Is It Benign or Is It a Pariah? Empirical Evidence for the Impact of the Common Myna (Acridotheres tristis) on Australian Birds

There is widespread concern over the impact of introduced species on biodiversity, but the magnitude of these impacts can be variable. Understanding the impact of an introduced species is essential for effective management. However, empirical evidence of the impact of an introduced species can be difficult to obtain, especially when the impact is through competition. Change in species abundance is often slow and gradual, coinciding with environmental change. As a result, negative impacts on native species through competition are poorly documented. An example of the difficulties associated with obtaining empirical evidence of impact due to competition comes from work on the Common Myna (Acridotheres tristis). The species is listed in the World's top 100 worst invaders, despite a lack of empirical evidence of its negative impacts on native species. We assessed the impact of the Common Myna on native bird abundance, using long-term data both pre and post its invasion. At the outset of our investigation, we postulated that Common Myna establishment would negatively affect the abundance of other cavity-nesting species and bird species that are smaller than it. We found a negative relationship between the establishment of the Common Myna and the long-term abundance of three cavity-nesting species (Sulphur-crested Cockatoo, Crimson Rosella, Laughing Kookaburra) and eight small bird species (Striated Paradoxes, Rufous Whistler, Willie Wagtail, Grey Fantail, Magpie-lark, House Sparrow, Silvereye, Common Blackbird). To the best of our knowledge, this finding has never previously been demonstrated at the population level. We discuss the key elements of our success in finding empirical evidence of a species impact and the implications for prioritisation of introduced species for management. Specifically, prioritization of the Common Myna for management over other species still remains a contentious issue.This work is supported in part by the Invasive Animals Cooperative Research Centre and the Australian National University. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Reasons Why Cows Were Removed From the SDSU Fairy Herd 1. Discriminant Analysis to Classify Cows with or without Reproductive Problems

One of the keys to financial success in the dairy business is the ability of management to detect herd problems and correct them instead of culling cows. It is well known that the average productive life of the dairy cow is less than 4 yr, which is short compared with her potential life. Involuntary removal of cows causes economic loss directly as a result of its effect on yearly milk production, increased replacement cost, and indirectly because the potential selection differential is reduced with premature loss of high producing cows. The degree of culling is related to important economic considerations such as the prices of milk and beef, as well as the prices of feed, and the cost and availability of labor. Studies on the disposal rates of cows from Dairy Herd Improvement Association (DHIA) and research herds have shown that a large portion of the cull cows were removed because of low production, reproductive problems, mastitis, sold for dairy purposes, and type related problems. Dairymen have indicated that low fertility is their number one herd problem despite the fact that there is no known infectious disease problem. Reproductive problems accounted for the largest amount of involuntary losses in studies of disposal rates of cows from DHIA and research herds. Reproductive failure in dairy cattle causes economic loss directly as a result of its adverse effect on yearly milk production and on surplus calves for sale, and indirectly because the potential selection differential is reduced with fewer replacements. Infertility in cows appears to be primarily a management problem. Heritability of breeding efficiency is low, thus, selection for breeding efficiency would not be effective and would be at the expense of other traits of economic importance which show a greater response to selection. Researchers have suggested that any effective evaluation of genetic differences for breeding efficiency among cows must await the development of new criteria. These tests should be simple and easily applied on a widespread basis. Most production variables considered in sire selection have medium to high repeatability and heritability estimates. Young sires are evaluated on first-lactation performance of this progeny, and any relationship with later performance of length of herd life would have an important bearing on the evaluations. Selection of highly productive cows without conscious emphasis on fertility will not lead to a population with markedly altered ability to reproduce. The reasons why cows were removed from the South Dakota State University dairy research herd were examined in this study. The results will serve as a guide for herdsmen and researchers to technical problems of management, breeding, and of disease on dairy farms. This study also examined the use of stepwise discriminant analysis to identify those cows with or without reproductive problems using the following selected discriminator variables: lactation number, yield of 305-ME milk, yield of 305-ME milk fat, age adjusted type score, difference from herdmates-milk, difference from herdmates-milk fat, percent protein-lactose-minerals (PLM), and yield of PLM. This analysis was also used to find a reduced set of discriminator variables

A Groovy Virtual Drummer:Learning by Imitation Using a Self-Organizing Connectionist Architecture

