulation of porcine-derived diaphragmatic scaffolds aiming at the development of clinically relevant tissue patches. A Finite Element (FE) model of the bioreactor membrane is developed, considering two different methods for gripping muscular tissue patch during the stimulation, i.e., suturing and clamping with pliers. Tensile tests are carried out on fresh and decellularized samples of porcine diaphragmatic tissue, and a fiber-reinforced hyperelastic constitutive model is assumed to describe the mechanical behavior of tissue patches. Numerical analyses are carried out by applying pressure to the bioreactor membrane and evaluating tissue strain during the stimulation phase. The bioreactor designed in this work allows one to mechanically stimulate tissue patches in a radial direction by uniformly applying up to 30% strain. This can be achieved by adopting pliers for tissue clamping. Contrarily, the use of sutures is not advisable, since high strain levels are reached in suturing points, exceeding the physiological strain range and possibly leading to tissue laceration. FE analysis allows the optimization of the bioreactor configuration in order to ensure an efficient transduction of mechanical stimuli while preventing tissue damage.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zsuzsanna Győri ◽  
Borbála Benedek

Purpose The purpose of this paper is to discuss the stakeholders of debt settlement programmes in general and some lessons learnt from the most significant debt settlement programmes of recent years in Hungary. The study also presents a planned debt settlement programme in Hungary. The paper explores and details behaviours and motivations of different stakeholders in debt settlement in general and also with reference to a specific case study. As for its main research question, the paper seeks to identify the preconditions of a successful debt settlement programme with specially emphasis on the poor. Design/methodology/approach Data from semi-structured in-depth expert interviews, documents and former research papers were collected for identifying previous Hungarian debt settlement programmes and potential lessons learnt. After a general discussion, based on primary and secondary sources, a case study is presented to obtain a more comprehensive understanding of opportunities and challenges of debt settlement. Findings Six preconditions of successful debt settlement targeting the poor are identified. In the case study, the existence and relevance of these preconditions are tested: the main finding is that they all are important for solving the situations, so a partial solution is not sufficient. In the scope of the case study, more precisely within the planned innovative banking solution, the motivations of the bank and the coordinator NGO are identified. On the part of the bank, motivations for solving social problems (both as far as business and moral issues are concerned) are relevant, while – as for the other party – the situation of the debtor is important to understand so that opportunities of cooperation can be identified. In addition, as other stakeholders also influence the potentials of the programme, their cooperative attitude is also needed. Research limitations/implications Limitations consist in generalisation: the study presents some cases from one single country and finally it focuses only on one specific case in one specific social and economic context in Hungary. Having recognized this risk, the author opted for basing research questions on theory, documented the process in detail, and also used triangulation through applying a multiple data collection (interview, content analysis, literature review) method. Practical implications Besides presenting an academic understanding of the phenomena, the goal of the study is to contextualize and interpret the case, to help the realization of currently frozen initiatives and to promote similar future ones. Social implications Indebtedness is a stressful situation affecting families, smaller communities and broader society as well. The planned cooperation of BAGázs and MagNet tries to help people excluded from the banking system. So that a deeper debt trap can be avoided, the goal of this programme is to purchase, partially discharge and reschedule pre-accumulated debts of carefully selected people who have regular income and are willing to undertake bearable repayment. The idea is very innovative with literally no good practice to follow. The research seeks to clarify the pitfalls and opportunities to help the realization of the project and similar future ones. Originality/value A certain form of values-based banking concerns the financial inclusion of the poor, e.g. debt settlement. Nevertheless, over-indebtedness and the settlement of existing debts as well as the relevance of such issues to the financial inclusion are not emphasized enough in the literature or in practice. Besides presenting an academic understanding of the phenomena, the goal of the study is to contextualize and interpret the case, to help the realization of currently frozen initiatives and to promote similar future ones.


2017 ◽  
Vol 7 (2) ◽  
pp. 125 ◽  
Author(s):  
Thomas Staubitz ◽  
Ralf Teusner ◽  
Christoph Meinel ◽  
Nishanth Prakash

Programming tasks are an important part of teaching computer programming as they foster students to develop essential programming skills and techniques through practice.  The design of educational problems plays a crucial role in the extent to which the experiential knowledge is imparted to the learner both in terms of quality and quantity. Badly designed tasks have been known to put-off students from practicing programming. Hence, there is a need for carefully designed problems. Cellular Automata programming lends itself as a very suitable candidate among problems designed for programming practice. In this paper, we describe how various types of problems can be designed using concepts from Cellular Automata and discuss the features which make them good practice problems with regard to instructional pedagogy. We also present a case study on a Cellular Automata programming exercise used in a MOOC on Test Driven Development using JUnit, and discuss the automated evaluation of code submissions and the feedback about the reception of this exercise by participants in this course. Finally, we suggest two ideas to facilitate an easier approach of creating such programming exercises.


