Distinguishing Mother–Infant Interaction From Stranger–Infant Interaction at 2, 4, and 6 Months of Age

Observers watched videotaped face‐to‐face mother–infant and stranger–infant interactions of 12 infants at 2, 4, or 6 months of age. Half of the observers saw each mother paired with her own infant and another infant of the same age (mother tapes) and half saw each infant paired with his or her mother and with a stranger (infant tapes). Observers were asked to judge which was the mother–infant dyad in each pair. Observers' accuracy improved as infants aged and was above chance for both mother and infant tapes when infants were 6 months. Differences between mother–infant and stranger–infant dyadic communication patterns also emerged as the infants aged. At 6 months, mother–infant dyads had more symmetrical communication and less asymmetrical communication than stranger–infant dyads.     

Working with young people from refugee backgrounds in Australia

Social workers who are new to working with young people who are refugees may feel overwhelmed, out of their depth and inclined to defer to powerful psychiatric discourse. Arguing a role for social work engagement with young people as they face the personal, social, communal, cultural, political and economic challenges of settlement, this paper proposes a reflexive, deconstructive and dialogical approach within a broadly ecological model. All settlement tasks require mediation through the powerful discourse (language, values, constructs, social practices) of both the young person's own community and those of the new context. Creating spaces where young people can identify and negotiate the forces vying to shape them underpins and complements the urgent task of combating ethnocentricity in Australian institutions.     

Classification of cyclical time series using complex demodulation

A new and innovative procedure based on time varying amplitudes for the classification of cyclical time series is proposed. In many practical situations, the amplitude of a cyclical component of a time series is not constant. Estimated time varying amplitudes obtained through complex demodulation of the time series are used as the discriminating variables in classical discriminant analysis. The aim of this paper is to demonstrate through simulation studies and applications to well-known data sets, that time varying amplitudes have very good discriminating power and hence their use in classical discriminant analysis is a simple alternative to more complex methods of time series discrimination.     

提取剂对紫薯花青素提取效果的影响及pH响应

花青素,是一种天然水溶性色素,因其对环境友好、安全无毒,且对pH变化敏感的特点,在智 能包装领域展现了独特的研究价值。以紫薯为原料,通过保持提取剂的总体积不变,改变提取剂中冰醋 酸和无水乙醇的体积比的方法,研究了提取剂中不同冰醋酸和无水乙醇的体积比对花青素提取效果的影 响,并分析了不同pH值下花青素溶液的显色反应。结果表明,不同配比的提取剂对紫薯中提取花青素有 较大影响。在冰醋酸和无水乙醇体积一定的条件下,通过紫外-可见吸收光谱、pH示差法等分析发现,冰 醋酸和无水乙醇的体积比为1:1时提取的花青素含量最高,显色效果明显。     

Approximations to Optimal k‐Unit Cycles for Single‐Gripper and Dual‐Gripper Robotic Cells

We consider the problem of scheduling operations in bufferless robotic cells that produce identical parts using either single‐gripper or dual‐gripper robots. The objective is to find a cyclic sequence of robot moves that minimizes the long‐run average time to produce a part or, equivalently, maximizes the throughput. Obtaining an efficient algorithm for an optimum k‐unit cyclic solution (k ≥ 1) has been a longstanding open problem. For both single‐gripper and dual‐gripper cells, the approximation algorithms in this paper provide the best‐known performance guarantees (obtainable in polynomial time) for an optimal cyclic solution. We provide two algorithms that have a running time linear in the number of machines: for single‐gripper cells (respectively, dual‐gripper cells), the performance guarantee is 9/7 (respectively, 3/2). The domain considered is free‐pickup cells with constant intermachine travel time. Our structural analysis is an important step toward resolving the complexity status of finding an optimal cyclic solution in either a single‐gripper or a dual‐gripper cell. We also identify optimal cyclic solutions for a variety of special cases. Our analysis provides production managers valuable insights into the schedules that maximize productivity for both single‐gripper and dual‐gripper cells for any combination of processing requirements and physical parameters.     

Expanding the Scope of Conflict: Interest Groups and Interstate Compacts*

This study looks at how the characteristics of states' interest group environments affect state participation in interstate compacts. Drawing on prominent theories of interest system characteristics, we hypothesize that interest group density and concentration will influence a state's propensity to join compacts. Method. Using pooled cross‐sectional time‐series event‐count models, we test our hypotheses for 48 states over a 30‐year period. Results. We find that states with denser interest group systems are more likely to join interstate compacts, but that greater concentration of organized interests in a few economic sectors impedes compact formation. Additional analyses show that the effects of state interest group systems vary across types of interest groups and compacts. In particular, the effects of interest group density appear to be driven primarily by not‐for‐profit groups generating increased state participation in noneconomic compacts. Conclusion. Interstate cooperation is influenced in important ways by characteristics of interest group environments.