Trang Quynh Nguyen, Elizabeth A. Stuart.

Source: The Annals of Applied Statistics, Volume 14, Number 1, 518--520.

Ilya Pavlyukevich, Georgiy Shevchenko.

Source: Bernoulli, Volume 26, Number 2, 1381--1409.

Abstract:
In this paper, we study the Stratonovich stochastic differential equation $mathrm{d}X=|X|^{alpha }circ mathrm{d}B$, $alpha in (-1,1)$, which has been introduced by Cherstvy et al. ( New J. Phys. 15 (2013) 083039) in the context of analysis of anomalous diffusions in heterogeneous media. We determine its weak and strong solutions, which are homogeneous strong Markov processes spending zero time at $0$: for $alpha in (0,1)$, these solutions have the form egin{equation*}X_{t}^{ heta }=((1-alpha)B_{t}^{ heta })^{1/(1-alpha )},end{equation*} where $B^{ heta }$ is the $ heta $-skew Brownian motion driven by $B$ and starting at $frac{1}{1-alpha }(X_{0})^{1-alpha }$, $ heta in [-1,1]$, and $(x)^{gamma }=|x|^{gamma }operatorname{sign}x$; for $alpha in (-1,0]$, only the case $ heta =0$ is possible. The central part of the paper consists in the proof of the existence of a quadratic covariation $[f(B^{ heta }),B]$ for a locally square integrable function $f$ and is based on the time-reversion technique for Markovian diffusions.

Peggy Cénac, Basile de Loynes, Yoann Offret, Arnaud Rousselle.

Source: Bernoulli, Volume 26, Number 2, 858--892.

Abstract:
The recurrence and transience of persistent random walks built from variable length Markov chains are investigated. It turns out that these stochastic processes can be seen as Lévy walks for which the persistence times depend on some internal Markov chain: they admit Markov random walk skeletons. A recurrence versus transience dichotomy is highlighted. Assuming the positive recurrence of the driving chain, a sufficient Fourier criterion for the recurrence, close to the usual Chung–Fuchs one, is given and a series criterion is derived. The key tool is the Nagaev–Guivarc’h method. Finally, we focus on particular two-dimensional persistent random walks, including directionally reinforced random walks, for which necessary and sufficient Fourier and series criteria are obtained. Inspired by ( Adv. Math. 208 (2007) 680–698), we produce a genuine counterexample to the conjecture of ( Adv. Math. 117 (1996) 239–252). As for the one-dimensional case studied in ( J. Theoret. Probab. 31 (2018) 232–243), it is easier for a persistent random walk than its skeleton to be recurrent. However, such examples are much more difficult to exhibit in the higher dimensional context. These results are based on a surprisingly novel – to our knowledge – upper bound for the Lévy concentration function associated with symmetric distributions.

Eric Beutner, Laurent Bordes, Laurent Doyen.

Source: Bernoulli, Volume 26, Number 1, 557--586.

Abstract:
Virtual age models are very useful to analyse recurrent events. Among the strengths of these models is their ability to account for treatment (or intervention) effects after an event occurrence. Despite their flexibility for modeling recurrent events, the number of applications is limited. This seems to be a result of the fact that in the semiparametric setting all the existing results assume the virtual age function that describes the treatment (or intervention) effects to be known. This shortcoming can be overcome by considering semiparametric virtual age models with parametrically specified virtual age functions. Yet, fitting such a model is a difficult task. Indeed, it has recently been shown that for these models the standard profile likelihood method fails to lead to consistent estimators. Here we show that consistent estimators can be constructed by smoothing the profile log-likelihood function appropriately. We show that our general result can be applied to most of the relevant virtual age models of the literature. Our approach shows that empirical process techniques may be a worthwhile alternative to martingale methods for studying asymptotic properties of these inference methods. A simulation study is provided to illustrate our consistency results together with an application to real data.

Zhuang Ma, Xiaodong Li.

Source: Bernoulli, Volume 26, Number 1, 432--470.

