Outbreak of Catopsilia pyranthe L. on Senna (Cassia angustifolia Vahl) and Migration in Western Arid Region of India

Background: Cassia angustifolia Vahl, senna, known for medicinal properties belongs to family fabacea is a hardy plant, suitable for saline and rainfed conditions serving as a host for caterpillars of Catopsilia pyranthe L. butterflies suffering up to 90 per cent defoliation. An attempt was made to record butterfly migrations due to an outbreak of the lepidopteron pest on senna which is the first report on butterfly migration in western arid region.Methods: Surveys made in different districts for accurate quantification of butterflies passing within 5 minute through a 10 meter wide strip. For diurnal pattern, observations were taken on hourly basis. Correlation of butterfly density with weather parameters was worked out.Result: Migration was mainly in South West direction in a steady line connecting Jaisalmer, Jodhpur, Pali, Sirohi and Ajmer. The highest density (1360 butterflies/10m/5 minute) accounting for 16,320.0 butterflies/10m/hour and 97,920.0 butterflies/10m/day recorded in Keru (Jodhpur) representing bell shape curve of diurnal movement with a maximum activity between 12.00 noon and 1.00 PM.

Why trees sleep? - explanations to diurnal branch movement

Physiological processes cause movements of tree stems and branches that follow a circadian rhythm, but there is a lack of quantitative understanding of the cause-and-effect relationships. We investigated the diurnal movement of tree branches using time-series of terrestrial laser scanning measurements coupled with measurements of environmental drivers and tree water status. Our results showed that diurnal movement of branches was largely explained by leaf water status. This conclusion was supported by the significantly lower overnight branch movement in leaf-off than leaf-on conditions. Our findings conclude that alteration in leaf water status causes systematic branch movements following a diurnal rhythm. Due to lower atmospheric water demand during the nighttime, tree branches settle down analogously to sleep as the amount of water in leaves is increasing. The results indicate that quantified movement of tree branches could help us to further monitor and understand the water relations of tree communities.

Optimization of the Bi-Axial Tracking System for a Photovoltaic Platform

The article deals with the optimization of the azimuthal tracking mechanism for a photovoltaic (PV) platform, which uses linear actuators as actuation elements for both movements (diurnal and elevation). In the case of diurnal movement, where the platform’s angular field of orientation is large, a mechanism with a relatively simple structure is used for amplifying the actuator’s stroke and avoiding the risk of the system locking itself (by limiting the values of the transmission angle). The optimization study targets the mechanical device, the control device, and the bi-axial tracking program (embodied by the laws of motion in time for the platform’s diurnal and elevation angles) with the purpose of obtaining a high input of solar radiation, with a minimal energy consumption to achieve tracking. The study is carried out by using a virtual prototyping platform, which includes Computer Aided Design (CAD), Multi-Body Systems (MBS), and Design for Control (DFC) computer applications. The mechanical and control devices of the solar tracker are integrated and tested in mechatronic concept. The simulations’ results, which were performed for a set of representative days throughout the year, prove the effectiveness of the proposed design.

Use of Ant Colony Optimization (ACO) for Post-Deployment Replanning of UMTS Networks

Inherent dynamism in user movement demands for post-deployment tuning of UMTS networks to minimize the total cost of ownership (TCO). Conventionally, UMTS operators so far have considered many-to-one mapping of RNCs to MSCs. However, such single-homed networks do not remain cost-effective over the passage of time, typically when subscribers later on begin to show specific mobility patterns such as diurnal movement. This necessitates topological extension of the network in terms of dual-homing of some selected RNCs to two MSCs simultaneously via direct fibre links, resulting in a many-to-two mapping in parts of the network. The aim of such selective dual-homing is to reduce handoff cost maximally at the expense of minimal increase in link cost, thereby reducing the TCO optimally. In this article, the authors have formulated the scenario as an integer linear programming problem, converted it into a state space search and then solved it using Ant Colony Optimization (ACO) technique. Compared to Simulated Annealing (SA) and Tabu Search (TS), ACO exhibits 10% to 15% improvement in solution quality.

Changes in coyote activity patterns due to reduced exposure to human persecution

Activity patterns in animals are influenced by a number of factors, including the animal's physiological adaptations, prey availability and distribution, and disturbances caused by predators and humans. We compared coyote (Canis latrans) activity patterns estimated using radio-tracking locations between 1983 and 1988 with those documented between 1996 and 1997 on the Pinon Canyon Maneuver Site, in southeastern Colorado. We tested the hypothesis that changes in the type of disturbance experienced by coyotes would result in changes in their activity patterns. Disturbance experienced by the coyote population studied during 1983-1988, included >50 years of intense exploitation (shooting and trapping by ranchers) and intensive removal efforts using aerial gunning. In contrast, coyotes tracked during 1996-1997 experienced some periodic disturbance from army maneuvers occurring in the area, but were not exposed to any direct form of persecution (e.g., shooting). From August 1983 to July 1988, 49 coyotes (26 males and 23 females) were tracked for >2400 h using radiotelemetry. From April 1996 to August 1997, 22 coyotes (12 males and 10 females) were tracked for >950 h. The average rate of diurnal movement of the coyotes in the 1996-1997 field study (mean = 0.97 km/h) was significantly higher than that of the coyotes in the 1983-1988 field study (mean = 0.68 km/h). This occurred despite no significant increase in the overall (24 h) rate of movement between the two field studies. Estimates of prey use by the coyotes in both field studies were obtained, to test an alternate hypothesis that prey switching might explain the changes in coyote movement patterns. However, there was no significant difference between the frequency of occurrence of diurnally versus nocturnally active mammalian prey species in the diets of coyotes in any season or overall between the 1983-1988 and 1996-1997 field studies. This study demonstrated that coyote activity patterns can be influenced by the type of disturbance experienced by the animal. A coyote population that had historically been exposed to human persecution shifted to higher levels of diurnal activity when exploitation ceased.