Body Mass Index Development from Birth to Early Adolescence; Effect of Perinatal Characteristics and Maternal Migration Background in a Swedish Cohort

Background

Well documented diversity in risk of developing overweight and obesity between children of immigrant and of native mothers, might be explained by different body mass index (BMI) development trajectories in relation to maternal and perinatal characteristics of offspring.

Objectives

To assess BMI development trajectories among children born to immigrant and to Swedish mothers from birth to adolescence in relation to perinatal characteristics.

Methods

A cohort of 2517 children born in Stockholm during 1994 to 1996 was followed with repeated measurement of height and weight at eleven time points until age 12 years. We estimated changes over time for BMI in relation to maternal and perinatal characteristics of offspring using mixed linear model analysis for repeated measure data.

Results

We observed a significant BMI change over time in children and time interaction with maternal migration status (P<0.0001). Estimated BMI over time adjusted for maternal and perinatal characteristics of offspring, showed slower BMI growth before age of 5, followed by an earlier plateau and steeper BMI growth after 5 years among children of immigrant mothers compared with children of Swedish mothers. These differences in BMI growth were more prominent among children with mothers from outside Europe.

Conclusion

Beside reinforcing early childhood as a crucial period in development of overweight, the observed slower BMI development at early childhood among children of immigrants followed by a steeper increase in BMI compared with children of Swedish mothers is important for further studies and for planning of preventive public health programs.     

Pyrogeography,historical ecology,and the human dimensions of fire regimes

In our 2011 synthesis (Bowman et al., Journal of Biogeography, 2011, 38 , 2223–2236), we argued for a holistic approach to human issues in fire science that we term ‘pyrogeography’. Coughlan & Petty (Journal of Biogeography, 2013, 40 , 1010–1012) critiqued our paper on the grounds that our ‘pyric phase’ model was built on outdated views of cultural development, claiming we developed it to be the unifying explanatory framework for all human–fire sciences. Rather, they suggest that ‘historical ecology’ could provide such a framework. We used the ‘pyric transition’ for multiple purposes but did not offer it as an exclusive explanatory framework for pyrogeography. Although ‘historical ecology’ is one of many useful approaches to studying human–fire relationships, scholars should also look to political and evolutionary ecology, ecosystems and complexity theories, as well as empirical generalizations to build an interdisciplinary fire science that incorporates human, ecological and biophysical dimensions of fire regimes.     

Three-dimensional Nuclear Telomere Organization in Multiple Myeloma

Multiple myeloma (MM) is preceded by monoclonal gammopathy of undetermined significance (MGUS). Up to date, it is difficult to predict an individual's time to disease progression and the treatment response. To examine whether the nuclear telomeric architecture will unravel some of these questions, we carried out. Three-dimensional (3D) telomere analysis on samples from patients diagnosed with MGUS and MM, as well as from patients who went into relapse. Telomere signal intensity, number of telomere aggregates, nuclear volume, and the overall nuclear telomere distribution (a/c ratio) were analyzed. The telomeric profiles allowed for the differentiation of the disease stages. The telomeric profiles of myeloma cells obtained from blood and bone marrow aspirates were identical. Based on this study, we discuss the use of 3D telomere profiling as a potential future tool for risk stratification and personalized treatment decisions.     

Relative strength of resource and predation limitation of heterotrophic nanoflagellates in a low-productive sea area

The magnitude of resource and predation limitation of heterotrophicnanoflagellates (HNF) was studied in two short-term enclosureexperiments performed in a low-productive sea area in the northernBaltic Sea in 2001. A cross-factorial design was used to simultaneouslyassess the relative importance of the two factors. Resourcelimitation was removed by adding bacteria, and predation limitationwas eliminated by selective filtration. The first experimentwas performed in June just after the spring bloom decline andthe second in September at the end of the productive season.Resource limitation prevailed during both experiments, contributingto 60% of the net growth increase in June and 74% in September.Removal of predators had a significant effect only in June.Evidence for simultaneous resource and predation limitationwas thus found only during the post-bloom situation. The resultswere applied to a model on resource and predation control ofHNF abundances. To evaluate seasonal differences, field dataon HNF and bacteria from a whole year study were applied tothe model. Except for a few occasions during spring, the modelindicated prevailing resource control of HNF at two locationswith slightly different productivity.     