Abstract:
Canonical correlation analysis (CCA) is a fundamental statistical tool for exploring the correlation structure between two sets of random variables. In this paper, motivated by the recent success of applying CCA to learn low dimensional representations of high dimensional objects, we propose two losses based on the principal angles between the model spaces spanned by the sample canonical variates and their population correspondents, respectively. We further characterize the non-asymptotic error bounds for the estimation risks under the proposed error metrics, which reveal how the performance of sample CCA depends adaptively on key quantities including the dimensions, the sample size, the condition number of the covariance matrices and particularly the population canonical correlation coefficients. The optimality of our uniform upper bounds is also justified by lower-bound analysis based on stringent and localized parameter spaces. To the best of our knowledge, for the first time our paper separates $p_{1}$ and $p_{2}$ for the first order term in the upper bounds without assuming the residual correlations are zeros. More significantly, our paper derives $(1-lambda_{k}^{2})(1-lambda_{k+1}^{2})/(lambda_{k}-lambda_{k+1})^{2}$ for the first time in the non-asymptotic CCA estimation convergence rates, which is essential to understand the behavior of CCA when the leading canonical correlation coefficients are close to $1$.

The ongoing investigation of the fatal shooting in Brunswick, Georgia, will also look at a neighbor of suspects Gregory and Travis McMichael who recorded video of the incident, authorities said.

Claudia Kirch, Matthew C. Edwards, Alexander Meier, Renate Meyer.

Source: Bayesian Analysis, Volume 14, Number 4, 1037--1073.

Abstract:
Nonparametric Bayesian inference has seen a rapid growth over the last decade but only few nonparametric Bayesian approaches to time series analysis have been developed. Most existing approaches use Whittle’s likelihood for Bayesian modelling of the spectral density as the main nonparametric characteristic of stationary time series. It is known that the loss of efficiency using Whittle’s likelihood can be substantial. On the other hand, parametric methods are more powerful than nonparametric methods if the observed time series is close to the considered model class but fail if the model is misspecified. Therefore, we suggest a nonparametric correction of a parametric likelihood that takes advantage of the efficiency of parametric models while mitigating sensitivities through a nonparametric amendment. We use a nonparametric Bernstein polynomial prior on the spectral density with weights induced by a Dirichlet process and prove posterior consistency for Gaussian stationary time series. Bayesian posterior computations are implemented via an MH-within-Gibbs sampler and the performance of the nonparametrically corrected likelihood for Gaussian time series is illustrated in a simulation study and in three astronomy applications, including estimating the spectral density of gravitational wave data from the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO).

Joris Mulder, Jean-Paul Fox.

Source: Bayesian Analysis, Volume 14, Number 2, 521--552.

Abstract:
The intraclass correlation plays a central role in modeling hierarchically structured data, such as educational data, panel data, or group-randomized trial data. It represents relevant information concerning the between-group and within-group variation. Methods for Bayesian hypothesis tests concerning the intraclass correlation are proposed to improve decision making in hierarchical data analysis and to assess the grouping effect across different group categories. Estimation and testing methods for the intraclass correlation coefficient are proposed under a marginal modeling framework where the random effects are integrated out. A class of stretched beta priors is proposed on the intraclass correlations, which is equivalent to shifted $F$ priors for the between groups variances. Through a parameter expansion it is shown that this prior is conditionally conjugate under the marginal model yielding efficient posterior computation. A special improper case results in accurate coverage rates of the credible intervals even for minimal sample size and when the true intraclass correlation equals zero. Bayes factor tests are proposed for testing multiple precise and order hypotheses on intraclass correlations. These tests can be used when prior information about the intraclass correlations is available or absent. For the noninformative case, a generalized fractional Bayes approach is developed. The method enables testing the presence and strength of grouped data structures without introducing random effects. The methodology is applied to a large-scale survey study on international mathematics achievement at fourth grade to test the heterogeneity in the clustering of students in schools across countries and assessment cycles.

Divyansh Agarwal, Jingshu Wang, Nancy R. Zhang.

Source: Statistical Science, Volume 35, Number 1, 112--128.

Abstract:
Single cell sequencing technologies are transforming biomedical research. However, due to the inherent nature of the data, single cell RNA sequencing analysis poses new computational and statistical challenges. We begin with a survey of a selection of topics in this field, with a gentle introduction to the biology and a more detailed exploration of the technical noise. We consider in detail the problem of single cell data denoising, sometimes referred to as “imputation” in the relevant literature. We discuss why this is not a typical statistical imputation problem, and review current approaches to this problem. We then explore why the use of denoised values in downstream analyses invites novel statistical insights, and how denoising uncertainty should be accounted for to yield valid statistical inference. The utilization of denoised or imputed matrices in statistical inference is not unique to single cell genomics, and arises in many other fields. We describe the challenges in this type of analysis, discuss some preliminary solutions, and highlight unresolved issues.

