Tidal Downsizing Model. III. Planets from sub-Earths to Brown Dwarfs: structure and metallicity preferences

We present population synthesis calculations of the Tidal Downsizing (TD) hypothesis for planet formation. Our models address the following observations: (i) most abundant planets being Super Earths; (ii) cores more massive than $\sim 5-15 M_\oplus$ are enveloped by massive atmospheres; (iii) the frequency of occurrence of close-in gas giant planets correlates strongly with metallicity of the host star; (iv) no such correlation is found for sub-Neptune planets; (v) presence of massive cores in giant planets; (vi) gas giant planets are over-abundant in metals compared to their host stars; (vii) this over-abundance decreases with planet's mass; (viii) a deep valley in the planet mass function between masses of $\sim 10-20 M_\oplus$ and $\sim 100 M_\oplus$. A number of observational predictions distinguish the model from Core Accretion: (a) composition of the massive cores is always dominated by rocks not ices; (b) the core mass function is smooth with no minimum at $\sim 3 M_\oplus$ and has no ice-dominated cores; (c) gas giants beyond 10 AU are insensitive to the host star metallicity; (d) objects more massive than $\sim 10 M_{\rm Jup}$ do not correlate or even anti-correlate with metallicity. The latter prediction is consistent with observations of low mass stellar companions. TD can also explain formation of planets in close binary systems. TD model is a viable alternative to the Core Accretion scenario in explaining many features of the observed population of exoplanets.Comment: Final version accepted by MNRAS. 26 page

Planets, debris and their host metallicity correlations

Recent observations of debris discs, believed to be made up of remnant planetesimals, brought a number of surprises. Debris disc presence does not correlate with the host star's metallicity, and may anti-correlate with the presence of gas giant planets. These observations contradict both assumptions and predictions of the highly successful Core Accretion model of planet formation. Here we explore predictions of the alternative Tidal Downsizing (TD) scenario of planet formation. In TD, small planets and planetesimal debris is made only when gas fragments, predecessors of giant planets, are tidally disrupted. We show that these disruptions are rare in discs around high metallicity stars but release more debris per disruption than their low [M/H] analogs. This predicts no simple relation between debris disc presence and host star's [M/H], as observed. A detected gas giant planet implies in TD that its predecessor fragment was not disputed, potentially explaining why DDs are less likely to be found around stars with gas giants. Less massive planets should correlate with DD presence, and sub-Saturn planets (M_{p} \sim 50 \M_{\oplus}) should correlate with DD presence stronger than sub-Neptunes (M_{p} \leq 15 \M_{\oplus}). These predicted planet-DD correlations will be diluted and weakened in observations by planetary systems' long term evolution and multi-fragment effects neglected here. Finally, although presently difficult to observe, DDs around M dwarf stars should be more prevalent than around Solar type stars.Comment: 12 pages, 11 figures, to be published in MNRA

Between Artifice & Authenticity: A Study of Postmodern Song Lyrics

Senior Project submitted to The Division of Languages and Literature of Bard College

The WIGGUM gene is required for proper regulation of floral meristem size in Arabidopsis

The study of cell division control within developing tissues is central to understanding the processes of pattern formation. The floral meristem of angiosperms gives rise to floral organs in a particular number and pattern. Despite its critical role, little is known about how cell division is controlled in the floral meristem, and few genes involved have been identified. We describe the phenotypic effects of mutations in WIGGUM, a gene required for control of cell proliferation in the floral and apical meristem of Arabidopsis thaliana. wiggum flowers contain more organs, especially sepals and petals, than found in wild-type flowers. This organ number phenotype correlates with specific size changes in the early floral meristem, preceding organ initiation. Genetic studies suggest that WIGGUM acts on a similar process but in a separate pathway than the CLAVATA1 and CLAVATA3 genes in meristem size regulation, and reveal interactions with other genes affecting meristem structure and identity. Analysis of double mutant phenotypes also reveals a role for WIGGUM in apical meristem function. We propose that WIGGUM plays a role in restricting cell division relative to cellular differentiation in specific regions of the apical and floral meristems

