Preparation of s i lvicul tural prescriptions i s a complex process in lodgepole pine ecosystems. Ecological factors and management decisions must be considered. The presence or absence of dwarf mistletoe in a stand i s one ecological factor that must be considered. Control of dwarf mistletoe i s possible through application of sound s i 1 vicul tural principles.

This paper studies the optimal control of an animal-vegetation system where growth in the animal stock is density independent. The ecological system is shown to have a limit cycle, under certain parameter values, but can also be stabilized by a simple harvesting rule. The managing unit maximizes profits from selling the meat, over an infinite planning horizon. With a domestic animal stock, cost...

BACKGROUND Drug-resistant tuberculosis (DR-TB) is a major public health problem caused by various factors. It is essential to systematically investigate the epidemiological and, in particular, the ecological factors of DR-TB for its prevention and control. Studies of the ecological factors can provide information on etiology, and assist in the effective prevention and control of disease. So it ...

Fecal indicator bacteria (FIB) have long been used as a marker of fecal pollution in surface waters subject to point source and non-point source discharges of treated or untreated human waste. In this paper, we set out to determine the source(s) of elevated FIB concentrations in Cucamonga Creek, a concrete-lined urban stream in southern California. Flow in the creek consists primarily of treate...

Mollusca are the second largest phylum of the animal kingdom, forming a major part of the world fauna. The Gastropoda is the only class of molluscs which have successfully invaded land. They are one of the most diverse groups of animals, both in shape and habit. Among gastropods, land snails (subclass: Pulmonata) are one of the most numerous with almost 35,000 described species of the world. Th...

Ecological Interface Design (EID) is a theoretical framework for designing interfaces for complex human – machine systems . This article investigates the utility of EID in inducing ef fective real-time operator control performance during both normal and abnormal conditions . Two interfaces for a thermal-hydraulic process were compared , an EID interface based on physical and functional (P 1 F) ...

To study the effectiveness of an integrated intervention of health Objective: worker training, a low-cost ecological mosquito ovitrap, and community engagement on spp. mosquito control over 10 months in 2015 in an Aedes urban remote community in Guatemala at risk of dengue, chikungunya and Zika virus transmission. We implemented a three-component integrated intervention Methods: consisting of...

Traditional hazard analysis techniques are grounded in reliability theory and analyze the human controller-if at all-in terms of estimated or calculated probabilities of failure. Characterizing sub-optimal human performance as "human error" offers limited explanation for accidents and is inadequate in improving the safety of human control in complex, automated systems such as today's aerospace ...

We discuss some properties of Lorentz invariant theories which allow for superluminal motion. We show that, if signals are always sent forward in time, closed curves along which signals propagate can be formed. This leads to problems with causality and with the second law of thermodynamics. Only if one singles out one frame with respect to which all signals travel forward in time, the formation...