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BACKGROUND: The effect of dehydration of ex vivo cartilage samples and rehydration with native synovial fluid or normal saline on quantitative ultrashort echo time (UTE) biomarkers are unknown. We aimed to investigate the effect of cartilage dehydration-rehydration on UTE biomarkers and to compare the rehydration capabilities of native synovial fluid and normal saline. METHODS: A total of 37 cartilage samples were harvested from patients (n=5) who underwent total knee replacement. Fresh cartilage samples were exposed to air to dehydrate for 2 hours after baseline magnetic resonance (MR) scanning, then randomly divided into two groups: one soaking in native synovial fluid (n=17) and the other in normal saline (n=20) to rehydrate for 4 hours. UTE-based biomarkers [T1, adiabatic T1r (AdiabT1r), macromolecular fraction (MMF), magnetization transfer ratio (MTR), and T2*] and sample weights were evaluated for fresh, dehydrated, and rehydrated cartilage samples. Differences and agreements between groups were assessed using the values of fresh cartilage samples as reference standard. RESULTS: Dehydrating in air for 2 hours resulted in significant weight loss (P=0.000). T1, AdiabT1r, and T2* decreased significantly while MMF and MTR increased significantly (all P0.0167, with Bonferroni correction) while T2* (P=0.001) still had significant differences compared with fresh samples. However, no significant differences were detected for any of the evaluated UTE biomarkers after rehydrating in normal saline (all P>0.05). No differences were detected in the agreement of UTE biomarker measurements between fresh samples and samples rehydrated with synovial fluid and normal saline. CONCLUSIONS: Cartilage dehydration resulted in significant changes in UTE biomarkers. Rehydrating with synovial fluid or normal saline had non-significant effect on all the evaluated UTE biomarkers except T2* values, which still had significant differences compared with fresh samples after rehydrating with synovial fluid. No significant difference was observed in the rehydration capabilities of native synovial fluid and normal saline.

This study examines the effects of English Learner (EL) status on subsequent Special Education (SPED) placement. Through a research-practice partnership, we link student demographic data and initial English proficiency assessment data across seven cohorts of test takers and observe EL and SPED programmatic participation for these students over 7 years. Our regression discontinuity (RD) estimates at the English proficiency margin consistently differ substantively from positive associations generated through regression analyses. RD evidence indicates that EL status had no effect on SPED placement at the English proficiency threshold. Grade-by-grade and subgroup RD analyses at this margin suggest that ELs were modestly underidentified for SPED during Grade 5 and that ELs whose primary language was Spanish were underidentified for SPED.

For over a decade, Immigration and Customs Enforcement (ICE) has formed partnerships allowing local police to enforce immigration law by identifying and arresting undocumented residents. Prior studies, using survey data with self-reported immigrant and citizenship status, provide mixed evidence on their demographic impact. This study presents new evidence based on Hispanic public school enrollment. We find local ICE partnerships reduce the number of Hispanic students by 10% within 2 years. We estimate partnerships enacted before 2012 displaced more than 300,000 Hispanic students. These effects are concentrated among elementary school students. We find no corresponding effects on the enrollment of non-Hispanic students and no evidence that ICE partnerships reduced pupil-teacher ratios or the percentage of students eligible for the National School Lunch Program.

Recent years have seen the spread of a litigation culture in the UK education sector, with members of the public increasingly seeking recourse to the law to appeal, complain, or achieve compensation. The increasing tendency of people to resort to litigation suggests that recourse to the law is seen as a more immediate form of taking education services to account. While in theory an effective accountability tool, this development has unfortunately produced some less than desirable consequences in educational institutions, most notably the avoidance of risk. This paper argues that such consequences need to be understood as a reflection of the limits placed on legal regulation, once it encounters the already highly regulated world of educational institutions. To flesh out this argument, this paper examines these limits as a set of consequences relating to the following: increasing juridification; the intersection of law and mechanisms of accountability, judgement and professional discretion; and the relation between risk and trust. The argument draws on the 'law in context' literature, as well as recent debates over the pathologies of legal freedom.