The Development of Colombian Bond Market.

Abstract: In this paper we explore the determinants and the consequences of the development of the corporate bond market in Colombia. We use a large firm-level dataset for the period 1997-2004 and find that the larger, more profitable and more leveraged firms have a higher probability to issue bonds. The econometric results also show that the larger the treasury bond market, the lower the probability that a firm will issue bonds, suggesting the presenceof a crowding out effect. On the demand side, the panel estimations indicate that investors with larger portfolios tend to hold more corporate bonds. Also, from the viewpoint of investors, average bond issue size is a critical variable. Finally, we find that sectors that have more corporate bonds (as percentage of total liabilities) have greater loan quality, and this result is stronger during periods of banking crises. We conclude that bond market development can play an important countercyclical role during periods of financial stress.Resumen: En este trabajo exploramos los determinantes y las consecuencias del desarrollo del mercado de bonos corporativos en Colombia. Utilizamos una muestra amplia con información por firma para el período 1997-2004 y encontramos que las firmas más grandes, rentables y apalancadas tienen una mayor probabilidad de emitir bonos. Los resultados econométricos también muestran que un mayor tamaño del mercado de deuda pública tiene un efecto negativo sobre la probabilidad de las firmas de emitir bonos, lo cual sugiere un efecto de crowding out. Por el lado de la demanda, las estimaciones de panel indican que los inversionistas con portafolios grandes tienen mayor probabilidad de adquirir bonos. Así mismo, desde el punto de vista de los inversionistas, el tamaño promedio de la emisión es una variable crítica. Finalmente, encontramos que los sectores económicos en donde la participación de los bonos dentro del total de pasivos es mayor, tienen una mejor calidad de la cartera y enfrentan con mayor fortaleza los períodos de crisis. Concluimos que el mercado de bonos puede tener un importante papel contra cíclico en períodos de stress financiero.Mercado de bonos, mercado financiero; Bonos corporativos, Inversionistas, Colombia

The Comparability of Men Who Have Sex With Men Recruited From Venue-Time-Space Sampling and Facebook: A Cohort Study

Background: Recruiting valid samples of men who have sex with men (MSM) is a key component of the US human immunodeficiency virus (HIV) surveillance and of research studies seeking to improve HIV prevention for MSM. Social media, such as Facebook, may present an opportunity to reach broad samples of MSM, but the extent to which those samples are comparable with men recruited from venue-based, time-space sampling (VBTS) is unknown. Objective: The objective of this study was to assess the comparability of MSM recruited via VBTS and Facebook. Methods: HIV-negative and HIV-positive black and white MSM were recruited from June 2010 to December 2012 using VBTS and Facebook in Atlanta, GA. We compared the self-reported venue attendance, demographic characteristics, sexual and risk behaviors, history of HIV-testing, and HIV and sexually transmitted infection (STI) prevalence between Facebook- and VTBS-recruited MSM overall and by race. Multivariate logistic and negative binomial models estimated age/race adjusted ratios. The Kaplan-Meier method was used to assess 24-month retention. Results: We recruited 803 MSM, of whom 110 (34/110, 30.9% black MSM, 76/110, 69.1% white MSM) were recruited via Facebook and 693 (420/693, 60.6% black MSM, 273/693, 39.4% white MSM) were recruited through VTBS. Facebook recruits had high rates of venue attendance in the previous month (26/34, 77% among black and 71/76, 93% among white MSM; between-race P=.01). MSM recruited on Facebook were generally older, with significant age differences among black MSM (P=.02), but not white MSM (P=.14). … See full text for complete abstract

Anomalous metamagnetic-like transition in a FeRh/Fe3_3Pt interface occurring at T120 K in the field-cooled-cooling curves for low magnetic fields

We report on the magnetic properties of a special configuration of a FeRh thin film. An anomalous behavior on the magnetisation vs. temperature was observed when low magnetic fields are applied in the plane of a thin layer of FeRh deposited on ordered Fe$_3$Pt. The anomalous effect resembles a metamagnetic transition and occur only in the field-cooled-cooling magnetisation curve at temperatures near 120 K in samples without any heat treatment.Comment: 7 pages, 5 figures. arXiv admin note: text overlap with arXiv:1008.195

Dyadic Characteristics and Intimate Partner Violence among Men Who Have Sex with Men.

