Buffering Effect Research Articles

Mobile device screen time is associated with poorer language development among toddlers: results from a large-scale survey

BackgroundDespite young children’s widespread use of mobile devices, little research exists on this use and its association with children’s language development. The aim of this study was to examine the associations between mobile device screen time and language comprehension and expressive language skills. An additional aim was to examine whether three factors related to the domestic learning environment modify the associations.MethodsThe study uses data from the Danish large-scale survey TRACES among two- and three-year-old children (n = 31,125). Mobile device screen time was measured as time spent on mobile devices on a normal day. Measurement of language comprehension and expressive language skills was based on subscales from the Five to Fifteen Toddlers questionnaire. Multivariable linear regression was used to examine the association between child mobile device screen time and language development and logistic regression to examine the risk of experiencing significant language difficulties. Joint exposure analyses were used to examine the association between child mobile device screen time and language development difficulties in combination with three other factors related to the domestic learning environment: parental education, reading to the child and child TV/PC screen time.ResultsHigh mobile device screen time of one hour or more per day was significantly associated with poorer language development scores and higher odds for both language comprehension difficulties (1–2 h: AOR = 1.30; ≥ 2 h: AOR = 1.42) and expressive language skills difficulties (1–2 h: AOR = 1.19; ≥ 2 h: AOR = 1.46). The results suggest that reading frequently to the child partly buffers the negative effect of high mobile device screen time on language comprehension difficulties but not on expressive language skills difficulties. No modifying effect of parental education and time spent by the child on TV/PC was found.ConclusionsMobile device screen time of one hour or more per day is associated with poorer language development among toddlers. Reading frequently to the child may have a buffering effect on language comprehension difficulties but not on expressive language skills difficulties.

Leaders as the targets of workplace bullying - prevalence and outcomes

PurposeBullying of leaders is an underexplored topic in organizational research. To fill this knowledge gap, the aims of this study were to determine the prevalence of bullying of leaders and to examine whether holding a formal leadership position influences the relationships between exposure to bullying and the outcomes job satisfaction and depression.MethodsData from two separate surveys were employed: (1) A cross-sectional occupation specific sample comprising 678 Norwegian child welfare social workers; (2) A nationally representative probability sample of 1,608 Norwegian employees with two time-points (6 months’ time-lag).ResultsAnalyzing multiple indicators of workplace bullying, holding a formal leadership position had no impact on the initial risk of being bullied. Analyses of prospective data showed that leaders report a somewhat stronger increase in levels of bullying over time compared to non-leaders, although the effect size was small. With exception of a small buffering effect on the cross-sectional association between exposure to bullying behaviors and job satisfaction in the second sample, holding a leadership position had no effect on the strength of the association between bullying and outcomes.ConclusionThe findings show that leaders have the same risk of being bullied and are influenced by bullying in roughly the same manner as non-leaders. Organizational measures and interventions against bullying should therefore consider leaders as a risk group in line with other employees.

Physiological and behavioral contagion/buffering effects of chronic unpredictable stress in a socially enriched environment: A preliminary study

Rodents are sensitive to the emotional state of conspecifics. While the presence of affiliative social partners mitigates the physiological response to stressors (buffering), the partners of stressed individuals show behavioral and endocrine changes indicating that stress parameters can be transmitted across the group members (contagion). In this study, we investigated the social contagion/buffering phenomena in behavior and neuroendocrine mechanisms after exposure to chronic stress, in groups of rats living in the PhenoWorld (PhW). Three groups were tested (8 stressed rats, 8 unstressed rats, and a mixed group with 4 and 4) and these were analyzed under 4 conditions: stressed (pure stress group, n = 8), unstressed (naive control group, n = 8), stressed from mixed group (stressed companion group, n = 8), unstressed from mixed group (unstressed companion group, n = 8. While naive control animals remained undisturbed, pure stress group animals were all exposed to stress. Half of the animals under the mixed-treatment condition were exposed to stress (stressed companion group) and cohabitated with their unstressed partners (unstressed companion group). We confirmed the well-established chronic unpredictable stress (CUS) effects in physiological, behavioral, and neuroendocrine endpoints; body weight gain, open arm entries and time in EPM, and oxytocin receptor expression levels in the amygdala decreased by stress exposure, whereas adrenal weight was increased by stress. Furthermore, we found that playing, rearing and solitary resting behaviors decreased, whereas huddling behavior increased by CUS. In addition, we detected significant increases (stress-buffering) in body weight gain and huddling behaviors between pure stress and stress companion animals, and significant stress contagion effects in emotional behavior and oxytocin receptor expression levels between naive control and control companion groups. Hence, we demonstrate buffering and contagion effects were evident in physiological parameters, emotional behaviors, and social home-cage behaviors of rats and we suggest a possible mediation of these effects by oxytocin neurotransmission. In conclusion, the results herein suggest that the stress status of animals living in the same housing environment influences the behavior of the group.

