The impact of terrorist attacks in G7 countries on international stock markets and the role of investor sentiment

We consider terrorism acts in G7 countries over the period 1998–2017 and examine their impact on a sample of stock market indices from 66 countries. Using an event-study methodology we find that stock markets decline significantly on the event day and on the following trading day. We further consider the investor sentiment following the attacks, based on the content of country-level news stories and social media sources, and find that indices in countries associated with higher declines in the post-event sentiment, exhibit significantly higher economic losses. Our data and results are robust to several settings; these include using samples of events from different studies, excluding the 9/11 terrorist attack from the sample of events, excluding stock market indices of G7 countries from the sample of equity data and utilizing more sophisticated event-study methodologies

Sea ice biogeochemistry and material transport across the frozen interface

Author Posting. © Oceanography Society, 2011. This article is posted here by permission of Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 24 no. 3 (2011): 202–218, doi:10.5670/oceanog.2011.72.The porous nature of sea ice not only provides a habitat for ice algae but also opens a pathway for exchanges of organic matter, nutrients, and gases with the seawater below and the atmosphere above. These constituents permeate the ice cover through air-ice gas exchange, brine drainage, seawater entrainment into the ice, and air-sea gas exchange within leads and polynyas. The central goal in sea ice biogeochemistry since the 1980s has been to discover the physical, biological, and chemical rates and pathways by which sea ice affects the distribution and storage of biogenic gases (namely CO2, O2, and dimethyl sulfide) between the ocean and the atmosphere. Historically, sea ice held the fascination of scientists for its role in the ocean heat budget, and the resulting view of sea ice as a barrier to heat and mass transport became its canonical representation. However, the recognition that sea ice contains a vibrant community of ice-tolerant organisms and strategic reserves of carbon has brought forward a more nuanced view of the "barrier" as an active participant in polar biogeochemical cycles. In this context, the organisms and their habitat of brine and salt crystals drive material fluxes into and out of the ice, regulated by liquid and gas permeability. Today, scientists who study sea ice are acutely focused on determining the flux pathways of inorganic carbon, particulate organics, climate-active gases, excess carbonate alkalinity, and ultimately, the role of all of these constituents in the climate system. Thomas and Dieckmann (2010) recently reviewed sea ice biogeochemistry, and so we do not attempt a comprehensive review here. Instead, our goal is to provide a historical perspective, along with some recent discoveries and observations to highlight the most outstanding questions and possibly useful avenues for future research

On the Validation of Satellite-Derived Sea Ice Surface Temperature

The surface temperature of sea ice controls the rate of ice growth and heat exchange between the ocean and the atmosphere. An algorithm for the satellite retrieval of ice surface temperature has recently been published, but due to the lack of validation data has not been extensively tested. In this paper, data from a recent Arctic field experiment is used in an attempt to validate that algorithm. While the procedure is, in principle, straightforward, we demonstrate that validation is complicated by a variety of factors, including incorrectly assumed atmospheric conditions, undetected clouds in the satellite data, spatial and temporal variability in the surface temperature field, and surface and satellite measurement errors. Comparisons between surface temperatures determined from upwelling broadband longwave radiation, spatial measurements of narrow-band radiation, thermocouples buried just below the snow surface, and narrow-band satellite data show differences of 1 to 13 degrees C. The range in these independent measurements indicates the need for specially designed validation experiments utilizing narrow-band radiometers on aircraft to obtain broad spatial coverage.Key words: ice surface temperature, Arctic climate, sea ice, AVHRRLa température de la surface de la glace de mer contrôle le taux de croissance de la glace et les échanges thermiques entre l'océan et l'atmosphère. Un algorithme d'extraction par satellite de la température de la surface de la glace a récemment été publié, mais n'a pu être mis à l'essai sur une grande échelle, en raison du manque de données de validation. On tente, dans cet article, de valider cet algorithme à l'aide de données provenant d'une expérience de terrain menée récemment dans l'Arctique. Si la procédure est, en principe, simple, on démontre que divers facteurs viennent compliquer cette validation, dont une évaluation incorrecte des conditions atmosphériques, la présence de nuages non détectés dans les données obtenues par satellite, une variabilité spatiale et temporelle dans la température de surface de l'aire expérimentale, et des erreurs dans les mesures prises sur le terrain même et par satellite. Des comparaisons entre les températures de surface déterminées à partir du rayonnement ascendant des ondes longues à large bande, des mesures spatiales du rayonnement à bande étroite, des thermocouples placés juste sous la surface de la neige et des données de satellite dans la bande étroite révèlent des différences allant de 1 à 3 °C. La différence qui existe dans ces mesures prises indépendamment montre bien la nécessité de mettre sur pied des expériences de validation conçues à des fins spécifiques, qui utilisent des radiomètres à bande étroite sur les avions en vue d'obtenir une grande couverture spatiale.Mots clés: température de la surface de la glace, climat de l’Arctique, glace de mer, radiomètre perfectionné à très haute résolutio

