Quantum simulation of thermodynamics in an integrated quantum photonic processor.

One of the core questions of quantum physics is how to reconcile the unitary evolution of quantum states, which is information-preserving and time-reversible, with evolution following the second law of thermodynamics, which, in general, is neither. The resolution to this paradox is to recognize that global unitary evolution of a multi-partite quantum state causes the state of local subsystems to evolve towards maximum-entropy states. In this work, we experimentally demonstrate this effect in linear quantum optics by simultaneously showing the convergence of local quantum states to a generalized Gibbs ensemble constituting a maximum-entropy state under precisely controlled conditions, while introducing an efficient certification method to demonstrate that the state retains global purity. Our quantum states are manipulated by a programmable integrated quantum photonic processor, which simulates arbitrary non-interacting Hamiltonians, demonstrating the universality of this phenomenon. Our results show the potential of photonic devices for quantum simulations involving non-Gaussian states.

Mode-splitting in a microring resonator for self-referenced biosensing.

Self-referenced biosensing based on mode-splitting on a microring resonator is experimentally demonstrated. A Bragg grating integrated on the surface of the ring provides coupling between the clockwise and counterclockwise travelling modes of the pristine ring resonator lifting their degeneracy. The amount of mode-splitting is directly related to the reflectivity of the grating and it is only affected by structurally modifying the grating. Environmental perturbations to the surroundings of the gratings, such as temperature and bulk refractive index variations, have a minor effect on the amount of mode-splitting. This principle allows the realization of a self-referenced sensing scheme based on the detection of variations of the mode-splitting induced by structural changes to the grating. In this work, a polymethyl methacrylate (PMMA) Bragg grating is integrated onto a ring resonator in Al2O3. It is shown both theoretically and experimentally that the amount of splitting of a resonance varies minimally under temperature or bulk refractive index perturbations. However, the structural change of attaching a layer of biomolecules inside the grating does affect its reflectivity and the amount of mode splitting present. This result represents the first proof-of-concept demonstration of an integrated mode-splitting biosensor insensitive to temperature and refractive index variations of the liquid matrix where the molecules to be detected are embedded. The reported results pave the road towards the realization of truly self-referenced biosensors.

Al2O3 microring resonators for the detection of a cancer biomarker in undiluted urine.

Concentrations down to 3 nM of the rhS100A4 protein, associated with human tumor development, have been detected in undiluted urine using an integrated sensor based on microring resonators in the emerging Al2O3 photonic platform. The fabricated microrings were designed for operation in the C-band (λ = 1565 nm) and exhibited a high-quality factor in air of 3.2 × 105. The bulk refractive index sensitivity of the devices was ~100 nm/RIU (for TM polarization) with a limit of detection of ~10-6 RIU. A surface functionalization protocol was developed to allow for the selective binding of the monoclonal antibodies designed to capture the target biomarker to the surface of the Al2O3 microrings. The detection of rhS100A4 proteins at clinically relevant concentrations in urine is a big milestone towards the use of biosensors for the screening and early diagnosis of different cancers. Biosensors based on this microring technology can lead to portable, multiplexed and easy-to-use point of care devices.

The Draw-A-Person Test: an indicator of children's cognitive and socioemotional adaptation?

The authors examined aspects of reliability and validity of the Goodenough-Harris Draw-A-Person Test (DAP; D. B. Harris, 1963). The participants were 115 seven- to nine-year-old students attending regular or special education schools. Three judges, with a modest degree of training similar to that found among practicing clinicians, rated the students' human figure drawings on developmental and personality variables. The authors found that counting details and determining developmental level in the DAP test could be carried out reliably by judges with limited experience. However, the reliability of judgments of children's social and emotional development and personality was insufficient. Older students and students attending regular schools received significantly higher scores than did younger students or students attending special education schools. The authors found that the success of the DAP test as an indicator of cognitive level, socioemotional development, and personality is limited when global judgments are used. The authors concluded that more specific, reliable, valid, and useful scoring systems are needed for the DAP test.

Family problems and youth unemployment.

This study attempted to determine the extent to which family and personal characteristics relate to the employment situation of adolescents. Data were drawn from the Utrecht Study of Adolescent Development (USAD), which investigated, longitudinally, a national sample of Dutch youths aged 12 to 24 years in 1991. Specifically, two waves of a sample of 955 non-school-going respondents between 18 and 27 years old were analyzed. Parental divorce, parental unemployment (only for males), low parental affective involvement, and adolescent relationship problems were related to youth unemployment, but educational career and work commitment were not. For males, parental unemployment demonstrated the strongest correlation with youth unemployment. For females, only variables in the relational domain played a role in explaining unemployment; relationship variables were also important predictors of male unemployment. The results suggest that the family factors included in this study are better predictors of youth unemployment than are the classic individual (personal) variables.

How do vocational and relationship stressors and identity formation affect adolescent mental health?

PURPOSE: This article examines the effects of stressors in both the vocational and relationship career of youngsters in the formation of their identity; the effects of identity formation on adolescent mental health; the influence of career stressors on mental health, directly or via identity, and differences in these effects on boys and girls. METHODS: Data were used from the Dutch national panel study, Utrecht Study of Adolescent Development, a study of developmental processes as they occur in the life course of young people during the 1990s. Using LISREL, we tested hypotheses on two waves of a sample of 1222 respondents between 15 and 24 years of age in Wave 1 (1991). RESULTS: The correlation between relationship stressors and relationship identity can be neglected, while vocational stressors lead to a less achieved vocational identity, particularly in boys. Occupational and relationship identity have similar effects on mental health (i.e., the more achieved the identity, the better the person's mental health). Vocational and especially relationship stressors lead to poorer mental health, but did not affect the mental health of boys and girls differently. The same goes for the influence of relationship and vocational identity formation on mental health. CONCLUSIONS: Career stressors, especially stressors in the relationship domain, appear to have significant long-term effects on adolescent mental health. Vocational and relationship identity formation are also significant predictors for adolescent mental health.

Transitions in family structure and adolescent well-being.

This article examines the effects of transitions in family structure on physical health, thoughts of suicide, mental health, relational well-being, and employment situation of adolescents from four family structures: stable intact families, conflict intact families, single-parent families, and stepfamilies. Data were used from the Utrecht Study of Adolescent Development (USAD), a study of developments in the life course of young people during the 1990s. Results are presented from over 2,500 respondents between 15 and 24 years of age. Their parents were also interviewed on a number of topics. Transition in family structure after marital problems, divorce, and remarriage does appear to have significant long-term effects on a number of adolescent well-being variables. Young people from single-parent families have the lowest scores on the different indicators; they are more likely to have relational problems and experience unemployment as compared with youngsters from stable intact families. Adolescents from conflict intact families and stepfamilies have moderate scores. These effects remain after controlling for family income, gender, age, and educational level.

Effects of parental divorce and youth unemployment on adolescent health.

The aim of this study is to gain more insight into the effects of two important events on adolescent health in the life course of youngsters, namely parental divorce and being unemployed. We made use of the dataset of the Utrecht Study of Adolescent Development, a longitudinal panel study, based on a representative sample of young people in the Netherlands (12-24 years old). We used the data of non-school-going youngsters who are at least 18 years old. Parental divorce does indeed have negative effects on adolescent health: however, this applies only for girls. Being unemployed or having been unemployed has negative effects on psychological health, especially for boys. But this experience does not have negative effects on physical health, either for boys or girls. Any conclusions on the consequences of parental divorce and youth unemployment for adolescent health have to be specified, at least for sex.