Sub-Saharan Africa has the highest natural twinning rate in the world. Unfortunately, due to lack of adequate care during pregnancy, labor and postnatally, twin mortality in Sub-Saharan Africa also remains very high. Thus, it has been estimated that one in five twins dies during the childhood years. In spite of this, surprisingly few twin studies have been conducted in the region, making additional epidemiological data much needed. In 2009, we established one of the first twin registries in Sub-Saharan Africa at the Bandim Health Project in Guinea-Bissau. The registry had two main objectives. First, we wanted to describe the twinning rate and mortality patterns among newborn twins, including mortality risk factors and hospitalization patterns. Such studies can help the local clinicians improve twin health by identifying the most vulnerable children. Second, and in light of the rapidly increasing diabetes rates in Africa, we wanted to use the registry to particularly focus on metabolic disorders. Twins are often born with low birth weight, which according to the ‘thrifty phenotype hypothesis’ could predispose them to metabolic disorders later in life. Yet, no such ‘fetal programming’ data have previously been available from African twins despite the fact that nutritional patterns and influences from other factors (e.g., infections) could be markedly different here compared to high-income settings. In this article, we summarize the findings and current status of the Guinea-Bissau twin registry.

Immigrant children in Denmark differ greatly in educational outcomes. This study examined whether systematic differences in majority language (L2) and preliteracy skills are apparent already at ages 2–6 in immigrant children in Denmark across regional immigration background. Danish language and preliteracy skills in 1,211 immigrant children in four regional groups (based on maternal origin) and 11,259 native Danish nonimmigrant children, all enrolled in Danish childcare centers, were assessed using an age- and gender-normed language assessment instrument. Hierarchical linear models showed that all four immigrant groups scored significantly lower than the native Danish group; the negative coefficients diminished but remained significant when socioeconomic background and having a native Danish father were controlled for. In addition, even with these controls, significant differences existed between some of the immigrant groups, suggesting that factors relating to regional immigrant background were important sources of differences in L2 development. A greater immigrant disadvantage for language than preliteracy skills was found; two immigrant groups did not differ significantly from the nonimmigrant Danish group for preliteracy skills. The results suggest that measures to reduce inequalities in long-term educational achievement between immigrant groups should be taken already before school with a particular focus on L2 language skills.

OBJECTIVES/SPECIFIC AIMS: To investigate the prognostic value of left ventricular mitral annular longitudinal displacement (LD) measured with color tissue Doppler imaging (TDI) in a large population suffering from acute coronary syndrome (ACS). METHODS/STUDY POPULATION: In total, 501 ACS patients underwent an echocardiography within 9 days after a percutaneous coronary intervention. Regional LD was obtained from the 6 mitral annular regions with TDI and GLD was calculated as an average. RESULTS/ANTICIPATED RESULTS: During a median follow-up time of 4.4 years 46 ACS patients suffered CVD. Mean value of GLD in the population was 8.11mm (±2.4). GLD and LD obtained from the inferior wall remained significant independent predictors after multivariate adjustment for clinical parameters, GLD (HR: 1.43, 95% CI: 1.12–1.82, p=0.014, per 1mm decrease), inferior LD (HR: 1.38, 95% CI: 1.14–1.66, p=0.001). Furthermore, inferior wall LD was the primary source of prognostic information in GLD since only inferior LD remained significant when both measures were included in the same model: GLD (HR: 0.95, 95% CI: 0.64–1.40, p=0.781); inferior LD (HR: 1.60, 95% CI: 1.15–2.22, p=0.005). Of all walls, only inferior wall LD remained as an independent predictor after multivariate adjustment. DISCUSSION/SIGNIFICANCE OF IMPACT: GLD provides independent prognostic information in ACS patients over and beyond all conventional echocardiographic measures. Regional inferior LD was the primary source of prognostic information gained from GLD. GLD proved to be a better predictor of cardiovascular events than conventional echocardiographic measures. This could lead to better risk stratification in the clinical setting and open up for earlier intervention in high-risk individuals.

High-dose vitamin A supplementation (VAS) may affect mortality to infectious diseases in a sex-differential manner. Here, we analysed the long-term immunological effects of neonatal vitamin A supplementation (NVAS) in 247 children, who had been randomly allocated to 50 000 or 25 000 IU vitamin A (15mg and 7·5mg retinol equivalents, respectively) or placebo at birth. At 4–6 months of age, we assessed bacille Calmette–Guérin (BCG) scarification, and we analysed in vitro responses of TNF-α, IL-5, IL-10, IL-13 and IFN-γ in whole blood stimulations to phytohaemagglutinin (PHA), purified protein derivative (PPD), tetanus toxoid and lipopolysaccharide. There were no differences between the two doses of NVAS, and thus they were analysed combined as NVAS (any dose) v. placebo. All analyses were performed unstratified and by sex. NVAS increased the chance of having a scar after BCG vaccination in females (NVAS v. placebo: 96 v. 71 %, proportion ratio: 1·24; 95 % CI 1·09, 1·42), but not in males (P for interaction=0·012). NVAS was associated with significant sex-differential effects on the pro- to anti-inflammatory cytokine ratios (TNF-α:IL-10) to PPD, tetanus toxoid and medium alone, which were increased in females but decreased in males. In addition, IL-17 responses tended to be increased in NVAS v. placebo recipients in males but not in females, significantly so for the PHA stimulation. The study corroborates sex-differential effects of VAS on the immune system, emphasising the importance of analysing VAS effects by sex.

