Estimating the critical and sensitive periods of investment in early childhood: A methodological note

This paper provides an overview of different quantitative methods available for the statistical analysis of longitudinal data regarding child development, and in particular the identification of critical and sensitive periods for later abilities. It draws heavily on the work on human skill formation developed by the economist James Heckman, which treats ability as a latent variable and explains its formation through the simultaneous estimation of structural equations of investments and achieved abilities across time. We distinguish between two specifications of the ability formation function. One of them (the ‘recursive’) format explains current ability as a function of the ability and investment at the immediately preceding period. The other (the ‘non-recursive’) format explains current ability as a function of a series of past investments. In order to fully examine critical and sensitive periods of investments, the non-recursive formulation needs to be used. Furthermore, true abilities of an individual cannot be directly observed: what we observe are the test scores, for example, on reading and writing. We outline an approach based on structural models that treats actual test scores as measurements of the latent ability variable, and show how it can be used in the recursive and non-recursive formulation. In order to fully examine critical and sensitive periods of investments, we argue that the non-recursive formulation of this structural model is necessary. However, the non-recursive formulation requires more data than the recursive formulation, and to the best of our knowledge, has never been used in the identification of critical and sensitive periods in early childhood development. (254wds

Sons and daughters: parental beliefs and child behaviour (evidence from the UK Millennium Cohort Study)

An extensive literature exists exploring the determinants of child behaviour, with increasing interest in its links with parental characteristics and beliefs. In this paper we explore a particular aspect of this relationship by looking at the parents' beliefs regarding how to treat boys and girls. A question in the third wave of the UK Millennium Cohort Study asks both the mother and father of 5-year olds whether they agree to the statement: 'Sons in families should be given more encouragement than daughters to do well at school'. We model both the determinants of parent's beliefs, as captured by this question; and the impact of these beliefs on the behaviour of 7 year old boys and girls, separately. The key findings of the paper suggest that parental agreement to the above statement does not have an impact on boys' behaviour; however, it has a detrimental impact on the behaviour of girls

Effectiveness of Husbands’ Support Exclusive Breastfeeding Facebook Programme During the COVID-19 Pandemic [Letter]

Hem Jivani,1 Aditi Popli2 1Maharishi Markandeshwar Institute Medical Science and Research, Maharishi Markandeshwar (Deemed to be University), Mullana, Haryana, 133207, India; 2Maharishi Markandeshwar Institute of Physiotherapy and Rehabilitation, Maharishi Markandeshwar (Deemed to be University), Mullana, Haryana, 133207, IndiaCorrespondence: Aditi Popli, Maharishi Markandeshwar Institute of Physiotherapy and Rehabilitation, Maharishi Markandeshwar (Deemed to be University), Mullana, Haryana, 133207, India, Tel +91 9896461613, Email [email protected]

Estimating the impact of health on NEET status

This paper uses a dynamic Structural Equation Model of ability formation to investigate the determinants of NEET (not in education, employment or training) status in adolescents, with special focus on health. The model addresses the issue of measurement error in estimating ability and mental health; and explores the determinants of ability and NEET status through time. The analysis finds that ability remains the key predictor of NEET status; and while general health plays an important role in the formation of ability for both girls and boys, the impact of mental health differs between the sexes

Multi-Sensory Stimuli Improve Relaxation and Sleep Quality in Rotating Shift Workers: A Randomized Controlled Trial [Letter]

Riya Kalra,* Kanu Goyal, Aditi Popli* Maharishi Markandeshwar Institute of Physiotherapy and Rehabilitation, Maharishi Markandeshwar (Deemed to Be University), Mullana, Haryana, 133207, India*These authors contributed equally to this workCorrespondence: Aditi Popli, Department of Physiotherapy, Maharishi Markandeshwar Institute of Physiotherapy and Rehabilitation, Maharishi Markandeshwar (Deemed to be University), Mullana, Haryana, 133207, India, Email [email protected]

Electrochemical decolorization of Reactive Black 5 in an undivided cell using Ti and graphite anodes: Effect of polypyrrole coating on anodes

Electrochemical decolorization of an azo dye Reactive Black 5 (RB5) was studied in an undivided cell using Ti and graphite, and polypyrrole (PPy) coated Ti (PPy-SLS-Ti) and graphite (PPy-SLS-G) anodes in the presence of sodium chloride as an electrolyte to investigate the effect of polypyrrol coating. The colour removal efficiencies were 52.6%, 96.3%, 51.6%, and 41.0% respectively, at the end of 90 minutes of electrolysis at current density of 5 mA/cm2. The presence of PPy coating resulted in lower decolorization than that in the absence of coating. No specific peak emerged in UV-Vis spectra obtained at various time points during electrolysis using uncoated Ti and Graphite anodes which indicated non-selective nature of oxidation process. In case of PPy-SLS/Ti and PPy-SLS/Graphite anodes, a peak at 254 nm emerged distinctly which was determined to be vinylsulfone (VS), an amine. Generation and accumulation of VS suggested that oxidation was suppressed and electrochemical reduction rather than oxidation, was a predominant mechanism responsible for RB5 decolourization in case of polypyrrole coated anodes. Normally, in an undivided cell, reactions on anode predominates (i.e. oxidation). The results obtained here may lead to development of anodes for undivided cells on which the extent of oxidation may be controlled by a suitable coating such as PPy

Parental ethnic identity and child development

We examine the relationship between parental ethnic identity and cognitive development in ethnic minority children. This aspect of parental identity may shape children’s cognitive outcomes through a direct influence on parenting behaviour, or by mediating parental access to social resources. Drawing an ethnic minority sample from a detailed UK cohort study, we find a negative association between maternal majority identity and children’s cognitive test scores. This result is driven by poor households, by those who lack local family support networks, and by those who mostly speak a foreign language at home. We suggest that differential access to social resources is the most persuasive explanation of this result. Differences in parenting behaviour do not seem to play an important role

Hybrid materials based on polyethylene and MCM-41 microparticles functionalized with silanes: catalytic aspects of in situ polymerization, crystalline features and mechanical properties

New nanocomposites based on polyethylene have been prepared by in situ polymerization of ethylene in presence of mesoporous MCM-41. The polymerization reactions were performed using a zirconocene catalyst either under homogenous conditions or supported onto mesoporous MCM-41 particles, which are synthesized and decorated post-synthesis with two silanes before polymerization in order to promote an enhanced interfacial adhesion. The existence of polyethylene chains able to crystallize within the mesoporous channels in the resulting nanocomposites is figured out from the small endothermic process, located at around 80 C, on heating calorimetric experiments, in addition to the main melting endotherm. These results indicate that polyethylene macrochains can grow up during polymerization either outside or inside the MCM-41 channels, these keeping their regular hexagonal arrangements. Mechanical response is observed to be dependent on the content in mesoporous MCM-41 and on the crystalline features of polyethylene. Accordingly, stiffness increases and deformability decreases in the nanocomposites as much as MCM-41 content is enlarged and polyethylene amount within channels is raised. Ultimate mechanical performance improves with MCM-41 incorporation without varying the final processing temperature