Tools for understanding the glycosaminoglycan biosynthesis

For cells to function correctly within an organism, they need different systems to communicate with each other. One crucial part of cell signaling is the proteoglycans (PGs) and glycosaminoglycans (GAGs), which are macromolecules that bind different signaling molecules and proteins necessary for processes such as growth and proliferation. Therefore, PGs and GAGs are involved in pathological processes like cancer and bacterial or viral infection. A tetrasaccharide linker connects several types of GAGs to the PG core protein, with the first carbohydrate being a xylose. Xylose is, due to its scarcity in mammalian cells, an attractive target for therapeutics. In GAG biosynthesis, the enzyme β4GalT7 galactosylates the xylose. Therefore, this enzyme could be interesting to target using synthetic xylosides that could act as substrates or inhibitors. These xylosides could allow us to understand and control the biosynthesis of GAGs. This thesis is focused on the design and synthesis of modified xylosides and how we can use these as tools to study the formation of GAGs. We decided to alter the carbohydrate itself to investigate if it is possible to design effective substrates or inhibitors for β4GalT7. We also decided to modify the aglycon, the part attached to the carbohydrate, to answer questions related to how cells process GAGs. This work has resulted in several new substances that, that enter cells, and work well as substrates and inhibitors of β4GalT7 to provide answers to how GAGs are structured, how they move within the cell, and how they interact with other biomolecules such as viral proteins. The results of this work pave the way for the use of synthetic xylosides to answer several questions about GAG-related processes and open up the possibility for creating tools for influencing and studying cells' expression of GAGs

Oh Mother: The Neglected Impact of School Disruptions

Temporary school closures (TSC) represent a major challenge to policymakers across the globe due to their potential impact on instructional time and student achievement. A neglected but equally important question relates to how such closures affect the labor market behavior of parents. This paper provides novel evidence on the effect of temporary school closures on parental labor market behavior, exploiting the prevalence of primary school teacher strikes across time and provinces in Argentina. We find clear evidence that temporary school closures negatively impact the labor market participation of mothers, in particular lower-skilled mothers less attached to the labor force and mothers in dual-income households who face a lower opportunity cost of dropping out of the labor force. This effect translates into a statistically significant and economically meaningful reduction in labor earnings: the average mother whose child is exposed to ten days of TSCs suffers a decline in monthly labor earnings equivalent to 2.92% of the mean. While we do not find any effects among fathers in general, fathers with lower predicted earnings than their spouses also experience negative labor market effects. This suggests that the parental response to TSCs depend, at least in part, on the relative income of each parent. A back-of-the-envelope calculation suggest that the aggregate impact of TSCs on annual parental earnings is more than $113 million, and that the average mother would be willing to forego 1.6 months of labor earnings in order to ensure that there are no TSCs while her child is in primary school.Centro de Estudios Distributivos, Laborales y Sociales (CEDLAS

The Long-run Effects of Teacher Strikes: Evidence from Argentina

This is the first paper to estimate the effect of teacher strikes on student long-run educational attainment and labor market outcomes. We exploit cross-cohort variation in the prevalence of teacher strikes within and across provinces in Argentina in a difference-in-difference framework to examine how exposure to teacher strikes during primary school affects long-run outcomes. We find robust evidence that teacher strikes worsen the labor market outcomes of these individuals when they are between the ages of 30 and 40: being exposed to the average incidence of teacher strikes during primary school (88 days) reduces annual labor market earnings by 2.99 percent. A back-of-the-envelope calculation suggests that this amounts to an aggregate earnings loss of $712 million in Argentina annually. This is equivalent to the cost of raising the average annual employment income of all primary school teachers in Argentina by 19 percent. We also find evidence of a decline in hourly wage, an increase in unemployment, an increase in the probability of not working or studying and a decline in the skill levels of the occupations into which students sort. Examining short- and long-run educational outcomes suggests that the labor market effects are driven, at least in part, by a reduction in educational attainment. Our analysis further identifies significant intergenerational treatment effects. Children of adults who were exposed to teacher strikes during primary school also experience adverse educational attainment effects.Centro de Estudios Distributivos, Laborales y Sociales (CEDLAS

Oh Mother: The Neglected Impact of School Disruptions

Temporary school closures (TSC) represent a major challenge to policymakers across the globe due to their potential impact on instructional time and student achievement. A neglected but equally important question relates to how such closures affect the labor market behavior of parents. This paper provides novel evidence on the effect of temporary school closures on parental labor market behavior, exploiting the prevalence of primary school teacher strikes across time and provinces in Argentina. We find clear evidence that temporary school closures negatively impact the labor market participation of mothers, in particular lower-skilled mothers less attached to the labor force and mothers in dual-income households who face a lower opportunity cost of dropping out of the labor force. This effect translates into a statistically significant and economically meaningful reduction in labor earnings: the average mother whose child is exposed to ten days of TSCs suffers a decline in monthly labor earnings equivalent to 2.92% of the mean. While we do not find any effects among fathers in general, fathers with lower predicted earnings than their spouses also experience negative labor market effects. This suggests that the parental response to TSCs depend, at least in part, on the relative income of each parent. A back-of-the-envelope calculation suggest that the aggregate impact of TSCs on annual parental earnings is more than $113 million, and that the average mother would be willing to forego 1.6 months of labor earnings in order to ensure that there are no TSCs while her child is in primary school.Centro de Estudios Distributivos, Laborales y Sociales (CEDLAS

