Ethnic Segregation and Educational Outcomes in Swedish Comprehensive Schools

We ask whether ethnic density in Swedish comprehensive schools affect teacher-assigned school grades in ninth grade (age 16). The data, based on two entire cohorts who graduated in 1998 and 1999 (188,000 pupils and 1,043 schools), link school information with Census data on social origin, and enable us to distinguish first- from second generation immigrants. Using multilevel analysis we find the proportion of first, but not the second, generation immigrant pupils in a school to depress grades in general, but particularly for (first generation) immigrant pupils. Passing a threshold of more than 40 percent immigrants reduces grades with around a fifth of a standard deviation, affecting fourteen percent of immigrant children. Our main results are robust to model specifications which address omitted variable bias both at individual- and school-level. One policy implication of our results is that desegregation policies which concentrated on the two per cent most segregated schools would probably improve school results and reduce ethnic inequality.Ethnic inequality; Immigrant schooling; Educational attainment; Contextual effects; Ethnic inequality; Immigrant schooling

Social Attributes And Economic Instability In Africa

How do the social characteristics of African economies affect their relative economic stability? This paper offers a new nominal definition of economic instability in terms of average standard deviations from the exponential growth path suggested by neoclassical growth theory under ideal conditions. We used the portion of the population that subsists on agriculture as an indication of how diverse and adaptable any particular economy is. Literacy rates may serve as a proxy for the quality and adaptability of the labor force in the various countries. Other variables used are urban population as a percentage of total population, life expectancy, infant mortality rates and the corruption perception index. These variables were all statistically significant in explaining economic instability with the exception of corruption perception index and infant mortality rates that were statistically insignificant

Social Attributes And Economic Instability In Africa

How do the social characteristics of African economies affect their relative economic stability? This paper offers a new nominal definition of economic instability in terms of average standard deviations from the exponential growth path suggested by neoclassical growth theory under ideal conditions. We used the portion of the population that subsists on agriculture as an indication of how diverse and adaptable any particular economy is. Literacy rates may serve as a proxy for the quality and adaptability of the labor force in the various countries. Other variables used are urban population as a percentage of total population, life expectancy, infant mortality rates and the corruption perception index. These variables were all statistically significant in explaining economic instability with the expectation of corruption perception index and infant mortality rates which were statistically insignificant

FURTHER STUDIES ON SPECIFIC TRANSPLANTATION ANTIGENS IN ROUS SARCOMA OF MICE

Mice allografted with different sarcomas, induced by the Schmidt-Ruppin variant of Rous sarcoma virus (RSV-SR), showed a resistance against subsequent isografting of 9 different Rous sarcomas. Transplantation resistance could also be induced by Rous mouse tumor cells x-irradiated with 8000 r or with cell-free tumor extracts, containing no demonstrable virus. No transplantation resistance could be demonstrated after allograft pretreatment with various polyoma tumors or non-viral tumors. Allograft pretreatment with Rous tumors induced no demonstrable resistance against isografting of polyoma tumors. Inoculation of RSV-SR or Rous chicken sarcoma suspension into adult mice gave no clear cut resistance against isografting of mouse sarcomas. Neither after allografting of Rous tumors nor after virus or chicken sarcoma inoculation into adult mice could virus-neutralizing activity be demonstrated in the sera. The results demonstrate the presence of common, specific transplantation antigen(s) in different Rous sarcomas in mice and speak against an identity between the transplantation antigen(s) and viral antigen(s)

Estimating Social and Ethnic Inequality in School Surveys: Biases from Child Misreporting and Parent Nonresponse

We study the biases that arise in estimates of social inequalities in children’s cognitive ability test scores due to (i) children’s misreporting of socio-economic origin and (ii) parents’ nonresponse. Unlike most previous studies, we are able to draw on linked register data with high reliability and almost no missingness and thereby jointly consider the impact of measurement error and nonresponse. Using data on 14-year-olds (n = 18,716) from a new survey conducted in England, Germany, the Netherlands, and Sweden (Children of Immigrants Longitudinal Survey in Four European Countries), we find that child reports on parental occupation are well aligned with parents’ reports in all countries, but reports on parental education less so. This leads to underestimation of socio-economic disparities when child reports of education are used, but not occupation. Selective nonresponse among parents turns out to be a real problem, resulting in similar underestimation. We also investigate conditional estimates of immigrant–non-immigrant disparities, which are surprisingly little affected by measurement error or nonresponse in socio-economic control variables. We conclude that school-based surveys on teenagers are well advised to include questions on parental occupation, while the costs for carrying out parental questionnaires may outweigh the gains

Damage-induced phosphorylation of Sld3 is important to block late origin firing.