The Signal Data Explorer: A high performance Grid based signal search tool for use in distributed diagnostic applications

We describe a high performance Grid based signal search tool for distributed diagnostic applications developed in conjunction with Rolls-Royce plc for civil aero engine condition monitoring applications. With the introduction of advanced monitoring technology into engineering systems, healthcare, etc., the associated diagnostic processes are increasingly required to handle and consider vast amounts of data. An exemplar of such a diagnosis process was developed during the DAME project, which built a proof of concept demonstrator to assist in the enhanced diagnosis and prognosis of aero-engine conditions. In particular it has shown the utility of an interactive viewing and high performance distributed search tool (the Signal Data Explorer) in the aero-engine diagnostic process. The viewing and search techniques are equally applicable to other domains. The Signal Data Explorer and search services have been demonstrated on the Worldwide Universities Network to search distributed databases of electrocardiograph data

Biosimilars clinical development program: Confirmatory clinical trials: A virtual/simulated case study comparing equivalence and non-inferiority approaches

AbstractAs part of long term commitment of the Biologicals and Vaccines Committee (B&V) of the International Federation of Pharmaceutical Manufacturers and Association (IFPMA) to provide expert input to the WHO on their recently finalized GUIDELINES ON EVALUATION OF SIMILAR BIOTHERAPEUTIC PRODUCTS (SBPs), and in response to WHO’s request, the IFPMA B&V prepared a clinical case study at a recent WHO workshop in Seoul, Korea. The case study, presented by Mark Fletcher on behalf of B&V, involved a model scenario for a clinical efficacy trial to support the approval of a Similar Biotherapeutic Product (SBP) as part of the required comparative clinical program against a Reference Biotherapeutic Product (RBP). A key goal was to understand and illustrate key clinical and statistical principles, and considerations described in the WHO Guidance for regulatory authorities when designing and implementing WHO guidelines and post-approval regulatory oversight for SBPs.Using this model SBP/RBP pair, an interactive discussion was carried out among the workshop participants on the pros and cons of using equivalence vs. non-inferiority designs to assess the two products’ similarity. Through discussion of the case, the complexity of demonstrating similar efficacy and safety of a SBP vs. RBP for biotherapeutic products is outlined and discussed in the context of the key principles laid out in the recently published WHO GUIDELINES ON EVALUATION OF SIMILAR BIOTHERAPEUTIC PRODUCTS (SBPs). The exercise illustrates the need for a case-by-case approach when interpreting clinical data from SBP dossiers to adequately assure similar efficacy and safety of SBPs for any studied indication