2015 ◽  
Vol 27 (3) ◽  
pp. 444-466 ◽  
Author(s):  
Ben Shepherd ◽  
Shintaro Hamanaka

Purpose – The purpose of this paper is to identify major challenges that Asia-Pacific policy makers face in drawing up international logistics policies, and to seek possible solutions to the problems. Design/methodology/approach – Case study method: the paper includes seven case studies that attempt to address various types of logistics challenges. The paper introduces both intra- and extra-regional examples of the ways in which those challenges have been overcome in particular contexts through concerted action by government and the private sector. Findings – There are a lot of interesting experiences of overcoming logistics challenges, both inside and outside the Asia-Pacific region. Good practice experiences can be replicated by other countries in the region. Originality/value – While there have been a lot of discussions on logistics policy reforms, this paper is one of the first attempts that clearly link challenges with concrete case experiences where those are overcome. The paper discusses very practical issues in an analytically sound manner, using case method.


2017 ◽  
Vol 19 (4) ◽  
pp. 187-198 ◽  
Author(s):  
Kathryn Mackay ◽  
Mary Notman

Purpose The purpose of this paper is to outline the duties and powers of the Adult Support and Protection (Scotland) Act (ASPSA) 2007 and place them in the wider Scottish adult protection legislative framework. It considers the potential value of a standalone adult safeguarding statute. Design/methodology/approach The authors draw upon their research and practice expertise to consider the merits of the ASPSA 2007. They take a case study approach to explore its implementation in one particular Scottish local authority, drawing on the qualitative and quantitative data contained in its annual reports. Findings Skilled, knowledgeable and well-supported practitioners are key to effective screening, investigations and intervention. Protection orders are being used as intended for a very small number of cases. Research limitations/implications The lack of national statistical reports means that there is limited scope for comparison between the local and national data. Practical implications Adult support and protection requires ongoing investment of time and leadership in councils and other local agencies to instigate and maintain good practice. Aspects that require further attention are self-neglect; capacity and consent and residents in care homes who pose potential risks to other residents and staff. Social implications ASPSA 2007 has helped to raise awareness of adults at risk of harm within the local communities and as social issue more generally. Originality/value The authors provide a critical appraisal of the implementation of Scottish adult safeguarding legislation over the last six years. They consider similar developments in England and Wales and argue for comparative research to test these out. Finally, they signpost future directions for bridging separate policy streams.


2007 ◽  
Vol 192 (1) ◽  
pp. 131-140 ◽  
Author(s):  
Christianne M A Reijnders ◽  
Nathalie Bravenboer ◽  
Annechien M Tromp ◽  
Marinus A Blankenstein ◽  
Paul Lips

Mechanical loading plays an essential role in maintaining skeletal integrity. Mechanical stimulation leads to increased bone formation. However, the cellular and molecular mechanisms that are involved in the translation of mechanical stimuli into bone formation, are not completely understood. Growth factors and osteocytes, which act as mechanosensors, play a key role during the bone formation after mechanical stimulation. The aim of this study was to characterize the role of IGF-I in the translation of mechanical stimuli into bone formation locally in rat tibiae. Fifteen female Wistar rats were randomly assigned to three groups (n = 5): load, sham-loaded, and control. The four-point bending model of Forwood and Turner was used to induce a single period of mechanical loading on the tibia shaft. The effects of mechanical loading on IGF-I mRNA expression were determined with non-radioactive in situ hybridization on decalcified tibiae sections, 6 h after the loading session. Endogenous IGF-I mRNA was expressed in trabecular and cortical osteoblasts, some trabecular and sub-endocortical osteocytes, intracortical endothelial cells of blood vessels, and periosteum. Megakaryocytes, macrophages, and myeloid cells also expressed IGF-I mRNA. In the growth plate, IGF-I mRNA was located in proliferative and hypertrophic chondrocytes. Mechanical loading did not affect the IGF-I mRNA expression in osteoblasts, bone marrow cells, and chondrocytes, but the osteocytes at the endosteal side of the shaft showed a twofold increase of IGF-I mRNA expression. The proportion of IGF-I mRNA positive osteocytes in loaded tibiae was 29.3 ± 12.9% (mean ± s.d.; n = 5), whereas sham-loaded and contra-lateral control tibiae exhibited 16.7 ± 4.4% (n = 5) and 14.7 ± 4.2% (n = 10) respectively (P < 0.05). Lamellar bone formation after a single mechanical loading session was observed at the endosteal side of the shaft. In conclusion, a single loading session results in a twofold up-regulation of IGF-I mRNA synthesis in osteocytes which are present in multiple layers extending into the cortical bone of mechanically stimulated tibia shaft 6 h after loading. This supports the hypothesis that IGF-I, which is located in osteocytes, is involved in the translation of mechanical stimuli into bone formation.


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