Association between the squat lobster Gastroptychus formosus and cold-water corals in the North Atlantic

Although there are no previous descriptions of the habits of chirostylids in the North Atlantic, it is likely that species in the genera Uroptychus, Eumunida and Gastroptychus have close ecological ties with deep-sea corals since they have all been recorded in trawl samples containing corals from ∼200m depth. We analysed in situ distribution of Gastroptychus formosus and potential hosts using a ROV at a range of north-eastern Atlantic sites and found that this species forms a close association with deep-sea corals that resembles the chirostylid-anthozoan associations reported in shallow Indo-Pacific waters. We update the known distribution for G. formosus, confirming that it is an amphiatlantic species that occurs along the Mid-Atlantic Ridge at least as far south as the Azores and along continental margins from the Canary Islands to Scotland at depths of 600-1700m. The adults have very specific habitat preferences, being only found on gorgonian and antipatharian corals with a strong preference for Leiopathes sp. as a host. This highly restricted habitat preference is likely to render chirostylids vulnerable to the impacts of demersal fishing both directly, as by-catch, and indirectly through habitat loss. © 2010 Marine Biological Association of the United Kingdom

Optimal design for the detection of a major gene segregation in crosses between 2 pure lines

A simulation method was used to compare different experimental designs for their power to detect a major gene using a maximum likelihood approach. The optimal design is most often the production of F2 as the only segregating genetic type, with a limited effect of the relative numbers of F2s and non-segregating groups (parentals and F1) on the power. Dominant genes were more easily detected than additive ones. A model dealing with the heteroskedasticity of the polygenic component was also studied

Introduction to the AdS/CFT correspondence

This is a pedagogical introduction to the AdS/CFT correspondence, based on lectures delivered by the author at the third IDPASC school. Starting with the conceptual basis of the holographic dualities, the subject is developed emphasizing some concrete topics, which are discussed in detail. A very brief introduction to string theory is provided, containing the minimal ingredients to understand the origin of the AdS/CFT duality. Other topics covered are the holographic calculation of correlation functions, quark-antiquark potentials and transport coefficients.Comment: 64 pages, 12 figures;v2: minor improvements;v3: references adde

A qualitative study of work-life balance amongst specialist orthodontists in the United Kingdom

Objective: To identify factors affecting work-life balance amongst male and female orthodontists in the United Kingdom. Design: A qualitative interview-based study with a cross-sectional design. Subjects: Specialist orthodontists working in specialist practice and the hospital service in the United Kingdom were selected by purposive sampling. Methods: In-depth semi-structured interviews were conducted with eighteen orthodontic specialists. Interview transcripts were analysed using Framework Analysis. Results: Four main themes pertaining to work-life balance in orthodontics were identified: work factors affecting work-life balance, life factors affecting worklife balance, perception and effects of work-life balance and suggestions for managing work-life balance within the profession. Conclusions: There was substantial variation in the work-life balance of the orthodontists interviewed in this study; however the majority reported high levels of career satisfaction despite difficulties maintaining a good work-life balance. Whilst there were some clear distinctions in the factors affecting work-life balance between the hospital environment and specialist practice (including additional professional commitments and teaching/training related issues), there were also a number of similarities. These included, the lack of flexibility in the working day, managing patient expectations, taking time off work at short notice and the ability to work part-time

Fear of crime and the role of the police

Social values such as safety and security needs of members of society are necessary to ensure a sustainable quality of life for all; guaranteed and protected by the Constitution. If this envisaged tranquility is disturbed or negatively affected by crime and fear of crime resulting from criminal victimisation, then both crime and fear crime become public concerns. The study presents two focal points: crime and fear of crime as well as the role of the police, which all exert a significant influence on the lives of citizens. Criminal victimisation may cause physical harm, feelings of anxiety, emotional instability, mistrust of the formal control structure, alienation, etc., that promotes fear of crime. Such factors may result in a break of social cohesion, curtailment of daily activities and withdrawal from society. Policing, on the other hand, personifies social order and the guaranteed protection of people in a manner consistent with democratic principles. A non-parametric survey research method, incorporating a closed-structured questionnaire has been implemented to capture data from two arbitrarily selected Eastern Cape samples: Mthatha and Butterworth, primarily to explore and describe perceptions pertaining to crime, fear of crime and the role of the police in terms of gender (N=300). Gender is an appropriate predictor of fear of crime. Having rated seven selected serious crimes, female respondents are significantly more fearful of criminal victimisation than their male counterparts. Cooperation with the police to report and prevent crime, call upon them in emergency situations, etc., is on a sound footing, with females virtually outnumbering the males in all those functions. This finding is further vouched for by the fact that females had more positive and less negative ‘police contact’ compared to male respondents. Improved police-public relations and dedicated police service delivery will become more and more inevitable. Keywords: Crime, Police, South Afric

