Search results for "Productivity."
showing 10 items of 557 documents
Soil degradation and its impact on desertification: A research design for Mediterranean environments
1988
Summary Much is said but little is known of the processes and linkages of soil degradation with desertification. With particular emphasis on South-East Spain, a research design is proposed to characterize the processes, their dynamics and effect on productivity. Through detailed monitoring of plot experiments at three slope positions, changes in soil physical and chemical parameters and analyses of runoff and eroded sediments will be related to induced destruction of the vegetation. Knowing the cause and process will lead to the identification of management techniques that may protect vulnerable Mediterranean environments.
Holocene millennial-scale productivity variations in the Sicily Channel (Mediterranean Sea)
2008
[1] The calcareous nannofossil assemblages of Ocean Drilling Program Hole 963D from the central Mediterranean Sea have been investigated to document oceanographic changes in surface waters. The studied site is located in an area sensitive to large-scale atmospheric and climatic systems and to high- and low-latitude climate connection. It is characterized by a high sedimentation rate (the achieved mean sampling resolution is <70 years) that allowed the Sicily Channel environmental changes to be examined in great detail over the last 12 ka BP. We focused on the species Florisphaera profunda that lives in the lower photic zone. Its distribution pattern shows repeated abundance fluctuations of …
Combined Stress Conditions in Melon Induce Non-additive Effects in the Core miRNA Regulatory Network
2021
Climate change has been associated with a higher incidence of combined adverse environmental conditions that can promote a significant decrease in crop productivity. However, knowledge on how a combination of stresses might affect plant development is still scarce. MicroRNAs (miRNAs) have been proposed as potential targets for improving crop productivity. Here, we have combined deep-sequencing, computational characterization of responsive miRNAs and validation of their regulatory role in a comprehensive analysis of response of melon to several combinations of four stresses (cold, salinity, short day, and infection with a fungus). Twenty-two miRNA families responding to double and/or triple …
Boosting Ethanol Productivity of Zymomonas mobilis 8b in Enzymatic Hydrolysate of Dilute Acid and Ammonia Pretreated Corn Stover Through Medium Optim…
2019
The presence of toxic degradation products in lignocellulosic hydrolysate typically reduced fermentation rates and xylose consumption rate, resulting in a decreased ethanol productivity. In the present study, Zymomonas mobilis 8b was investigated for high cell density fermentation with cell recycling to improve the ethanol productivity in lignocellulosic hydrolysate. The fermentation performances of Z. mobilis 8b at various conditions were first studied in yeast extract-tryptone medium. It was found that nutrient level was essential for glucose and xylose co-fermentation by Z. mobilis 8b and high cell density fermentation with cell recycling worked well in yeast extract-tryptone medium for …
Adapting a Phage to Combat Phage Resistance
2020
Phage therapy is becoming a widely recognized alternative for fighting pathogenic bacteria due to increasing antibiotic resistance problems. However, one of the common concerns related to the use of phages is the evolution of bacterial resistance against the phages, putatively disabling the treatment. Experimental adaptation of the phage (phage training) to infect a resistant host has been used to combat this problem. Yet, there is very little information on the trade-offs of phage infectivity and host range. Here we co-cultured a myophage FCV-1 with its host, the fish pathogen Flavobacterium columnare, in lake water and monitored the interaction for a one-month period. Phage resistance was…
Incentive Schemes, Private Information and the Double-Edged Role of Competition for Agents
2013
This paper examines the effect of imperfect labor market competition on the efficiency of compensation schemes in a setting with moral hazard and risk-averse agents, who have private information on their productivity. Two vertically differentiated firms compete for agents by offering contracts with fixed and variable payments. The superior firm employs both agent types in equilibrium, but the competitive pressure exerted by the inferior firm has a strong impact on contract design: For high degrees of vertical differentiation, i.e. low competition, low-ability agents are under-incentivized and exert too little effort. For high degrees of competition, high-ability agents are over-incentivized…
Evaluating European railway deregulation using different approaches
2012
Abstract There has recently been a great deal of interest in the impacts of the deregulating and restructuring measures in the European railway sector. A vast amount of literature is devoted to analyzing the effects of these deregulation and restructuring measures on efficiency and productivity and the results are not totally unambiguous. However, while most of the papers show that the introduction of competition within the sector (in both passenger and freight markets) has had a positive impact in terms of efficiency and productivity, the impact of vertical separation has produced different results in the literature. The contribution of this paper to the existing literature is twofold. Fir…
Are you a good employee or simply a good guy? Influence costs and contract design
2013
We develop a principal–agent model with a moral hazard problem in which the principal has access to a hard signal (the level of output) and a soft behavioral signal (the supervision signal) about the agent's level of effort. In our model, the agent can initiate influence activities and manipulate the behavioral signal. These activities are costly for the principal as they detract the agent from the productive task. We show that the agent's ability to manipulate the behavioral signal leads to low-powered incentives and increases the cost of implementing the efficient equilibrium as a result. Interestingly, the fact that manipulation activities entail productivity losses may lead to the desig…
A DEA-based transport heliports' efficiencies evaluation
2015
Purpose - The purpose of the study is the evaluation of the efficiencies of a group of small Italian airports and the comparison with a set of transport heliports to show the difference in the productivity of the two types of infrastructures. Design/methodology/approach - The methodology used for the evaluation is the data envelopment analysis (DEA). Findings - The better performance of the heliports compared to the small inefficient airports. Research limitations/implications - This research is limited by the field of application and the weaknesses of the DEA methodology. However, it could be the first step for further works that will include more accurate models. Practical implications - …
Learning Pros and Cons of Model-Driven Development in a Practical Teaching Experience
2016
Current teaching guides on Software Engineering degree focus mainly on teaching programming languages from the first courses. Conceptual modeling is a topic that is only taught in last courses, like master courses. At that point, many students do not see the usefulness of conceptual modeling and most of them have difficulty to reach the level of abstraction needed to work with them. In order to make the learning of conceptual modeling more attractive, we have conducted an experience where students compare a traditional development versus a development using conceptual models through a Model-Driven Development (MDD) method. This way, students can check on their own pros and cons of working w…