VOLUME 287 (2012) PAGES 44508–44517In Fig. 1A, the wrong image for the control group was presented. The authors inadvertently cropped the control images in Fig. 1, A and E, from the same raw image. Fig. 1A has now been corrected and does not affect the results or conclusions of the work. The authors sincerely apologize for their mistake during figure preparation and for any inconvenience this may have caused readers.jbc;295/19/6781/F1F1F1Figure 1A.

Invitation Only Research Event

Event participants

Annette Bohr, Associate Fellow, Russia and Eurasia Programme, Chatham House
Kassymkhan Kapparov, Founder, Economist.kz
Joanna Lillis, Reporter, The Guardian, The Economist and The Independent
Kate Mallinson, Associate Fellow, Russia and Eurasia Programme, Chatham House
Dossym Satpayev, Director, Kazakhstan Risk Assessment Group; Member of the Presidium, Kazakhstan Council on International Relations
Chair: James Nixey, Head, Russia and Eurasia Programme, Chatham House

27 November 2019

A partial handover of political power through an orchestrated transition takes Kazakhstan into uncharted territory. Will it be able to pursue modernization and reform, and break from its authoritarian past?

Invitation Only Research Event

Event participants

Kirsty Brimelow QC, Barrister, Doughty Street Chambers
Miles Jackson, Associate Professor of Law, University of Oxford
Anton Korynevych, Representative of the President of Ukraine for Crimea
Oleksandra Matviychuk, Head of the Board, Centre for Civil Liberties
Taras Tsymbrivksyy, Head, USAID Human Rights in Action Program; Ukrainian Helsinki Human Rights Union

Ketel Marte does not lack for confidence when it comes to switching from second base/shortstop to center field, which is where he's expected to see a lot of time this season.

4 November 2019

Invitation Only Research Event

Invitation Only Research Event

1 April 2020

Considerations of justice and social equity are as important for the circular economy transition as they are in the contexts of low-carbon transitions and digitalization of the economy. This paper sets out the just transition approach, and its relevance in climate change and energy transition debates.

These fact sheets provide a sketch of key characteristics of the foreign-born and English Learner (EL) populations in select states. The fact sheets look at the demographics of these states, discuss EL student outcomes as measured by standardized tests, and conclude with an overview of state accountability mechanisms that affect ELs under relevant provisions of the Every Student Succeeds Act and predecessor No Child Left Behind Act.

With a history of encouraging workers to emigrate to relieve unemployment at home, Tunisia now has 11 percent of its population living abroad. The factors underlying the 2011 revolution that sparked the Arab Spring have also fueled emigration desires for many Tunisians. This country profile explores historical and current trends in Tunisia from colonial settlement to the aftermath of the Arab Spring, and the new focus on migrant rights at home and abroad.

From being a source of labor emigration to the Gulf region to a destination for refugees from Syria, sub-Saharan Africa, and elsewhere, Egypt has long experienced different forms of mobility. This article, which profiles the trends and policies that have shaped Egypt's migration history, focuses on its long-standing use of migration as a soft-power tool to achieve its foreign policy aims and as a safety valve for political discontent.

 By Abbe Herzig, AMS Director of Education Many of us are experiencing stress as schools, colleges and universities move instruction out of the classroom. Fortunately, even if distance learning is new to you, it isn’t new, and there is a … Continue reading →

ADA Practice Transitions, a service offered by the ADA focused on helping dentists make the process of joining or leaving a practice successful, is offering a free three-month trial.

Michael E. Bowen
Jun 1, 2010; 28:99-106
Feature Articles

These tools encourage school administrators to gather as much information as possible about the students who will be entering kindergarten and the early-learning offerings in their communities.

DeVos slammed for remarks on HBCU's, a new Senate measure could overturn Obama-era ESSA rules on accountability, and more.

Indiana's efforts to give students more control over their academic transcripts may prove a boon for researchers and school reformers, too.