The nuts and bolts of the UK kit car movement, 1949-2009: an ecological analysis

The one qualitative and two empirical chapters of this thesis addresses the following theory fragments of organizational ecology: (1) the theoretical construction and empirical evidence in support of a frequency code, (2) organizational vital rates with respect to multiple category membership (3) measuring population dynamics: diversity and the engagement niche. (1) the theoretical construction and empirical evidence in support of a frequency code. The theory of the code (Polos et al, 2002; Hannan et al., 2007) is a relatively novel theoretical construction in ecology, with little - if any - explicit empirical/qualitative research conducted in this area. This chapter highlights how the present construction of a code is unsuited in its application to a specific sub - set of the audience: critics. General audience members are unable to dedicate time and effort in understanding all aspects of an offering or organization; they look at only a small set of feature values. Should an object satisfy this schema, the object takes on a taken for granted character. The fewer the feature values assessed by an audience member, the higher the taken for grantedness of the object. By devising a frequency code, the role of the critic - reducing uncertainty to audience members by assessing all aspects of an object - can be fully appreciated. Although all aspects of the objects are scrutinized, some feature values might come under more scrutiny than others. It is this aspect of the frequency code that determines an object’s taken for granted character. Should all of the features be subjected to low scrutiny, the taken for granted character of the object is high; should the feature values be subjected to higher scrutiny, the taken for granted character of the object is lower. Restating aspects of the theory leads to insights that can be qualitatively assessed with respect to critical reviews of kit cars. By using content analysis to support the theory development, it is hoped the issue of defining and measuring codes is progressed further by researchers, and the insight garnered from qualitative data analysis can be applied more often to studies assessing codes. (2) organizational vital rates with respect to multiple category membership. Category generalism (those which claim membership of more than one labeled category) and category specialism (those which claim membership of a single labeled category) have focussed on audience appeal, whether it be via critical attention of securities (Zuckerman, 1999; 2000), film reviews (Zuckerman and Kim, 2003; Zuckerman, Kim, Ukanwa, and von Rittman, 2003; Hsu, 2006) or wine reviews (Negro et al, 2010). Category specialists have higher audience appeal and fitness at a given position than category generalists. Such appeal might manifest itself in the form of greater coverage by critics (Hsu, 2006) and more favorable reviews (Hsu, 2006; Negro et al., 2010), to a higher probability of selling a product at online auction (Hsu et al., 2009). One of the limitations of these studies is that they do not have sufficient temporal length to investigate core ecological and evolutionary dynamics of entry and exit rates. By having the complete history of the UK kit car movement from its inception in 1949 to 2009, attempts can be made at applying multiple category membership to a long term evolutionary perspective. Empirical evidence supports the hypotheses that the interaction of density of category generalists (those organizations which produce both type authentic and craft authentic product offerings) inhibits the legitimation of the category specialist identities (type authentic category specialists and craft authentic category specialists). This interaction between density of category generalists and category specialists lowers the founding rate and increases the failure rate of category specialists. Although the lower appeal of category generalists has been documented, the deleterious effect of increasing category generalist density on the vital rates (and legitimation) of category specialist identities has not been assessed. (3) measuring population dynamics: diversity and the engagement niche. Measuring the engagement niche (Hannan et al., 2007) of an organization is a complex task, with different ways in which a variable can be constructed (Hannan et al., 2007; Hsu et al., 2009). This chapter examines the effect of constructing variables that capture the engagement niche of an organizationin a competitive environment. It starts with a relatively basic construction, then builds up to one that considers competition within a product category, and then one within the population. The merits or otherwise of each variable and their implications to researchers are discussed in detail. It concludes with comparing the Simpson Index of diversity against the Shannon entropy measure with the intention of analyzing the particular strengths of each diversity measure. The differing variables capturing the engagement niche illustrate the attention required by the analyst when deciding on how to conceptualize the engagement niche.

Conflict in voluntary organizations : a field study

This field study examined the relationships among the perception of conflict, the style of conflict management, and organizational commitment in the executive teams of voluntary organizations. The study was conducted in executive teams of 17 intact voluntary organizations with at least a three-year history. The organizations were nonprofit groups of four types; religious organizations (churches), community service organizations, recreational organizations and college sororities. The executive teams, (N = 113), consisting of the boards of directors and the paid administrative staff were surveyed. Conflict awareness and style were measured using the ROCI-I and ROCI-II instruments (Rahim, 1983). Organizational commitment scores were derived from self-report inventories using a seven-point Likert scale. Comparisons of the scores of these voluntary (non-profit) executive teams were made with the published national norms for the ROCI-I and ROCI-II instruments. The results showed that voluntary executive teams reported significantly less intrapersonal, intragroup, and intergroup conflict than the managerial population. The voluntary executive teams were also more likely to use an integrative, obliging, or avoiding conflict management style than the national managerial population from which the norms were derived. The ROCI measures in the study did not significantly correlate with a measure of organizational commitment. Numerous suggestions for further research were made