Understanding vulnerability for depression from a cognitive neuroscience perspective: a reappraisal of attentional factors and a new conceptual framework

We propose a framework to understand increases in vulnerability for depression after recurrent episodes that links attention processes and schema activation to negative mood states, by integrating cognitive and neurobiological findings. Depression is characterized by a mood-congruent attentional bias at later stages of information processing. The basic idea of our framework is that decreased activity in prefrontal areas, mediated by the serotonin metabolism which the HPA axis controls, is associated with an impaired attenuation of subcortical regions, resulting in prolonged activation of the amygdala in response to stressors in the environment. Reduced prefrontal control in interaction with depressogenic schemas leads to impaired ability to exert attentional inhibitory control over negative elaborative processes such as rumination, leading in turn to sustained negative affect. These elaborative processes are triggered by the activation of negative schemas after confrontation with stressors. In our framework, attentional impairments are postulated as a crucial process in explaining the increasing vulnerability after depressive episodes, linking cognitive and biological vulnerability factors. We review the empirical data on the biological factors associated with the attentional impairments and detail how they are associated with rumination and mood regulation. The aim of our framework is to stimulate translational research

Product Return Handling

In this article we focus on product return handling and warehousingissues. In some businesses return rates can be well over 20% andreturns can be especially costly when not handled properly. In spiteof this, many managers have handled returns extemporarily. The factthat quantitative methods barely exist to support return handlingdecisions adds to this. In this article we bridge those issues by 1)going over the key decisions related with return handling; 2)identifying quantitative models to support those decisions.Furthermore, we provide insights on directions for future research.reverse logistics;decision-making;quantitative models;retailing and warehousing

Optimal Zone Boundaries for Two-class-based Compact 3D AS/RS

Compact, multi-deep (3D), Automated Storage and Retrieval Systems (AS/RS) are becoming more common, due to new technologies, lower investment costs, time efficiency and compact size. Decision-making research on these systems is still in its infancy. We study a particular compact system with rotating conveyors for the depth movement and a Storage/Retrieval (S/R) machine for the horizontal and vertical movement of unit loads. We determine the optimal storage zone boundaries for such systems with two product classes: high and low turnover, by minimizing the expected Storage/Retrieval (S/R) machine travel time. We propose a mixed-integer nonlinear programming model to determine the zone boundaries. A decomposition algorithm and a one dimensional search scheme are developed to solve the model. The algorithm is complex, but the results are appealing since most of them are in closed-form and easy to apply to optimally layout the 3D AS/RS rack. The results are compared with those under random storage, and show that a significant reduction of the machine travel time can be obtained. Finally, a practical example is studied to demonstrate the use and validate our findings.AS/RS;Class-based storage;Order picking;Storage rack design;Travel time model

Urban Distribution: The Impacts of Different Governmental Time-Window Schemes

Local authorities increasingly use time-access regulations to improve social sustainability issues, such as the attractiveness of a city centre, the shopping climate, or to reduce the nuisance caused by urban freight transport. However, these time-windows increase delivery costs and the environmental burden. This paper evaluates five different time-window schemes on their social, environmental, and economic impacts. The first scheme examines the current time-window policy scheme. In the second scheme time-windows are harmonized between different cities. The third scheme moves all deliveries to the night. The fourth and fifth schemes evaluate the consequences of the proposal by the Dutch committee for urban distribution (committee Sakkers). The fourth scheme includes noise-legislation for delivering during the night, the fifth does not. This research includes interviews with several Dutch policy-making officials and is further based on a multiple-case study of fourteen large retail chains in different sectors and with different formulas. The results show that the current time-window scheme performs worst. The best time-window scheme would be a combination of the proposal of the committee Sakkers and the harmonization scenario.City Logistics;Retail Logistics;Sustainability;Time-Window Regulation;Urban Goods Movement

