The Glitches and Rotational History of the Highly Energetic Young Pulsar PSR J0537–6910

We present a timing and glitch analysis of the young X-ray pulsar PSR J0537−6910, located within the Large Magellanic Cloud, using 13 yr of data from the now-decommissioned Rossi X-ray Timing Explorer. Rotating with a spin period of 16 ms, PSR J0537−6910 is the fastest-spinning and most energetic young pulsar known. It also displays the highest glitch activity of any known pulsar. We have found 42 glitches over the data span, corresponding to a glitch rate of 3.2 yr−1, with an overall glitch activity rate of $8.8\times {10}^{-7}\,{\mathrm{yr}}^{-1}$. The high glitch frequency has allowed us to study the glitch behavior in ways that are inaccessible in other pulsars. We observe a strong linear correlation between spin frequency glitch magnitude and wait time to the following glitch. We also find that the post-glitch spin-down recovery is well described by a single two-component model fit to all glitches for which we have adequate input data. This consists of an exponential amplitude $A=(7.6\pm 1.0)\times {10}^{-14}\,{{\rm{s}}}^{-2}$, decay timescale $\tau ={27}_{-6}^{+7}\,\mathrm{day}$s, and linear slope $m=(4.1\pm 0.4)\times {10}^{-16}\,{{\rm{s}}}^{-2}\,{\mathrm{day}}^{-1}$. The latter slope corresponds to a second frequency derivative $\ddot{\nu }=(4.7\pm 0.5)\times {10}^{-22}\,{{\rm{s}}}^{-3}$, from which we find an implied braking index $n=7.4\pm 0.8$. We also present a maximum likelihood technique for searching for periods in event-time data, which we used to both confirm previously published values and determine rotation frequencies in later observations. We discuss the implied constraints on glitch models from the observed behavior of this system, which we argue cannot be fully explained in the context of existing theories

Project manager-to-project allocations in practice: an empirical study of the decision-making practices of a multi-project based organization

Empirical studies that examine how managers make project manager-to-project (PM2P) allocation decisions in multi-project settings are currently limited. Such decisions are crucial to organizational success. An empirical study of the PM2P practice, conducted in the context of Botswana, revealed ineffective processes in terms of optimality in decision-making. A conceptual model to guide effective PM2P practices was developed. The focus of this study is on deploying the model as a lens to study the PM2P practices of a large organization, with a view to identify and illustrate strengths and weaknesses. A case study was undertaken in the mining industry, where core activities in terms of projects are underground mineral explorations at identified geographical regions. A semi-structured interview protocol was used to collect data from 15 informants, using an enumeration. Integrated analysis of both data types (using univariate descriptive analysis for the quantitative data, content and thematic analysis for the qualitative data) revealed strengths in PM2P practices, demonstrated by informants’ recognition of some important criteria to be considered. The key weaknesses were exemplified by a lack of effective management tools and techniques to match project managers to projects. The findings provide a novel perspective through which improvements in working practices can be made

Accretion, Outflows, and Winds of Magnetized Stars

Many types of stars have strong magnetic fields that can dynamically influence the flow of circumstellar matter. In stars with accretion disks, the stellar magnetic field can truncate the inner disk and determine the paths that matter can take to flow onto the star. These paths are different in stars with different magnetospheres and periods of rotation. External field lines of the magnetosphere may inflate and produce favorable conditions for outflows from the disk-magnetosphere boundary. Outflows can be particularly strong in the propeller regime, wherein a star rotates more rapidly than the inner disk. Outflows may also form at the disk-magnetosphere boundary of slowly rotating stars, if the magnetosphere is compressed by the accreting matter. In isolated, strongly magnetized stars, the magnetic field can influence formation and/or propagation of stellar wind outflows. Winds from low-mass, solar-type stars may be either thermally or magnetically driven, while winds from massive, luminous O and B type stars are radiatively driven. In all of these cases, the magnetic field influences matter flow from the stars and determines many observational properties. In this chapter we review recent studies of accretion, outflows, and winds of magnetized stars with a focus on three main topics: (1) accretion onto magnetized stars; (2) outflows from the disk-magnetosphere boundary; and (3) winds from isolated massive magnetized stars. We show results obtained from global magnetohydrodynamic simulations and, in a number of cases compare global simulations with observations.Comment: 60 pages, 44 figure

The Marine Microbial Eukaryote Transcriptome Sequencing Project (MMETSP): Illuminating the Functional Diversity of Eukaryotic Life in the Oceans through Transcriptome Sequencing

