17,448 research outputs found

    Targeting Non-Cognitive Skills to Improve Cognitive Outcomes: Evidence from a Remedial Education Intervention

    Get PDF
    A growing body of research highlights the importance of non-cognitive skills as determinants of young people's cognitive outcomes at school. However, little evidence exists about the effects of policies that specifically target students' non-cognitive skills as a way to improve educational achievements. In this paper, we shed light on this issue by studying a remedial education programme aimed at English secondary school pupils at risk of school exclusion and with worsening educational trajectories. The main peculiarity of this intervention is that it solely targets students' non-cognitive skills – such as self-confidence, locus of control, self-esteem and motivation – with the aim of improving pupils' records of attendance and end-of-compulsory-education (age 16) cognitive outcomes. We evaluate the effect of the policy on test scores in standardized national exams at age-16 using both least squares and propensity-score matching methods. Additionally, we exploit repeated observations on pupils’ test scores to control for unobservables that might affect students’ outcomes and selection into the programme. We find little evidence that the programme significantly helped treated youths to improve their age-16 test outcomes. We also find little evidence of heterogeneous policy effects along a variety of dimensions.cognitive and non-cognitive skills; policy evaluation; secondary schooling

    Consistent Approximations to Impulsive Optimal Control Problems

    Full text link
    We analyse the theory of consistent approximations given by Polak and we use it in an impulsive optimal control problem. We reparametrize the original system and build consistent approximations for this new reparametrized problem. So, we prove that if a sequence of solution of the consistent approximations is converging, it will converge to a solution of the reparametrized problem, and, finally, we show that from a solution of the reparametrized problem we can find a solution of the original one

    Waist-to-height ratio is independently related to whole and central body fat, regardless of the waist circumference measurement protocol, in non-alcoholic fatty liver disease patients

    Get PDF
    This is the peer reviewed version of the following article: Pimenta N.M., Cortez-Pinto H., Melo X., Silva-Nunes J., Sardinha L.B. & Santa-Clara H. (2017) Waist-to-height ratio is independently related to whole and central body fat, regardless of the waist circumference measurement protocol, in non-alcoholic fatty liver disease patients. J Hum Nutr Diet. 30, 185–192, which has been published in final form atdoi: 10.1111/jhn.12410. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.Background: Waist-to-height ratio (WHtR) has been reported as a prefer-able risk related body fat (BF) marker, although no standardised waistcircumference measurement protocol (WCmp) has been proposed. Thepresent study aimed to investigate whether the use of a different WCmpaffects the strength of relationship between WHtR and both whole andcentral BF in non-alcoholic fatty liver disease (NAFLD) patients.Methods: BF was assessed with dual energy X-ray absorptiometry (DXA) in28 NAFLD patients [19 males, mean (SD) 51 (13) years and nine females,47 (13) years]. All subjects also underwent anthropometric evaluationincluding height and waist circumference (WC) measurement using fourdifferent WCmp (WC1, minimal waist; WC2, iliac crest; WC3, mid-distancebetween iliac crest and lowest rib; WC4, at the umbilicus) and WHtR wascalculated using each WC measurements (WHtR1, WHtR2, WHtR3 andWHtR4, respectively). Partial correlations were conducted to assess the rela-tion of WHtR and DXA assessed BF.Results: All WHtR were particularly correlated with central BF, includingabdominal BF (r = 0.80, r = 0.84, r = 0.84 and r = 0.78, respectively, forWHtR1, WHtR2, WHtR3 and WHtR4) and central abdominal BF (r = 0.72,r = 0.77, r = 0.76 and r = 0.71, respectively, for WHtR1, WHtR2, WHtR3and WHtR4), after controlling for age, sex and body mass index. There wereno differences between the correlation coefïŹcients obtained between allstudied WHtR and each whole and central BF variable.Conclusions: Waist-to-height ratio was found a suitable BF marker in thepresent sample of NAFLD patients and the strength of the relationshipbetween WHtR and both whole and central BF was not altered by usingdifferent WCmp in the present sample of NAFLD patients.FUNDING SOURCES The first author of this paper was supported by a research grant (PhD scholarship) from the Foundation for Science and Technology (FCT), Ministry of Education and Science of Portugal (grant: SFRH/ BD/ 70515/ 2010). The present study was funded by: the Centre for the Study of Human Performance, Portuguese Foundation for Science and Technology, Lisbon, Portugal.info:eu-repo/semantics/publishedVersio