Mechanical testing and engineering applicability analysis of SAP concrete used in buffer layer design for tunnels in active fault zones

Abstract To tackle the challenge of dislocation damage when tunnels traverse active fault zones, this study introduces the concept of using brittle buffer materials for anti-dislocation. Building on this concept, we propose a novel concrete buffer material utilizing large-sized spherical super absorbent polymers (SAP) as a porogen, aimed at ensuring the safety of tunnel structures during active fault dislocations. To investigate the feasibility and superiority of SAP concrete as a buffer material compared to other similar materials, we prepared samples with three different SAP concrete proportions and conducted a series of physical and mechanical tests. The results show that SAP pre-hydrated with 0.2 mol·L−1 sodium carbonate solution exhibits a slower rate of moisture loss in the cement slurry, aiding the hydration reaction of concrete. The permeability coefficient of SAP concrete is approximately 10−7 cm·s−1, slightly lower than foam concrete of the same density level. SAP concrete buffer material demonstrates significant brittleness, in contrast to the mostly ductile nature of other buffers such as foam concrete and rubberized concrete. Utilizing the brittle nature of SAP concrete materials, when applied to tunnels affected by stick–slip active fault dislocations, its instantaneous loss of compressive capacity provides excellent yield performance, thus protecting the tunnel lining from damage. However, under certain circumferential pressure conditions, both the peak and residual strength of SAP concrete significantly increase. High peak and residual strengths do not favor the effective buffering effect of SAP concrete; therefore, an approach involving the intermittent arrangement of precast buffer blocks has been proposed for application.

Bail-ins and market discipline: Evidence from China

We examine the effect of bail-in event on the market discipline for Chinese banks, exploiting the bankruptcy of Baoshang Bank and subsequent write-down as a quasi-natural experiment. Using the bond data of banks from 2016 to 2021, we find that the bail-in event leads to higher issuance spreads for bonds with write-down clauses. This effect is more pronounced for bonds issued by small banks, and banks in regions with weaker local fiscal strength. A higher proportion of CoCo bond in the bank capital increase the risk-taking of small banks. CoCo bond issuance reduces the spread of Negotiable Certificates of Deposit (NCDs) after the event due to a stronger buffer effect. We underscore the role of bail-in event in imposing market discipline in an emerging economy like China.

Effects of Pitch Stabilization Buffer on the Dynamic Performance of Frame-Type Landing Gear

During the landing and taxiing process of aircraft, the frame-type landing gear (FTLG) usually generates large pitch vibrations under external excitation. Excessive vibration increases localized loads on the landing gear, which may lead to localized failure of the structure. To minimize this undesirable vibration, a passive oil–pneumatic pitch-stabilizing buffer (PSB) is designed in this paper to provide pitch damping. This paper applies the basic principles of dynamics to establish a dynamic model of FTLG considering the influence of PSB. And based on the design of experiments (DOE) method, by changing the filling parameters and structural parameters of PSB, the results of the changes of the frame vibration angle, angular velocity, and landing gear load are obtained, so as to analyze the effects of different parameters on the dynamic performance of the landing gear in the landing and taxiing process. The results demonstrate that increasing the oil damping coefficient of PSB and decreasing the installation angle of PSB on the main strut during the landing period resulted in less frame vibration and lower wheelset load ratios, but increased the landing overloads of landing gears. In the taxiing phase, increasing the PSB air spring stiffness can effectively reduce the frame vibration caused by the uneven road surface. The PSB structural parameters have little effect on the dynamic performance of FTLG.

