Performance Management in Portfolio School Districts

Explores the challenges of performance-based oversight of portfolio districts -- districts trying to provide diverse types of schools with common standards and accountability -- and the capacities needed. Includes profiles and best practices

High fertility in city suburbs: compositional or contextual effects?

Fertility rates are known to be higher in city suburbs. One interpretation is that the suburban ‘context’ influences the behaviour of individuals who reside there while an alternative is that the ‘composition’ of the suburban population explains the higher fertility levels. Furthermore, suburban in-migrants who intend to have children may have a significant influence on suburban fertility rates. Using Finnish longitudinal register data we show that fertility rates are higher in the suburbs and rural areas and lower in the cities. While fertility variation across these residential contexts decreases significantly after controlling for women’s demographic and socio-economic characteristics, it does not disappear entirely suggesting that the local context may have some influence on fertility. While movers to suburbs do display higher fertility levels than non-migrant residents, their overall impact is not great because they form a small share of the suburban population.Finland, event history analysis, fertility, migration, residential mobility, rural areas, suburban areas, urban areas

Does cohabitation prior to marriage raise the risk of marital dissolution and does this effect vary geographically?

A number of studies show that premarital cohabitation increases the risk of subsequent marital dissolution. Some argue that this is a consequence of selection effects and that once these are controlled for premarital cohabitation has no effect on dissolution. We extend this research by examining whether the effects of premarital cohabitation on marital dissolution vary across settlements within a country. Using retrospective event-history data from Austria, we model equations for union formation and dissolution jointly to control for unobserved selectivity of cohabiters or non-cohabiters. Our results show that those who cohabit prior to marriage have a higher risk of marital dissolution. However, once selection effects are controlled for, the risks of marital dissolution for those who cohabit prior to marriage are significantly lower than for those who marry directly. We show that strong selection effects relate to both cohabitation and direct marriage and these effects are consistent across all settlements.Austria, divorce, event history analysis, rural areas, urban areas

Fermented beverages with health-promoting potential: Past and future perspectives

peer-reviewedFermentation is an ancient form of food preservation, which also improves the nutritional content of foods. In many regions of the world, fermented beverages have become known for their health-promoting attributes. In addition to harnessing traditional beverages for commercial use, there have recently been innovative efforts to develop non-dairy probiotic fermented beverages from a variety of substrates, including soy milk, whey, cereals and vegetable and fruit juices. On the basis of recent developments, it is anticipated that fermented beverages will continue to be a significant component within the functional food market

High suburban fertility: evidence from four Northern European countries

This study examines fertility variation across different residential contexts in four Northern European countries: Denmark, Finland, Norway and Sweden. We move beyond the conventional urban-rural focus of most previous studies of within-nation variations in fertility by distinguishing between urban centres and suburbs of cities and towns. We base our study on aggregate and individual-level register data and our analysis shows that fertility levels are significantly higher in suburbs than in urban centres; this pattern has persisted over the past quarter of a century for all four countries. A parity-specific analysis of Swedish register data reveals that total fertility varies between central cities and suburbs due to the relatively high first- and second-birth propensities in the suburbs. Further analysis shows that fertility variation between the central cities and suburbs persists after controlling for women’s socioeconomic characteristics. We discuss the role of various factors in accounting for high suburban fertility including omitted individual characteristics, contextual factors and selective residential moves of couples planning to have a child.Europe, fertility, suburban areas

Sequencing-Based Analysis of the Bacterial and Fungal Composition of Kefir Grains and Milks from Multiple Sources

peer-reviewedKefir is a fermented milk-based beverage to which a number of health-promoting properties have been attributed. The microbes responsible for the fermentation of milk to produce kefir consist of a complex association of bacteria and yeasts, bound within a polysaccharide matrix, known as the kefir grain. The consistency of this microbial population, and that present in the resultant beverage, has been the subject of a number of previous, almost exclusively culture-based, studies which have indicated differences depending on geographical location and culture conditions. However, culture-based identification studies are limited by virtue of only detecting species with the ability to grow on the specific medium used and thus culture-independent, molecular-based techniques offer the potential for a more comprehensive analysis of such communities. Here we describe a detailed investigation of the microbial population, both bacterial and fungal, of kefir, using high-throughput sequencing to analyse 25 kefir milks and associated grains sourced from 8 geographically distinct regions. This is the first occasion that this technology has been employed to investigate the fungal component of these populations or to reveal the microbial composition of such an extensive number of kefir grains or milks. As a result several genera and species not previously identified in kefir were revealed. Our analysis shows that the bacterial populations in kefir are dominated by 2 phyla, the Firmicutes and the Proteobacteria. It was also established that the fungal populations of kefir were dominated by the genera Kazachstania, Kluyveromyces and Naumovozyma, but that a variable sub-dominant population also exists.The Alimentary Pharmabiotic Centre is a research centre funded by Science Foundation Ireland (SFI), through the Irish Government’s National Development Plan. The authors and their work were supported by SFI CSET grant APC CSET 2 grant 07/CE/B1368

