An optimization approach applied to the optimal stratification problem

A new optimization algorithm is presented to solve the stratification problem. Assuming the number L of strata and the total sample size n are fixed, we obtain strata boundaries by using an objective function associated with the variance. In this problem, strata boundaries must be determined so that the elements in each stratum are more homogeneous among themselves. To produce more homogeneous strata, this paper proposes a new algorithm that uses the Greedy Randomized Adaptive Search Procedure (GRASP) methodology. Computational results are presented for a set of problems, with the application of the new algorithm and some algorithms from literature.     

Analyse diachronique d'un conseil traditionnel (Colombie)*

This paper is concerned with the role of the traditional council of authorities (cabildo) in a Columbian community of Indian origin. It is shown that its evolution reflects that of the community, since the cabildo has always been essentially an interaction mechanism between the community and the external society, more than the head of an autonomous body. Moreover, this mechanism has mostly been a tool, in the hands of the colonial and, later, national upper class, for manipulating the Indians. The institution was first imposed upon the Indians to ensure their political submission to and economic integration into colonial capitalistic society. In Columbia, this leads to a relatively rapid acculturation of the Indians. During the Republic, a major change occurred when the national economy ceased to rest upon a tributary exploitation of the Indians: landlord/tenant relationships made local community structures useless. Many managed to survive, though, when they were able to keep a certain amount of land on which their members could lead an independent life. The community under study was among these, although its lands were drastically reduced (the better parts being grabbed by adjacent landowners). The local authorities, left without any power to stop these abuses, saw their roles confined to the solution of internal petty disputes. From 1920 on, the further integration of the community in the national economy, through intensive cash-cropping, has gradually made even this reduced role redundant. The author believes that in the study of peasant political systems, a diachronic study of the interrelationships between the economic and the political level is necessary if the understanding is to be complete.     

Radical Social Movements in Western Europe: A Configurational Analysis

There has been little comparative research on the differences across radical social movements in the context of consolidated democracies. This paper analyses the squatting movement, as an exemplary case of contemporary radical movement. This study aims to identify the causal contexts that explain the differences of strengths within these movements across 52 large cities in Western Europe. It examines three main hypotheses drawn from the literature on social movements concerning the characteristics of political systems, the availability of resources and the presence of economic grievances. We use fuzzy sets qualitative comparative analysis (fsQCA) to identify configurations of causal conditions. The findings show that diverse contexts (multi-causation) lead to strong movements. A first causal context combines grievances, resources and closed or unresponsive institutions, and is typically found in Southern European cities. A second context highlights the presence of robust far-right parties in combination with less severe grievances and relative scarcity of resources, and is typically found in Northern European cities. These findings demonstrate that resources and grievances are quasi-necessary conditions for strong radical movements, although polarization can lead to a similar outcome where these characteristics are not present.     

The Run Sum R Chart with Fast Initial Response

A fast initial response (FIR) feature for the run sum R chart is proposed and its ARL performance estimated by a Markov chain representation. It is shown that this chart is more sensitive than several R charts with runs rules proposed by different authors. We conclude that the run sum R chart is simple to use and a very effective tool for monitoring increases and decreases in process dispersion.     

Cognitive-Behavioral Interventions for Anxiety Disorders: Rapid Review Suggestion of Larger Effects among Hispanic than Non-Hispanic White People

ABSTRACT

Anxiety disorders are common among Hispanic people. Evidence-based guidelines indicate cognitive-behavioral interventions (CBI), but they were developed primarily with non-Hispanic white (NHW) people. This rapid scoping review and meta-analysis clarified the relative effectiveness of CBI with Hispanics and NHW people with anxiety disorders and explored the clinical effects of cultural modifications among Hispanic people. Evidence from nine studies in the United States and one in Puerto Rico was synthesized. Meta-analysis of four randomized controlled trials (RCT) found no statistically or practically significant differences between Hispanic and NHW participants on anxiety alleviation. Both groups enjoyed large clinical benefits. However, a significantly greater drop-out rate among Hispanic participants was found. Meta-analytic adjustment for this study characteristic of loss to follow-up suggested a somewhat larger clinical benefit among NHW people. Scoping synthesis of six non-RCTs suggested that deep cultural adaptations of CBI would substantially improve outcomes among Hispanic people. Consistent with Hispanic-paradox and barrio advantage theories such culturally sensitive interventions may well take beneficial Hispanic outcomes beyond those of NHW people. This field's synthetic knowledge, therefore, essentially consists of two competing hypotheses that will require rigorous testing with a necessarily larger and better controlled RCT than has been represented in this field thus far.     

ARL-Design of S Charts with k-of-k Runs Rules

The standard S chart signals an out-of-control condition when one point exceeds a control limit. It can be augmented with runs rules to improve its performance in detecting assignable causes. A commonly used rule signals when k consecutive points exceed a control limit. This rule can be used alone or to supplement the standard chart. In this article we derive ARL expressions for charts with the k-of-k runs rule. We show how to design S charts with this runs rule, compare their ARL performance, and make a control chart recommendation when it is important to monitor for both increases and decreases in process dispersion.     

Influence of water quality and habitat conditions on amphibian community metrics in rivers affected by urban activity

Urban Ecosystems - Anuran amphibians are highly dependent on aquatic ecosystems. Many amphibian species are exhibiting population declines primarily due to habitat destruction and water quality...     

Cemeteries and biodiversity conservation in cities: how do landscape and patch-level attributes influence bird diversity in urban park cemeteries?

Urban Ecosystems - Cemeteries can help conserve biodiversity in urban landscapes, but their capacity to support native species is likely to be influenced by variables at different spatial scales....     

Immigrant Transnational Organizations and Development: A Comparative Study1

This article explores how ninety Colombian, Dominican, and Mexican transnational immigrant organizations pursue philanthropic projects that aid in the development of their country or community of origin. We find that each nationality's context of exit and reception affects the origin, strength, and character of their organizations. We produce “maps” of the interaction of transnational organizations with each country of origin and conduct multivariate regressions to establish determinants of key organizational characteristics, including their degree of formalization and form of creation. Generally, Colombian organizations assume more middle‐class forms, Dominican organizations stem largely from politics in the country of origin, and Mexican organizations are primarily hometown associations with greater involvement of the national state. We observe that regardless of nationality, transnational immigrant organizations’ members are older, better‐established, and possess above‐average levels of education, suggesting that participation in transnational activities and assimilation are not incompatible. The character of proactive activities by each national state are examined. Theoretical implications for immigrant adaptation and community/national development are discussed.