Early childhood teachers' beliefs and practices related to peer learning : a mixed methods study : a thesis presented in partial fulfilment of the requirements of the degree of Doctor of Philosophy in Education at Massey University, Manawatū, New Zealand

This study investigated New Zealand early childhood teachers’ beliefs and practices related to peer learning, as little is known about how teachers support peer learning in play based settings. A mixed methods exploratory sequential research design was used. The first phase of the study consisted of case studies, which comprised interviews and observations of teachers in three early childhood centres. Filmed observations of teachers’ practices as they supported opportunities for peer learning were undertaken. Stimulated recall interviews were then completed to gain a deeper understanding of teachers’ intentions about this aspect of their practice. Constant comparative analysis was used to analyse the case studies, including the use of the NVivo programme for content analysis. The second phase of the study was a nationwide survey sent to early childhood teachers. The questions for the survey were derived from analyses of the case studies and extant literature. Survey data was interpreted using descriptive statistics and coding of open ended questions. Findings from both phases were used to answer the research questions. The study revealed teachers’ beliefs about peer learning recognised the social, participatory nature of learning, alongside provision of opportunities for individual exploration and discovery. Balancing these beliefs created a tension for teachers and at times they struggled to express their role in supporting peer learning. The need for teachers to better articulate and deepen their understanding of their role in this type of learning is implicated in these findings. This study found the early childhood setting played a critical role in mediating teachers’ practices and beliefs about peer learning. Therefore children had varied experiences of peer learning as teachers supported children’s agency amongst their peers in different ways. This finding was of concern, as teachers who work in settings that do not actively promote peer learning may not effectively support children’s potential as teachers of their peers. Participants espoused beliefs about child-led learning, however observations revealed teachers’ intentional support of peer learning. This finding highlighted a major contradiction between teachers’ beliefs and practices whilst revealing teachers’ inability to take ownership of their intentional teaching practices. Teachers used the curriculum guidelines from Te Whāriki related to wellbeing and a sense of belonging to support peer learning; the role of children as knowledge constructors was less closely aligned with teachers’ beliefs and practices. This finding draws into question teachers’ understandings of how to implement peer learning across the curriculum strands whilst implying the need for further investigation about how young children’s learning is assessed

New foundations for qualitative physics

Physical reality is all the reality we have, and so physical theory in the standard sense is all the ontology we need. This, at least, was an assumption taken almost universally for granted by the advocates of exact philosophy for much of the present century. Every event, it was held, is a physical event, and all structure in reality is physical structure. The grip of this assumption has perhaps been gradually weakened in recent years as far as the sciences of mind are concerned. When it comes to the sciences of external reality, however, it continues to hold sway, so that contemporary philosophers B even while devoting vast amounts of attention to the language we use in describing the world of everyday experience B still refuse to see this world as being itself a proper object of theoretical concern. Here, however, we shall argue that the usual conception of physical reality as constituting a unique bedrock of objectivity reflects a rather archaic view as to the nature of physics itself and is in fact incompatible with the development of the discipline since Newton. More specifically, we shall seek to show that the world of qualitative structures, for example of colour and sound, or the commonsense world of coloured and sounding things, can be treated scientifically (ontologically) on its own terms, and that such a treatment can help us better to understand the structures both of physical reality and of cognition

Reversibility of cell surface label rearrangement

Cell surface labeling can cause rearrangements of randomly distributed membrane components. Removal of the label bound to the cell surface allows the membrane components to return to their original random distribution, demonstrating that label is necessary to maintain as well as to induce rearrangements. With scanning electron microscopy, the rearrangement of concanavalin A (con A) and ricin binding sites on LA-9 cells has been followed by means of hemocyanin, a visual label. The removal of con A from its binding sites at the cell surface with alpha- methyl mannoside, and the return of these sites to their original distribution are also followed in this manner. There are labeling differences with con A and ricin. Under some conditions, however, the same rearrangements are seen with both lectins. The disappearance of labeled sites from areas of ruffling activity is a major feature of the rearrangements seen. Both this ruffling activity and the rearrangement of label are sensitive to cytochalasin B, and ruffling activity, perhaps along with other cytochalasin-sensitive structure, may play a role in the rearrangements of labeled sites

Celebrating Haldane's `Luttinger liquid theory'

This short piece celebrates Haldane's seminal J. Phys. C 14, 2585 (1981) paper laying the foundations of the modern theory of Luttinger liquids in one-dimensional systems.Comment: Viewpoint for Journal of Physics: Condensed Matte