OBJECTIVE: Although the research community has begun to recognize intimate partner violence (IPV) as an important issue in same-sex relationships, there has been a lack of attention to characteristics of these relationships that may be associated with IPV. In particular, there has been a lack of attention paid to the associations between dyadic characteristics and IPV in same-sex relationships. This paper examined associations between dyadic characteristics, including relationship satisfaction, communal coping and efficacy, and perpetrating and experiencing IPV among a sample of United States men who have sex with men (MSM). METHODS: We collected data via an online survey with 528 MSM, who were greater than 18 years of age and reported at least one male sex partner in the last 12 months. The analysis examined dyadic factors associated with reporting of experiencing and perpetrating emotional violence, physical violence, and sexual violence. RESULTS: The prevalence of violence in the sample ranged from nine percent reporting perpetrating sexual violence to 33% of men reporting experiencing emotional violence. MSM who reported greater satisfaction with their relationship or who reported a higher degree of concordance with their partner on lifestyle choices were less likely to report experiencing or perpetrating emotional violence. MSM who perceived a stigma to being in a male same-sex couple were less likely to report experiencing or perpetrating sexual violence. CONCLUSION: The results presented here demonstrate high levels of IPV among MSM and that dyadic characteristics are associated with the occurrence of IPV. Understanding relationship characteristics associated with increased IPV among same-sex male couples can contribute to the development of more accurate IPV screening tools, and more sensitively and appropriately designed intervention messages

CAMCAT: an oil spill forecasting system for the Catalan-Balearic Sea based on the MFS products

International audienceThe Prestige oil spill crisis (2002?2003), one of the worst oil spills that affected the Atlantic Spanish coastal line, pointed out that some management tools are needed in the form of laws, regulations and technical procedures. In particular, the issues are contingency planning and prevention against marine pollution and prediction for a proper response. In that background, the Catalan local government approved the CAMCAT (2004), a Regional contingency plan against marine pollution, to be framed within the (Spanish) National Contingency Plan. The CAMCAT contemplated the implementation of a Regional Forecasting System for the North-Western Mediterranean area, intended to help Catalan Authorities during any pollution emergency. The Laboratory of Maritime Engineering (LIM/UPC) has been responsible for the implementation of this Regional CAMCAT Forecasting System that is based (nested) on existing larger Forecasting Systems/Products, and it integrates several coastal observational data. The present paper is aiming to make an overview of the several scientific and technical activities related to the implementation and validation of the CAMCAT System

Mixtures of independent component analyzers for EEG prediction

This paper presents a new application of independent component analysis mixture modeling (ICAMM) for prediction of electroencephalographic (EEG) signals. Demonstrations in prediction of missing EEG data in a working memory task using classic methods and an ICAMM-based algorithm are included. The performance of the methods is measured by using four error indicators: signal-to-interference (SIR) ratio, Kullback-Leibler divergence, correlation at lag zero and mean structural similarity index. The results show that the ICAMM-based algorithm outperforms the classical spherical splines method which is commonly used in EEG signal processing. Hence, the potential of using mixtures of independent component analyzers (ICAs) to improve prediction, as opposed on estimating only one ICA is demonstrated.This work has been supported by Generalitat Valenciana under grants PROMETEO/2010/040 and ISIC/2012/006Safont Armero, G.; Salazar Afanador, A.; Vergara Domínguez, L.; Gonzalez, A.; Vidal Maciá, AM. (2012). Mixtures of independent component analyzers for EEG prediction. En Green and smart technology with sensor applications. Springer Verlag (Germany). 338:328-335. doi:10.1007/978-3-642-35251-5_46S328335338Common, P., Jutten, C.: Handbook of Blind Source Separation: Independent Component Analysis and Applications. Academic Press, USA (2010)Salazar, A., Vergara, L., Serrano, A., Igual, J.: A general procedure for learning mixtures of independent component analyzers. Pattern Recognition 43(1), 69–85 (2010)Lee, T.W., Lewicki, M.S., Sejnowski, T.J.: ICA mixture models for unsupervised classification of non-gaussian classes and automatic context switching in blind signal separation. IEEE Transactions on Pattern Analysis and Machine Intelligence 22(10), 1078–1089 (2000)Salazar, A., Vergara, L.: ICA mixtures applied to ultrasonic nondestructive classification of archaeological ceramics. Eurasip Journal on Advances in Signal Processing 2010, article ID 125201, 11 pages (2010), doi:10.1155/2010/125201Klein, C., Feige, B.: An independent component analysis (ICA) approach to the study of developmental differences in the saccadic contingent negative variation. Biological Psychology 70, 105–114 (2005)Makeig, S., Westerfield, M., Jung, T.P., Covington, J., Townsend, J., Sejnowski, T.J., Courchesne, E.: Functionally Independent Components of the Late Positive Event-Related Potential during Visual Spatial Attention. Journal of Neuroscience 19(7), 2665–2680 (1999)Wibral, M., Turi, G., Linden, D.E.J., Kaiser, J., Bledowski, C.: Decomposition of working memory-related scalp ERPs: Crossvalidation of fMRI-constrained source analysis and ICA. Internt J. of Psychol. 67, 200–211 (2008)Castellanos, N.P., Makarov, V.A.: Recovering EEG brain signals: Artifact suppression with wavelet enhanced independent component analysis. Journal of Neuroscience Methods 158, 300–312 (2006)Salazar, A., Vergara, L., Miralles, R.: On including sequential dependence in ICA mixture models. Signal Processing 90, 2314–2318 (2010)Dayan, P., Abbot, L.F.: Theoretical neuroscience: computational and mathematical modeling of neural systems. The MIT Press (2001)Sternberg, S.: High-speed scanning in human memory. Science 153(3736), 652–654 (1966)Raghavachari, S., Lisman, J.E., Tully, M., Madsen, J.R., Bromfield, E.B., Kahana, M.J.: Theta oscillations in human cortex during a working-memory task: evidence for local generators. J. of Neurophys. 95, 1630–1638 (2006)Gorriz, J.M., Puntonet, C.G., Salmeron, G., Lang, E.W.: Time series prediction using ICA algorithms. In: Proc. of 2nd IEEE Internat. W. on Intellig Data Acquisition and Advanc. Comp. Systems: Tech. and App., pp. 226–230 (2003)Lin, C.-T., Cheng, W.-C., Liang, S.-F.: An On-line ICA-Mixture-Model-Based Self-Constructing Fuzzy Neural Network. IEEE Transactions on Circuits and Systems I: Regular Papers 52(1), 207–221 (2005)Lee, T.W., Girolami, M., Sejnowski, T.J.: Independent component analysis using an extended InfoMax algorithm for mixed sub-gaussian and super-gaussian sources. Neural Computation 11(2), 417–441 (1999)Perrin, F., Pernier, J., Bertrand, D., Echallier, J.F.: Spherical splines for scalp potential and current density matching. Electroencep. and Clin. Neurophys. 72, 184–187 (1989)Wang, Z., Bovik, A., Sheikh, H., Simoncelli, E.: Image quality assessment: from error visibility to structural similarity. IEEE Transactions on Image Processing 13(4), 600–612 (2004