Compressive force generation by a bundle of living biofilaments

To study the compressional forces exerted by a bundle of living stiff filaments pressing on a surface, akin to the case of an actin bundle in filopodia structures, we have performed particulate Molecular Dynamics simulations of a grafted bundle of parallel living (self-assembling) filaments, in chemical equilibrium with a solution of their constitutive monomers. Equilibrium is established as these filaments, grafted at one end to a wall of the simulation box, grow at their chemically active free end and encounter the opposite confining wall of the simulation box. Further growth of filaments requires bending and thus energy, which automatically limit the populations of longer filaments. The resulting filament sizes distribution and the force exerted by the bundle on the obstacle are analyzed for different grafting densities and different sub- or supercritical conditions, these properties being compared with the predictions of the corresponding ideal confined bundle model. In this analysis, non-ideal effects due to interactions between filaments and confinement effects are singled out. For all state points considered at the same temperature and at the same gap width between the two surfaces, the force per filament exerted on the opposite wall appears to be a function of a rescaled free monomer density $\hat{\rho}_1^{\rm eff}$. This quantity can be estimated directly from the characteristic length of the exponential filament size distribution $P$ observed in the size domain where these grafted filaments are not in direct contact with the wall. We also analyze the dynamics of the filament contour length fluctuations in terms of effective polymerization ($U$) and depolymerization ($W$) rates, where again it is possible to disentangle non-ideal and confinement effects.Comment: 24 pages, 7 figure

In silico identification of bacteriocin gene clusters in the gastrointestinal tract, based on the Human Microbiome Project’s reference genome database

peer-reviewedBackground The human gut microbiota comprises approximately 100 trillion microbial cells which significantly impact many aspects of human physiology - including metabolism, nutrient absorption and immune function. Disturbances in this population have been implicated in many conditions and diseases, including obesity, type-2 diabetes and inflammatory bowel disease. This suggests that targeted manipulation or shaping of the gut microbiota, by bacteriocins and other antimicrobials, has potential as a therapeutic tool for the prevention or treatment of these conditions. With this in mind, several studies have used traditional culture-dependent approaches to successfully identify bacteriocin-producers from the mammalian gut. In silico-based approaches to identify novel gene clusters are now also being utilised to take advantage of the vast amount of data currently being generated by next generation sequencing technologies. In this study, we employed an in silico screening approach to mine potential bacteriocin clusters in genome-sequenced isolates from the gastrointestinal tract (GIT). More specifically, the bacteriocin genome-mining tool BAGEL3 was used to identify potential bacteriocin producers in the genomes of the GIT subset of the Human Microbiome Project’s reference genome database. Each of the identified gene clusters were manually annotated and potential bacteriocin-associated genes were evaluated. Results We identified 74 clusters of note from 59 unique members of the Firmicutes, Bacteroidetes, Actinobacteria, Fusobacteria and Synergistetes. The most commonly identified class of bacteriocin was the >10 kDa class, formerly known as bacteriolysins, followed by lantibiotics and sactipeptides. Conclusions Multiple bacteriocin gene clusters were identified in a dataset representative of the human gut microbiota. Interestingly, many of these were associated with species and genera which are not typically associated with bacteriocin production.CJW, CMG and PDC are supported by a SFI PI award to PDC “Obesibiotics” (11/PI/1137)

Natural and Synthetic Corticosteroids Inhibit Uptake\u3csub\u3e2\u3c/sub\u3e-Mediated Transport in CNS Neurons

In addition to exerting actions via mineralocorticoid and glucocorticoid receptors, corticosteroids also act by inhibiting uptake2, a high-capacity monoamine transport system originally described in peripheral tissues. Recent studies have demonstrated that uptake2 transporters are expressed in the brain and play roles in monoamine clearance, suggesting that they mediate some corticosteroid effects on physiological and behavioral processes. However, the sensitivity of brain uptake2 to many natural and synthetic corticosteroids has not been characterized. Cultured rat cerebellar granule neurons (CGNs) were previously shown to exhibit corticosterone-sensitive accumulation of the uptake2 substrate1-methyl-4-phenylpyridinium (MPP+). We examined the expression of uptake1 and uptake2 transporters in CGNs, and tested the effects of a variety of natural and synthetic corticosteroids on accumulation of [3H]-MPP+ by these cells. Cultured rat CGNs expressed mRNA for three uptake2-like transporters: organic cation transporters 1 and 3, and the plasma membrane monoamine transporter. They did not express mRNA for the dopamine or norepinephrine transporters, and expressed very little mRNA for the serotonin reuptake transporter. Accumulation of [3H]-MPP+ by CGNs was dose-dependently inhibited by corticosterone and decynium-22, known inhibitors of uptake2. Accumulation of MPP+ was also dose-dependently inhibited, with varying efficacies, by aldosterone, 11-deoxycorticosterone, cortisol, and cortisone, and by the synthetic glucocorticoids betamethasone, dexamethasone and prednisolone, and the glucocorticoid receptor antagonist RU38486. These studies demonstrate that uptake2 in the CNS is inhibited by a variety of natural and synthetic corticosteroids, and suggest that inhibition of uptake2-mediated monoamine clearance may underlie some behavioral and physiological effects of these hormones

The effect of performance stages on subwoofer polar and frequency responses

Precise control of low-frequency energy is a common requirement at large-scale live events, whereby sound energy transmitted into performance areas and outside event grounds must be limited. Industry-standard sound system design and prediction software typically omits any acoustical effect a performance stage will have on the overall system response (both in terms of polar and frequency response).This research highlights the significant effect a stage can have on subwoofer performance, where in particularly poor cases directionality is lost and the frequency response is strongly colored by resonances. This work puts forward recommendations for subwoofer system configurations that avoid unwanted stage effects as much as possible to maintain the desired (and predicted) system performance