Moonlighting Behavior: Theory and Evidence

Two labor supply issues that have received substantial attention are the responsiveness of labor supply to wage changes and the imposition of labor supply constraints. Adjusting hours worked on a second job may be the practical and perhaps only available response to either event yet, most labor supply studies only examine behavior on the primary job. Examining the motives for moonlighting provides evidence on both the wage-responsiveness of labor supply in general and the existence and consequences of labor supply constraints. If, for instance, workers moonlight only when constrained on their primary jobs, then moonlighting itself implies that labor supply constraints exist and so supports the previous literature that incorporates these constraints (e.g. Hamm 1982, 1986). Regardless of the motive for moonlighting, allowing for potential labor supply adjustments on more than one job may very will alter the much-accepted conclusion regarding the inelasticity f male labor supply (for surveys, see Killingsworth 1983 or Pencavel 1986). By ignoring moonlighting behavior, researchers may be eliminating the most significant avenue for short term labor supply adjustments. Our research substantially improves the manner in which moonlighting is examined, and in so doing sheds new light on male labor supply elasticities. Specifically, we devise a theoretical model that permits different reasons for moonlighting and considers moonlighting in tandem with labor supply behavior on the primary job. Estimating both primary and secondary job hours equations using panel data from the SIPP (Survey of Income and Program Participation ) for prime-aged men, we find evidence that the decision to moonlight is quite responsive to wage changes (on both jobs) and arises from at least two distinct motives. Furthermore, properly modeling primary job hours constraints and differences in moonlighting motives reveals that the desired labor supply of prime-aged males is much more wage-elastic than typically assumed. Why do some people choose to moonlight? The predominant view is that it results from a constraint on hours worked on the primary job (Shishko and Rostker (1976), O'Connell (1979) and Krishnan (1990)). Due to workweek restrictions, economic conditions or other institutional factors, the worker is unable to work (or earn) as much as he or she desires on the primary job (PJ), and may thus consider taking a second job. The decision to moonlight hinges on a comparison between the reservation wage and the wage earned on a second job (SJ). The reservation wage and, there fore, the decision to moonlight will depend in part on the number of hours worked on the primary job. A major shortcoming of the aforementioned studies is the inclusion of (exogenous) primary job hours in moonlighting equations estimated for all workers (even non-moonlighters), many of whom may be unconstrained on their primary jobs. Indeed, estimating hours worked on the PJ as a choice variable is the purpose of a great many labor supply studies. To treat is as fixed and exogenous for all workers in inconsistent with basic economic theory and will likely lead to biased parameter estimates. Our econometric model corrects this misspecification and predicts which workers are constrained on their primary jobs. Another explanation for moonlighting behavior is that labor supplied to different jobs may not be perfect substitutes or, put differently, the age paid and utility lost form the foregone leisure may not completely reflect the benefits and costs to working. For example, working on the primary job may provide the worker with the credentials to take on a higher paying second job, such as a university professor who engages in consulting. Or, working on the second job may provide some pleasure (or less displeasure) but pay less than the primary job, such as a musician who has a "regular" job by day and performs at night. In either example, the costs and benefits of both jobs are more complex than the monetary wages paid and the forgone value of leisure. When faced with such nonpecuniary benefits and costs, optimizing behavior may lead a worker to take two jobs. Whereas Shishko and Rostker (1976) and others acknowledge that such a motive may exist, only Lilja (1991) explores it theoretically and empirically. Using Finnish data, the author finds evidence that this second motive better explains male moonlighting behavior that the first, more popular view. We build on Lilja's work by constructing a more consistent theoretical model and by explicitly modeling the behavior on the first job. Our research examines moonlighting behavior recognizing that workers may moonlight because of constraints on their primary jobs or because the two jobs are heterogeneous. We make no a priori assumptions regarding the existence of PJ constraints. We choose the SIPP data for our empirical analysis because it has detailed information on the second job that is superior to that available in other surveys (namely the panel Study of Income Dynamics, National Longitudinal Survey, and Current Population Survey), and it has a short (four month) survey period that permits us to better observe worker movements into and out of jobs. Cross-sectional data likely understate the true degree of moonlighting. In sum, our results help answer the questions of who moonlights and why, as well as provide new evidence of the wage-responsiveness of labor supply on both jobs and the prevalence of labor supply constraints.moonlighting, second, jobs, labor, Conway, Kimmel