Comparison of four statistical methods for detection of a major gene in a progeny test design

In livestock improvement it is common to design a progeny test of sires in order to estimate their breeding values. The data recorded for these estimate are useful for the detection of major genes. They are the n.m performances Yij of m progeny j of n sires i. These data need to be corrected for the polygenic influence of the sire on its progeny (sire i effect Ui). Four statistical tests of the segregation of a major gene are compared. The first (ﺎSA for "segregation analysis") is the classical ratio of the likelihoods under Ho (no major gene) and H1 (a major gene is segregating). The parameters describing the population (means and standard deviations within genotype) are estimated by maximizing the marginal likelihood of the Yij. The other statistics studied are approximations of this ﺎSA statistic where the sire i effect (Ui) is considered as a fixed effect (ﺎ FE statistic) or, following Elsen et al. (1988) and Höschele (1988), where the parameters, and Ui, are estimated maximizing the joint likelihood of Ui and Yij (ﺎME and ﺎME2 statistics). Simulation studies were done in order to describe the distribution of these statistics. It is shown that ﺎSA and ﺎME1 are the most powerful test, followed by ﺎME2 whose relative loss of power ranged between 20 and 40%, depending on the H1 case studied, when 400 progeny are measured (n = m = 20). The segregation analysis, based on direct maximization of the likelihood, required 30 times more computation time than the ﺎME test using an EM algorithm.Il est fréquent, en sélection, de tester sur descendance, des mâles, afin d’estimer leur valeur génétique. Les données recueillies dans ce but peuvent être utilisées afin de mettre en évidence un gène majeur. Elles sont constituées des n.m performances Yij de m descendants j de n mâles i. Ces données doivent être corrigées pour l’effet polygénique du père (Ui) sur ses descendants. Quatre tests statistiques de mise en évidence d’un tel gène majeur sont comparés. Le premier (ﺎSA pour "segregation analysis") est le rapport classique des vraisemblances sous Ho (pas de gène majeur) et sous H1 (existence d’un gène majeur). Les paramètres caractéristiques de la population (moyennes et écarts types intragénotype) sont estimés en maximisant la vraisemblance marginale des Yij Les autres statistiques de tests sont des approximations de ﺎSA pour lesquelles, soit l’effet père Ui est considéré comme un effet fixé (test IFE) soit, comme proposé par Elsen et al. (1988) et Höschele (1988), les paramètres, et Ui, sont obtenus en maximisant la vraisemblance conjointe des Yij et des Ui (test ﺎME1 et ﺎME2 Nous avons réalisé des simulations afin de décrire les distributions de ces tests. ﺎSA et ﺎME1 sont les tests les plus puissants, suivi par ﺎME2 dont la perte relative de puissance varie entre 20 et 40% selon l’hypothèse H1 étudiées, quand 400 descendants sont mesurés (n = m =20). L’analyse de ségrégation, réalisée par maximisation directe de la vraisemblance, demande 30 fois plus de temps de calcul que les tests ﺎME réalisés l’aide d’un algorithme EM

New observations on Saturnella saturnus (Steinecke) Fott: the first British record of a little-known enigmatic ‘green’ alga

Saturnella saturnus was discovered in March 2014 in open-water pools on blanket peatland at the Moor House - Upper Teesdale National Nature Reserve, straddling Cumbria and County Durham in NE England. This is the first record for the British Isles of a little-known alga known previously only from a few peat bog areas, mainly in mainland Europe. The literature is reviewed and new observations presented on its morphology and reproduction based on LM examination of living cells. New observations on the chloroplast structure and cytoplasmic inclusions (especially oil droplets) are discussed in relation to the findings of earlier studies. Doubt attaches as whether it is a chlorophyte or a xanthophyte and the identity of small spherical inclusions that have been frequently interpreted as autospores. It occurs in Upper Teesdale in pools that are that are small, relatively newly formed and mostly well-oxygenated. Also discussed is its relationship to Trochiscia, another coloniser of peatland pools. Photographic images are presented for the first time and comments made on its ecology in the context of blanket bog conservation projects and apparent rarity

Skew-Unfolding the Skorokhod Reflection of a Continuous Semimartingale

The Skorokhod reflection of a continuous semimartingale is unfolded, in a possibly skewed manner, into another continuous semimartingale on an enlarged probability space according to the excursion-theoretic methodology of Prokaj (2009). This is done in terms of a skew version of the Tanaka equation, whose properties are studied in some detail. The result is used to construct a system of two diffusive particles with rank-based characteristics and skew-elastic collisions. Unfoldings of conventional reflections are also discussed, as are examples involving skew Brownian Motions and skew Bessel processes.Comment: 20 pages. typos corrected, added a remark after Proposition 2.3, simplified the last part of Example 2.