    Waist circumference in Liver Disease

    Get PDF
    Background Central fat accumulation is important in Non-alcoholic Fatty Liver Disease (NAFLD) etiology. It is unknown weather any commonly used waist circumference (WC) measurement protocol (mp), as whole and central fat accumulation marker, is preferable for patients with NAFLD. The present study sought to find a preferable WC mp to be used in patients with NAFLD, based on three-fold criterion. Material and methods Body fat (BF) was assessed through Dual Energy X-ray Absorptiometry (DXA) in 28 patients with NAFLD (19 males, 51 + 13 yrs, and 9 females, 47 + 13 yrs). WC was measured using four different WC mp (WC1-narrowest torso, WC2- just above iliac crest, WC3- mid-distance between iliac crest and last rib and WC4- at the umbilicus). Results All WC measurements were highly correlated particularly with central BF depots, including trunk BF (r=0.78; r=0.82; r=0.82; r=0.84; respectively for WC1, WC2, WC3 and WC4) abdominal BF (r=0.78; r=0.78; r=0.80; r=0.72; respectively for WC1, WC2, WC3 and WC4) and central abdominal BF (r=0.76; r=0.77; r=0.78; r=0.68; respectively for WC1, WC2, WC3 and WC4), controlling for age, sex and body mass index. There were no differences between the correlation coefficients obtained between all studied WC measurements and each whole and central analyzed BF variable. Conclusion All studied WC mp seem suitable for use in patients with NAFLD, particularly as central BF clinical assessment tool, though not interchangeably. Hence biological and precision criteria alone did not sanction the superiority of any WC mp. Practical criteria may endorse WC measured at the iliac crest.info:eu-repo/semantics/publishedVersio

    Waist-to-Hip Ratio is Related to Body Fat Content and Distribution Regardless of the Waist Circumference Measurement Protocol, in Non-Alcoholic Fatty Liver Disease Patients

    Get PDF
    Central accumulation and distribution of body fat (BF) is an important cardiometabolic risk factor. Waist-to-hip ratio (WHR), commonly elevated in non-alcoholic fatty liver disease (NAFLD) patients, has been endorsed as a risk related marker of central BF content and distribution, but no standardized waist circumference measurement protocol (WCmp) has been proposed. We aimed to investigate whether using different WCmp affects the strength of association between WHR and BF content and distribution in NAFLD patients. BF was assessed with Dual Energy X-ray Absorptiometry (DXA) in 28 NAFLD patients (19 males, 51 ± 13 yrs, and 9 females, 47 ± 13 yrs). Waist circumference (WC) was measured using four different WCmp (WC1: minimal waist; WC2: iliac crest; WC3: mid-distance between iliac crest and lowest rib; WC4: at the umbilicus) and WHR was calculated accordingly (WHR1, WHR2, WHR3 and WHR4, respectively). High WHR was found in up to 84.6% of subjects, depending on the WHR considered. With the exception of WHR1, all WHR correlated well with abdominal BF (r=0.47 for WHR1; r=0.59 for WHR2 and WHR3; r=0.58 for WHR4) and BF distribution (r=0.45 for WHR1; r=0.56 for WHR2 and WHR3; r=0.51 for WHR4), controlling for age, sex and body mass index (BMI). WHR2 and WHR3 diagnosed exactly the same prevalence of high WHR (76.9%). The present study confirms the strong relation between WHR and central BF, regardless of WCmp used, in NAFLD patients. WHR2 and WHR3 seemed preferable for use in clinical practice, interchangeably, for the diagnosis of high WHR in NAFLD patients.co-financed by national funds through the Programa Operacional do Alentejo (ALENT-07-0262-FEDER-001883)info:eu-repo/semantics/publishedVersio

    A joint replenishment competitive location problem

    Get PDF
    Competitive Location Models seek the positions which maximize the market captured by an entrant firm from previously positioned competitors. Nevertheless, strategic location decisions may have a significant impact on inventory and shipment costs in the future affecting the firm’s competitive advantages. In this work we describe a model for the joint replenishment competitive location problem which considers both market capture and replenishment costs in order to choose the firm’s locations. We also present an metaherusitic method to solve it based on the Viswanathan’s (1996) algorithm to solve the Replenishment Problem and an Iterative Local Search Procedure to solve the Location Problem.N/

    A regret model applied to the maximum coverage location problem with queue discipline

    Get PDF
    This article discusses issues related to the location and allocation problems where is intended to demonstrate, through the random number generation, the influence of congestion of such systems in the final solutions. It is presented an algorithm that, in addition to the GRASP, incorporates the Regret with the pminmax method to evaluate the heuristic solution obtained in regard to its robustness for different scenarios. To the well know Maximum Coverage Location Problem from Church and Revelle [1] an alternative perspective is added in which the choice behavior of the server does not only depend on the elapsed time from the demand point looking to the center, but also includes the waiting time for service conditioned by a waiting queue.N/

    A regret model applied to the facility location problem with limited capacity facilities

    Get PDF
    This article addresses issues related to location and allocation problems. Herein, we intend to demonstrate the influence of congestion, through the random number generation, of such systems in final solutions. An algorithm is presented which, in addition to the GRASP, incorporates the Regret with the pminmax method to evaluate the heuristic solution obtained with regard to its robustness for different scenarios. Taking as our point of departure the Facility Location Problem proposed by Balinski [27], an alternative perspective is added associating regret values to particular solutions.N/
    • 

    corecore