The Long-run Effects of Teacher Strikes: Evidence from Argentina

This is the first paper to estimate the effect of teacher strikes on student long-run educational attainment and labor market outcomes. We exploit cross-cohort variation in the prevalence of teacher strikes within and across provinces in Argentina in a difference-in-difference framework to examine how exposure to teacher strikes during primary school affects long-run outcomes. We find robust evidence that teacher strikes worsen the labor market outcomes of these individuals when they are between the ages of 30 and 40: being exposed to the average incidence of teacher strikes during primary school (88 days) reduces annual labor market earnings by 2.99 percent. A back-of-the-envelope calculation suggests that this amounts to an aggregate earnings loss of $712 million in Argentina annually. This is equivalent to the cost of raising the average annual employment income of all primary school teachers in Argentina by 19 percent. We also find evidence of a decline in hourly wage, an increase in unemployment, an increase in the probability of not working or studying and a decline in the skill levels of the occupations into which students sort. Examining short- and long-run educational outcomes suggests that the labor market effects are driven, at least in part, by a reduction in educational attainment. Our analysis further identifies significant intergenerational treatment effects. Children of adults who were exposed to teacher strikes during primary school also experience adverse educational attainment effects.Centro de Estudios Distributivos, Laborales y Sociales (CEDLAS

Experiences of Habitual Physical Activity in Maintaining Roles and Functioning among Older Adults: A Qualitative Study

Physically active older adults have reduced risk of functional restrictions and role limitations. Several aspects may interrelate and influence habitual physical activity (PA). However, older adults’ own perspectives towards their PA need to be addressed. The aim of this study was to explore the experiences of habitual physical activity in maintaining roles and functioning among older adult Palestinians ≥60 years.Data were collected through in-depth interviews based on a narrative approach. Seventeen participants were recruited (aged 64–84 years). Data were analyzed using a narrative interpretative method. Findings.Three central narratives were identified, “keepmoving, stay healthy,” “social connectedness, amotive to stay active,” and “adapting strategies to age-related changes.” Conclusion. Habitual physical activity was perceived as an important factor to maintain functioning and to preserve active roles in older adults.Walking was the most prominent pattern of physical activity and it was viewed as a vital tool to maintain functioning among the older adults. Social connectedness was considered as a contributing factor to the status of staying active. To adapt the process of age-related changes in a context to stay active, the participants have used different adapting strategies, including protective strategy, awareness of own capabilities, and modifying or adopting new roles.The authors thank all the participants for their valuable contributions to this study

Does Increasing Risk Widen Gender Gaps?

We examine the response to an exogenous change in the risk profile of an important educational choice – requesting a regrade. We demonstrate how ostensibly gender-neutral policies can generate gaps across men and women because they differ in their perceptions of risk. Specifically, we show that an exogenous shift in the risk of requesting a regrade augmented the regrade request gap by nearly 100 percent. We show that this has consequential implications for students through its impact on their grade points. These findings reveal how gender differences identified in the lab manifest when men and women make real world decisions

How Do Firms Respond to Unions?

This paper provides a comprehensive assessment of the margins along which firms in Norway respond to increased union density, using legislative changes in the tax deductibility of union dues as a quasi-exogenous shock to firm-level unionization rates. Despite higher personnel costs driven by a union wage premium, the average manufacturing firm increases employment and scales up production, charges higher prices in the product market, enjoys higher nominal value added per worker, and experiences no decrease in profits. We show that this result is a direct implication of the labor- and product-market power that the average manufacturing firm possesses, in combination with a reallocation of inputs and industry revenue shares from smaller and less unionized firms to larger and more unionized firms. Larger firms are, therefore, increasing employment and output at the same time their ability to mark up prices is growing, thereby preventing negative profit effects. For the broader private sector in which firms do not hold much price- or wage-setting power, we observe the opposite result: the average firm reduces employment and profit falls. We synthesize these findings through a partial-equilibrium model of firm decision-making that incorporates union bargaining, product-market price-setting power, and labor market monopsony power

The Effect of Labor Market Competition on Firms, Workers, and Communities

This paper isolates the impact of labor market competition on firms, workers, and communities. A shock to labor mobility from Sweden to Norway caused a substantial increase in labor competition for Swedish firms on the border with Norway. Using unique register data linked across the two countries, we show that Swedish firms respond by raising wages and reducing their workforces. The retained workers are of lower quality, resulting in a drop in value added and an increasing probability of market exit. Communities experience population flight, declining business activity, increased inequality, and increased support for worker protection parties. Norwegian firms benefit through cheaper labor costs, and there is evidence of Norwegian workers being displaced. The communities see increased support for anti-integration parties. We conclude that shocks to labor market competition, while benefiting certain workers, may have detrimental effects on local communities due to adverse effects on firm survival and business activity

Ambulatory Function and Perception of Confidence in Persons with Stroke with a Custom-Made Hinged versus a Standard Ankle Foot Orthosis

Objective. The aim was to compare walking with an individually designed dynamic hinged ankle foot orthosis (DAFO) and a standard carbon composite ankle foot orthosis (C-AFO). Methods. Twelve participants, mean age 56 years (range 26–72), with hemiparesis due to stroke were included in the study. During the six-minute walk test (6MW), walking velocity, the Physiological Cost Index (PCI), and the degree of experienced exertion were measured with a DAFO and C-AFO, respectively, followed by a Stairs Test velocity and perceived confidence was rated. Results. The mean differences in favor for the DAFO were in 6MW 24.3 m (95% confidence interval [CI] 4.90, 43.76), PCI −0.09 beats/m (95% CI −0.27, 0.95), velocity 0.04 m/s (95% CI −0.01, 0.097), and in the Stairs Test −11.8 s (95% CI −19.05, −4.48). All participants except one perceived the degree of experienced exertion lower and felt more confident when walking with the DAFO. Conclusions. Wearing a DAFO resulted in longer walking distance and faster stair climbing compared to walking with a C-AFO. Eleven of twelve participants felt more confident with the DAFO, which may be more important than speed and distance and the most important reason for prescribing an AFO