Peer Ethnicity and Achievement: a Meta-analysis Into the Compositional Effect

This study reports a meta-analysis on the effects of ethnic minority share in school on achievement test scores. Best evidence from the studies that have appeared thus far on this topic shows that these compositional effects appear small in general, but may be larger when the ethnic minority group is African Americans in the USA, than when the minority group consists of immigrants. A high share of students from an ethnic minority group seems to affect the achievement from students belonging to the same ethnic group more, than the achievement of students belonging to the ethnic majority or to other ethnic minority groups. Effects of the share of immigrants on test scores of ethnic majority students even seem to be close to zero. Several robustness checks confirm our results. The review concludes with a discussion of implications for research and policy practice.academic achievement, meta-analysis, racial composition, school segregation, ethnic groups

The effect of peer socioeconomic status on student achievement: a meta-analysis

Previous studies on the effects on students' test scores of their peers' socioeconomic status (SES) reported varying results. A meta-regression analysis including 30 studies on the topic shows that the compositional effect that researchers find is strongly related to how they measure SES and to their model choice. If they measure SES dichotomously (e.g. free lunch eligibility) or include several average SES-variables in one model, they find smaller effects than when using a composite that captures several SES-dimensions. Composition measured at cohort/school level is associated with smaller effects than composition measured at class level. Researchers estimating compositional effects without controlling for prior achievement or not taking into account the potential for omitted variables bias, risk overestimating the effect. Correcting for a large set of not well thought-over covariates may lead to an underestimation of the compositional effect, by artificially explaining away the effect. Little evidence was found that effect sizes differ with sample characteristics such as test type (language vs. math) and country. Estimates for a hypothetical study, making a number of "ideal" choices, suggest that peer SES may be an important determinant of academic achievement.

Mauerpark Berlin – Investigating Design Language at Multiple Scales

The Mauerpark Berlin is a recently completed, contemporary park in Berlin (GER) designed by German landscape architect Gustav Lange (1937-2022) on the void of the former Death Strip of the Berlin Wall. Spatially, Lange preserved the openness of this urban void in the design concept while creating carefully placed design interventions throughout the park. Typically, Lange applies basic geometric shapes and ordering spatial compositions that are balanced with moments of randomness. This paper investigates the relationship of ordering design strategies with tactical, random moments in the design of Mauerpark Berlin. The method is a design analysis at three scales. The analysis investigates the overall composition of the whole park to smaller areas and further down to the scale of design objects and focal areas. Findings reveal that the design language applies a formal design vocabulary with principal geometric compositions and shapes and is balanced through variations and exceptions. This phenomenon is increasing gradually from the larger scales to the smaller design scales. From a more close-up perspective, geometries and lines are broken up to reveal gaps and thus increase diversity and intricacy in the design. These qualities seem to lead to moments of unpredictability, self-authored, spontaneous appropriation through users, unprogrammed and ever-changing activities through people or random distribution of pioneering, vagabonding plants. Overall, this study is relevant for those who are involved in the creation, restoration, or maintenance of larger parks in urban contexts that serve diverse users and audiences

Potentials and Limitations of Implementing Linear Infiltration Systems on Urban Streets

Increasing infiltration systems in urban environments has become a major focus of our discipline to reduce the harmful impact of stormwater on urban watersheds. Two recent studies were conducted by the author of this paper (Sleegers and Brabec; 2013, Sleegers, 2013) with the focus on evaluating the aesthetics of linear urban infiltration systems on urban streets. Each study revealed challenges and limitations of these systems on various levels. What are the crucial criteria to propagate infiltration along streets, raise their acceptance and make them more usable? The purpose of this paper is to investigate the challenges and limitations of urban infiltration systems and propose recommendations for further implementation