Origins of replication are activated throughout the S phase of the cell cycle such that some origins fire early and others fire late to ensure that each chromosome is completely replicated in a timely fashion. However, in response to DNA damage or replication fork stalling, eukaryotic cells block activation of unfired origins. Human cells derived from patients with ataxia telangiectasia are deficient in this process due to the lack of a functional ataxia telangiectasia mutated (ATM) kinase and elicit radioresistant DNA synthesis after γ-irradiation(2). This effect is conserved in budding yeast, as yeast cells lacking the related kinase Mec1 (ATM and Rad3-related (ATR in humans)) also fail to inhibit DNA synthesis in the presence of DNA damage. This intra-S-phase checkpoint actively regulates DNA synthesis by inhibiting the firing of late replicating origins, and this inhibition requires both Mec1 and the downstream checkpoint kinase Rad53 (Chk2 in humans). However, the Rad53 substrate(s) whose phosphorylation is required to mediate this function has remained unknown. Here we show that the replication initiation protein Sld3 is phosphorylated by Rad53, and that this phosphorylation, along with phosphorylation of the Cdc7 kinase regulatory subunit Dbf4, blocks late origin firing in Saccharomyces cerevisiae. Upon exposure to DNA-damaging agents, cells expressing non-phosphorylatable alleles of SLD3 and DBF4 (SLD3-m25 and dbf4-m25, respectively) proceed through the S phase faster than wild-type cells by inappropriately firing late origins of replication. SLD3-m25 dbf4-m25 cells grow poorly in the presence of the replication inhibitor hydroxyurea and accumulate multiple Rad52 foci. Moreover, SLD3-m25 dbf4-m25 cells are delayed in recovering from transient blocks to replication and subsequently arrest at the DNA damage checkpoint. These data indicate that the intra-S-phase checkpoint functions to block late origin firing in adverse conditions to prevent genomic instability and maximize cell survival

Joint space width of the tibiofemoral and of the patellofemoral joint in chronic knee pain with or without radiographic osteoarthritis: a 2-year follow-up

AbstractObjectives: To assess the interval change of the minimal joint space width (MJS) in radiographs of the tibiofemoral (TF) joint and of the patellofemoral (PF) joint with a 2-year follow-up in middle-aged people with longstanding knee pain with or without radiographic osteoarthritis (OA) and to study the precision of the MJS measurements.Design: In the format of a prospective study of early OA the signal knee in 55 people, 28 men and 27 women (aged 41–57 years, median 50), with chronic knee pain at inclusion was examined with a 2-year interval (median 25 months, range 21–30). The MJS of the TF joint was measured using a flexed PA view in weightbearing and the MJS of the PF joint using an axial view in standing.Results: The MJS of the TF joint decreased medially by 0.056±0.44mm (n.s.) and increased laterally by 0.080±0.51mm (n.s.) during the time of observation. In knees with an MJS medially that was less or the same as compared with the lateral compartment, the MJS decreased by 0.14±0.38mm (p=0.038) and in a subgroup of these knees, without osteophytes, the MJS decreased by 0.14±0.27mm (p=0.018). The MJS of the PF joint decreased by 0.019mm (n.s.) during the time of observation. The coefficient of variation for intra- and interobserver MJS measurements of the TF joint was 1.0 and 1.1% medially and 2.3 and 2.7% laterally, and for measurement error 6.9% medially and 4.8% laterally, respectively. The coefficient of variation for intra- and interobserver MJS measurements of the PF joint was 8.1 and 5.8% medially and 7.5 and 10.1% laterally and for the measurement error it was 8.1% medially and 8.5% laterally, respectively.Conclusions: A statistically significant reduction of the MJS was only demonstrated in the medial compartment of the TF joint in those individuals who had an MJS in this compartment which was less or the same as compared with the lateral compartment as well as in a subgroup of these knees without osteophytes. The radiographic examinations and the MJS measurements were reproducible