Benjamin Meyer
Jul 3, 2019; 39:5326-5335
Systems/Circuits

Jeremy R. Manning
Oct 28, 2009; 29:13613-13620
BehavioralSystemsCognitive

WR Softky
Jan 1, 1993; 13:334-350
Articles

To view more press releases, please visit http://www.snl.com/irweblinkx/news.aspx?iid=1024452.

Op-ed by Mr Agustín Carstens, General Manager of the BIS, published in The Business Times Singapore, 13 November 2019.

We can adapt flexibly to environment changes and search for the most appropriate rule to a context. The orbital prefrontal cortex (PFo) has been associated with decision making, rule generation and maintenance, and more generally has been considered important for behavioral flexibility. To better understand the neural mechanisms underlying the flexible behavior, we studied the ability to generate a switching signal in monkey PFo when a strategy is changed. In the strategy task, we used a visual cue to instruct two male rhesus monkeys either to repeat their most recent choice (i.e., stay strategy) or to change it (i.e., shift strategy). To identify the strategy switching-related signal, we compared nonswitch and switch trials, which cued the same or a different strategy from the previous trial, respectively. We found that the switching-related signal emerged during the cue presentation and it was combined with the strategy signal in a subpopulation of cells. Moreover, the error analysis showed that the activity of the switch-related cells reflected whether the monkeys erroneously switched or not the strategy, rather than what was required for that trial. The function of the switching signal could be to prompt the use of different strategies when older strategies are no longer appropriate, conferring the ability to adapt flexibly to environmental changes. In our task, the switching signal might contribute to the implementation of the strategy cued, overcoming potential interference effects from the strategy previously cued. Our results support the idea that ascribes to PFo an important role for behavioral flexibility.

SIGNIFICANCE STATEMENT We can flexibly adapt our behavior to a changing environment. One of the prefrontal areas traditionally associated with the ability to adapt to new contingencies is the orbital prefrontal cortex (PFo). We analyzed the switching related activity using a strategy task in which two rhesus monkeys were instructed by a visual cue either to repeat or change their most recent choice, respectively using a stay or a shift strategy. We found that PFo neurons were modulated by the strategy switching signal, pointing to the importance of PFo in behavioral flexibility by generating control over the switching of strategies.

Behavior can be guided by neuronal activity in visual, auditory, or somatosensory cerebral cortex, depending on task requirements. In contrast to this flexible access of cortical signals, several observations suggest that behaviors depend more on neurons in later areas of visual cortex than those in earlier areas, although neurons in earlier areas would provide more reliable signals for many tasks. We recorded from neurons in different levels of visual cortex of 2 male rhesus monkeys while the animals did a visual discrimination task and examined trial-to-trial correlations between neuronal and behavioral responses. These correlations became stronger in primary visual cortex as neuronal signals in that area became more reliable relative to the other areas. The results suggest that the mechanisms that read signals from cortex might access any cortical area depending on the relative value of those signals for the task at hand.

SIGNIFICANCE STATEMENT Information is encoded by the action potentials of neurons in various cortical areas in a hierarchical manner such that increasingly complex stimulus features are encoded in successive stages. The brain must extract information from the response of appropriate neurons to drive optimal behavior. A widely held view of this decoding process is that the brain relies on the output of later cortical areas to make decisions, although neurons in earlier areas can provide more reliable signals. We examined correlations between perceptual decisions and the responses of neurons in different levels of monkey visual cortex. The results suggest that the brain may access signals in any cortical area depending on the relative value of those signals for the task at hand.