Microbial ecology is plagued by problems of an abstract nature. Cell sizes are so small and population sizes so large that both are virtually incomprehensible. Niches are so far from our everyday experience as to make their very definition elusive. Organisms that may be abundant and critical to our survival are little understood, seldom described and/or cultured, and sometimes yet to be even seen. One way to confront these problems is to use data of an even more abstract nature: molecular sequence data. Massive environmental nucleic acid sequencing, such as metagenomics or metatranscriptomics, promises functional analysis of microbial communities as a whole, without prior knowledge of which organisms are in the environment or exactly how they are interacting. But sequence-based ecological studies nearly always use a comparative approach, and that requires relevant reference sequences, which are an extremely limited resource when it comes to microbial eukaryotes

Changes to tuart woodland in Yalgorup National Park over four decades

The condition of the tuart tree (Eucalyptus gomphocephala), a coastal southwestern Australian woodland species, has declined dramatically within parts of its distribution over the last decade, particularly within Yalgorup National Park. Prior to the park being gazetted in 1968, some of the woodlands were used for cattle grazing. Frequent, light, understorey burns were carried out to encourage grass fodder growth. Earlier, Aboriginal use is believed to have involved a similar regime to facilitate hunting and access. Since gazettal, the majority of the park has either been excluded from fire, or burnt infrequently by wildfire and prescribed fire. Consequently, from 1968 to the present, most fires are thought to have been more intense due to increased fuel loads. Alterations in disturbance patterns (particularly fire) elsewhere, have been linked with vegetation changes (composition and structure) and in some instances, declining tree health. For tuart woodland, it has been proposed that increased abundance and vigour of the lower storey peppermint tree (Agonis flexuosa) and a decline in the health of tuart trees are consequences of reduced fire frequency. Sample plot data from the mid – late 1970s and photographs from 1957 are contrasted with the 2003/2004 situation to describe changes in tuart woodland. Declining tuart health, changes in the health and abundance of some understorey species (for example, fewer Banksia attenuata) and a shift towards peppermint dominance are revealed. The contribution of changing fire regimes to these trends is explored. While a link between fire and changes to the woodland may be established, factors underlying the loss of tuart dominance remain to be determined. An integrated research project is in progress to examine the range of decline factors

Governare e gestire l'innovazione: cosa i manager devono sapere di project, program e portfolio management

Solo attraverso l'innovazione sono possibili i grandi cambiamenti che vengono richiesti in un mondo dinamico. Le innovazioni, però, non accadono da sole. Per renderle reali devono passare attraverso l'implementazione dei progetti (ovvero un insieme di attività con obiettivi ben definiti e con tempistiche e risorse limitate). A loro volta i progetti, per essere di successo, richiedono alcune accortezze, tra queste spicca il supporto del top management. I manager non possono essere spettatori passivi dei progetti ma soggetti attivi che contribuiscono alla loro realizzazione. Saper gestire i progetti è divenuto, infatti, un fattore critico di successo. Il libro si propone quindi di dare strumenti ai manager per capire la gestione dei progetti (i concetti chiavi e le caratteristiche più importanti di project, program e portfolio management) e le indicazioni operative per vederli realizzati (come governarli e gestirli e come determinare se i benefici attesi sono stati raggiunti). L'approccio molto operativo lo rende uno strumento snello e completo per aumentare la consapevolezza di cosa potrebbe (e dovrebbe) essere fatto per sviluppare, migliorare e supportare le innovazioni più importanti all'interno delle organizzazioni. La versione italiana è stata arricchita con tre casi di buona gestione dei progetti in organizzazioni italiane pubbliche e private. Tra i diversi spunti offerti, i casi sottolineano nuovamente come le figure manageriali non possano essere ai margini dei progetti ma attori fondamentali per la loro corretta gestione e quindi per il successo dell'organizzazione

Tree performance and Root-zone salt accumulation in three dryland Australian plantations

