The coming revolution of biotechnology: A critique of Buttel

Frederick Buttel was one of the pioneers in studying the social impacts of biotechnology, claiming originally that it will involve profound changes in social structure. Recently Buttel turned around his argument proposing that, rather than revolutionary, biotechnology is more a substitutionist technological form to be applied to declining sectors of the economy than an epoch-making technology. This paper provides both external and internal critiques of Buttel's new position based on the concept of the third technological revolution, looking at the impact of new technologies as a global and interrelated phenomenon, and not on an individual case-by-case basis. The concluding section suggests the necessity of bringing into the analysis those living in the Third World: 60% of this population lives from agriculture and will be affected by the deployment of agricultural biotechnologies, whether through substitutionism or through totally new products.     

The Self-Fulfilling Property of Trust: An Experimental Study

A person is said to be ‘trust responsive’ if she fulfils trust because she believes the truster trusts her. The experiment we report was designed to test for trust responsiveness and its robustness across payoff structures, and to discriminate it from other possible factors making for trustworthiness, including perceived kindness, perceived need and inequality aversion. We elicit the truster’s confidence that the trustee will fulfil, and the trustee’s belief about the truster’s confidence after the trustee receives evidence relevant to this. We find evidence of strong trust responsiveness. We also find that perceptions of kindness and of need increase trust responsiveness, and that they do so only in conjunction with trust responsiveness.      

Conceptualizing Emergent States: A Strategy to Advance the Study of Group Dynamics

In this review, we aim to advance work on group and team dynamics by examining how important elements of dynamism are embedded in the current literature on emergent states in groups. We use the concept of emergence as an organizing frame, building block, and critical lens, first summarizing key aspects of the extant literature on emergence, and then drawing four core characteristics of emergent phenomena from this literature. We use these characteristics to organize our review and examine how emergent states are portrayed in the past decade of groups literature. We end by exploring challenges to the development of a more dynamic perspective and by offering specific suggestions to guide and advance future work on groups and teams.     

A step-by-step algorithm for combining diagnostic tests

Combining data of several tests or markers for the classification of patients according to their health status for assigning better treatments is a major issue in the study of diseases such as cancer. In order to tackle this problem, several approaches have been proposed in the literature. In this paper, a step-by-step algorithm for estimating the parameters of a linear classifier that combines several measures is considered. The optimization criterion is to maximize the area under the receiver operating characteristic curve. The algorithm is applied to different simulated data sets and its performance is evaluated. Finally, the method is illustrated with a prostate cancer staging database.     

Latent Tuberculosis Infection Screening Acceptability among Migrant Farmworkers

Latent tuberculosis (TB) infection is routinely diagnosed using the tuberculin skin test (TST). New methods of detection more specific than TST such as QuantiFERON TB Gold In‐Tube (QFT‐GIT) have been developed but evidence remains limited on their acceptability among migrant farmworkers. This article examined the acceptability of screening tests among migrant farmworkers working on the Arizona‐Mexico border. We conducted a cross‐sectional survey of migrant farmworkers via questionnaire. Of 83 participants interviewed, 53 (63.9%) believed that TB was a serious disease that could result in death and 59 (71.1%) considered TB a health concern in their community. Sixty‐four participants (77.1%) rated QFT‐GIT test as performing better than TST. Our study demonstrates preference for QFT‐GIT results over TST, and highlights migrant farmworkers’ considering themselves at risk of TB and TB as a health concern. Policies that create easy access and culturally appropriate, affordable healthcare for this vulnerable population should be encouraged.     

Cross-National Indices with Gender-Differentiated Data: What Do They Measure? How Valid Are They?

The two cross-national indices with gender-differentiated data introduced by the UNDP in 1995, as well as several other such indices developed subsequently, are an important resource for researchers and policy makers interested in gender disparities. Yet questions remain regarding how these indices should be interpreted and how valid they are. Relying on a framework that synthesizes key guidelines concerning the methodology of measurement, this article offers an assessment of indices currently used to study gender disparities on a global scale and sheds light on these unresolved questions. We answer two questions—what do these indices with gender-differentiated data actually measure? and, how valid are these indices?—and discuss the implications of our assessment for users and producers of gender indices.     

Population models reveal synergistic fitness effects of climate change and urbanization on poison ivy (Toxicodendron radicans) via disruption of seed dispersal interactions

Urban Ecosystems - Two of the most important human disturbances on natural ecosystems are urbanization and climate change. While their individual effects are well-documented, how the combined...     

Limit laws for the cumulative number of ties for the maximum in a random sequence

Let {_Xn,n?1}$\{X_n,n?1\}$ be a sequence of independent identically distributed random variables, taking nonnegative integer values. An observation _Xn$X_n$ is a tie for the maximum if _Xn=max{_X1,…,_Xn-1}$X_n=\max \{X_1,\dots ,X_{n-1}\}$. In this paper, we obtain weak and strong laws of large numbers and central limit theorems for the cumulative number of ties for the maximum among the first n$n$ observations.     

Monitoring and modeling the urban growth of two mid-sized Chilean cities

Chile's economic development model changed drastically in 1973. Public policy liberalization ended and the market became the principal entity for regulating growth, including urban growth. The implementation of this new model resulted in unprecedented urban growth, markedly impacting the landscape. In mid-sized cities, this spatial growth has been especially significant. Two examples of such mid-sized cities are Chillán and Los Ángeles, located in the Biobío Region, in the so-called Central Valley. This research analyzed the land use/cover change in Chillán and Los Ángeles from 1978 to 1998, identified the patterns of urban growth and the fragmentation of the urban space, applying GIS and remote sensing tools. The main driving forces of the urban changes were analyzed and the model to predict the land use/cover changes was applied. Our results show the importance of monitoring and modeling rapid urban growth for attaining sustainable mid-sized cities in developing countries that are strongly dependent on export of natural resources. Monitoring and modeling could also help to avoid a repetition of the errors that produced the unsustainable growth characteristic of large Latin American cities.