Inhibition of potato polyphenol oxidase by anions and activity in various carboxylate buffers (pH 4.8) at constant ionic strength

The activity of potato polyphenol oxidase (tyrosinase) toward DL-3,4-dihydroxyphenylalanine (K(M) 5.39 mM) was studied using a variety of carboxylate buffers at a common pH and ionic strength. Enzyme activity, greatest in citrate and least in oxalate, correlated with increasing carboxyl concentration and molecular mass. The lower activity in oxalate was attributed to more effective chelation of a copper(II) form of the enzyme by the oxalate dianion. Sodium halide salts inhibited the enzyme. Although there was little difference in inhibition between sodium and potassium salts, the degree and type of inhibition was anion dependent; K(is), values for NaCl and KCl, (competitive inhibitors) were 1.82 and 1.62 mM, whereas Na(2) SO(4) and K(2) SO(4) (mixed inhibitors) had K(is) and K(ii) values in the 250 to 450 mM range.     

Manipulation of salicylate content in Arabidopsis thaliana by the expression of an engineered bacterial salicylate synthase

Salicylic acid (SA) plays a central role as a signalling molecule involved in plant defense against microbial attack. Genetic manipulation of SA biosynthesis may therefore help to generate plants that are more disease-resistant. By fusing the two bacterial genes pchA and pchB from Pseudomonas aeruginosa, which encode isochorismate synthase and isochorismate pyruvate-lyase, respectively, we have engineered a novel hybrid enzyme with salicylate synthase (SAS) activity. The pchB-A fusion was expressed in Arabidopsis thaliana under the control of the constitutive cauliflower mosaic virus (CaMV) 35S promoter, with targeting of the gene product either to the cytosol (c-SAS plants) or to the chloroplast (p-SAS plants). In p-SAS plants, the amount of free and conjugated SA was increased more than 20-fold above wild type (WT) level, indicating that SAS is functional in Arabidopsis. P-SAS plants showed a strongly dwarfed phenotype and produced very few seeds. Dwarfism could be caused by the high SA levels per se or, perhaps more likely, by a depletion of the chorismate or isochorismate pools of the chloroplast. Targeting of SAS to the cytosol caused a slight increase in free SA and a significant threefold increase in conjugated SA, probably reflecting limited chorismate availability in this compartment. Although this modest increase in total SA content did not strongly induce the resistance marker PR-1, it resulted nevertheless in enhanced disease resistance towards a virulent isolate of Peronospora parasitica. Increased resistance of c-SAS lines was paralleled with reduced seed production. Taken together, these results illustrate that SAS is a potent tool for the manipulation of SA levels in plants.     

Nutrient runoff dynamics in a rural catchment: Influence of land-use changes, climatic fluctuations and ecotechnological measures

The main trend in land-use changes in the Porijõgi River catchment, south Estonia, is a significant increase in abandoned lands (from 1.7% in 1987 to 10.5% in 1997), and a decrease in arable lands (from 41.8 to 23.9%). Significant climatic fluctuations occurred during the last decades. Milder winters (increase of air temperature in February from −7.9 to −5.5°C during the period 1950–1997) and a change in the precipitation pattern have influenced the mean annual water discharge. This results in more intensive material flow during colder seasons and decreased water runoff in summer. During the period 1987–1997 the runoff of total-N, total-P, SO₄, and organic material (after BOD₅) decreased from 25.9 to 5.1, from 0.32 to 0.13, from 78 to 48, and from 7.4 to 3.5 kg ha⁻¹ year⁻¹, respectively. Most significant was a 4–20-fold decrease in agricultural subcatchments while in the forested upper-course catchment the changes were insignificant. Variations of total-N, and total-P runoff in both the entire catchment and its agricultural subcatchments are well described by the change of land use (including fertilization intensity), soil parameters and water discharge. In small agricultural subcatchments the rate of fertilization was found to be the most important factor affecting nitrogen runoff, while land-use pattern plays the main role in larger mosaic catchments. Ecotechnological measures (e.g. riparian buffer zones and buffer strips, constructed wetlands) to control nutrient flows from agricultural catchments are very important.