Importancia de la información contable para el análisis y predicción de la viabilidad de las explotaciones agrícolas

Spanish and Western agriculture show a continuous decrease in the numberof farms. One of the main factors for this trend is the economicnon-viability of many of the existing farms. In addition, interrelationshipof agriculture with other industries is growing. Thus, policymakers, banks,creditors and other stakeholders are interested in predicting farm viability.The aim of this paper is to provide empirical evidence that the use ofaccounting-based information could significantly improve understandingand prediction of various degrees of farm viability. Two multinomial logitmodels were applied to a sample of farms of Catalonia, Spain. One modelincluded non-accounting-based variables, while the other also consideredaccounting-based variables. It was found that accounting added significantinformation to predict various degrees of farm viability. This findingreveals, both the need of encouraging the little existing use of accountingby farms and to develop appropriate accounting standards for agriculture.

Modelling state dependence and feedback effects between poverty, employment and parental home emancipation among European youth

Youth is one of the phases in the life-cycle when some of the most decisivelife transitions take place. Entering the labour market or leaving parentalhome are events with important consequences for the economic well-beingof young adults. In this paper, the interrelationship between employment,residential emancipation and poverty dynamics is studied for eight Europeancountries by means of an econometric model with feedback effects. Resultsshow that youth poverty genuine state dependence is positive and highly significant.Evidence proves there is a strong causal effect between poverty andleaving home in Scandinavian countries, however, time in economic hardshipdoes not last long. In Southern Europe, instead, youth tend to leave theirparental home much later in order to avoid falling into a poverty state that ismore persistent. Past poverty has negative consequences on the likelihood ofemployment.

A finite-population revenue management model and a risk-ratio procedure for the joint estimation of population size and parameters

Many dynamic revenue management models divide the sale period into a finite number of periods T and assume, invoking a fine-enough grid of time, that each period sees at most one booking request. These Poisson-type assumptions restrict the variability of the demand in the model, but researchers and practitioners were willing to overlook this for the benefit of tractability of the models. In this paper, we criticize this model from another angle. Estimating the discrete finite-period model poses problems of indeterminacy and non-robustness: Arbitrarily fixing T leads to arbitrary control values and on the other hand estimating T from data adds an additional layer of indeterminacy. To counter this, we first propose an alternate finite-population model that avoids this problem of fixing T and allows a wider range of demand distributions, while retaining the useful marginal-value properties of the finite-period model. The finite-population model still requires jointly estimating market size and the parameters of the customer purchase model without observing no-purchases. Estimation of market-size when no-purchases are unobservable has rarely been attempted in the marketing or revenue management literature. Indeed, we point out that it is akin to the classical statistical problem of estimating the parameters of a binomial distribution with unknown population size and success probability, and hence likely to be challenging. However, when the purchase probabilities are given by a functional form such as a multinomial-logit model, we propose an estimation heuristic that exploits the specification of the functional form, the variety of the offer sets in a typical RM setting, and qualitative knowledge of arrival rates. Finally we perform simulations to show that the estimator is very promising in obtaining unbiased estimates of population size and the model parameters.

Extra burden of psychosomatic complaints among adolescents suffering from chronic conditions.

OBJECTIVE:: To determine whether there are differences in health perception and health care use among adolescents with psychosomatic symptoms (PS), with chronic conditions (CCs), and with both conditions compared with healthy controls. METHODS:: By using the SMASH02 database, 4 groups were created: youths with PS but no CCs (N = 1010); youths with CCs but no PS (N = 497); youths with both psychosomatic symptoms and chronic conditions (PSCC, N = 213); and youths with neither PS nor CC (control, N = 5709). We used χ tests and analysis of variance to compare each variable between the 4 groups. In a second step, all health and health care use variables were included in a multinomial regression analysis controlling for significant (p < .05) background variables and using the control group as the reference. RESULTS:: Overall, PS and PSCC youths were significantly more likely to rate their health as poor, to be depressed, and to have consulted several times their primary health care provider or a mental health professional than their healthy peers. With the exception of being depressed, PSCC adolescents reported worse health perception and higher health care use than CC and PS. CONCLUSIONS:: Although PS youths do not define PS as a CC, it should be considered as one. Moreover, having PS represents an additional burden to chronically ill adolescents. Health professionals dealing with adolescents must be aware of the deleterious health effects that PS can have on adolescents and have this diagnosis in mind to better target the treatment and improve their management.

Acute alcohol consumption and injury: risk associations and attributable fractions for different injury mechanisms.

