A bimodal correlation between host star chromospheric emission and the surface gravity of hot Jupiters

The chromospheric activity index logR'HK of stars hosting transiting hot Jupiters appears to be correlated with the planets' surface gravity. One of the possible explanations is based on the presence of condensations of planetary evaporated material located in a circumstellar cloud that absorbs the CaII H&K and MgII h&k resonance line emission flux, used to measure chromospheric activity. A larger column density in the condensations, or equivalently a stronger absorption in the chromospheric lines, is obtained when the evaporation rate of the planet is larger, which occurs for a lower gravity of the planet. We analyze here a sample of stars hosting transiting hot Jupiters tuned in order to minimize systematic effects (e.g., interstellar medium absorption). Using a mixture model, we find that the data are best fit by a two-linear-regression model. We interpret this result in terms of the Vaughan-Preston gap. We use a Monte Carlo approach to best take into account the uncertainties, finding that the two intercepts fit the observed peaks of the distribution of logR'HK for main-sequence solar-like stars. We also find that the intercepts are correlated with the slopes, as predicted by the model based on the condensations of planetary evaporated material. Our findings bring further support to this model, although we cannot firmly exclude different explanations. A precise determination of the slopes of the two linear components would allow one to estimate the average effective stellar flux powering planetary evaporation, which can then be used for theoretical population and evolution studies of close-in planets.Comment: 23 pages, 4 figures, 1 table, accepted for publication in ApJ

Appearance or reality? Monitoring of employer branding in public network space: the Glassdoor case

To what extent does Employer Branding (EB) express the real\u2010life company working environment or merely constitutes a well\u2010orchestrated organizational image? After reconstructing its significance and impact on the managing of the human resource cycle (recruitment, commitment, and retention) this study describes three ways of monitoring EB: internal, professional and public control. They each make use of a variety of tools in order to assess the extent to which the appearance of the employer corresponds to an authentic reality. Then, there is a presentation of the features and critical issues of a case of public EB control: Glassdoor.com. More specifically, this is followed by descriptions of the structure, services and critical implications of the crowdsourcing\u2010based platform of Glassdoor.com (retaliatory, improper, frivolous and illusionistic utilizations). Implications which may affect the platform\u2019s validity as a monitoring tool of EB. The article ends with several considerations regarding the use of the site as a research\u2010 tool. Research sources: literature reviews, Glassdoor\u2010site analysis, specialized web\u2010 journals, social\u2010media, studies that used Glassdoor for research purposes. Method: theoretical and empirical data\u2010processing

Politiche del lavoro e ricerca del personale

Riassunto \u2013 Una buona parte degli studi e delle politiche del lavoro in questi ultimi anni si \ue8 concentrata sulla capacit\ue0 dell\u2019offerta di cercare lavoro. Pochi studi hanno affrontato il tema della domanda di lavoro e di come le politiche possano influenzare la ricerca del personale. Scopo del presente articolo \ue8 comprendere l\u2019impatto delle politiche del lavoro sulla ricerca del personale con particolare riferimento alle organizzazioni d\u2019impresa. Dopo avere esaminato le variabili strategiche, organizzative e ambientali che influenzano la ricerca del personale lo studio si concentra sull\u2019analisi delle politiche attive e passive del lavoro in Europa e in Italia. I risultati che emergono mettono in evidenza che le politiche del lavoro impattano su alcuni aspetti significativi della ricerca di personale: il turnover, l\u2019occupabilit\ue0 delle persone, la ri- collocazione, l\u2019efficienza del matching tra domanda e offerta di lavoro, la competitivit\ue0 dei candidati e la loro produttivit\ue0, l\u2019efficiente allocazione dell\u2019offerta, lo spiazzamento della do- manda, il grado di selettivit\ue0 e trasparenza del processo di reclutamento. Considerazioni di sintesi e alcune osservazioni sulle implicazioni organizzative, sui limiti dello studio e sul suo contributo alla ricerca concludono l\u2019articolo

“The Same Staff Can Be Enough”. Employers’ Resilience Strategies in Recruitment Decisions

Studies on resilience have sprung from a need to understand the survival strategies of organizations when faced with the emergence of unexpected, potentially destructive and negative events in the lives of the organizations. This article, on the other hand, intends to highlight organizational resilience when confronted with unexpected positive events, seldom considered by such studies. This is the well-known macroeconomic phenomenon of the time lag between economic growth and labor demand at the moment that a regressive economic cycle is reversed. With which strategies do companies, in the face of such an event, transform a resilient attitude into real resilient behavior? Five strategies of organizational resilience are identified: Flexibility of working hours, staff re-allocation, minimization of turnover and absenteeism, job redesign, and reorganization of operations. A summary of results, managerial implications, contributions to studies and indications for future research conclude the article

Local Statistical Modeling via Cluster-Weighted Approach with Elliptical Distributions

Cluster Weighted Modeling (CWM) is a mixture approach regarding the modelisation of the joint probability of data coming from a heterogeneous population. Under Gaussian assumptions, we investigate statistical properties of CWM from both the theoretical and numerical point of view; in particular, we show that CWM includes as special cases mixtures of distributions and mixtures of regressions. Further, we introduce CWM based on Student-t distributions providing more robust fitting for groups of observations with longer than normal tails or atypical observations. Theoretical results are illustrated using some empirical studies, considering both real and simulated data.Cluster-Weighted Modeling, Mixture Models, Model-Based Clustering

Analysis of orbital floor blowout fractures using anonymized computed tomography scans