The research in this thesis aims to enable robots to imitate humans. Learning by imitation is a fundamental part of human behaviour, since it allows humans to acquire motor skills simply by demonstration; seen from a robotic viewpoint you can easily “program” your fellow humans by showing them what to do. Would it not be great if the same mechanism could be used to program robots? A robot is programmed by specifying the torque of its motors. The torque can be regarded as the force or strength that is the result of muscles contracting or relaxing. Typical approaches to determine motor torques that will lead to a desired behaviour include setting them manually, i.e. on a trial-and-error basis, or specifying them by mathematical equations. Neither of these are intuitive to most humans, so most robot behaviours are programmed by engineers. However, if an engineer was to design a preprogrammed housekeeping robot, it would be very hard to program all the possible behaviours the robot could be expected to perform, even in such a limited domain. It is much more cost-efficient to make the robot learn what to do. This would allow the robot to adapt to its human owner, and not the other way around. Since humans easily learn new behaviours by imitating others, it would be ideal if humans could use the same technique to transfer motor knowledge to robots. I believe research in this area could be of great help to bridge the human-robot interaction gap that currently exists, so that you could have truly intelligent robots that could assist people in everyday life. To understand imitation learning, knowledge of psychology and neuroscience is required. The research in this thesis has taken an interdisciplinary approach, studying the desired mechanism on both a behavioural and neuroscientific level. I have focused on imitation in a musical setting. The system can both see and hear, and seeks to imitate the perceived behaviour. The application has been to create an intelligent virtual drummer, that imitates both the physical playing style (i.e. the movement of the arms) as well as the musical playing style (i.e. the groove) of the teacher. The virtual drummer will then both look and sound like a human drummer. The research in this thesis presents a multi-modal architecture for imitation of human movements. I have been working on simulated robots due to limits of time and money, however the principles of my research have been developed in a platformindependent way, so it should be applicable to real robots as well.PhD i informasjons- og kommunikasjonsteknologiPhD in Information and Communications Technolog

Robotic optical observations of compact binary millisecond pulsars

Denne masteroppgaven fokuserer på robotiske optiske observasjoner av den kompakte dobbeltstjerne-millisekundpulsaren PSR J1048+2339, utført ved hjelp av Joan Oró-teleskopet (TJO). Som en del av masterarbeidet ble en programvare produsert for å effektivisere observasjoner tatt med TJO. Denne programvaren ble anvendt på data av PSR J1048+2339 samlet inn i løpet av en periode på fire måneder i 2020 av teleskopet. Vi presenterer funnene fra disse observasjonene, supplert med data samlet inn fra Nordic Optical Telescope (NOT). Oppgaven utforsker den teoretiske bakgrunnen for nøytronstjerner og dekker emner som nøytronstjernedannelse, ulike fysiske parametere og nøytronstjerners utvikling. Vi undersøker hvordan feltet for observasjonsastrofysikk påvirkes av moderne, robotiske, optiske observasjonsmetoder, inkludert bruk av heldekkende undersøkelser av nattehimmelen (sky surveys) og små robotiske teleskoper. Fra dette utgangspunktet utvikler og implementerer vi en brukervennlig programvare og demonstrerer dens praktiske fordeler for observatører som benytter TJO. Videre presenterer vi resultatene av optiske fotometriske observasjoner av den kompakte dobbeltstjerne-millisekundpulsaren PSR J1048+2339, utført både ved hjelp av TJO og NOT. Dataene viser konsekvente, asymmetriske lyskurver med ett enkelt maksimum. Dette enkle makimumet i lyskurven tyder på at kompanjongstjernen er bestrålt av millisekundpulsaren, mens asymmetrien kan være resultatet av et sjokk mellom stjernene som følge av interaksjonen mellom pulsarvinden og kompanjongvinden. Grunnet den sirkulære bevegelsen til stjernene om hverandre kan dette sjokket flyttes mot siden av kompanjongstjernen som er vendt vekk fra bevegelsesretningen. Lyskurvene viser ulike grader av asymmetri mellom ulike bånd, noe som potensielt kan tilskrives den underliggende ellipsoidale modulasjonen som forventes av en deformert kompanjonstjerne. Vi spekulerer i om dette kan skyldes en varm flekk, som følge av pulsarstrålingen, med høyest temperatur ved fase 0.45.This master's thesis focuses on the robotic optical observations of the compact binary millisecond pulsar PSR J1048+2339, obtained using the Joan Oró Telescope (TJO). As part of the thesis work, a pipeline to streamline the observations taken with the TJO was developed. This pipeline was applied to observations of PSR J1048+2339 taken with the TJO over a four-month period in 2020. We present the findings from these observations, complemented by data gathered from the Nordic Optical Telescope (NOT). The thesis also presents the theoretical background for the study of neutron stars, covering topics such as their formation, physical parameters, and evolution. We discuss how the field of observational astrophysics is shaped by modern robotic optical observing methods, including the use of sky surveys and small robotical telescopes. Building upon this, we develop and implement a user-friendly pipeline and demonstrate its practical advantages for observers utilizing the TJO. Furthermore, we present the results of optical photometric observations of the compact binary millisecond pulsar PSR J1048+2339 obtained from both the TJO and the NOT. The data reveal consistent single-peaked asymmetrical light curves over the course of four months of observations. The single-peaked nature of the light curve points to an irradiated companion. We find a strong asymmetry; the flux maximum is observed about $0.1$ orbital cycles before superior conjunction of the companion star. This might be the result of a swept-back intra-binary shock. We speculate that this disparity may lead to a hotspot with its highest temperature occurring at phase 0.45