OBJECTIVE: Most studies on alcohol as a risk factor for injuries have been mechanism specific, and few have considered several mechanisms simultaneously or reported alcohol-attributable fractions (AAFs)-which was the aim of the current study. METHOD: Data from 3,592 injured and 3,489 noninjured patients collected between January 2003 and June 2004 in the surgical ward of the emergency department of the Lausanne University Hospital (Switzerland) were analyzed. Four injury mechanisms derived from the International Classification of Diseases, 10th Revision, were considered: transportation-related injuries, falls, exposure to forces and other events, and interpersonal violence. Multinomial logistic regression models were calculated to estimate the risk relationships of different levels of alcohol consumption, using noninjured patients as quasi-controls. The AAFs were then calculated. RESULTS: Risk relationships between injury and acute consumption were found across all mechanisms, commonly resulting in dose-response relationships. Marked differences between mechanisms were observed for relative risks and AAFs, which varied between 15.2% and 33.1% and between 10.1% and 35.9%, depending on the time window of consumption (either 6 hours or 24 hours before injury, respectively). Low and medium levels of alcohol consumption generally were associated with the most AAFs. CONCLUSIONS: This study underscores the implications of even low levels of alcohol consumption on the risk of sustaining injuries through any of the mechanisms considered. Substantial AAFs are reported for each mechanism, particularly for injuries resulting from interpersonal violence. Observation of a so-called preventive paradox phenomenon is discussed, and prevention or intervention measures are described.

Malaria haplotype frequency estimation.

We present a Bayesian approach for estimating the relative frequencies of multi-single nucleotide polymorphism (SNP) haplotypes in populations of the malaria parasite Plasmodium falciparum by using microarray SNP data from human blood samples. Each sample comes from a malaria patient and contains one or several parasite clones that may genetically differ. Samples containing multiple parasite clones with different genetic markers pose a special challenge. The situation is comparable with a polyploid organism. The data from each blood sample indicates whether the parasites in the blood carry a mutant or a wildtype allele at various selected genomic positions. If both mutant and wildtype alleles are detected at a given position in a multiply infected sample, the data indicates the presence of both alleles, but the ratio is unknown. Thus, the data only partially reveals which specific combinations of genetic markers (i.e. haplotypes across the examined SNPs) occur in distinct parasite clones. In addition, SNP data may contain errors at non-negligible rates. We use a multinomial mixture model with partially missing observations to represent this data and a Markov chain Monte Carlo method to estimate the haplotype frequencies in a population. Our approach addresses both challenges, multiple infections and data errors.

Drinking Patterns and Their Predictive Factors in CONTROL: a 12-Month Prospective Study in a Sample of Alcohol-Dependent Patients Initiating Treatment.

Aims: To describe the drinking patterns and their baseline predictive factors during a 12-month period after an initial evaluation for alcohol treatment. Methods CONTROL is a single-center, prospective, observational study evaluating consecutive alcohol-dependent patients. Using a curve clustering methodology based on a polynomial regression mixture model, we identified three clusters of patients with dominant alcohol use patterns described as mostly abstainers, mostly moderate drinkers and mostly heavy drinkers. Multinomial logistic regression analysis was used to identify baseline factors (socio-demographic, alcohol dependence consequences and related factors) predictive of belonging to each drinking cluster. ResultsThe sample included 143 alcohol-dependent adults (63.6% males), mean age 44.6 ± 11.8 years. The clustering method identified 47 (32.9%) mostly abstainers, 56 (39.2%) mostly moderate drinkers and 40 (28.0%) mostly heavy drinkers. Multivariate analyses indicated that mild or severe depression at baseline predicted belonging to the mostly moderate drinkers cluster during follow-up (relative risk ratio (RRR) 2.42, CI [1.02-5.73, P = 0.045] P = 0.045), while living alone (RRR 2.78, CI [1.03-7.50], P = 0.044) and reporting more alcohol-related consequences (RRR 1.03, CI [1.01-1.05], P = 0.004) predicted belonging to the mostly heavy drinkers cluster during follow-up. Conclusion In this sample, the drinking patterns of alcohol-dependent patients were predicted by baseline factors, i.e. depression, living alone or alcohol-related consequences and findings that may inform clinicians about the likely drinking patterns of their alcohol-dependent patient over the year following the initial evaluation for alcohol treatment.

Disordered eating behaviors: what about boys?