The orbits are bony structures of the skull that house the globe, extraocular muscles, nerves, blood vessels, lacrimal apparatus, and adipose tissue. Each orbit protects the globe, while the supportive tissues allow the globe to move in three dimensions (horizontal, vertical, and torsional). The orbital floor comprises the maxillary, palatine, and zygomatic bones, and the walls of the orbit function as a physical barrier from blunt trauma to the eye, an anchor for muscles and ligaments to attach, and additionally serve as a window for neurovasculature to travel through. Because of its position and its thin bony walls, it is susceptible to fractures, and in a lot of cases surgery is required as part of the treatment to repair the resulting defect with an implant. In this context, the present work had the purpose to analyze medical computed tomography (CT) and cone beam computed tomography (CBCT) – also called digital volume tomography (DVT) - imaging data from anonymized patients with orbital floor defects for the measurement of the length, the depth, the total area, and the defect area of them using the software called VG STUDIOMAX (Volume Graphics GmbH, Heildelberg, Germany) designed for industrial CT examinations. The analysis of medical imaging data is equally possible, but new for the case of orbital floor defects. The method was successfully done, and some of the results obtained on this work are similar to the values obtained on the literature. The main values obtained for length measurements of total orbital floor were 28,18 ± 2,93 mm and 27,93 ± 2,70 mm for left and right side respectively (p = 0,83). The main values obtained for depth measurements of total orbital floor were 29,80 ± 2,80 mm and 29,40 ± 3,03 mm for left and right side respectively (p = 0,74). The main values obtained for length and depth of orbital floor defects were 13,61 ± 4,98 and 17,38 ± 5,82 respectively (p = 0,14). By conventional criteria, these differences are considered to be not statistically significant showing reproducible results, however, no studies were found to compare it with. The main values obtained for total surface area were 632,89 ± 147,44 mm² and 641,76 ± 150,09 mm² for left and right side respectively (p = 0,88) and the main value obtained for defect surface area 403,28,32 ± 132,15 mm², being similar to other studies. The mean value for defect and total area ratio obtained on this work, 65,00 ± 15,00, a little higher than the ones calculated on the other studies found in literature.As órbitas são estruturas ósseas do crânio que abrigam o globo terrestre, músculos extraoculares, nervos, vasos sanguíneos, aparelho lacrimal e tecido adiposo. Cada órbita protege o globo ocular, enquanto os tecidos de suporte permitem que o globo se mova em três dimensões (horizontal, vertical e de torção). O piso (ou assoalho) orbital compreende os ossos maxilares, palatinos e zigomáticos, e as paredes da órbita funcionam como uma barreira física contra traumas no olho, uma âncora para os músculos e ligamentos se fixarem, e adicionalmente servem como uma janela para a neurovasculatura viajar através. Devido a sua posição e suas finas paredes ósseas, é suscetível a fraturas e, em muitos casos, é necessária cirurgia como parte do tratamento para reparar o defeito resultante com um implante. Neste contexto, o presente trabalho teve a finalidade de analisar imagens de tomografia computadorizada médica (TC) e de tomografia computadorizada de feixe cônico (TCFC) - também chamada tomografia digital de volume (TDV) – de pacientes anônimos com defeitos no piso orbital para a medição do comprimento, da profundidade, da área total e da área defeituosa dos mesmos, utilizando o software chamado VG STUDIOMAX (Volume Graphics GmbH, Heildelberg, Alemanha) projetado para exames de TC industriais. A análise de dados de imagens médicas é igualmente possível, mas nova para o caso de defeitos orbitais do piso. O método foi realizado com sucesso e alguns dos resultados obtidos neste trabalho são semelhantes aos valores obtidos na literatura. Os valores médios obtidos para as medidas de comprimento do piso orbital total foram 28,18 ± 2,93 mm e 27,93 ± 2,70 mm para os lados esquerdo e direito respectivamente (p = 0,83). Para as medidas de profundidade do piso orbital total obteve-se 29,80 ± 2,80 mm e 29,40 ± 3,03 mm para os lados esquerdo e direito respectivamente (p = 0,74). Para as medidas de comprimento e profundidade dos defeitos do piso orbital obteve-se 13,61 ± 4,98 e 17,38 ± 5,82 respectivamente (p = 0,14). Por critérios convencionais, estas diferenças são consideradas como não estatisticamente significativas mostrando resultados reprodutíveis, entretanto, não foram encontrados estudos para compará-los. Os valores obtidos para a área de superfície total foram 632,89 ± 147,44 mm² e 641,76 ± 150,09 mm² para os lados esquerdo e direito respectivamente (p = 0,88) e o valor obtido para a área de superfície do defeito foi 403,28 ± 132,15 mm², sendo similares a outros estudos. O valor médio para a razão entre o defeito e a área total obtido neste trabalho foi de 65,00 ± 15,00, um pouco maior do que os valores calculados em outros estudos encontrados na literatura

Labour Market Policies and Recruitment in Europe and Italy

Over the last few years, most studies and labour market policies have focused on the competence of people seeking employment. Few studies have tackled the issue from the point of view of employers and how policy might affect the personnel recruitment. The aim of this article is to try to understand the im- pact of labour policy on the processes involved in seeking personnel, with specific reference to business organizations. After examining the strategic, or- ganisational and environmental variables that affect the personnel recruit- ment, the study focuses on analysing active and passive labour policies in Eu- rope and Italy. The results that emerge highlight the fact that labour policy af- fects certain specific aspects of the personnel recruitment: employee turnover, an individual\u2019s employability, outplacement, efficiency of matching between job supply and demand, competitiveness of candidates and their productivity, efficient allocation of job offers, crowding-out effect, degree of selectivity and contingency of search campaigns. The article ends with a few observations regarding the limitations of the study and future research