Study on the soft-landing of large inertia valve based on multi-objective optimization of annular gap

Variable valve mechanism and its technology are widely used in vehicle diesel engines. As a critical component, the performance of reciprocating actuator is the guarantee for the realization of electro-hydraulic variable valve. In order to solve the problem of high setting speed in electro-hydraulic camless variable valve system, a variable valve actuator based on annular gap buffer is proposed and optimized to realize quick closing and soft landing. The experimental results show that the actuator can achieve the purpose of setting buffer, and the setting speed is 0.5 m/s with 15 ms of closing time. AMESim is used to build the system simulation model and calibrated by experiments. The simulated lift curve is close to the experimental curve, and its Pearson coefficient is 0.9995. The influence of structural parameters on the system driving ability and buffering effect is studied through the model. According to the simulation results, the annular gap eccentricity will affect the buffering effect. When the eccentricity increases from 0.005 to 0.035 mm, the landing velocity increases by 0.1 m/s and the valve closing time decreases by 0.9 ms. NSGA-II method is used to optimize the structural parameters of the annular gap, and an obvious Pareto front is obtained and the optimal solution is applied in next experiments. The landing speed is reduced from 0.5 to 0.25 m/s, and the landing time is still less than 15 ms. This paper provides a simple cushioning scheme for electro-hydraulic camless variable valve soft landing which is independent of proportional valve.

Preventing workplace mistreatment and improving workers’ mental health: a scoping review of the impact of psychosocial safety climate

BackgroundWork environment is rapidly evolving, unfortunately, it is also becoming increasingly hostile for workers due mostly to common psychosocial hazards. This situation is posing significant challenges for organisations to protect the psychological well-being of their workers. Hence, this review aims to map studies to understand the influence of psychosocial safety climate (PSC) on workplace mistreatment and mental health of workers.MethodsThe guidelines outlined by Arksey and O’Malley were adopted for this review. PubMed, Scopus, Web of Science, JSTOR, Google and Google Scholar were searched for relevant papers. Only peer-reviewed studies that measured PSC using PSC-12, PSC-8 or PSC-4 were included in this review.ResultsThirty-eight studies met the inclusion criteria. This review found that PSC has a negative association with workplace mistreatment such as bullying, harassment, violence, discrimination and abuse. Further, PSC has a positive association with psychological well-being, personal resilience and hope. Low level organisational PSC also promotes psychological distress, stress, depression, cognitive weariness and emotional exhaustion. The buffering effect of PSC is well-established. Moreover, PSC mediates the association between health-centric leadership and workers’ psychological health problems. The inverse relationship between PSC and depressive symptoms was stronger for females than males.ConclusionOrganisations should prioritise training and development of supervisors to enhance their supportive skills, encourage respectful behaviour, encourage the use of resources promote open and bottom-up communication and provide guidance on conflict resolution. By promoting a high PSC context, organisations can create a culture that discourages mistreatment, leading to increased employee well-being, job satisfaction, and productivity.

Expression of GCaMP6s in the dentate gyrus induces tonic–clonic seizures

GCaMP is a genetically encoded calcium indicator (GECI) widely used in neuroscience research. It measures intracellular Ca2+ level by fluorescence changes as it directly binds to Ca2+. In this process, the effect of this calcium buffer on the intracellular calcium signaling and cell physiology is often not taken into consideration. However, growing evidence from calcium imaging studies shows GCaMP expression under certain conditions can generate aberrant activity, such as seizures. In this study, we examined the effect of GCaMP6 expression in the dentate gyrus (DG) on epileptogenesis. We found that viral expression of GCaMP6s but not GCaMP6f in the DG induces tonic–clonic seizures several weeks after viral injection. Cell-type specific expression of GCaMP6s revealed the granule cells (GCs) as the key player in GCaMP6s-induced epilepsy. Finally, by using slice electrophysiology, we demonstrated that GCaMP6s expression increases neuronal excitability in the GCs. Together, this study highlights the ability of GCaMP6s in DG-associated epileptogenesis.

Evaluation of the SARS-CoV-2 RNA detection reagent LAMPdirect Genelyzer KIT using nasopharyngeal swab and saliva samples

The LAMPdirect Genelyzer KIT allows for the detection of SARS-CoV-2 RNA in saliva samples with a loop-mediated isothermal amplification (LAMP) method and generates results within 20 min. It has been approved by the Pharmaceuticals and Medical Devices Agency in Japan. In this study, the performance of the LAMPdirect Genelyzer KIT was compared with that of the RT-qPCR reference method using 50 nasopharyngeal swabs and 100 saliva samples. In addition, we evaluated the applicability of an alternative reverse transcriptase and the effects of an inactivation buffer. The total agreement rates were 80.0 % and 82.0 % for nasopharyngeal and saliva samples, respectively. When considering samples at the detection limit (50 copies/reaction) that increases the chance of transmission between humans, the total agreement rates were 100% and 94.1% for nasopharyngeal and saliva samples, respectively. The LAMP method is simple, fast, and inexpensive, making it useful for small medical institutions or rural areas.