Doubts exist about the effectiveness of establishing trees near saline discharge areas on farmland to manage dryland salinity. These centre on low rates of water uptake from saline water tables, salt accumulation in tree root zones and the consequent poor growth and survival of trees. Despite this, trees still survive in many plantations established adjacent to saline discharge areas and land-holders often favour such locations, as they do not compete for arable land such as that occurs with plantings in recharge areas. Tree performance and salt accumulation were assessed in three experimental plantations established adjacent to saline discharge areas 20 1325 years ago. These were all in the 400 13600 mm rainfall zone of south-western Australia. Mean soil salinity, within 1 m of the surface, ranged from 220 to 630 mS m"121, while permanent ground-waters occurred within 2 135 m of the surface and had electrical conductivities ranging from 175 to 4150 mS m"121. The study confirmed the low growth rates expected for trees established over shallow, saline water tables in a relatively low rainfall environment, with estimated wood volumes in Eucalyptus cladocalyx, E. spathulata, E. sargentii, E. occidentalis and E. wandoo of between 0.5 and 1.5 m3 ha"121 yr"121. Values of up to 3 m3 ha"121 yr"121 were obtained on soils with low salinity (70%) of several Eucalyptus species confirms that discharge plantations species can persist, despite increasing soil salinity. However, the long-term sustainability of such plantings (50 13100 years) without broader landscape treatment of the present hydrological imbalance must be questioned

Bird communities in small native remnants of contrasting understorey condition within bluegum plantations

The area of agricultural land converted to commercial plantations across Australia has expanded rapidly and includes large areas (0.5 M ha) planted to Tasmanian Blue Gum (Eucalyptus globulus) (National Forest Inventory 2005). The outcome of this for biodiversity conservation is still being evaluated. In general, plantations support more native faunal species than farmland, but less than native vegetation remnants (Lindenmayer & Hobbs 2004). However, the value of small remnants (<5 ha) to native fauna in plantations is unclear. For birds in plantations, small remnants may be important ‘stepping stones’ or provide small, high quality habitat patches within a larger habitat mosaic (Fischer & Lindenmayer 2002), especially for species that can exploit resources within plantations (Loyn et al. 2007). However, degradation by weed invasion can reduce the value of small remnants for bird conservation (Loyn 1987). A better understanding of the biodiversity value of small remnants is needed given that many plantation companies operating under forest product certification are now formulating approaches to managing biodiversity within their estates. Therefore, we examined bird communities in Tasmanian Blue Gum plantations (hereafter called bluegum plantations’), contrasting plantation areas with small remnants with predominantly exotic, and native, understoreys. Implications for remnant management and monitoring are discussed

The distribution and impact of Mycosphaerella cryptica on regenerating Eucalyptus gomphocephala

Mycosphaerella cryptica is one of the most destructive foliar pathogens of eucalypts in plantations in southern Australia. The majority of research on this pathogen has been conducted in plantations, with little focus on its distribution and impact on eucalypts in native forest. Tuart (Eucalyptus gomphocephala) is magnificent woodland tree endemic to Western Australia. With almost 75% of its original area cleared and concerns for the health of those remaining, the recruitment of tuart is highly important. The study of pathogens and pests that pose a threat to seedling survival will contribute to ensuring the regeneration of the remaining woodlands. Mycosphaerella cryptica has been recorded on E.marginata (Jarrah), E. diversicolor (Karri) and E. patens (Blackbutt) in native forests. In the present study we carried out surveys of regenerating stands of tuart between 2003 and 2005, confirming the presence of M. cryptica throughout all stands surveyed, and in some cases contributing to mortality of seedlings. These findings are somewhat surprising given M. cryptica has not previously been recorded from tuart in native forests. In addition to these surveys, trials were established in Yalgorup N.P. in the native forest to investigate how the presence/absence of ashbeds and competition with midstorey (mainly Agonis flexuosa) affects the survival and growth of planted seedlings. These trials were assessed seasonally over a 14 month period for phytophagous insect attack and fungal pathogen damage. Initial assessments at 12 weeks confirmed the presence of M. cryptica associated with leaf lesions (also known as Crinkle Leaf). Over the subsequent 12 month period the severity of Crinkle Leaf increased across the trial and in some cases resulted in seedling mortality. In comparison to phytophagous insect damage, at the final assessment Crinkle Leaf was by for the most dominant category of damage. Comparisons were made between the climatic conditions, seasonal growth patterns, and severity of Crinkle Leaf at the study site and in eastern Victoria where previous studies on M. cryptica have been conducted. Seasonal periods of infection by M. cryptica differed between the two sites. We propose that this is due to optimal conditions for spread and infection of the pathogen, and growth of the seedlings occurring in winter in Yalgorup N .P. compared with summer in eastern Victoria. Knowledge gained in this study provides important information for disease management and will benefit restoration/regeneration initiatives of this threatened species of eucalypt