PURPOSE: To determine the characteristics specific to boys with disordered eating behaviors (DEB) and the general context in which these DEB occur. METHOD: Data were drawn from the SMASH02 database, a survey carried out among post-mandatory school students in Switzerland aged 16-20 years in 2002. Only males (N=3890) were included, and were classified into into one of four groups based on their level of concern about weight/food and on their eating behaviors, as follows: group 1: one concern without behavior (N=862); group 2: more than one concern without behavior (N=361); group 3: at least one behavior (N=798); and a control group (N=1869), according to previously validated items. Groups were compared for personal, family, school, experience of violence, and health-compromising behaviors variables on the bivariate level. All significant variables were included in a multinomial logistic regression using Stata 9 software. RESULTS: About one-half of the boys reported either a concern or unhealthy eating behavior. Compared with the control group, boys from the three groups were more likely to be students and to report a history of sexual abuse, delinquency, depression, and feeling fat. In addition, boys from group 3 were more likely to report a history of dieting, early puberty, peer teasing, having experienced violence, frequent inebriation, and being overweight. CONCLUSION: DEB concern adolescent males more frequently than thought and seem to be integrated in a general dysfunctional context, in which violence is predominant. Adolescent males also need to be screened for DEB. Moreover, prevention programs should target the increasing social and media pressure regarding boys ideal body shape and raise public consciousness about this phenomenon.

Efficient total variation algorithm for fetal brain MRI reconstruction.

Fetal MRI reconstruction aims at finding a high-resolution image given a small set of low-resolution images. It is usually modeled as an inverse problem where the regularization term plays a central role in the reconstruction quality. Literature has considered several regularization terms s.a. Dirichlet/Laplacian energy, Total Variation (TV)- based energies and more recently non-local means. Although TV energies are quite attractive because of their ability in edge preservation, standard explicit steepest gradient techniques have been applied to optimize fetal-based TV energies. The main contribution of this work lies in the introduction of a well-posed TV algorithm from the point of view of convex optimization. Specifically, our proposed TV optimization algorithm or fetal reconstruction is optimal w.r.t. the asymptotic and iterative convergence speeds O(1/n2) and O(1/√ε), while existing techniques are in O(1/n2) and O(1/√ε). We apply our algorithm to (1) clinical newborn data, considered as ground truth, and (2) clinical fetal acquisitions. Our algorithm compares favorably with the literature in terms of speed and accuracy.

Exploring the periodicity of cardiovascular events in Switzerland: variation in deaths and hospitalizations across seasons, day of the week and hour of the day.

PURPOSE: The purpose of this study is to explore the periodical patterns of events and deaths related to cardiovascular disease (CVD), acute myocardial infarction (AMI) and stroke in Swiss adults (≥ 18 years). METHODS: Mortality data for period 1969-2007 (N=869,863 CVD events) and hospitalization data for period 1997-2008 (N=959,990 CVD events) were used. The annual, weekly and circadian distribution of CVD-related deaths and events were assessed. Multivariate analysis was conducted using multinomial logistic regression adjusting for age, gender and calendar year and considering deaths from respiratory diseases, accidents or other causes as competitive events. RESULTS: CVD deaths and hospitalizations occurred less frequently in the summer months. Similar patterns were found for AMI and stroke. No significant weekly variation for CVD deaths was found. Stratification by age and gender showed subjects aged <65 years to present a higher probability of dying on Mondays and Saturday, only for men. This finding was confirmed after multivariate adjustment. Finally, a circadian variation in CVD mortality was observed, with a first peak in the morning (8-12 am) and a smaller second peak in the late afternoon (2-6 pm). This pattern persisted after multivariate adjustment and was more pronounced for AMI than for stroke. CONCLUSION: There is a periodicity of hospitalizations and deaths related to CVD, AMI and stroke in Switzerland. This pattern changes slightly according to the age and sex of the subjects. Although the underlying mechanisms are not fully identified, preventive measures should take into account these aspects to develop better strategies of prevention and management of CVD.

Intentional risk reduction practices of men in Switzerland who have anal intercourse with casual male partners.

OBJECTIVE: To identify prevalence of and factors associated with intentional use of HIV risk reduction practices by men who have sex with men during anal intercourse with casual partners. METHODS: Cross-sectional survey pertaining to the Swiss HIV behavioral surveillance system, using an anonymous self-administered questionnaire in a self-selected sample of men who have sex with men (n = 2953). Multinomial regression was used to estimate factors associated with reporting either "no or inconsistent condom use" or "one or more risk reduction practices" over "consistent condom use." RESULTS: 57.2% reported anal intercourse with casual partner(s) over the last 12 months. Of these, 24.0% declared having used a risk reduction practice (73.8% of those who did not use condoms consistently). HIV-positive people were more likely to have done so. Most predictors were similarly associated to both regression categories. Four significant predictors were common to both regression categories: Internet partner seeking, age, age squared, and the interaction between HIV status positive and number of partners. The only association that differed markedly between the 2 regression categories was having a number of partners above median, significantly associated with the risk reduction category. CONCLUSIONS: Although condom use is the most frequent protection strategy in anal intercourse with casual partners, risk reduction practices are highly prevalent. However, there are no clear differences regarding predictors between risk reduction practices and inconsistent or no condom use. This suggests that risk reduction is an opportunistic response rather than a strategy per se.