Persistent alterations in neuronal activity elicit homeostatic plastic changes in synaptic transmission and/or intrinsic excitability. However, it is unknown whether these homeostatic processes operate in concert or at different temporal scales to maintain network activity around a set-point value. Here we show that chronic neuronal hyperactivity, induced by M-channel inhibition, triggered intrinsic and synaptic homeostatic plasticity at different timescales in cultured hippocampal pyramidal neurons from mice of either sex. Homeostatic changes of intrinsic excitability occurred at a fast timescale (1–4 h) and depended on ongoing spiking activity. This fast intrinsic adaptation included plastic changes in the threshold current and a distal relocation of FGF14, a protein physically bridging Na_v1.6 and K_v7.2 channels along the axon initial segment. In contrast, synaptic adaptations occurred at a slower timescale (~2 d) and involved decreases in miniature EPSC amplitude. To examine how these temporally distinct homeostatic responses influenced hippocampal network activity, we quantified the rate of spontaneous spiking measured by multielectrode arrays at extended timescales. M-Channel blockade triggered slow homeostatic renormalization of the mean firing rate (MFR), concomitantly accompanied by a slow synaptic adaptation. Thus, the fast intrinsic adaptation of excitatory neurons is not sufficient to account for the homeostatic normalization of the MFR. In striking contrast, homeostatic adaptations of intrinsic excitability and spontaneous MFR failed in hippocampal GABAergic inhibitory neurons, which remained hyperexcitable following chronic M-channel blockage. Our results indicate that a single perturbation such as M-channel inhibition triggers multiple homeostatic mechanisms that operate at different timescales to maintain network mean firing rate.

SIGNIFICANCE STATEMENT Persistent alterations in synaptic input elicit homeostatic plastic changes in neuronal activity. Here we show that chronic neuronal hyperexcitability, induced by M-type potassium channel inhibition, triggered intrinsic and synaptic homeostatic plasticity at different timescales in hippocampal excitatory neurons. The data indicate that the fast adaptation of intrinsic excitability depends on ongoing spiking activity but is not sufficient to provide homeostasis of the mean firing rate. Our results show that a single perturbation such as M-channel inhibition can trigger multiple homeostatic processes that operate at different timescales to maintain network mean firing rate.

The suspects were found drunk and hiding under a tarpaulin, reportedly in possession of small stones from the fire-ravaged cathedral

A Guanaco (Lama guanicoe) surveys its surroundings from a vantage point at sunset, with the imposing Torres del Paine (Chile) in the background. Scouts like this individual keep an eye out for predators.

Police used their conductive energy weapons four times during the arrest of a 31-year-old man who they say was smashing windows with a piece of rebar.

A 40-year-old man has been arrested and charged in connection with two break-ins at the Thunder Bay District Health unit offices, the Thunder Bay Police Service announced in a written release Friday.

The Bank of Canada, the Bank of England, the Bank of Japan, the European Central Bank, the Sveriges Riksbank and the Swiss National Bank, together with the Bank for International Settlements (BIS), have created a group to share experiences as they assess the potential case for central bank digital currency (CBDC) in their home jurisdictions. (Press release, 21 January 2020)

Winnipeg police officers who arrested a man who then went into medical distress and later died were not at fault, an investigation by Manitoba's police watchdog has found.

Laurie Garrett (date: 5/9/2020 - Rank: 3)

Music Division Archivist Morgen Stevens-Garmon reflects upon American playwright, screenwriter, and librettist Terrence McNally, who died of complications due to COVID-19 on March 24, 2020.

The Mississauga Food Bank says a $100,000 donation made earlier this week by New York Knicks rookie RJ Barrett will provide 200,000 meals as part of the community's fight against the COVID-19 pandemic.

A sports writer covering the strange return of South Korea's baseball season says fans should brace for similarly odd experience in Toronto, if and when the 2020 season begins.

Late Thursday, Georgia father and son Gregory McMichael and Travis McMichael were arrested in connection with the death of Ahmaud Arbery, a 25-year-old black man.

An inmate at the Calgary Remand Centre has tested positive for COVID-19, marking the first time a case has been reported at an Alberta correctional facility.

This report summarises the main results of a stocktake conducted by the Basel Committee of its members' initiatives on climate-related financial risks.

Bank of Finland Research Discussion Papers by Eleonora Granziera and Markus Sihvonen

Netherlands Bank DNB Occasional Studies by Peter Wierts and Harro Boven

Denver Newsroom, Apr 24, 2020 / 03:32 pm (CNA).- A Catholic lawyer says his arrest last Saturday is part of mainland China’s wide-ranging efforts to tighten control over Hong Kong.

His ordeal follows his participation in months of pro-democracy protests on the island, which have been slowed by the coronavirus pandemic.

