Do technology shocks drive hours up or down? A little evidence from an agnostic procedure

This paper analyzes the robustness of the estimate of a positive productivity shock on hours to the presence of a possible unit root in hours. Estimations in levels or in first differences provide opposite conclusions. We rely on an agnostic procedure in which the researcher does not have to choose between a specification in levels or in first differences. We find that a positive productivity shock has a negative impact effect on hours, but the effect is much shorter lived, and disappears after two quarters. The effect becomes positive at business-cycle frequencies, although it is not significant. © 2005 Cambridge University Press.

Child work and labour among orphaned and abandoned children in five low and middle income countries.

BACKGROUND: The care and protection of the estimated 143,000,000 orphaned and abandoned children (OAC) worldwide is of great importance to global policy makers and child service providers in low and middle income countries (LMICs), yet little is known about rates of child labour among OAC, what child and caregiver characteristics predict child engagement in work and labour, or when such work infers with schooling. This study examines rates and correlates of child labour among OAC and associations of child labour with schooling in a cohort of OAC in 5 LMICs. METHODS: The Positive Outcomes for Orphans (POFO) study employed a two-stage random sampling survey methodology to identify 1480 single and double orphans and children abandoned by both parents ages 6-12 living in family settings in five LMICs: Cambodia, Ethiopia, India, Kenya, and Tanzania. Regression models examined child and caregiver associations with: any work versus no work; and with working <21, 21-27, and 28+ hours during the past week, and child labour (UNICEF definition). RESULTS: The majority of OAC (60.7%) engaged in work during the past week, and of those who worked, 17.8% (10.5% of the total sample) worked 28 or more hours. More than one-fifth (21.9%; 13% of the total sample) met UNICEF's child labour definition. Female OAC and those in good health had increased odds of working. OAC living in rural areas, lower household wealth and caregivers not earning an income were associated with increased child labour. Child labour, but not working fewer than 28 hours per week, was associated with decreased school attendance. CONCLUSIONS: One in seven OAC in this study were reported to be engaged in child labour. Policy makers and social service providers need to pay close attention to the demands being placed on female OAC, particularly in rural areas and poor households with limited income sources. Programs to promote OAC school attendance may need to focus on the needs of families as well as the OAC.

Working at the interface of phylogenetics and population genetics: a biogeographical analysis of Triaenops spp. (Chiroptera: Hipposideridae).

New applications of genetic data to questions of historical biogeography have revolutionized our understanding of how organisms have come to occupy their present distributions. Phylogenetic methods in combination with divergence time estimation can reveal biogeographical centres of origin, differentiate between hypotheses of vicariance and dispersal, and reveal the directionality of dispersal events. Despite their power, however, phylogenetic methods can sometimes yield patterns that are compatible with multiple, equally well-supported biogeographical hypotheses. In such cases, additional approaches must be integrated to differentiate among conflicting dispersal hypotheses. Here, we use a synthetic approach that draws upon the analytical strengths of coalescent and population genetic methods to augment phylogenetic analyses in order to assess the biogeographical history of Madagascar's Triaenops bats (Chiroptera: Hipposideridae). Phylogenetic analyses of mitochondrial DNA sequence data for Malagasy and east African Triaenops reveal a pattern that equally supports two competing hypotheses. While the phylogeny cannot determine whether Africa or Madagascar was the centre of origin for the species investigated, it serves as the essential backbone for the application of coalescent and population genetic methods. From the application of these methods, we conclude that a hypothesis of two independent but unidirectional dispersal events from Africa to Madagascar is best supported by the data.

The spacing effect depends on an encoding deficit, retrieval, and time in working memory: evidence from once-presented words.

The spacing effect in list learning occurs because identical massed items suffer encoding deficits and because spaced items benefit from retrieval and increased time in working memory. Requiring the retrieval of identical items produced a spacing effect for recall and recognition, both for intentional and incidental learning. Not requiring retrieval produced spacing only for intentional learning because intentional learning encourages retrieval. Once-presented words provided baselines for these effects. Next, massed and spaced word pairs were judged for matches on their first three letters, forcing retrieval. The words were not identical, so there was no encoding deficit. Retrieval could and did cause spacing only for the first word of each pair; time in working memory, only for the second.

Later Life Consequences of Developmental Mitochondrial DNA Damage in C. elegans

Mitochondria are responsible for producing the vast majority of cellular ATP, and are therefore critical to organismal health [1]. They contain thir own genomes (mtDNA) which encode 13 proteins that are all subunits of the mitochondrial respiratory chain (MRC) and are essential for oxidative phosphorylation [2]. mtDNA is present in multiple copies per cell, usually between 103 and 104 , though this number is reduced during certain developmental stages [3, 4]. The health of the mitochondrial genome is also important to the health of the organism, as mutations in mtDNA lead to human diseases that collectively affect approximately 1 in 4000 people [5, 6]. mtDNA is more susceptible than nuclear DNA (nucDNA) to damage by many environmental pollutants, for reasons including the absence of Nucleotide Excision Repair (NER) in the mitochondria [7]. NER is a highly functionally conserved DNA repair pathway that removes bulky, helix distorting lesions such as those caused by ultraviolet C (UVC) radiation and also many environmental toxicants, including benzo[a]pyrene (BaP) [8]. While these lesions cannot be repaired, they are slowly removed through a process that involves mitochondrial dynamics and autophagy [9, 10]. However, when present during development in C. elegans, this damage reduces mtDNA copy number and ATP levels [11]. We hypothesize that this damage, when present during development, will result in mitochondrial dysfunction and increase the potential for adverse outcomes later in life.