A sense of coherence (SOC) among the fathers of children with chronic illnesses.

This study focuses on the fathers of children with chronic illnesses in an effort to clarify how the stressor and the father's sense of coherence (SOC) influence their mental health and how the father's SOC is associated with the social support. Cross-sectional study. We conducted a self-reported questionnaire survey of 137 respondents (51 fathers of children with chronic illnesses, 86 fathers of healthy children) were statistically using ANOVA. The fathers' stressor was significantly related to their SOC. Furthermore, the SOC of the fathers majorly influenced their mental health, while having a buffering effect on the stressor with respect to depression. And their SOC was significantly positively associated with the social support. Our findings underscore that father's SOC has a buffering effect on self-mental health and is important for maintaining mental health and enhancing SOC to reduce the stressors of these fathers with respect to depression.

Machine-assisted quantification of droplet boiling upon multiple solid materials

The intricate nature of droplet wetting and boiling on heated nano-/micro-structured surfaces has significant implications for practical applications. However, the multitude of factors influencing these liquid-vapor-solid interactions complicates the understanding of boiling behaviors across a wide range of operating conditions. In this study, we examined droplet impingement boiling over a large range of Weber numbers (We) on various surfaces, from smooth to nano-micro hierarchical ones, and from stationary to vibrated ones. The results indicate that the nano-micro hierarchical surface possesses the greatest heat transfer ability due to its superior superhydrophilicity, enhanced by nano-structures, and the vapor buffer effect caused by micro-structures. Additionally, vibration significantly improves boiling performance by 55.4%. However, contrary to previous findings, a higher We does not always enhance heat transfer performance due to a pronounced water hammer effect. We discovered that when the net pressure reaches a threshold value (∼ 90 kPa), a new phenomenon - jet flow - occurs, leading to a deterioration in heat transfer. Utilizing our database, we trained a machine learning framework to generate accurate droplet boiling data, providing a droplet boiling law that can extensively predict heat transfer performance. This paper proposes a fusion of physics and artificial intelligence to enhance our understanding and application of droplet boiling phenomena. Our findings are expected to contribute to the development of more efficient droplet-based boiling heat transfer devices and configurations across a wider range of industrial settings.

Minority stress, perceived social support, and depression in people diverse in sexual and gender minority status

ABSTRACT The study examines the relationships between experienced heterosexism, perceived social support, and depression in people diverse in sexual and gender minority (SGM) identity. The cross-sectional online study was performed in Poland among 509 SGM people, with an average age of 22 years (M = 22.39, SD = 4.78). Minority stress was assessed using the Daily Heterosexist Experiences Questionnaire (DHEQ), perceived social support was measured by the Multidimensional Scale of Perceived Social Support (MSPSS), and depression symptoms were evaluated using the Center for Epidemiologic Studies Depression Scale – Revised (CESD-R). The study supported a buffering effect of social support from family and friends in the relationship between minority stress and depression symptoms. Network analysis (NA) showed that minority stress from family of origin, mediated by low family support, plays a key and bridging role in increasing suicidal ideation, especially in dual SGM individuals. Friends are the most important source of support for people with a single SGM identity. Therefore, to prevent suicidal thoughts in LGBTQ+ people at increased risk of depression, systemic therapy should be used in addition to interventions focusing on coping with minority stress and symptoms of depression.

CRF binding protein activity in the hypothalamic paraventricular nucleus is essential for stress adaptations and normal maternal behaviour in lactating rats