Hong Kong police arrested 81-year-old Martin Lee, along with 14 other pro-democracy protestors, on April 18. Lee has been demonstrating for universal suffrage in Hong Kong for nearly 40 years, and this is his first arrest, the Washington Post reports.

CNA spoke with one of Lee’s close friends, who said Lee and those arrested with him are currently bailed out of prison, and are safe.

Lee, the founder of Hong Kong’s Democratic Party, wrote in an April 21 column in the Washington Post that he was arrested for taking part in protests last year against an extradition bill— now withdrawn— which would have allowed the Chinese government to extradite alleged criminals from Hong Kong to the mainland to stand trial.

Hong Kong is currently facing two plagues from China, Lee wrote: the coronavirus (COVID-19) and “attacks on our most basic human rights.”

“We can all hope a vaccine is soon developed for the coronavirus. But once Hong Kong’s human rights and rule of law are rolled back, the fatal virus of authoritarian rule will be here to stay,” Lee wrote.

He said that the free press in Hong Kong was vital for alerting the world to the dangers of the coronavirus, even as Chinese state media sought to repress information about the outbreak.

Now, Chinese authorities are attempting to pass legislation to increase their influence over Hong Kong, Lee said.

Hong Kong is a special administrative region of China. Hong Kongers enjoy freedom of worship and evangelization, while in mainland China, there is a long history of persecution for Christians who run afoul of the government.

In January, China appointed Luo Huining as the head of the powerful Central Liaison Office in Hong Kong. Luo last week intensified calls for Communist China to exercise more control in Hong Kong by passing “national security legislation.”

The legislation would outlaw “sedition, subversion and the theft of state secrets,” Lee wrote.

This is not the first time the legislation has been introduced— in 2003, widespread protests against the measure led China to withdraw it.

The passing of such a “subversion” law would give China even more power to quash Hong Kongers’ freedoms, Lee warned.

“These vague standards are designed to protect the Chinese Communist Party and undermine core freedoms of Hong Kong, such as freedoms of religion, assembly and the press — including the reporting of pandemics that embarrass Beijing,” he wrote.

The Justice and Peace Commission of the Diocese of Hong Kong released a statement condemning the arrests April 18, calling for an end to all arrests until an independent commission can be established, and for the police to return the mobile phones of all arrested persons in order to ensure their privacy.

The diocese also reiterated that the government must respond to the demands for which the pro-democracy demonstrators have been calling for months, which include an independent inquiry into police tactics.

A Hong Kong friend of Lee, who declined to be identified for safety, said they believe Sun Li Jun— the deputy public security minister for Hong Kong who oversees the Chinese secret police— wanted to send a message of power ahead of Chinese Workers’ Day celebration on May 1.

The friend believes Sun— who is reportedly under investigation by China for corruption— ordered the arrests to show that the authorities have control of the pro-democracy movement in Hong Kong.

“As the followers of God, we will keep praying for [Hong Kong] and let our Lord lead the way,” Lee’s friend told CNA.

“In HK we all love China and Chinese people but we are against CCP [Chinese Communist Party] for what they did to all of us now and before.”

An estimated 1 million protesters turned out at the first major pro-democracy demonstration in Hong Kong on June 6, 2019.

Catholics have played a major role in the protests, which continued after the extradition bill was revoked. Protestors largely called for the resignation of chief executive Carrie Lam— herself a Catholic— more open elections in the region, and an investigation into police brutality allegations.

In October, the legislature of Hong Kong completed the process of officially withdrawing the controversial extradition bill.

“Had the extradition bill been passed, we could have faced trial already in China instead of Hong Kong,” Lee noted in his column.

The impetus for the bill was a case involving a young Hong Kong man whom Taiwan requested be extradited for an alleged murder. Hong Kong previously has no formal extradition agreements with mainland China or Taiwan.

Christians and advocates widely opposed the bill, fearing that the Chinese government, which already seeks to control and suppress Christianity on the mainland, would use it to further tighten its grip on free exercise of religion in Hong Kong.

 

A year after Zanu (PF)’s election victory and the formation of a new government, Zimbabwe’s politics and economy are increasingly precarious. Immediate prospects for a sustained recovery remain bleak, made worse by dire economic decline, endemic governance failures and tension over ruling-party succession.

