Behavioral responses of rural and urban greater white-toothed shrews (Crocidura russula) to sound disturbance

Urban Ecosystems - The development of urban areas imposes challenges that wildlife must adapt to in order to persist in these new habitats. One of the greatest changes brought by urbanization has...     

Improving flexibility and efficiency by adding parallelism to genetic algorithms

In this paper we develop a study on several types of parallel genetic algorithms (PGAs). Our motivation is to bring some uniformity to the proposal, comparison, and knowledge exchange among the traditionally opposite kinds of serial and parallel GAs. We comparatively analyze the properties of steady-state, generational, and cellular genetic algorithms. Afterwards, this study is extended to consider a distributed model consisting in a ring of GA islands. The analyzed features are the time complexity, selection pressure, schema processing rates, efficacy in finding an optimum, efficiency, speedup, and resistance to scalability. Besides that, we briefly discuss how the migration policy affects the search. Also, some of the search properties of cellular GAs are investigated. The selected benchmark is a representative subset of problems containing real world difficulties. We often conclude that parallel GAs are numerically better and faster than equivalent sequential GAs. Our aim is to shed some light on the advantages and drawbacks of various sequential and parallel GAs to help researchers using them in the very diverse application fields of the evolutionary computation.     

Rethinking assimilation theory for a new era of immigration

"We argue that assimilation theory has not lost its utility for the study of contemporary immigration to the United States. In making our case, we review critically the canonical account of assimilation provided by Milton Gordon and others; we refer to Shibutani and Kwan's theory of ethnic stratification to suggest some directions to take in reformulating assimilation theory. We also examine some of the arguments frequently made to distinguish between the earlier mass immigration of Europeans and the immigration of the contemporary era and find them to be inconclusive. Finally, we sift through some of the evidence about the socioeconomic and residential assimilation of recent immigrant groups. Though the record is clearly mixed, we find evidence consistent with the view that assimilation is taking place, albeit unevenly."     

Analysis of Cultural Indicators: A Comparison of Their Conceptual Basis and Dimensions

Multiple organizations and institutions have been resorting to indicators on diverse aspects of culture (e.g., creativity, social cohesion, cultural vitality, economic participation), according to their particular purposes and views of what is to be measured. This paper presents results from a research report of a qualitative study that analyzed 35 papers on cultural indicators found via Internet, based on four categories: purpose, assumptions about culture, concept of culture they sustain, and dimensions of indicators considered. Results show that even when the importance of culture is widely recognized in the papers, most of them propose indicators without having solid theoretical foundations, and with an emphasis on the relation between culture and economy. Also, most of the documents do not have a definition of culture or present an instrumental conceptualization of it, where culture is valued not as an end in itself but as a resource than can serve to development.     

Response‐adaptive designs for binary responses: How to offer patient benefit while being robust to time trends?

Response‐adaptive randomisation (RAR) can considerably improve the chances of a successful treatment outcome for patients in a clinical trial by skewing the allocation probability towards better performing treatments as data accumulates. There is considerable interest in using RAR designs in drug development for rare diseases, where traditional designs are not either feasible or ethically questionable. In this paper, we discuss and address a major criticism levelled at RAR: namely, type I error inflation due to an unknown time trend over the course of the trial. The most common cause of this phenomenon is changes in the characteristics of recruited patients—referred to as patient drift. This is a realistic concern for clinical trials in rare diseases due to their lengthly accrual rate. We compute the type I error inflation as a function of the time trend magnitude to determine in which contexts the problem is most exacerbated. We then assess the ability of different correction methods to preserve type I error in these contexts and their performance in terms of other operating characteristics, including patient benefit and power. We make recommendations as to which correction methods are most suitable in the rare disease context for several RAR rules, differentiating between the 2‐armed and the multi‐armed case. We further propose a RAR design for multi‐armed clinical trials, which is computationally efficient and robust to several time trends considered.     

Sequential Monte Carlo for rare event estimation

This paper discusses a novel strategy for simulating rare events and an associated Monte Carlo estimation of tail probabilities. Our method uses a system of interacting particles and exploits a Feynman-Kac representation of that system to analyze their fluctuations. Our precise analysis of the variance of a standard multilevel splitting algorithm reveals an opportunity for improvement. This leads to a novel method that relies on adaptive levels and produces, in the limit of an idealized version of the algorithm, estimates with optimal variance. The motivation for this theoretical work comes from problems occurring in watermarking and fingerprinting of digital contents, which represents a new field of applications of rare event simulation techniques. Some numerical results show performance close to the idealized version of our technique for these practical applications.     

Corporate social responsibility and corporate governance in Italian SMEs: the experience of some “spirited businesses”

The study proposes to individuate the relationship between social engagement, social statements and governance of SMEs. Does an adhesion to the philosophy and to the practices of CSR, which are reflected in a firm’s mission and accountability, positively influences its governance? If so, is this influence more or less significant for SMEs with respect to large-sized firms? This paper winds itself around these questions and describes the principle findings that have emerged from a qualitative investigation focused on a selected group of “cohesive” Italian SMEs, in which their management complies with both economic and social issues. The empirical study finds that the diffusion of CSR is tied above all to the entrepreneur’s values and orientation and to the company embeddedness to the local socio-economic environment. The concluding reflections trace the features of a territorial model of socially responsible orientation centered on the best practices of SMEs who are excellent examples of “spirited businesses” and are part of a network (which includes institutions, trade associations, non-profit organizations, etc.) that contributes to the diffusion of an orientation towards CSR and to sustainability across the territory.     

Adherence to Mediterranean diet and risk of prostate cancer

In Europe, countries following the traditional Mediterranean Diet (MeDi), particularly Southern European countries, have lower prostate cancer (PCa) incidence and mortality compared to other European regions. In the present study, we investigated the association between the MeDi and the relative risk of PCa and tumor aggressiveness in a Spanish population. Among individual score components, it has been found that subjects with PCa were less likely to consume olive oil as the main culinary fat, vegetables, fruits and fish than those without. However, these differences were not statistically significative. A high intake of fruit, vegetables and cooked tomato sauce Mediterranean style (sofrito) was related to less PCa aggressiveness. Results showed that there are no differences in the score of adherence to the Mediterranean dietary patterns between cases and controls, with mean values of 8.37?±?1.80 and 8.25?±?2.48, respectively. However, MeDi was associated with lower PCa agressiveness according to Gleason score. Hence, relations between Mediterranean dietary patterns and PCa are still inconclusive and merit further investigations. Further large-scale studies are required to clarify the effect of MeDi on prostate health, in order to establish the role of this diet in the prevention of PCa.     

Precautionary saving in Spain during the great recession: evidence from a panel of uncertainty indicators

The aim of this paper is to empirically study the effect of uncertainty on private consumption using a sample of Spanish households, and therefore, to test the existence of a precautionary motive for saving. Using data provided by the Spanish Survey of Household Finances and the Labour Force Survey we construct several uncertainty measures that are commonly used in the literature and an additional indicator based on job insecurity data, and we consequently estimate different econometric models under the life-cycle/permanent income hypothesis, including these measures of uncertainty. Our results are twofold: first, we find evidence in favour of the precautionary saving hypothesis. Secondly, we find that, unlike other variables related to the performance of the labour market (such as the unemployment rate) the job insecurity indicator is an appropriate variable to approximate income uncertainty in any macroeconomic context.