Representing, planning and evaluating audit evidence with belief function theory.

This paper presents a framework for the representation, planning and evaluation of uncertain audit evidence using a belief-function approach. We only consider the case of a financial statement audit. The framework allows for the modeling of audit risk and audit evidence at different levels of detail, thereby incorporating dependencies at all levels. It provides the information needed to plan an efficient audit and provides means for intermediate and final evaluation. The paper includes a basic introduction to belief-function theory. Then the framework is described in detail, first for aggregation purposes, then for disaggregation. Next, it is explained how different types of audit evidence should be represented. Finally, we use the audit of the sales and collection cycle and one other fictitious cycle to illustrate representation as well as planning and intermediate and final evaluation. We conclude with a discussion.Planning; Theory;

Generalizing about trade show effectiveness: a cross-national comparison.

Trade shows are a multi-billion dollar business in the US and the UK, but little is known about the determinants of trade show effectiveness. In this paper, we build a model that explains differences in trade show effectiveness across industries, across companies and across two countries. We focus on the differences in trade show effectiveness measured in a similar way across similar samples of 171 US and 135 UK firm-show experiences between 1980 and 1991. While the similarities outweigh the differences, we find evidence that trade shows are viewed differently by exhibitors and attendees in these two countries. We are able to make substantial generalizations about the effect of various show selection (go-not go) variables (booth size, personnel, etc.) on observed performance. We discuss the implications of our research for developing benchmarks for trade show performance and for better global management of the business marketing communications mix.Effectiveness; Trade;

Highly seasonal climate and reproductive phenology in the Mayombe forest: contribution of historical data from the Luki Reserve in the Democratic Republic of Congo

peer reviewedEn Afrique, la phénologie reproductive des arbres tropicaux, majoritairement annuelle, semble présenter une certaine régularité. Cette étude documente les variations intra- et interannuelles de la phénologie reproductive des arbres de la forêt du Mayombe à partir des données historiques de la Réserve de Luki (République démocratique du Congo). Le diamètre de reproduction des espèces exploitées pour le bois, encore largement méconnu, a été également examiné pour les espèces suffisamment représentées dans les données. Le suivi phénologique de 3 642 arbres appartenant à 158 espèces et 39 familles a été réalisé tous les 10 jours de 1948 à 1957. Les statistiques circulaires ont été utilisées pour tester le synchronisme de la phénologie entre arbres, à l’échelle de la communauté, pour la forêt dans son ensemble, et individuellement pour 87 espèces, dont 35 espèces bien représentées (n ≥ 20 arbres), 16 espèces commerciales et 36 autres espèces. Des régressions logistiques ont permis de déterminer le diamètre de fructification (minimum et régulier) de ces espèces. Pour la majorité des espèces, la floraison était régulière, annuelle et largement saisonnière (81,6 %, 71 espèces). Les pics étaient plus marqués pour la floraison que pour la fructification, plus étalée dans le temps, bien que significativement agrégée temporellement. La majorité des arbres et des espèces fleurissaient entre décembre et février, pendant la petite saison sèche, bien que des fleurs et des fruits étaient observables toute l’année à l’échelle de la communauté. Seules 13 espèces ont montré une relation significative entre le diamètre et la reproduction, parmi lesquelles sept espèces de canopée, cinq de sous-bois et une héliophile. Pour ces espèces, la moyenne du diamètre minimum de reproduction était de 17,3 cm

Variation in Onset of Leaf Unfolding and Wood Formation in a Central African Tropical Tree Species