Acne vulgaris is an extraordinarily common skin condition in adolescents. The mainstays of acne treatment have remained largely unchanged over recent years. In the context of increasing antibiotic resistance worldwide, there is a global movement away from antibiotic monotherapy toward their more restrictive use. Classically reserved for nodulocystic acne, isotretinoin has become the drug of choice by dermatologists for moderate to severe acne. Given the virtually ubiquitous nature of acne in teenagers, there remains an appreciable need for novel therapies. In this article, we will cover the currently used acne treatments, evaluate the issues and data supporting their use, explore the issues of compliance and the mental health implications of acne care, and recommend directions for the field of acne management in adolescents in the years ahead.

A 53-year-old man has been arrested in connection with smuggling firearms into the country.

Nicola Sturgeon won plaudits from some unlikely quarters this week for her “grown-up conversation” on lifting the lockdown.

Dig into what two leading Democratic presidential candidates have to say in their platforms about charter schools with Education Week's detailed analysis.

Former Vice President Joe Biden’s recent remarks on his willingness to work with segregationists resurrected his long-ago efforts to oppose school busing. Will it hurt his campaign?

A three-judge panel from the 9th U.S. Circuit Court of Appeals ruled against a proposed plan that would have paid certain student-athletes as much as $5,000 annually in deferred compensation.

IN the years BC (Before Covid), my morning routine was consistent. First, perusal of the paper, starting with the sport followed by the death notices. Continued absence from the latter represented a pretty good start to the day. Omnipresent coronavirus has reversed that order. Now, my first port of call is the ever-expanding family notices. Worryingly, for a man in his eighth decade, the deaths section lengthens daily. Equally concerning, is my proximity to the average age of those whose demise

Former Vice President Joe Biden’s recent remarks on his willingness to work with segregationists resurrected his long-ago efforts to oppose school busing. Will it hurt his campaign?

The swirl of attention around Democratic presidential candidate Elizabeth Warren’s story of being forced out of a teaching job when she was pregnant intensifies the spotlight on her background and K-12 credentials.

Dig into what two leading Democratic presidential candidates have to say in their platforms about charter schools with Education Week's detailed analysis.

Primary care providers (PCPs) identify patients with undescended testis (UDT) and refer them to surgical specialists. Referral beyond the recommended times for orchiopexy has been reported, and PCPs' accuracy in identifying and distinguishing UDTs from retractile testes has been questioned.

We describe 3 observations that are strongly correlated with UDT, that is, birth history of UDT, prematurity, and visible scrotal asymmetry. UDT diagnoses are best made by 8 months of age, to reduce confusion with testicular retraction and to facilitate timely orchiopexy. (Read the full article)

Media reports suggest that adolescents are being charged with sex crimes and even placed on sex offender registries because of participating in the "sexting" of sexual images, but the nature and outcomes of such incidents have not been described empirically.

This is the first study to examine types of sexting cases handled by police. It informs clinicians by identifying characteristics of "aggravated" versus milder incidents and finding that most youth were not arrested. Sex offender registration was rare. (Read the full article)

Most childhood HIV is acquired through perinatal transmission, some of which is preventable. Practitioners need to understand what proportion of perinatally acquired HIV infections are attributable to missed prevention opportunities.

Missed prevention opportunities include lack of early HIV testing for pregnant women; suboptimal use of antiretroviral medications during pregnancy, labor, or delivery or for the neonate; breastfeeding; and vaginal delivery when maternal viral load was ≥1000 copies/mL. (Read the full article)

Although there is some older literature examining how arrest prevalence accumulates through adolescence and adulthood, there is no contemporary research examining the arrest histories of a representative sample of American youth.

Using a contemporary US sample of adolescents and young adults, we estimated the cumulative arrest prevalence through age 23. The results suggest a substantial increase in the cumulative prevalence of arrest since the 1960s. (Read the full article)

Studies in the Netherlands show that pubertal blockade at Tanner 2/3 prevents unwanted sex characteristics and improves psychological functioning. Endocrine Society guidelines (2009) recommend pubertal suppression for adolescents with gender identity disorder until approximately age 16.

This is the first study of a US cohort of children and adolescents with gender identity disorder. Patients were referred for medical treatment to a pediatric center that supports a multidisciplinary Gender Management Service. (Read the full article)