In the Gaussian sequence model $Y= heta_0 + varepsilon$ in $mathbb{R}^n$, we study the fundamental limit of approximating the signal $ heta_0$ by a class $Theta(d,d_0,k)$ of (generalized) splines with free knots. Here $d$ is the degree of the spline, $d_0$ is the order of differentiability at each inner knot, and $k$ is the maximal number of pieces. We show that, given any integer $dgeq 0$ and $d_0in{-1,0,ldots,d-1}$, the minimax rate of estimation over $Theta(d,d_0,k)$ exhibits the following phase transition: egin{equation*} egin{aligned} inf_{widetilde{ heta}}sup_{ hetainTheta(d,d_0, k)}mathbb{E}_ heta|widetilde{ heta} - heta|^2 asymp_d egin{cases} kloglog(16n/k), & 2leq kleq k_0,\ klog(en/k), & k geq k_0+1. end{cases} end{aligned} end{equation*} The transition boundary $k_0$, which takes the form $lfloor{(d+1)/(d-d_0) floor} + 1$, demonstrates the critical role of the regularity parameter $d_0$ in the separation between a faster $log log(16n)$ and a slower $log(en)$ rate. We further show that, once encouraging an additional '$d$-monotonicity' shape constraint (including monotonicity for $d = 0$ and convexity for $d=1$), the above phase transition is eliminated and the faster $kloglog(16n/k)$ rate can be achieved for all $k$. These results provide theoretical support for developing $ell_0$-penalized (shape-constrained) spline regression procedures as useful alternatives to $ell_1$- and $ell_2$-penalized ones.

The $p$-tensor Curie-Weiss model is a two-parameter discrete exponential family for modeling dependent binary data, where the sufficient statistic has a linear term and a term with degree $p geq 2$. This is a special case of the tensor Ising model and the natural generalization of the matrix Curie-Weiss model, which provides a convenient mathematical abstraction for capturing, not just pairwise, but higher-order dependencies. In this paper we provide a complete description of the limiting properties of the maximum likelihood (ML) estimates of the natural parameters, given a single sample from the $p$-tensor Curie-Weiss model, for $p geq 3$, complementing the well-known results in the matrix ($p=2$) case (Comets and Gidas (1991)). Our results unearth various new phase transitions and surprising limit theorems, such as the existence of a 'critical' curve in the parameter space, where the limiting distribution of the ML estimates is a mixture with both continuous and discrete components. The number of mixture components is either two or three, depending on, among other things, the sign of one of the parameters and the parity of $p$. Another interesting revelation is the existence of certain 'special' points in the parameter space where the ML estimates exhibit a superefficiency phenomenon, converging to a non-Gaussian limiting distribution at rate $N^{frac{3}{4}}$. We discuss how these results can be used to construct confidence intervals for the model parameters and, as a byproduct of our analysis, obtain limit theorems for the sample mean, which provide key insights into the statistical properties of the model.

This paper proposes a stochastic variant of the stable matching model from Rasulkhani and Chow [1] which allows microtransit operators to evaluate their operation policy and resource allocations. The proposed model takes into account the stochastic nature of users' travel utility perception, resulting in a probabilistic stable operation cost allocation outcome to design ticket price and ridership forecasting. We applied the model for the operation policy evaluation of a microtransit service in Luxembourg and its border area. The methodology for the model parameters estimation and calibration is developed. The results provide useful insights for the operator and the government to improve the ridership of the service.

Dimitris Bertsimas, Bart Van Parys.

Source: The Annals of Statistics, Volume 48, Number 1, 300--323.

Abstract:
We present a novel binary convex reformulation of the sparse regression problem that constitutes a new duality perspective. We devise a new cutting plane method and provide evidence that it can solve to provable optimality the sparse regression problem for sample sizes $n$ and number of regressors $p$ in the 100,000s, that is, two orders of magnitude better than the current state of the art, in seconds. The ability to solve the problem for very high dimensions allows us to observe new phase transition phenomena. Contrary to traditional complexity theory which suggests that the difficulty of a problem increases with problem size, the sparse regression problem has the property that as the number of samples $n$ increases the problem becomes easier in that the solution recovers 100% of the true signal, and our approach solves the problem extremely fast (in fact faster than Lasso), while for small number of samples $n$, our approach takes a larger amount of time to solve the problem, but importantly the optimal solution provides a statistically more relevant regressor. We argue that our exact sparse regression approach presents a superior alternative over heuristic methods available at present.

Emmanuel J. Candès, Pragya Sur.

Source: The Annals of Statistics, Volume 48, Number 1, 27--42.