Silky windgrass and annual bluegrass are among the most troublesome weeds in northern European winter crops, while problems with rattail fescue have been especially linked to direct-drilling practices. This study investigated the germination patterns of silky windgrass, annual bluegrass, and rattail fescue in multiple water potentials and temperature regimes. Temperature and water potential effects were similar between silky windgrass and rattail fescue, but differed from annual bluegrass. The three grass weeds were able to germinate under low water potential (−1.0 MPa), although water potentials ≤−0.25 MPa strongly delayed their germination. Silky windgrass and rattail fescue seeds were able to germinate at 1 C, while the minimum temperature for annual bluegrass germination was 5 C. Germination of silky windgrass and rattail fescue was very similar across temperature and water potentials, which implies similar emergence flushes under field conditions, allowing management interventions to follow the same scheme.

This study investigates the determinants of the fertility transition in the United States from 1850 to the end of the 20th century. We find a robust negative relation between years of schooling and fertility. The magnitude of our baseline estimate suggests that the rise in schooling accounts for about 60% of the US fertility decline. In contrast, we find no evidence of a robust relation between income per capita and fertility. This pattern corroborates theories stressing the importance of human capital investments in generating a transition from high to low fertility.

As WHO recommends vitamin A supplementation (VAS) at vaccination contacts after age 6 months, many children receive VAS together with measles vaccine (MV). We aimed to investigate the immunological effect of VAS given with MV. Within a randomised placebo-controlled trial investigating the effect on overall mortality of providing VAS with vaccines in Guinea-Bissau, we conducted an immunological sub-study of VAS v. placebo with MV, analysing leucocyte counts, whole blood in vitro cytokine production, vitamin A status and concentration of C-reactive protein (CRP). VAS compared with placebo was associated with an increased frequency of CRP≥5 mg/l (28 v. 12 %; P=0·005). Six weeks after supplementation, VAS had significant sex-differential effects on leucocyte, lymphocyte, monocyte and basophil cell counts, decreasing them in males but increasing them in females. Mainly in females, the effect of VAS on cytokine responses differed by previous VAS: in previous VAS recipients, VAS increased the pro-inflammatory and T helper cell type 1 (Th1) cytokine responses, whereas VAS decreased these responses in previously unsupplemented children. In previous VAS recipients, VAS was associated with increased IFN-γ responses to phytohaemagglutinin in females (geometric mean ratio (GMR): 3·97; 95 % CI 1·44, 10·90) but not in males (GMR 0·44; 95 % CI 0·14, 1·42); the opposite was observed in previously unsupplemented children. Our results corroborate that VAS provided with MV has immunological effects, which may depend on sex and previous VAS. VAS may increase the number of leucocytes, but also repress both the innate and lymphocyte-derived cytokine responses in females, whereas this repression may be opposite if the females have previously received VAS.

The oral [13C]bicarbonate technique (o13CBT) was assessed for the determination of short-term energy expenditure (EE) under field conditions. A total of eight Alaskan huskies were fed two experimental diets in a cross-over experiment including two periods of 3 weeks. Effects of diets on EE, apparent total tract digestibility (ATTD) and on plasma hormones, blood lactate and glucose were furthermore investigated. The percentages of metabolisable energy derived from protein (P), fat (F) and carbohydrates (C) were 26:58:16 in the PFC diet and 24:75:1 in the PF diet. Measurements of EE were performed in the post-absorptive state during rest. Blood samples were collected during rest and exercise and ATTD was determined after days with rest and with exercise. EE was higher (P < 0·01) in period 2 than in period 1 (68 v. 48 kJ/kg body weight0·75 per h). The ATTD of organic matter, crude protein and crude fat was higher (P < 0·01) in the PF diet compared with the PFC diet, and lower (P < 0·01) for total carbohydrates. Exercise did not affect ATTD. Higher (P < 0·01) insulin-like growth factor 1 and leptin concentrations were measured when fed the PF diet compared with the PFC diet. Concentrations of insulin decreased (P < 0·01), whereas cortisol and ghrelin increased (P < 0·05), after exercise. There was no effect of diet on blood lactate and glucose, but higher (P < 0·001) lactate concentrations were measured in period 1 than in period 2. The results suggest that the o13CBT can be used in the field to estimate short-term EE in dogs during resting conditions. Higher ATTD and energy density of the PF diet may be beneficial when energy requirements are high.

