A Non-Uniform Predictor-Observer for a Networked Control System

International Journal of Control, Automation and Systems - This paper presents a Non-Uniform Predictor-Observer (NUPO) based control approach in order to deal with two of the main problems related...     

The effect of neighbourhood on rodent communities: an example from Pampean agroecosystems

Pampean region agroecosystems are devoted to agricultural and farming activities, but in the crop field matrix there are relicts of remnant natural habitats. Poultry farms mainly harbour commensal species as house mice and rats, which are rarely present in surrounding habitats. We assessed if neighbourhood to poultry farms affect the presence of Mus musculus in crop fields and their borders, and if rodent community in poultry farms is influenced by the species present in surrounding crop fields and borders. We found that habitat had a significant effect on the abundance of M. musculus. This species showed higher abundance in poultry farms than in crop field borders. Calomys laucha was the unique native species that was captured in farm sheds. We found higher abundance of native species in crop field borders than in crop fields independent of the proximity to the poultry farms. We conclude that rodent communities in poultry farms are little influenced by the surroundings, and show a dominance of M. musculus independently of the presence of native rodent species in neighbour habitats. On the other hand, farms do not export M. musculus to surrounding habitats, and borders only function as corridors for dispersal among farms, while crop fields are rarely used.     

Structural elements of coordination mechanisms in collaborative planning processes and their assessment through maturity models: Application to a ceramic tile company

Maturity is defined as a measure to evaluate the capabilities of an organization in regards to a certain discipline. The Collaborative Planning Process is a very complex process and Coordination mechanisms are especially relevant in this field to align the plans of the supply chain members. The objective of this paper is to develop a maturity model and a methodology to perform assessment for the Structural Elements of Coordination Mechanisms in the Collaborative Planning Process. Structural elements are specified in order to characterize coordination mechanisms in a collaborative planning context and they have been defined as key areas to be assessed by the maturity model. The identified structural elements are: number of decision-makers, collaboration level, interdependence relationships nature, interdependence relationships type, number of coordination mechanisms, information exchanged, information processing, decision sequence characteristics and stopping criteria. Structural elements are assessed using the scheme of five levels: Initial, Repeatable, Defined, Managed and Optimized. This proposal has been applied to a ceramic tile company and the results are also reported.     

Changes in the swimming activity and the glutathione S-transferase activity of Jenynsia multidentata fed with microcystin-RR

We report the effects of sublethal doses of microcystin-RR (MC-RR) on the swimming activity of Jenynsia multidentata as well as the simultaneous response of its detoxication system by measuring glutathion S-transferase (GST) activities in the liver and brain of fish. MC-RR was applied on the food pellets at doses of 0.01, 0.1 and 1 microg g(-1). Swimming activity was recorded 10 min each hour over 24h by using a computer-based image processing system, which facilitates quantification of two measures of fish swimming behaviour (average velocity, movement percentage). Results show that low levels of cyanotoxin increased the swimming activity, while the highest dose used produced significant changes with respect to control group only since approximately 20 h of exposure, when the swimming activity was decreased. On the other hand, GST activity was significantly increased only in the liver and brain of fish fed with the highest MC-RR dose. Both results suggest that fish are reacting to the stress caused by low doses of MC-RR by increasing their swimming activity, raising further questions on the probable neurotoxicity of MCs, and presenting the behavioural change as a good biomarker of early toxic stress. On the other hand, fish reduced their swimming speed at the highest MC-RR dose, when the detoxication activity began, which can be hypothesized to be a reallocation of their energy, favouring detoxication over swimming activity.     

Influence of crystal quality on the excitation and propagation of surface and bulk acoustic waves in polycrystalline AlN films

We investigate the excitation and propagation of acoustic waves in polycrystalline aluminum nitride films along the directions parallel and normal to the c-axis. Longitudinal and transverse propagations are assessed through the frequency response of surface acoustic wave and bulk acoustic wave devices fabricated on films of different crystal qualities. The crystalline properties significantly affect the electromechanical coupling factors and acoustic properties of the piezoelectric layers. The presence of misoriented grains produces an overall decrease of the piezoelectric activity, degrading more severely the excitation and propagation of waves traveling transversally to the c-axis. It is suggested that the presence of such crystalline defects in c-axis-oriented films reduces the mechanical coherence between grains and hinders the transverse deformation of the film when the electric field is applied parallel to the surface.     

Industrial effluents and surface waters genotoxicity and mutagenicity evaluation of a river of Tucuman, Argentina

Assessment of water pollution and its effect upon river biotic communities and human health is indispensable to develop control and management strategies. The aim of this work was to ascertain the biotoxicity of water pollution in samples from industrial effluent discharge areas of Tucumán, Argentina by means of biological tests. Chemical characterization of the water pollution was verified by measuring dissolved oxygen concentration or levels of suspended matter and salts. Genotoxic/mutagenic potential was determined using Allium anaphase-telophase and Ames/Salmonella tests. All samples were phytotoxic and genotoxic for Allium roots. Micronucleus and anaphase aberrations were observed, but they did not show mutagenic effects on Salmonella typhimurium, TA98 and TA100 strains with and without metabolic activation (S9). Our results show the importance of testing industrial effluents by chemical methods and complementary biological tests to optimize the control policy on these environmental samples.     

Colovaginal anastomosis: a unique complication of end-to-end anastomosis stapler use in low anterior resection

Anastomotic staplers have been used in colorectal surgery for several years. End-to-end stapler use for low anterior resection, as well as for other procedures, is common in surgical practice. These staplers have allowed more extended, lower resections of the colorectum without loss of bowel continuity or sphincter function. There have been reported complications of stapler use, with anastomotic stricture and leakage being the most common. We report here a unique complication of direct colovaginal anastomosis using the end-to-end stapler during a low anterior resection of an early-stage rectal adenocarcinoma.