To test this hypothesis, 1st larval stage (L1) C. elegans are exposed to 3 doses of 7.5J/m2 ultraviolet C radiation 24 hours apart, leading to the accumulation of mtDNA damage [9, 11]. After exposure, many mitochondrial endpoints are assessed at multiple time points later in life. mtDNA and nucDNA damage levels and genome copy numbers are measured via QPCR and real-time PCR , respectively, every 2 day for 10 days. Steady state ATP levels are measured via luciferase expressing reporter strains and traditional ATP extraction methods. Oxygen consumption is measured using a Seahorse XFe24 extra cellular flux analyzer. Gene expression changes are measured via real time PCR and targeted metabolomics via LC-MS are used to investigate changes in organic acid, amino acid and acyl-carnitine levels. Lastly, nematode developmental delay is assessed as growth, and measured via imaging and COPAS biosort.

I have found that despite being removed, UVC induced mtDNA damage during development leads to persistent deficits in energy production later in life. mtDNA copy number is permanently reduced, as are ATP levels, though oxygen consumption is increased, indicating inefficient or uncoupled respiration. Metabolomic data and mutant sensitivity indicate a role for NADPH and oxidative stress in these results, and exposed nematodes are more sensitive to the mitochondrial poison rotenone later in life. These results fit with the developmental origin of health and disease hypothesis, and show the potential for environmental exposures to have lasting effects on mitochondrial function.

Lastly, we are currently working to investigate the potential for irreparable mtDNA lesions to drive mutagenesis in mtDNA. Mutations in mtDNA lead to a wide range of diseases, yet we currently do not understand the environmental component of what causes them. In vitro evidence suggests that UVC induced thymine dimers can be mutagenic [12]. We are using duplex sequencing of C. elegans mtDNA to determine mutation rates in nematodes exposed to our serial UVC protocol. Furthermore, by including mutant strains deficient in mitochondrial fission and mitophagy, we hope to determine if deficiencies in these processes will further increase mtDNA mutation rates, as they are implicated in human diseases.

When Working Memory and Attention Compete: Characterizing the Dynamic Interdependence between our Mental Workspace and External Environment

All of us are taxed with juggling our inner mental lives with immediate external task demands. For many years, the temporary maintenance of internal information was considered to be handled by a dedicated working memory (WM) system. It has recently become increasingly clear, however, that such short-term internal activation interacts with attention focused on external stimuli. It is unclear, however, exactly why these two interact, at what level of processing, and to what degree. Because our internal maintenance and external attention processes co-occur with one another, the manner of their interaction has vast implications for functioning in daily life. The work described here has employed original experimental paradigms combining WM and attention task elements, functional magnetic resonance imaging (fMRI) to illuminate the associated neural processes, and transcranial magnetic stimulation (TMS) to clarify the causal substrates of attentional brain function. These studies have examined a mechanism that might explain why (and when) the content of WM can involuntarily capture visual attention. They have, furthermore, tested whether fundamental attentional selection processes operate within WM, and whether they are reciprocal with attention. Finally, they have illuminated the neural consequences of competing attentional demands. The findings indicate that WM shares representations, operating principles, and cognitive resources with externally-oriented attention.

A price worth paying?: Women and work – choice, constraint or satisficing

Purpose – Are women held back or holding back? Do women choose their jobs/careers or are they structurally or normatively constrained? The purpose of this paper is to shed fresh light on these questions and contribute to an on-going debate that has essentially focused on the extent to which part-time work is women’s choice, the role of structural and organisational constraints and the role of men in excluding women. Design/methodology/approach – The paper uses data from interviews with 80 working women – both full-time and part-time – performing diverse work roles in a range of organisations in the south east of England. Findings – It was found that many women do not make strategic job choices, rather they often ‘‘fall into’’ jobs that happen to be available to them. Some would not have aspired to their present jobs without male encouragement; many report incidents of male exclusion; and virtually all either know or suspect that they are paid less than comparable men. Those working reduced hours enjoy that facility, yet they are aware that reduced hours and senior roles are seen as incompatible. In short, they recognise both the positive and negative aspects of their jobs, whether they work full or part-time, whether they work in male-dominated or female-dominated occupations, and whatever their position in the organisational hierarchy. Accordingly, the paper argues that the concept of ‘‘satisficing’’, i.e. a decision which is good enough but not optimal, is a more appropriate way to view women’s working lives than are either choice or constraint theories. Originality/value – There is an ongoing, and often polarised, debate between those who maintain that women choose whether to give preference to work or home/family and others who maintain that women, far from being self-determining actors, are constrained structurally and normatively. Rather than supporting these choice or constraint theories, this paper argues that ‘‘satisficing’’ is a more appropriate and nuanced concept to explain women’s working lives.

The emotional costs of caring incurred by men and women in the British labour market

This study investigates whether men and women in caring occupations experience more negative job-related feelings at the end of the day compared to the rest of the working population. The data are from Wave Nine of the British Household Panel Survey (1999) where respondents were asked whether, at the end of the working day, they tended to keep worrying or have trouble unwinding, and the extent to which work left them feeling exhausted or “used up.” Their responses to these questions were used to develop ordinal dependent variables. Control variables in the models include: number of children, age, hours worked per week, managerial responsibilities and job satisfaction, all of which have been shown in previous research to be significantly related to “job burnout.” The results are that those in caring occupations are more likely to feel worried, tense, drained and exhausted at the end of the working day. Women in particular appear to pay a high emotional cost for working in caring occupations. Men do not emerge unscathed, but report significantly lower levels of worry and exhaustion at the end of the day than do women.

Keeping it together: a guide for support staff working with people whose behaviour is challenging

This guide has been written for support staff, working with people with learning disabilities, who are new to challenging behaviour or facing it for the first time. It is a self-help guide and provides practical and realistic information on how direct care staff can develop strageties to support people whose behaviour is challenging and develop their skills in this area.