To ensure the unrestricted expression of maternal behaviour peripartum, activity of the corticotropin-releasing factor (CRF) system needs to be minimised. CRF binding protein (CRF-BP) might be crucial for this adaptation, as its primary function is to sequester freely available CRF and urocortin1, thereby dampening CRF receptor (CRF-R) signalling. So far, the role of CRF-BP in the maternal brain has barely been studied, and a potential role in curtailing activation of the stress axis is unknown.We studied gene expression for CRF-BP and both CRF-R within the paraventricular nucleus (PVN) of the hypothalamus. In lactating rats, Crh-bp expression in the parvocellular PVN was significantly higher and Crh-r1 expression in the PVN significantly lower compared to virgin rats. Acute CRF-BP inhibition in the PVN with infusion of CRF(6–33) increased basal plasma corticosterone concentrations under unstressed conditions in dams. Furthermore, while acute intra-PVN infusion of CRF increased corticosterone secretion in virgin rats, it was ineffective in vehicle (VEH)-pre-treated lactating rats, probably due to a buffering effect of CRF-BP. Indeed, pre-treatment with CRF(6–33) reinstated a corticosterone response to CRF in lactating rats, highlighting the critical role of CRF-BP in maintaining attenuated stress reactivity in lactation. To our knowledge, this is the first study linking hypothalamic CRF-BP activity to hypothalamic-pituitary-adrenal axis regulation in lactation. In terms of behaviour, acute CRF-BP inhibition in the PVN under non-stress conditions reduced blanket nursing 60 min and licking/grooming 90 min after infusion compared to VEH-treated rats, while increasing maternal aggression towards an intruder. Lastly, chronic intra-PVN inhibition of CRF-BP strongly reduced maternal aggression, with modest effects on maternal motivation and care.Taken together, intact activity of the CRF-BP in the PVN during the postpartum period is essential for the dampened responsiveness of the stress axis, as well as for the full expression of appropriate maternal behaviour.

Preparation and application of soil conditioner using iron ore tailings-biochar composite material

Iron ore tailings (IOT) are industrial solid wastes that pose environmental threats. This study prepared IOT-biochar composite materials as multifunctional soil conditioners through an in-situ growth method. Biochar served as a carrier to improve the dispersity and reactivity of IOT in soil. The IOT-biochar composite (FeOT-BC) showed balanced impacts on soil properties, increasing pH, organic matter and available nutrients compared to IOT alone. This was due to the buffering effects of biochar. In pot experiments, FeOT-BC significantly promoted rice plant growth compared to IOT alone. The improvements were attributed to the improved soil fertility and increased microbial activities induced by biochar. The results suggest that integrating IOT with biochar can mitigate the negative effects of tailings and convert them into a value-added product. The biochar component can optimize the performance of IOT by moderating soil acidification, enhancing nutrient release from iron minerals, and stimulating microbial activities. The IOT-biochar composite materials integrate the functionalities of both components for optimized soil conditioning effects, providing a promising strategy for comprehensive tailings utilization.

Highly efficient bioregeneration of high temperature-pyrolyzed biochar after trichloroethylene adsorption through biodegradation of Dehalococcoides

Biochars was widely employed to immobilize chlorinated aliphatic hydrocarbons (CAHs) in groundwater. Biodegradation of adsorbed CAHs may be able to regenerate biochars, but was scarcely explored. In this study, therefore, biodegradation of trichloroethylene (TCE) adsorbed on a biochar prepared at 700 °C (WBC700) by Dehalococcoides mccartyi 195 (Dhc 195) was investigated. Aqueous TCE was completely degraded to ethene by Dhc 195 within 28 days, while 87.5 % of WBC700-adsorbed TCE was degraded to ethene within 63 days. The slower biodegradation of WBC700-adsorbed TCE could be attributed to its lower accessibility to Dhc 195 caused by the steric effects of WBC700. The adsorption capacity of WBC700 for TCE remained 80.4 % after five adsorption-bioregeneration cycles, indicating that the microbial degradation could be a highly efficient method to regenerate biochars. The microbial degradation was mainly through the electron transfer from Dhc 195 to TCE mediated by biochars as electron conductor or shuttle, but was not assisted by desorption or extracellular redox active species. Compared with biodegradation of aqueous TCE, the biodegradation of WBC700-adsorbed TCE by Dhc 195 had a wider pH tolerance and required more VB12, due to the buffer effect and adsorption of WBC700, respectively. The obtained results could provide a cost-effective method of biochar regeneration for CAHs removal in groundwater.