Professional Black South African women : body image, cultural expectations and the workplace

The study explored the body image of Professional Black South African women, cultural expectations, and their experiences in Westernised working milieus, utilising a phenomenological approach and qualitative exploratory design, located within Constructionism. Data were collected through purposive sampling (and snowballing) through individual face-to-face voice-recorded semi-structured interviews with 11 participants in/around Gauteng. Analysis was done through content analysis utilising thematic networks (Attride-Stirling). Major findings: Western values have influenced participants; Lower weight and thinness do not automatically correspond with assumptions about HIV/AIDS, instead correspond with healthier lifestyle choices; Body shape not weight or size was the prominent area of focus for most participants; Clothes size determines perception of overweight; Overweight has consequences. Forty-five per cent of participants were content with their bodies, 18% dissatisfied/unhappy, 18% satisfied, one happy, one apathetic. Tswanas were generally smaller-figured; Zulus, Northern Sotho/Pedi, Xhosa in general traditionally expected full-bodied women. Overt expectations in the workplace were not found.PsychologyM.A. (Psychology

Φιλαρμονική Ορχήστρα της Νέας Υόρκης: Συγκριτική μελέτη του ρεπερτορίου από τις περιοδείες της ορχήστρας υπό τη διεύθυνση των αρχιμουσικών Δημήτρη Μητρόπουλου και Lorin Maazel

Η μελέτη των προγραμμάτων των συμφωνικών συναυλιών δύναται να αναδείξει σημαντικά στοιχεία για το καλλιτεχνικό όραμα του εκάστοτε μαέστρου. Στην παρούσα πτυχιακή εργασία, εξετάζονται τα προγράμματα των αρχιμουσικών Δημήτρη Μητρόπουλου και Lorin Maazel από τις περιοδείες τους με τη Φιλαρμονική Ορχήστρα της Νέας Υόρκης, από το 1950 μέχρι το 1957 και από το 2002 μέχρι το 2009 αντίστοιχα. Στο πρώτο από τα τέσσερα κεφάλαια της εργασίας γίνεται μια σύντομη αναφορά στην ιστορία της ορχήστρας και στο υπόβαθρο του Μητρόπουλου. Στο δεύτερο κεφάλαιο εξετάζεται η πορεία του Μητρόπουλου με την ορχήστρα και στη συνέχεια αναλύεται το ρεπερτόριο του στις περιοδείες. Στο τρίτο κεφάλαιο γίνεται μια επισκόπηση της καλλιτεχνικής πορείας του Maazel και της πορείας του με την ορχήστρα, ενώ στη συνέχεια αναλύεται το πρόγραμμά του στις περιοδείες. Τέλος, στο τέταρτο κεφάλαιο γίνεται σύγκριση των προγραμμάτων των δύο μαέστρων. Οι κυριότερες τάσεις και οι διαφορές που αναδύθηκαν έχουν να κάνουν με το ποσοστό εκτέλεσης έργων από την περίοδο του ρομαντισμού και του 20ού αιώνα, με τη διαδοχή των μουσικών ειδών των κομματιών, καθώς και με τις εκτελέσεις έργων από συγκεκριμένους συνθέτες. Συνεπώς, η παρούσα μελέτη συμβάλει στη κατανόηση του καλλιτεχνικού οράματος των δύο μαέστρων στις περιοδείες τους με τη Φιλαρμονική Ορχήστρα της Νέας Υόρκης.Studying the repertoire of symphonic concerts may reveal important elements of a conductor’s artistic vision. This study examines the repertoire of conductors Dimitri Mitropoulos and Lorin Maazel during their tours with the New York Philharmonic Orchestra, from 1950 till 1957 and from 2002 till 2009 respectively. The first of the four chapters briefly reviews the orchestra’s history and Mitropoulos’ background. The second chapter examines Mitropoulos’ course with the orchestra and investigates his repertoire during the tours. The third chapter provides an overview of Maazel’s artistic trajectory and of his tenure with the orchestra, while it concludes with an investigation of his repertoire during the tours. Finally, the fourth chapter compares the two maestros’ repertoire. The main trends and differences that were revealed have to do with the percentage of performances from the era of romanticism and the 20th century, with the sequence of pieces’ music genres, as well as with the performance of pieces from specific composers. Conclusively, this work contributes to understanding the two maestros’ artistic vision during their tours with the New York Philharmonic Orchestra