Who Moonlights and Why?: Evidence from the SIPP

Multiple job-holding is a significant characteristic of the labor market, with approximately 6 percent of all employed males reporting a second job in 1993 (Mishel and Bernstein, 1995, p. 226). Moonlighting reflects growing financial stress arising from declining earnings, as well as an increased need for flexibility to combine work and family. Approximately 40 percent of moonlighters report taking the second job due to economic hardship. Additionally, moonlighting is a reflection of the worker's choice to pursue entrepreneurial activities while maintaining the financial stability offered by the primary job. To restate in economic terminology, moonlighting arises from at least two distinct reasons. First, many individuals hold multiple jobs due to some sort of constraint on the primary job that limits that job's earnings capacity. Second, moonlighting may arise because the labor supplied to the two jobs are not perfect substitutes. That is, the wage paid and utility lost from the forgone leisure may not completely reflect the benefits and costs to working. For example, working on the primary job may provide the worker with the credentials to acquire a higher paying second job, such as a university psychologist testifying in a jury trial. Or, working on the second job may provide some satisfaction not received in the same amount or manner from the primary job, such as a comedian who has a "regular" job by day and performs at night. In either example, the costs and benefits of both jobs are more complex than the monetary wages paid and the forgone value of leisure. When faced with such nonpecuniary benefits and costs, optimizing behavior may lead a worker to take two jobs. In contrast to workers who moonlight because they are constrained on their primary jobs (PJ), we expect these kinds of moonlighters to moonlight for longer periods of time because optimizing behavior leads them to supply labor to more than one job, even in the long run. We might also expect to see smaller wage differences between jobs for such workers and the second job (SJ) wage could even be higher than the primary job wage in some situations. Previous research on moonlighting, including Shishko and Rostker (1976), O'Connell (1979) and Krishnan (1990), acknowledges that multiple motives may exist but focuses only on the constraint motive. In related studies, Paxson and Sicherman (1994) explore moonlighting as an alternative avenue for adjusting short-run labor supply, and Abdukadir (1992) examines the possibility that moonlighting is caused by short-term liquidity constraints. Another possible motivation for moonlighting is that certain types of job situations present greater opportunities for tax evasion. Plewes and Stinson (1991) provide survey evidence from the 1989 Current Population Survey of the many distinct reasons for moonlighting reported by workers. The only research in the moonlighting literature that models the joint motives for moonlighting correctly while controlling for the endogeneity of primary job hours are Lilja (1991) and Conway and Kimmel (1994). The latter improves upon Lilja (1991) by specifying a more plausible utility maximizing model and developing a superior instrument for PJ hours. This research examines the characteristics of moonlighters and the length of their moonlighting episodes with the goal of understanding who moonlights and why. The data are for prime-aged men and are drawn from the 1984 Survey of Income and Program Participation (SIPP) panel. The primary advantages of the SIPP are the detailed information provided on up to two jobs (including job start and end dates) and the relatively short length of time (four months) covered by each interview of the survey. Both of these qualities make it possible to identify brief (as well as long) periods of moonlighting, movements into and out of jobs, and the characteristics associated with each job. Because moonlighting may be motivated by short-term financial needs, being able to observe short moonlighting durations is important. We begin by studying the personal and job-related characteristics of moonlighters and how the length of the moonlighting episode varies with these characteristics. We then estimate a duration model with unobserved heterogeneity to identify formally the determinants of moonlighting behavior when multiple motives may exist. Our expectation is that individuals who moonlight because they are constrained on their primary jobs might do so for shorter periods than those who are "job-packaging." Therefore, the hazard rate for workers who moonlight because of primary job constraints should be greater than for those with alternative motives, ceteris paribus. The mixed hazard function will vary as the composition of the sample changes with the duration of the moonlighting episode. By exploring the importance of heterogeneity and the direction of duration dependence of the mixed and structural hazard functions, we gain new insights into the determinants of moonlighting behavior. The descriptive analyses reveal that most moonlighters in our sample work full-time on their primary jobs and 15 to 20 hours a week on lower paying second jobs, and, in spite of those long hours, tend to be poorer than the average worker. Yet, a significant minority earns a higher wage on their second job. Our duration model results suggest that the structural hazard increases over time and there is significant unobserved heterogeneity. Taken together, these results are consistent with the presence of multiple motives for moonlighting, with the constraint motive being the most common.moonlighting, jobs, Kimmel, Conway

Supply response of West African agricultural households

This paper explores the implications of preference heterogeneity between wives and husbands in nonresource-pooling rural West African households for the effect of crop price changes on agricultural production, i.e., their supply response. A "semi-cooperative" game-theoretic model of household decisionmaking, in which household members make unilateral time and income allocation decisions and negotiate over who controls these resources, is proposed. The model is used to show that Pareto efficiency in both production and consumption do not hold. It is then employed to simulate the supply response to cotton price increases accompanying agricultural sector liberalization in Burkina Faso in the early 1980s. The simulated semi-cooperative model predicts the cotton supply response of (monogamous) Burkinabé households to be 25 percent below that which would ensue in households facing the same production constraints yet whose members have identical preferences. The analysis indicates that in nonresource-pooling agricultural households, preference heterogeneity can be expected to mute supply response and may do so in a quantitatively significant manner. It illustrates how an intrahousehold approach that allows for such heterogeneity and for disaggregation of resource control by gender contributes to a better understanding of price effects.Gender ,Resource management. ,Households Decision making. ,Household resource allocation ,

Three-generation baryon and lepton number violation at the LHC

One of the most puzzling questions in particle physics concerns the status of the baryon (B) and lepton (L) quantum numbers. On the theoretical side, most new physics scenarios naturally lead to their non-conservation and some amount of violation is actually needed to explain the baryon asymmetry of the Universe. On the experimental side, low-energy constraints such as those on proton decay are so stringent that it is generally believed that no B and L violation will ever be seen in laboratories. We observe that this apparent contradiction, however, disappears when the flavor symmetries involving all three generations are taken into account. We then identify model-independent classes of B and/or L violating six-fermion-based processes that indeed simultaneously satisfy low-energy constraints and produce clearly identifiable signals at the LHC. Finally, through simplified models, we study two classes characterized by (\Delta B;\Delta L) = (\pm 1;\pm 3) and (\pm 2; 0), that lead to particularly striking signatures (t \mu^+ e^+ and \bar t \bar t + jets, respectively).Comment: 5 pages, 2 figures, 1 table; v2: version to appear in Phys.Lett.