Landscape position mediates drought vulnerability in California valley oak (Quercus lobata)

Future climate change will exacerbate drought stress in water-limited ecosystems. However, topography can alter the fine-scale climatic and hydrologic conditions that mediate plant response to meteorological drought. Here, with six new valley oak (Quercus lobata) tree-ring width chronologies, we assess how topography acts as a mediating factor on tree growth and drought sensitivity. Because valley oaks are known to be highly dependent on subsurface water, we predicted that trees growing in riparian sites would be less sensitive to precipitation variability due to greater access to groundwater. Trees were sampled in the Tehachapi Mountains of California across a landscape gradient of sites ranging from 375–1650 m elevation and across upland (55–69 m mean height above nearest drainage) and riparian (2–6 m mean height above the nearest drainage) hillslope positions. Interannual tree growth patterns and drought sensitivity varied substantially in association with hillslope position and elevation. Valley oak radial growth showed a consistently weaker response to precipitation at riparian sites. The influence of hillslope position on drought sensitivity varied with elevation, such that the riparian buffering effect was weakest at sites higher in the watershed and strengthened, progressively, toward the lower elevation sites with greater climatic water deficit. Upland tree growth exhibited a strong response to high-frequency interannual precipitation variability at the high elevation site, whereas trees at lower elevation upland sites responded more to low-frequency decadal trends in precipitation, possibly reflecting hydrogeological processes by which precipitation feeds groundwater lower in the watershed. Our results are consistent with groundwater-dependence of valley oak and indicate that riparian habitats are the most likely refugia for the species during prolonged drought.

Development and characterization of ceramic-polymeric hybrid scaffolds for bone regeneration: incorporating of bioactive glass BG-58S into PDLLA matrix

In recent years, there has been a notable surge of interest in hybrid materials within the biomedical field, particularly for applications in bone repair and regeneration. Ceramic-polymeric hybrid scaffolds have shown promising outcomes. This study aimed to synthesize bioactive glass (BG-58S) for integration into a bioresorbable polymeric matrix based on PDLLA, aiming to create a bioactive scaffold featuring stable pH levels. The synthesis involved a thermally induced phase separation process followed by lyophilization to ensure an appropriate porous structure. BG-58S characterization revealed vitreous, bioactive, and mesoporous structural properties. The scaffolds were analyzed for morphology, interconnectivity, chemical groups, porosity and pore size distribution, zeta potential, pH, in vitro degradation, as well as cell viability tests, total protein content and mineralization nodule production. The PDLLA scaffold displayed a homogeneous morphology with interconnected macropores, while the hybrid scaffold exhibited a heterogeneous morphology with smaller diameter pores due to BG-58S filling. The hybrid scaffold also demonstrated a pH buffering effect on the polymer surface. In addition to structural characteristics, degradation tests indicated that by incorporating BG-58S modified the acidic degradation of the polymer, allowing for increased total protein production and the formation of mineralization nodules, indicating a positive influence on cell culture.

The role of perceived social support in mitigating the impact of parenting stress on children’s effortful control

Effortful control, the ability to suppress a dominant response over a subdominant one, is a fundamental aspect of self-regulation. It has been observed that higher levels of parenting stress are associated with lower levels of effortful control in children. Perceived social support, an important factor in reducing parenting stress, may act as a buffer against the negative effects of parenting stress on children’s effortful control skills. To investigate this assumption, we collected data from 199 mothers in Türkiye, who had children between the ages of 3 and 6 years. Mothers reported on their parenting stress levels, perceived social support, and their children’s effortful control. Our results revealed that perceived social support moderated the relationship between parenting stress and children’s effortful control after controlling for socioeconomic status. Moreover, the buffering effect of perceived social support became stronger as the level of social support increased, subsequently weakening the relationship between parenting stress and children’s effortful control. These findings suggest that parental perceived social support plays a pivotal role in mitigating the adverse effects of parenting stress on healthy child development. These cross-sectional findings warrant a longitudinal investigation into the interrelations among parenting stress, perceived social support, and children’s effortful control.

International reserves, currency depreciation and public debt: New evidence of buffer effects in Africa

The paper adds to the literature on the issue of public debt in African economies, by investigating the role foreign exchange reserves play in improving the level of indebtedness and as buffer of the negative effect of exchange rate depreciation while considering the exchange rate policy. Our results show a direct link between the level of foreign currency reserves and that of external debt in Africa. Particularly, we demonstrate that higher foreign currency reserves tend to decrease the public debt stock to GDP. This effect is even more significant when countries go through high exchange rate depreciation episodes (10% or higher). This impact, however, is not homogenous among country groups, as only countries with a floating exchange regime tend to benefit from this buffer effect compared to anchored regimes. In a time where most African economies face severe exchange rate depreciation episodes following the U.S. monetary tightening policy, central bankers and policy makers need to consider a plethora of policy issues including interventions in the FX market to mitigate depreciations and maintain a sustainable public debt stock.