Phytoremediation as Green Infrastructure and a Landscape of Experiences

The idea of reconciling landscapes through remediation is not new to the discipline of landscape architecture. However the potential of using transformative remediation to build urban form as a large-scale landscape network and that makes the process of remediation part of an urban landscape experience is still underdeveloped in theory and practice. This paper examines how a remediation process could be exhibited and become a staged design element, and how landscapes of cleaning can become part of the urban infrastructure to create new neighborhoods for research, education, working, and living. The example of two adjacent sites on the contaminated Elbe – Island in Hamburg, Wilhelmsburg Germany demonstrates how the purification process of water and soils can be showcased and experienced by the public and how the landscape framework becomes part of the urban infrastructure. The paper proposes a structural landscape framework for how remediation could become an artistic, aesthetically pleasing intervention with environmental value

Racial discrimination in the sharing economy:Evidence from Airbnb markets across the world

Online peer-to-peer platforms aim to reduce anonymity and increase trust by displaying personal information about sellers. However, consumers may also rely on the names and profile photos of sellers to avoid sellers from certain social groups. Here we analyze more than 100,000 Airbnb rentals to test whether consumers discriminate against hosts from racial minorities. If consumers prefer to stay with a White host, then hosts from racial minorities should be able to charger lower prices for similar rentals. In Study 1, we analyzed 96,150 Airbnb listings across 24 cities, 14 countries, and 3 continents and found that non-White hosts charge 2.74% lower prices for qualitatively similar rentals. In Study 2, a preregistered analysis of 12,648 listings across 14 cities in the United States showed that, compared to White hosts, Black hosts charge 7.39% lower prices and Asian hosts charge 5.94% lower prices. Even though the magnitude of the price penalties varied, they emerged consistently across most cities. In sum, the current findings suggest that there is widespread discrimination against Airbnb hosts from racial minorities

University urban design centers in the planning and implementation of urban greenways. – Possible strategies for the UMass Amherst Design Center in Springfield, MA.

University supported community design centers in the United States provide an institutional alternative for urban design and planning. They are a link between the innovative and educational milieu of the university and professional practice. Design centers provide the infrastructure that allows faculty and students’ research opportunities and projects that intersect with the practice of urban design and planning, with the goal of improving the physical and consequently, the social environment. This paper assesses the following goals that nascent community design centers should pursue in the planning and design of greenways: 1. focus on developing a collective vision and a tangible plan through public participation, service learning and visualization, 2. execute interdisciplinary and inter-institutional collaboration, 3. establish public-private partnerships, 4. search funds for staffing and implementation with a high proportion from private capital or foundations, 5. pursue a step - by step approach with visible results

Utilizing Phytotechnologies: Redesigning Abandoned Gas Stations

Hazardous pollutants that exist in contaminated soils represent a threat to human, animal, and environmental health if left unmanaged. Phytoremediation in the U.S. was generally named and formally established in the 1980s and applied as an alternative method using plants to cleanse contaminated soils on site in a more economically and environmentally friendly way than removing contaminated soils off site. High expectations and mixed performances with failures outnumbering successes led to a crash of phytoremediation with a decline in environmental research funding by the early 2000s. “Phyto”, a book by landscape architects Kennen and Kirkwood (2015) recently reintroduces the subject with a more approachable set of planning, engineering and design tools. One commonly occurring site with a history of perpetuating contaminated land is the abandoned gas station. Abandoned gas stations are highly visible in the landscape and if soils are contaminated then remediation costs can hinder redevelopment. The focus of this paper is the redesign of abandoned gas stations through phytotechnologies by applying and expanding Kennen and Kirkwood’s (2015) framework

Understanding Alzheimer Disease at the interface between genetics and transcriptomics

Over 25 genes are known to affect the risk of developing Alzheimer disease (AD), the most common neurodegenerative dementia. However, mechanistic insights and improved disease management remains limited, due to difficulties in determining the functional consequences of genetic associations. Transcriptomics is increasingly being used to corroborate or enhance interpretation of genetic discoveries. These approaches, which include second and third generation sequencing, single-cell sequencing, and bioinformatics, reveal allele-specific events connecting AD risk genes to expression profiles, and provide converging evidence of pathophysiological pathways underlying AD. Simultaneously, they highlight brain region- and cell-type-specific expression patterns, and alternative splicing events that affect the straightforward relation between a genetic variant and AD, re-emphasizing the need for an integrated approach of genetics and transcriptomics in understanding AD. © 2018 The Author