Individually mark–mass release–resight study elucidates effects of patch characteristics and distance on host patch location by an insect herbivore

1. How organisms locate their hosts is of fundamental importance in a variety of basic and applied ecological fields, including population dynamics, invasive species management and biological control. However, tracking movement of small organisms, such as insects, poses significant logistical challenges. 2. Mass-release and individual–mark–recapture techniques were combined in an individually mark–mass release–resight (IMMRR) approach to track the movement of over 2000 adult insects in an economically important plant–herbivore system. Despite its widespread use for the biological control of the invasive thistle Carduus nutans, the host-finding behaviour of the thistle head weevil Rhinocyllus conicus has not previously been studied. Insects were released at different distances from a mosaic of artificially created host patches with different areas and number of plants to assess the ecological determinants of patch finding. 3. The study was able to characterize the within-season dispersal abilities and between-patch movement patterns of R. conicus. Weevils found host plant patches over 900 m away. Large patches, with tall plants, situated close to the nearest release point had the highest first R. conicusresights. Patch area and plant density had no effect on the number of weevils resighted per plant; however, R. conicus individuals were more likely to disperse out of small patches and into large patches. 4. By understanding how R. conicus locates host patches of C. nutans, management activities for the control of this invasive thistle can be better informed. A deeper mechanistic understanding of host location will also improve prediction of coupled plant–herbivore spatial dynamics in general

A Comparison of Two Methods of Quantifying Mating Success in Low Density Gypsy Moth (Lymantria dispar) Populations

The gypsy moth (Lymantria dispar) is a defoliating pest native to Europe and invasive to North America. The gypsy moth is subject to depressed mating success in low density populations, which may restrict spread of the forest pest. Research focusing on gypsy moth density as it relates to mating behavior has often used counts of males caught in pheromone-baited delta traps as a proxy to estimate the probability of female mating success. The purpose of this project was to determine whether pheromone trap counts provide accurate estimates of female mating success probability, by comparing data gathered from pheromone-baited delta traps to data gathered on mating success of tethered females. To determine the relationship between number of males caught in delta traps and the probability of successful mating, male catch counts in traps were compared to mating success of tethered females in a mass male release experiment. The relationship between delta trap catch of males and female mating success was quantified using a Bayesian framework, which explicitly incorporates uncertainties in the model. Vegetative cover in the study plots was reduced to a single measure through principal components analysis and included as an independent factor in the model. The data suggest that delta traps reduce the male’s ability to find a female by 67%; thus, results garnered from delta trap catch counts tend to underestimate the underlying ability of males to locate and mate with females. Thick understory vegetation further reduced the male’s ability to locate a female, and further reduced the effectiveness of delta traps. Future studies that seek to use counts of males in pheromone-baited traps as a proxy for mating success should consider using an adjustment factor to equate the two methods of quantifying reproductive behavior in the gypsy moth.https://scholarscompass.vcu.edu/uresposters/1271/thumbnail.jp

Mapping the future

Individual space time patterns of serial burglary offenders: mapping risk for operational responses This paper reports on research into the space-time behaviour of burglary crime, in particular that of individual serial offenders, and on an extension to the use of the near repeat phenomena in operational policing in Bournemouth as reported at last years’ conference. Analysis appertaining to serial burglary offending over a period of several years was undertaken with access to full offending histories. Little research has been undertaken on this issue with the use of individual offender data, previous work predominantly utilising recorded crime data with reference to crime scene behavioural indicators. Two stages were involved, the first of which can be described as ‘area analysis’, the purpose being to ascertain if space-time clusters (or ‘near repeats’) were manifest in recorded crime data for the study area. The results were used to inform the second stage comprising of crime series’ analysis of identified prolific burglary offenders to establish their propensity to commit offences close in space and close in time. The work required the development of a new methodology to ascertain and describe potential space-time patterns of individuals. Closest offending behaviour of individuals was established in terms of both time and distance and descriptive statistics with measures of skewness utilised as indicators of overall behaviour. The results add to previous academic findings in the field of crime prevention, providing further evidence that current ‘repeat offence’ crime reduction policies need reviewing and expanding to take account of the element of contagious risk apparent in burglary crime. Concerning individual offending behaviour indications from this work are that most serial burglary offenders commit ‘near repeat’ burglaries, there is a common range of time spans and distance bands within which such offending is carried out. The result of this recent research strongly suggests that serial offenders identify minimum distances from previous offences within which they will prefer not to offend further until a certain minimum time has elapsed. In other words offenders mentally place spatial and temporal buffers around past crime locations and avoid offending within the spatial buffer until the time buffer has ‘expired’. In an effort to retain an operational output the author further developed empirical analysis of serial offending patterns in order to identify small space spatial behaviour of active serial burglary offenders. Simple spreadsheet functions are used in such a way that a serial offender’s personal space-time buffers can be determined as his/her series of crimes develops. This in turn suggests areas and time spans where an offence is unlikely to take place and therefore conversely where the risk of offending is greater. Such mapping therefore creates both enforcement and reduction opportunities that are empirically led. Dorset Police are currently utilising this new analytical method in order to enhance identification and linking of crime series and provide additional evidence led pro-active enforcement opportunities. To date it has proved to be a useful and valid tool, in particular for planning both overt and covert patrol/observation strategies that will be exampled within the presentation

Derek Johnson Dante\u27s Inferno Mini Magazine

https://digital.sandiego.edu/ital-347/1004/thumbnail.jp

Segmentation of slap fingerprints

This thesis describes a novel algorithm that segments the individual fingerprints in a multi-print image. The algorithm identifies the distal phalanx portion of each finger that appears in the image and labels them as an index, middle, little or ring finger. The accuracy of this algorithm is compared with the publicly-available reference implementation, NFSEG, part of the NIST Biometric Image Software (NBIS) suite developed at National Institute of Standards and Technology (NIST). The comparison is performed over large set of fingerprint images captured from unique individuals

Design and testing of an independently controlled urea-SCR system for marine diesel applications

Diesel engine emissions for on-road, stationary and marine applications are regulated through new EPA standards. The most difficult species of exhaust gas constituents to reduce are oxides of nitrogen, NOx. The use of urea selective catalytic reduction (SCR) is promising for NO x abatement as a retrofit application. This work focused on the reduction of NOx by use of a stand alone urea injection system, applicable to marine diesel engines. Most current systems communicate with engine controls to predict NOx emissions based on signals such as torque and engine speed. Many marine engines employ mechanical injection technology and lack communication abilities. This system estimated NOx and measured exhaust flow independent of engine parameters. The system used independent exhaust sensor inputs to estimate NOx levels and exhaust gas flow rate. These sensor inputs were used in an independent controller and an open loop model to estimate the necessary amount of urea needed. The controller then used pulse width modulation (PWM) to power an automotive style injector for urea delivery. The goal of this work was to reduce the engine out NO x levels by 50 percent. Emissions tests were conducted at the West Virginia University\u27s Engine Research Center. The data were analyzed to determine the NOx reduction ability of the system. NOx reduction capabilities of 41-67% were shown on the Non Road Transient Cycle (NRTC) and ICOMIA E5 Steady State cycles. The system was optimized during testing to minimize the dilute ammonia slip to cycle averages of 5-7 ppm. The goal of 50% reduction of NOx can be achieved dependent upon cycle. Further research with control optimization and possible use of oxidation catalysts is recommended to further improve the systems NOx reduction capabilities while minimizing ammonia slip