Abstract:
This paper rigorously establishes that the existence of the maximum likelihood estimate (MLE) in high-dimensional logistic regression models with Gaussian covariates undergoes a sharp “phase transition.” We introduce an explicit boundary curve $h_{mathrm{MLE}}$, parameterized by two scalars measuring the overall magnitude of the unknown sequence of regression coefficients, with the following property: in the limit of large sample sizes $n$ and number of features $p$ proportioned in such a way that $p/n ightarrow kappa $, we show that if the problem is sufficiently high dimensional in the sense that $kappa >h_{mathrm{MLE}}$, then the MLE does not exist with probability one. Conversely, if $kappa <h_{mathrm{MLE}}$, the MLE asymptotically exists with probability one.

Wei-Kuo Chen.

Source: The Annals of Statistics, Volume 47, Number 5, 2734--2756.

Abstract:
We consider the problem of detecting a deformation from a symmetric Gaussian random $p$-tensor $(pgeq3)$ with a rank-one spike sampled from the Rademacher prior. Recently, in Lesieur et al. (Barbier, Krzakala, Macris, Miolane and Zdeborová (2017)), it was proved that there exists a critical threshold $eta_{p}$ so that when the signal-to-noise ratio exceeds $eta_{p}$, one can distinguish the spiked and unspiked tensors and weakly recover the prior via the minimal mean-square-error method. On the other side, Perry, Wein and Bandeira (Perry, Wein and Bandeira (2017)) proved that there exists a $eta_{p}'<eta_{p}$ such that any statistical hypothesis test cannot distinguish these two tensors, in the sense that their total variation distance asymptotically vanishes, when the signa-to-noise ratio is less than $eta_{p}'$. In this work, we show that $eta_{p}$ is indeed the critical threshold that strictly separates the distinguishability and indistinguishability between the two tensors under the total variation distance. Our approach is based on a subtle analysis of the high temperature behavior of the pure $p$-spin model with Ising spin, arising initially from the field of spin glasses. In particular, we identify the signal-to-noise criticality $eta_{p}$ as the critical temperature, distinguishing the high and low temperature behavior, of the Ising pure $p$-spin mean-field spin glass model.

Chih-Yuan Hsu, Yi-Hau Chen, Ruoh-Rong Yu, Tsung-Wei Hung.

Source: The Annals of Applied Statistics, Volume 14, Number 1, 160--177.

Abstract:
Workers in Taiwan overall have been suffering from long-lasting wage stagnation since the mid-1990s. In particular, there seems to be little mobility for the wages of Taiwanese workers to transit across wage quantile groups. It is of interest to see if certain groups of workers, such as female, lower educated and younger generation workers, suffer from the problem more seriously than the others. This work tries to apply a systematic statistical approach to study this issue, based on the longitudinal data from the Panel Study of Family Dynamics (PSFD) survey conducted in Taiwan since 1999. We propose the quantile transition regression model, generalizing recent methodology for quantile association, to assess the wage status transition with respect to the marginal wage quantiles over time as well as the effects of certain demographic and job factors on the wage status transition. Estimation of the model can be based on the composite likelihoods utilizing the binary, or ordinal-data information regarding the quantile transition, with the associated asymptotic theory established. A goodness-of-fit procedure for the proposed model is developed. The performances of the estimation and the goodness-of-fit procedures for the quantile transition model are illustrated through simulations. The application of the proposed methodology to the PSFD survey data suggests that female, private-sector workers with higher age and education below postgraduate level suffer from more severe wage status stagnation than the others.

“The timing couldn’t have been worse for refugees from Syria passing through Macedonia.” An OM worker shares about conditions in a Macedonian refugee transit camp.

A l’approche de la décision de la SADC, il est important qu’elle porte toute son attention sur les mesures qui permettent de garantir l’équité de traitement entre les protagonistes. Sans modifier le texte de la feuille de route, les autorités ont la possibilité de prouver leur volonté de garantir la neutralité du processus, afin que l’opposition soit libre de faire le choix d’entrer ou non dans cette transition sur une base équilibrée. Le rejet des autorités de ces mesures exposerait leur absence de volonté de voir se dérouler une transition et des élections crédibles. Il démontrerait également leur choix de plonger le pays dans l’instabilité plutôt que d’accepter des mesures qui renforcent la transition. Le refus de l’opposition d’adhérer au processus ne pourrait plus être justifié par un déséquilibre de la solution proposée.

During the last few months, new options for resolving the Madagascar crisis have emerged in the form of the most recent roadmap proposed by the mediation team of the Southern African Development Community (SADC). Accepted by the authorities and rejected by elements of the opposition, the roadmap remains the subject of debate and there is still no agreement on how to achieve a peaceful transition. In a few weeks from now, the SADC is due to make a statement on the document and accept, reject or amend it. There are other options for changing the course of events without changing the roadmap and these should be explored as quickly as possible.

