Differential competitive ability of morphologically diverse spring wheat genotypes

Non-Peer ReviewedSixteen genotypes of common spring wheat (T. aestivum) were grown under conditions of simulated weed competition at Saskatoon in 1991 and 1992. Weeds consisted of cultivated oat (Avena sativa cv. Waldern) and Oriental mustard (Brassica juncea cv. Cutlass) sown at two densities (48 and 96 seeds m2 per weed species), and a weed free control. Seedling establishment, % ground cover, and seed yield for all three species was recorded as was wheat tiller number, spike number, maximum height, LAI (Ieaf area index), leaf orientation, and flag leaf length and size. Significant (p =0.01) weed rate by genotype interactions involving changes in genotype rank were detected for grain yield, indicating differences in competitive ability existed among the wheat genotypes. The highest yielding genotypes under weed free conditions were not necessarily the highest yielding under weedy conditions. Yield reductions averaged over two weed densities ranged from 36 to 52 %. Genotypes which exhibited lower yield reductions also showed greater suppression of weed growth. Although competitive genotypes were generally taller than non-competitive genotypes, other traits such as tillering capacity and leaf length were important determinants of competitive ability

It’s a Hard-Knock Life: Child Labor Practices and Compliance with IMF Agreements

How does IMF lending impact child labor? We argue that, as compliance with IMF reforms increases, child labor increases. IMF loans can help governments avoid bankruptcy, prevent debt defaults, and credibly signal a commitment to pro-market reforms which should generate trade and investment. However, IMF policies associated with revenue and social policies can have negative impacts on child labor. Education reforms undermine the quality of schooling, making child labor more likely. Healthcare reforms undermine the quality of healthcare; when parents are ill or injured, their children are more likely to enter the workforce to make up for lost income. Similarly, social safety net reforms reduce the ability of families to access a safety net during times of hardship and make it more likely that children are pushed into the labor market to keep families afloat. To test our argument, we use a control function selection model on a sample of 70 IMF borrowers between 2002 and 2016. Using new datasets on IMF compliance and child labor, we find that increased compliance with IMF reforms worsens child labor practices. Revenue and social policy compliance in particular are associated with an increase in child labor

Application of wearable sensors in actuation and control of powered ankle exoskeletons: a Comprehensive Review

Powered ankle exoskeletons (PAEs) are robotic devices developed for gait assistance, rehabilitation, and augmentation. To fulfil their purposes, PAEs vastly rely heavily on their sensor systems. Human–machine interface sensors collect the biomechanical signals from the human user to inform the higher level of the control hierarchy about the user’s locomotion intention and requirement, whereas machine–machine interface sensors monitor the output of the actuation unit to ensure precise tracking of the high-level control commands via the low-level control scheme. The current article aims to provide a comprehensive review of how wearable sensor technology has contributed to the actuation and control of the PAEs developed over the past two decades. The control schemes and actuation principles employed in the reviewed PAEs, as well as their interaction with the integrated sensor systems, are investigated in this review. Further, the role of wearable sensors in overcoming the main challenges in developing fully autonomous portable PAEs is discussed. Finally, a brief discussion on how the recent technology advancements in wearable sensors, including environment—machine interface sensors, could promote the future generation of fully autonomous portable PAEs is provided

Maternal Blood Lead Levels and the Risk of Pregnancy-Induced Hypertension: The EDEN Cohort Study

International audienceBACKGROUND: Prior studies revealed associations of environmental lead exposure with risks of hypertension and elevated blood pressure. OBJECTIVE: We examined the effect of blood lead levels on blood pressure and the incidence of pregnancy-induced hypertension (PIH) in the second and third trimesters of pregnancy. METHODS: One thousand seventeen pregnant women were enrolled in two French municipalities between 2003 and 2005 for the EDEN (Etude des Déterminants pré et post natals du développement et de la santé de l' Enfant) cohort study. Blood lead concentrations were measured by atomic absorption spectrometry in mothers between 24 and 28 weeks of gestation. RESULTS: PIH was diagnosed in 106 subjects (10.9%). Age, parity, weight gain, alcohol, smoking habits, and calcium supplementation were comparable between hypertensive and nonhypertensive women. Lead levels were significantly higher in PIH cases (mean +/- SD, 2.2 +/- 1.4 mug/dL) than in normotensive patients (1.9 +/- 1.2 mug/dL; p = 0.02). Adjustment for potential confounder effects slightly attenuated but did not eliminate the significant association between blood lead levels and the risk of PIH (adjusted odds ratio of PIH = 3.3; 95% confidence interval, 1.1-9.7). We also observed geographic differences in lead exposure and in the incidence of PIH and found significant correlations between blood lead levels and unadjusted as well as adjusted systolic and diastolic blood pressures after 24 weeks of gestation. CONCLUSIONS: These findings confirm the relationship between blood lead levels at mid-pregnancy and blood pressure and suggest that environmental lead exposure may play an etiologic role in PIH