Who Cares? A comparison of informal and formal care provision in Spain, England and the USA

This paper investigates the prevalence of incapacity in performing daily activities and the associations between household composition and availability of family members and receipt of care among older adults with functioning problems in Spain, England and the United States of America (USA). We examine how living arrangements, marital status, child availability, limitations in functioning ability, age and gender affect the probability of receiving formal care and informal care from household members and from others in three countries with different family structures, living arrangements and policies supporting care of the incapacitated. Data sources include the 2006 Survey of Health, Ageing and Retirement in Europe for Spain, the third wave of the English Longitudinal Study of Ageing (2006), and the eighth wave of the USA Health and Retirement Study (2006). Logistic and multinomial logistic regressions are used to estimate the probability of receiving care and the sources of care among persons age 50 and older. The percentage of people with functional limitations receiving care is higher in Spain. More care comes from outside the household in the USA and England than in Spain. The use of formal care among the incapacitated is lowest in the USA and highest in Spain.

Young innovative firms and R&D strategies: is the Spanish case different?

This paper analyzes the profile of Spanish young innovative companies (YICs) and the determinants of innovation and imitation strategies. The results for an extensive sample of 2,221 Spanish firms studied during the period 2004–2010 show that YICs are found in all sectors, although they are more concentrated in high-tech sectors and, in particular, in knowledge-intensive services (KIS). Three of every four YICs are involved in KIS. Our results highlight that financial and knowledge barriers have much impact on the capacity of young, small firms to innovate and to become YICs, whereas market barriers are not obstacles to becoming a YIC. Public funding, in particular from the European Union, makes it easier for a new firm to become a YIC. In addition, YICs are more likely to innovate than mature firms, although they are more susceptible to sectoral and territorial factors. YICs make more dynamic use of innovation and imitation strategies when they operate in high-tech industries and are based in science parks located close to universities. Keywords: innovation strategies, public innovation policies, barriers to innovation, multinomial probit model. JEL Codes: D01, D22 , L60, L80, O31

Analysis of sensitivity with respect to a compositional parameter : A comment on 'Local sensitivity analysis for compositional data with application to soil texture in hydrologic modelling' by L. Loosvelt and co-authors

A comment about the article “Local sensitivity analysis for compositional data with application to soil texture in hydrologic modelling” writen by L. Loosvelt and co-authors. The present comment is centered in three specific points. The first one is related to the fact that the authors avoid the use of ilr-coordinates. The second one refers to some generalization of sensitivity analysis when input parameters are compositional. The third tries to show that the role of the Dirichlet distribution in the sensitivity analysis is irrelevant

Adding tobacco to cannabis: its frequency and likely implications.

INTRODUCTION: Young cannabis users are at increased risk of later cigarette initiation and progression to nicotine addiction. The present study addresses the frequency at which mulling (adding tobacco to cannabis smoked as joints) is performed and in which way this practice varies according to cigarette smoking status. METHODS: Data were issued from the Swiss 2007 European School Survey Project on Alcohol and other Drugs (ESPAD). A total of 881 past month cannabis users (mean age 15 years, boys 60.1%) were inquired on mulling using an anonymous self-administered questionnaire. Participants were further grouped according to their cigarette smoking status (daily, occasional, former, and never-smokers). RESULTS: Four of every 5 cannabis users depicted mulling as frequently performed. The highest occurrence was found among daily cigarette smokers (DSC; 90.3%), while former cigarette smokers reported the lowest (58.9%). The multinomial logistic regression showed DSC more likely reporting mulling as frequent compared with never-smokers (risk ratio = 3.56 [95% CI 1.55-8.21]). Conclusions: Mulling appears to be a very common process among young cannabis users, especially among concomitant cigarette smokers. Nevertheless, the majority of cigarette abstainers also reported frequently adding tobacco to the cannabis they smoke. Because it may represent a significant exposition to nicotine, mulling should be taken into account when assessing substance use among adolescents and in supporting their quitting attempts.