The paper presents millimeter-wave (mm-wave) signal sources using a hetero-integrated InP-on-BiCMOS semiconductor technology. Mm-wave signal sources feature fundamental frequency voltage-controlled oscillators (VCOs) in BiCMOS, which drive frequency multiplier–amplifier chains in transferred-substrate (TS) InP-DHBT technology, heterogeneously integrated on top of the BiCMOS wafer in a wafer-level bonding process. Both circuits are biased through a single set of bias pads and compact low-loss transitions from BiCMOS to InP circuits and vice versa have been developed, which allows seamless signal routing through both technologies exhibiting 0.5 dB insertion loss up to 200 GHz. One VCO operates at 82 GHz with a tuning range of 600 MHz and an output power of approximately 8 dBm. A frequency doubler combined with this VCO circuit delivers 0 dBm at 164 GHz and a frequency tripler with a similar VCO delivers −10 dBm at 246 GHz. Another hetero-integrated W-band doubler–amplifier circuit demonstrates 12.9 dBm saturated output power with 5.9 dB conversion gain at 96 GHz. A direct comparison of the TS InP-DHBT MMIC with either silicon or traditional AlN carrier substrates shows the favorable properties of the hetero-integrated process discussed here. The results demonstrate the feasibility of hetero-integrated circuits operating well above 100 GHz.

In this paper, the small- and large-signal modeling of InP heterojunction bipolar transistors (HBTs) in transferred substrate (TS) technology is investigated. The small-signal equivalent circuit parameters for TS-HBTs in two-terminal and three-terminal configurations are determined by employing a direct parameter extraction methodology dedicated to III–V based HBTs. It is shown that the modeling of measured S-parameters can be improved in the millimeter-wave frequency range by augmenting the small-signal model with a description of AC current crowding. The extracted elements of the small-signal model structure are employed as a starting point for the extraction of a large-signal model. The developed large-signal model for the TS-HBTs accurately predicts the DC over temperature and small-signal performance over bias as well as the large-signal performance at millimeter-wave frequencies.

Noninversion tillage with tine- or disc-based cultivations prior to crop establishment is the most common way of reducing tillage for arable cropping systems with small grain cereals, oilseed rape, and maize in Europe. However, new regulations on pesticide use might hinder further expansion of reduced-tillage systems. European agriculture is asked to become less dependent on pesticides and promote crop protection programs based on integrated pest management (IPM) principles. Conventional noninversion tillage systems rely entirely on the availability of glyphosate products, and herbicide consumption is mostly higher compared to plow-based cropping systems. Annual grass weeds and catchweed bedstraw often constitute the principal weed problems in noninversion tillage systems, and crop rotations concurrently have very high proportions of winter cereals. There is a need to redesign cropping systems to allow for more diversification of the crop rotations to combat these weed problems with less herbicide input. Cover crops, stubble management strategies, and tactics that strengthen crop growth relative to weed growth are also seen as important components in future IPM systems, but their impact in noninversion tillage systems needs validation. Direct mechanical weed control methods based on rotating weeding devices such as rotary hoes could become useful in reduced-tillage systems where more crop residues and less workable soils are more prevalent, but further development is needed for effective application. Owing to the frequent use of glyphosate in reduced-tillage systems, perennial weeds are not particularly problematic. However, results from organic cropping systems clearly reveal that desisting from glyphosate use inevitably leads to more problems with perennials, which need to be addressed in future research.

Twins traditionally retain a special status in many African societies. In Guinea-Bissau, twins are often well regarded yet still suffer from a very high mortality, especially in the perinatal and infant period. At the Bandim Health Project, a health and demographic surveillance site, we have recently established one of the first twin registries in Sub-Saharan Africa. Our short-term aim is to describe twin mortality and morbidity in order to design appropriate health interventions. Our long-term goal is a large-scale database to explore the pathogenesis of prevalent diseases; for example, diabetes mellitus, metabolic syndrome, and infectious diseases such as HIV, tuberculosis, and malaria. A major focus area is also the etiology of low birth weight and how epigenetic processes might modulate the consequences of low birth weight in Sub-Saharan Africa. For this, monozygotic twin studies represent a powerful tool. Though twin studies have been carried out by the Bandim Health Project for more than 30 years, the renewed registry described here was officially established in 2009 and includes both a cohort of newborn twins and a cohort of young and adult twins. Currently more than 1,500 twins are being followed in the two cohorts combined. We believe that the registry holds exciting possibilities and will encourage the establishment of further twin registries across the region.