Community groups and sports not connected to school can help students stay more connected academically during a critical transition period, according to a study of low-income students in New York City.

Health care transition services assist youth with special health care needs (YSHCN) in transitioning to adult care without gaps in services or health insurance coverage. Less than half of YSHCN receive anticipatory assistance in this transition; receipt of these services for youth with autism spectrum disorder is unknown.

Youth with autism spectrum disorder receive transition services half as often as youth with special health care needs. Quality of health care is associated with increased receipt of health care transition services. Presence of comorbid conditions decreased receipt of transition services. (Read the full article)

Most children with type 1 diabetes get care from pediatric-trained providers, and must transfer care to adult providers once in adulthood. The timing of this change in providers and its relationship to glycemic control is not well understood.

In this cohort, the estimated median age to transition to adult care was 20.1 years and 77% had left pediatric care by age 21. Leaving pediatric care was associated with a 2.5-fold increase in odds of having poor glycemic control. (Read the full article)

The importance of transition from pediatric to adult health care for youth with special health care needs has gained increasing attention over the past decade, but fewer than half of this population received needed transition preparation in 2005–2006.

This study reports on transition findings from the 2009–2010 National Survey of Children with Special Health Care Needs and finds no discernible improvements since 2005–2006. New clinical recommendations and care processes should help to accelerate transition improvements in the future. (Read the full article)

Transition from pediatric to adult care is often reported to be unsuccessful. Little evidential research has examined the actual proportion of youth in pediatric versus adult care or impact on health status outcomes after transferring from pediatric to adult care.

Our article extends the literature by providing health transition outcome data, something that has been recognized as a critical gap to developing evidence-based programming and health care transition policy. (Read the full article)

There is growing understanding of the detrimental effect of paternal depression on children. The transition to fatherhood is a unique time for men. Identifying which fathers are at-risk and when will inform effective methods to help men and their families.

Nonresident fathers have the highest depression symptom scores, peaking before entering fatherhood. Although resident fathers’ scores decrease preceding entry into fatherhood, there is a significant increase from 0 to 5 years of their child’s life when key parent–infant attachment occurs. (Read the full article)

Adolescents with chronic disease are a diverse population with common needs for transition. Disease-specific interventions have shown promise at improving patient outcomes but with substantial personnel and resource costs. Whether a generic approach across diseases may be useful is unknown.

This study is among the first to evaluate a generic (across disease) approach to transition of adolescents to adult care. The approach demonstrated promise and cost savings due to reduced personnel requirement and use of low-cost technology dissemination methods. (Read the full article)

The US health care system transition to the ICD-10-CM will occur in October 2015. The logistical and financial impact of the transition for billing codes frequently used by pediatricians has not been studied.

The findings of this study evaluate the government-provided mappings from ICD-9-CM to ICD-10-CM for accuracy and provide the diagnostic codes used by pediatricians, which may be adversely affected by the transition to ICD-10-CM. (Read the full article)

Neurocognitive deficits, academic delays, and behavioral and emotional problems are well documented in school-age children in relation to socioeconomic disadvantage and residential instability. Despite adversity, early intervention can facilitate healthy cognitive, emotional, and social development.

Homeless youth demonstrated elevated rates of untreated psychiatric disorders, low academic achievement, and impaired neurocognition. Mental health and neurocognitive symptoms were associated with vocational outcome. Intervention beyond employment services alone is needed to improve functioning. (Read the full article)

More children with special health care needs are surviving to adulthood and entering the adult health care system. Effective transition of care can promote continuity of developmental and age-appropriate care for these individuals.

Existing studies provide modest transition care support. Methods for providing transition care warrant attention, and future research needs are wide ranging. Consistent and accepted measures of transition success are critical to establishing an adequate body of literature to affect practice. (Read the full article)

The built environment may affect weight status by presenting opportunities or barriers for exercise and nutritious eating. Although there is substantial cross-sectional evidence linking neighborhood factors and childhood obesity, causal uncertainty remains, owing to conceptual and methodological challenges.

This prospective study examined neighborhood influences on obesity during the transition to adolescence, a sensitive period for excess weight gain. Girls living in neighborhoods characterized by physical disorder or increased access to food and service retailers exhibited higher obesity risk. (Read the full article)