Inorganic carbon dynamics of melt-pond-covered first-year sea ice in the Canadian Arctic

Melt pond formation is a common feature of spring and summer Arctic sea ice, but the role and impact of sea ice melt and pond formation on both the direction and size of CO2 fluxes between air and sea is still unknown. Here we report on the CO2-carbonate chemistry of melting sea ice, melt ponds and the underlying seawater as well as CO2 fluxes at the surface of first-year landfast sea ice in the Resolute Passage, Nunavut, in June 2012. Early in the melt season, the increase in ice temperature and the subsequent decrease in bulk ice salinity promote a strong decrease of the total alkalinity (TA), total dissolved inorganic carbon (T CO2) and partial pressure of CO2 (pCO2) within the bulk sea ice and the brine. As sea ice melt progresses, melt ponds form, mainly from melted snow, leading to a low in situ melt pond pCO2 (36 μatm). The percolation of this low salinity and low pCO2 meltwater into the sea ice matrix decreased the brine salinity, TA and T CO2, and lowered the in situ brine pCO2 (to 20 μatm). This initial low in situ pCO2 observed in brine and melt ponds results in air-ice CO2 fluxes ranging between -0.04 and -5.4 mmolm-2 day-1 (negative sign for fluxes from the atmosphere into the ocean). As melt ponds strive to reach pCO2 equilibrium with the atmosphere, their in situ pCO2 increases (up to 380 μatm) with time and the percolation of this relatively high concentration pCO2 meltwater increases the in situ brine pCO2 within the sea ice matrix as the melt season progresses. As the melt pond pCO2 increases, the uptake of atmospheric CO2 becomes less significant. However, since melt ponds are continuously supplied by meltwater, their in situ pCO2 remains undersaturated with respect to the atmosphere, promoting a continuous but moderate uptake of CO2 (∼-1 mmolm-2 day-1) into the ocean. Considering the Arctic seasonal sea ice extent during the melt period (90 days), we estimate an uptake of atmospheric CO2 of -10.4 Tg of Cyr-1. This represents an additional uptake of CO2 associated with Arctic sea ice that needs to be further explored and considered in the estimation of the Arctic Ocean's overall CO2 budget

Molecular recognition of N-acetyltryptophan enantiomers by β-cyclodextrin

The enantioselectivity of β-cyclodextrin (β-CD) towards L- and D-N-acetyltryptophan (NAcTrp) has been studied in aqueous solution and the crystalline state. NMR studies in solution show that β-CD forms complexes of very similar but not identical geometry with both L- and D-NAcTrp and exhibits stronger binding with L-NAcTrp. In the crystalline state, only β-CD-L-NAcTrp crystallizes readily from aqueous solutions as a dimeric complex (two hosts enclosing two guest molecules). In contrast, crystals of the complex β-CD-D-NAcTrp were never obtained, although numerous conditions were tried. In aqueous solution, the orientation of the guest in both complexes is different than in the β-CD-L-NAcTrp complex in the crystal. Overall, the study shows that subtle differences observed between the β-CD-L,D-NAcTrp complexes in aqueous solution are magnified at the onset of crystallization, as a consequence of accumulation of many soft host-guest interactions and of the imposed crystallographic order, thus resulting in very dissimilar propensity of each enantiomer to produce crystals with β-CD