A multi-isotope analysis of Neolithic human groups in the Yonne valley, Northern France: insights into dietary patterns and social structure

With the arrival of the Neolithic to Europe, new ways of life and new subsistence strategies emerged. In the Paris Basin (northern France), the appearance of some monumental funerary structures during theMiddle Neolithic highlights in particular the increasing complexity of the social organisation. At the same time, several sites, such as open-air cemeteries, do not display any evidence of such arrangement. In the southeast of this area, the two primary routes of neolithisationmeet. Several funerary parameters attest to the diverse influence received from other surrounding cultures. In order to assess potential differences in diet, and therefore on purported social distinctions at the inter- and intra-site level, stable isotope analyses (carbon, nitrogen and sulphur) were performed on bone collagen of humans (n = 177) and non-human animals (n = 62) fromseven archaeological sites located in the same area (< 10 km). This study is the biggest so far on French Neolithic material and thus allows for an extensive investigation at a regional scale. Results show that the human nitrogen isotopic ratios are relatively enriched in nitrogen-15 comparing to those of the domesticated animals. This reflects a trophic step that is rarely observed elsewhere in the surrounding Neolithic people, particularly for humans of the biggest site Gurgy 'Les Noisats'. Though zooarchaeological data support a predominant cattle consumption, here, we propose a mixed protein consumption of cattle and pig, possibly complemented with some freshwater resources. Furthermore, carbon, nitrogen and sulphur isotopic ratios suggest some slight differences between sexes and sites. This sexual distinction has rarely been identified in the diet within a Neolithic context. Some variations over time were also detected. On the whole, this study seems to support previous observations made from burial practices about a specific regional Neolithic pattern in the Paris Basin as well as bring new elements into discussion of social organisation in human populations

A case–control study to assess the effectiveness of pertussis vaccination during pregnancy on newborns, Valencian community, Spain, 1 March 2015 to 29 February 2016

In the Valencian Community (Spain), the programme of maternal pertussis vaccination during pregnancy started in January 2015. The objective of this study was to estimate in this region the vaccine effectiveness (VE) in protecting newborns against laboratory-confirmed pertussis infection. A matched case–control study was undertaken in the period between 1 March 2015 and 29 February 2016. Twenty-two cases and 66 controls (+/− 15 days of age difference) were included in the study. Cases were non-vaccinated infants < 3 months of age at disease onset testing positive for pertussis by real-time PCR. For every case three unvaccinated controls were selected. Odds ratios (OR) were calculated by multiple conditional logistic regression for association between maternal vaccination and infant pertussis. Other children in the household, as well as mother- and environmental covariates were taken into account. The VE was calculated as 1 − OR. Mothers of five cases (23%) and of 41 controls (62%) were vaccinated during pregnancy. The adjusted VE was 90.9% (95% confidence interval (CI): 56.6 to 98.1). The only covariate in the final model was breastfeeding (protective effect). Our study provides evidence in favour of pertussis vaccination programmes for pregnant women in order to prevent whooping cough in infants aged less than 3 months