The networks of the solo self-employed and their success

An increasing proportion of the Dutch labour market is formed by the solo selfemployed (i.e. one person enterprises, mainly offering their own human capital). Knowledge on solo self-employed is still limited and this makes tailoring policy measures towards this group difficult. Their network position may play a crucial role in economic performance of solo self-employed, as resources available are by definition limited. They are likely to depend heavily on their professional networks for acquisition and mobilizing additional resources. In this paper we use a specially constructed panel of solo self-employed from the Netherlands to explore the motives, gestation and spatial extent of their networks. (Multinomial) logit models are used to relate network position to their economic performance. The results suggest that the motives for and gestation of cooperation between solo self-employed differ from other groups of entrepreneurs. In contrast to existing ideas about network benefits, information sharing and knowledge spill-overs are not an important motive for solo self-employed. Rather, they focus on executing jobs and joint acquisition. Finally, we find that in terms of success a good network position is negatively related to economic performance. In more detail, cooperation on scope is connected to success, whereas joined acquisition is related to poor performing solo self-employed. It seems that solo self-employed reach out to their colleagues when business is slow. �

Managing Multilaterals’ Effectiveness: Which way forward?

There has been an increase in the attention paid to the measurement of the performance of development aid and of aid agencies. While the monitoring and evaluation of aid delivered by bilateral agencies has been a well-established practice for quite some time, the measurement of the performance of Multilateral Organizations (MOs) by bilateral back-donors, and the use of this information in improved bilateral policies towards these same MOs is more recent. But of late there has been a mushrooming of bilateral initiatives that try to assess MO performance. Currently bilateral donors seem to be moving toward a more harmonized approach through the introduction of assessments that are organized by networks of donors. How the information from these assessments is being used in policy-making, however, is far from clear. This paper analyzes the current state of affairs in the field of assessing multilaterals. It feeds into the debate on how bilateral donors should effectively and efficiently manage the performance of the MOs they fund. The analysis of three country cases (Belgium, the Netherlands and the United Kingdom) reveals significant differences in the performance management of multilaterals by bilaterals. The paper examines these differences in the light of the literature on performance measurement. It argues that while donors are increasing their efforts in measuring the performance of multilaterals, the use of this information often remains insufficient. The good example set by the UK is closely linked to administrative and political features of this country and difficult to just duplicate by other countries. The field of managing the performance of MOs remains scattered, unsystematic, and above all, challenging.

Optimal Storage Rack Design for a 3D Compact AS/RS with Full Turnover-Based Storage

Compact, multi-deep (3D) automated storage and retrieval systems (AS/RS) are becoming increasingly popular for storing products with relatively low turnover on a compact area. An automated storage/retrieval crane takes care of movements in the horizontal and vertical direction in the rack, and a gravity conveying mechanism takes care of the depth movement. An important question is how to layout such systems to minimize the product storage and retrieval times. Although much attention has been paid to 2D AS/RS, multi-deep systems have hardly been studied. This paper studies the impact of system layout on crane travel time. We calculate the rack dimensions that minimize single-command cycle time under the full-turnover-based storage policy. We prove the expected travel time is minimized when the rack is square-in-time in horizontal and vertical directions and the conveyor’s dimension is the longest. We compare the model’s results with the performance of the random storage policy and show a significant crane travel time reduction can be obtained. We illustrate the findings of the study by applying them in a practical example.AS/RS;Warehousing;Order Picking;Storage Rack Design;Travel Time Model;Turnover-Based Storage

Performance Approximation and Design of Pick-and-Pass Order Picking Systems

In this paper, we discuss an approximation method based on G/G/m queuing network modeling using Whitt’s (1983) queuing network analyzer to analyze pick-and-pass order picking systems. The objective of this approximation method is to provide an instrument for obtaining rapid performance estimates (such as order lead time and station utilization) of the order picking system. The pick-and-pass system is decomposed into conveyor pieces and pick stations. Conveyor pieces have a constant processing time, whereas the service times at a pick station depend on the number of order lines in the order to be picked at the station, the storage policy at the station, and the working methods. Our approximation method appears to be sufficiently accurate for practical purposes. It can be used to rapidly evaluate the effects of the storage methods in pick stations, the number of order pickers at stations, the size of pick stations, the arrival process of customer orders, and the impact of batching and splitting orders on system performance.simulation;warehousing;order picking;queuing network;pick-and-pass