A diversity of phenological strategies has been reported for tropical tree species. Defoliation and seasonal dormancy of cambial activity inform us on how trees cope with water stress during the dry season, or maximize the use of resources during the rainy season. Here, we study the matching between leaf phenology (unfolding and shedding) and cambial activity for Prioria balsamifera, a key timber species in the Democratic Republic of Congo. In particular, we (i) evaluated the seasonality of cambial activity and synchrony of phenology among trees in response to climate and (ii) identified the seasonality of leaf phenology and its relation with cambial phenology. The study was conducted in the Luki Man and Biosphere Reserve, located in the Mayombe forest at the southern margin of the Congo Basin. Historic defoliation data were collected every ten days using weekly crown observations whereas recent observations involved timelapse cameras. Cambial pinning was performed on ten trees during 20 months and radius dendrometers were installed on three trees during 13 months. Tree rings were measured on cores from 13 trees and growth synchrony was evaluated. We found that P. balsamifera defoliates annually with a peak observed at the end of the dry season and the beginning of the rainy season. The new leaves unfolded shortly after shedding of the old leaves. The peak defoliation dates varied across years from September 12 to November 14 and the fraction of number of trees that defoliated at a given time was found to be negatively correlated with annual rainfall and temperature; during the dry season, when precipitation and temperatures are the lowest. Wood formation (radial growth), was found to be highly seasonal, with cambial dormancy occurring during the dry season and growth starting at the beginning of the rainy season. Individual ringwidth series did not cross date well. The within species variability of leaf phenology and cambial rhythms provides indication about resistance of the population against climatic changes

Mass signature of supernova νμ\nu_\mu and ντ\nu_\tau neutrinos in SuperKamiokande

The $\nu_\mu$ and $\nu_\tau$ neutrinos (and their antiparticles) from a Galactic core-collapse supernova can be observed in a water-\v{C}erenkov detector by the neutral-current excitation of $^{16}$O. The number of events expected is several times greater than from neutral-current scattering on electrons. The observation of this signal would be a strong test that these neutrinos are produced in core-collapse supernovae, and with the right characteristics. In this paper, this signal is used as the basis for a technique of neutrino mass determination from a future Galactic supernova. The masses of the $\nu_\mu$ and $\nu_\tau$ neutrinos can either be measured or limited by their delay relative to the $\bar{\nu}_e$ neutrinos. By comparing to the high-statistics $\bar{\nu}_e$ data instead of the theoretical expectation, much of the model dependence is canceled. Numerical results are presented for a future supernova at 10 kpc as seen in the SuperKamiokande detector. Under reasonable assumptions, and in the presence of the expected counting statistics, $\nu_\mu$ and $\nu_\tau$ masses down to about 50 eV can be simply and robustly determined. The signal used here is more sensitive to small neutrino masses than the signal based on neutrino-electron scattering.Comment: 13 pages including 5 figures, to appear in Phys. Rev. D; second version has minor corrections and is in two-column for

The AQUA-FONTIS study: protocol of a multidisciplinary, cross-sectional and prospective longitudinal study for developing standardized diagnostics and classification of non-thyroidal illness syndrome

<p>Abstract</p> <p>Background</p> <p>Non-thyroidal illness syndrome (NTIS) is a characteristic functional constellation of thyrotropic feedback control that frequently occurs in critically ill patients. Although this condition is associated with significantly increased morbidity and mortality, there is still controversy on whether NTIS is caused by artefacts, is a form of beneficial adaptation, or is a disorder requiring treatment. Trials investigating substitution therapy of NTIS revealed contradictory results. The comparison of heterogeneous patient cohorts may be the cause for those inconsistencies.</p> <p>Objectives</p> <p>Primary objective of this study is the identification and differentiation of different functional states of thyrotropic feedback control in order to define relevant evaluation criteria for the prognosis of affected patients. Furthermore, we intend to assess the significance of an innovative physiological index approach (SPINA) in differential diagnosis between NTIS and latent (so-called "sub-clinical") thyrotoxicosis.</p> <p>Secondary objective is observation of variables that quantify distinct components of NTIS in the context of independent predictors of evolution, survival or pathophysiological condition and influencing or disturbing factors like medication.</p> <p>Design</p> <p>The <b>a</b>pproach to a <b>qua</b>ntitative <b>f</b>ollow-up <b>o</b>f <b>n</b>on-<b>t</b>hyroidal <b>i</b>llness <b>s</b>yndrome (AQUA FONTIS study) is designed as both a cross-sectional and prospective longitudinal observation trial in critically ill patients. Patients are observed in at least two evaluation points with consecutive assessments of thyroid status, physiological and clinical data in additional weekly observations up to discharge. A second part of the study investigates the neuropsychological impact of NTIS and medium-term outcomes.</p> <p>The study design incorporates a two-module structure that covers a reduced protocol in form of an observation trial before patients give informed consent. Additional investigations are performed if and after patients agree in participation.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov NCT00591032</p

Scientific merits and analytical challenges of tree-ring densitometry

R.W. was supported by NERC grant NE/K003097/1.X-ray microdensitometry on annually-resolved tree-ring samples has gained an exceptional position in last-millennium paleoclimatology through the maximum latewood density parameter (MXD), but also increasingly through other density parameters. For fifty years, X-ray based measurement techniques have been the de facto standard. However, studies report offsets in the mean levels for MXD measurements derived from different laboratories, indicating challenges of accuracy and precision. Moreover, reflected visible light-based techniques are becoming increasingly popular and wood anatomical techniques are emerging as a potentially powerful pathway to extract density information at the highest resolution. Here we review the current understanding and merits of wood density for tree-ring research, associated microdensitometric techniques, and analytical measurement challenges. The review is further complemented with a careful comparison of new measurements derived at 17 laboratories, using several different techniques. The new experiment allowed us to corroborate and refresh ?long-standing wisdom?, but also provide new insights. Key outcomes include; i) a demonstration of the need for mass/volume based re-calibration to accurately estimate average ring density; ii) a substantiation of systematic differences in MXD measurements that cautions for great care when combining density datasets for climate reconstructions; and iii) insights into the relevance of analytical measurement resolution in signals derived from tree-ring density data. Finally, we provide recommendations expected to facilitate future inter-comparability and interpretations for global change research.Publisher PDFPeer reviewe

Mass signature of supernova νμ\nu_\mu and ντ\nu_\tau neutrinos in the Sudbury Neutrino Observatory

Core-collapse supernovae emit of order $10^{58}$ neutrinos and antineutrinos of all flavors over several seconds, with average energies of 10--25 MeV. In the Sudbury Neutrino Observatory (SNO), which begins operations this year, neutrinos and antineutrinos of all flavors can be detected by reactions which break up the deuteron. For a future Galactic supernova at a distance of 10 kpc, several hundred events will be observed in SNO. The $\nu_\mu$ and $\nu_\tau$ neutrinos and antineutrinos are of particular interest, as a test of the supernova mechanism. In addition, it is possible to measure or limit their masses by their delay (determined from neutral-current events) relative to the $\bar{\nu}_e$ neutrinos (determined from charged-current events). Numerical results are presented for such a future supernova as seen in SNO. Under reasonable assumptions, and in the presence of the expected counting statistics, a $\nu_\mu$ or $\nu_\tau$ mass down to about 30 eV can be simply and robustly determined. If zero delay is measured, then the mass limit is independent of the distance $D$. At present, this seems to be the best possibility for direct determination of a $\nu_\mu$ or $\nu_\tau$ mass within the cosmologically interesting range. We also show how to separately study the supernova and neutrino physics, and how changes in the assumed supernova parameters would affect the mass sensitivity.Comment: 12 pages including 4 figures, submitted to Phys. Rev.

Understanding the interplay between social and spatial behaviour

According to personality psychology, personality traits determine many aspects of human behaviour. However, validating this insight in large groups has been challenging so far, due to the scarcity of multi-channel data. Here, we focus on the relationship between mobility and social behaviour by analysing trajectories and mobile phone interactions of ∼1000 individuals from two high-resolution longitudinal datasets. We identify a connection between the way in which individuals explore new resources and exploit known assets in the social and spatial spheres. We show that different individuals balance the exploration-exploitation trade-off in different ways and we explain part of the variability in the data by the big five personality traits. We point out that, in both realms, extraversion correlates with the attitude towards exploration and routine diversity, while neuroticism and openness account for the tendency to evolve routine over long time-scales. We find no evidence for the existence of classes of individuals across the spatio-social domains. Our results bridge the fields of human geography, sociology and personality psychology and can help improve current models of mobility and tie formation