Changes In Margin Research Articles

Online vulnerability assessment of Zone-3 distance relays against static load Encroachment: A novel approach based on fault chain theory

One of the main factors in triggering cascading outages is the undesired operation of zone-3 vulnerable distance relays under static load encroachment. In this paper, to avoid the contribution of vulnerable relays in cascading outages, a novel online vulnerability assessment method based on fault chain theory is proposed to identify the critical relays. The main idea is to use the fault chain theory to model the process of valid successive line outages that occur step by step and lead to load encroachment into zone-3 distance relay. A novel normalized prediction index based on relay margin change, margin sensitivity variation, load encroachment factor and overload tolerance of the line is proposed to predict the next possible outage. The distance relays involved in most fault chains are identified as vulnerable relays requiring to be controlled. A suitable index is presented to detect the critical relays. In this regard, an optimal control strategy is also proposed to restore the acceptable operating margins of the identified vulnerable zone-3 distance relays in the system’s emergency condition. The validity of the proposed approach is evaluated on New England 39 bus system to confirm the effectiveness and benefits of the proposed method. The obtained results are exciting.

Frequency and Voltage Compliance Capabilities of Grid-Forming Wind Turbines in Offshore Wind Farms in Weak AC Grids

Weak grid conditions challenge the grid integration of offshore wind farms. Especially grids with low inertia and large grid impedance questions frequency and voltage compliance capabilities. Grid-forming wind turbines are a promising technology for weak grids due to the nature of their control strategy. This paper explains the difference in how weak grid conditions are described in the literature and shows how the voltage stability margin changes with the short-circuit ratio and X/R ratio. With that knowledge, the frequency and voltage compliance capabilities of three grid-forming controls in an offshore wind farm are investigated and benchmarked. These three controls are a droop control, a virtual synchronous machine, and a synchronverter. This was done by quantifying their performance during a frequency disturbance with sensitivity to the short-circuit ratio, X/R ratio, and the inertia constant, H. It is concluded that the virtual synchronous machine is the most compliant grid-forming control and that DC-link modeling is of great importance when testing compliance during frequency disturbances.

Margin Forecasts by Managers and Analysts

In this article, the authors study qualitative margin forecasts made by managers in their earnings conference calls as well as forecast revisions of gross margins by financial analysts. Maintaining margins in cases when the costs of input factors rise indicates strength because the firm can pass these increased costs onto its customers. Increased margins when sales increase indicate strong market power by the firm or a better utilization of fixed resources. Decreasing margins when revenues increase typically indicate a strategy of capturing market share. Due to the recent difficulties in supply chains caused by the pandemic and then by inflation pressures, it became more important to study changes in margins forecasted by managers and analysts. The authors provide evidence that these forecasts can improve portfolio returns, especially when used in conjunction with forecast revisions of sales and earnings.

The Effects of Government Spending in the Eurozone

Abstract Using a newly assembled rich dataset at the regional level, this paper provides novel empirical evidence on the effects of fiscal policy in the Eurozone. Our baseline estimates reveal a government spending relative output multiplier around 2, an employment multiplier of 1.4, and a cost per job created of approximately €30,000. Moreover, we find that a regional fiscal stimulus leads to a significant increase in private investment, productivity, and durable consumption. The labor share also increases, as do total hours worked driven by changes in the extensive margin (total employment), whereas the intensive margin (hours per worker) barely reacts. Contrary to the common policy narrative of strong positive spillover effects, we estimate only small regional fiscal spillovers. Finally, our findings reveal strong heterogeneities across economic sectors, states of the economy, and member states.

From Economics to Earnings: A Macro-Based Equity Earnings Growth Forecasting Model

Earnings growth measures the change in a company’s reported net income through time. It is arguably the most widely observed measure of the growth and the profitability of a business, and a critical driver of equity returns. Though many practitioners have relied on historical averages to inform earnings growth expectations, research has found a relationship between earnings growth and prevailing economic growth. Building on prior research that connects earnings growth with real GDP growth, the authors split the earnings growth into two parts—revenue growth and changes in profit margins—and identifies multiple macroeconomic factors that have historical relationships separately with each. The authors find that revenue growth can historically be explained by world GDP growth, US GDP growth and payout ratios, and changes in profit margins can be explained by labor costs trade intensity. Upon conducting the out of sample test, this article offers a robust solution on predicting future earnings growth with macroeconomic factors and provides an important framework for understanding a key component of equity returns.

Normalization of tumor markers and a clear resection margin affect progression-free survival of patients with unresectable pancreatic cancer who have undergone conversion surgery

BackgroundWith the advent of intensive combination regimens, an increasing number of patients with unresectable pancreatic cancer (UPC) have regained the opportunity for surgery. We investigated the clinical benefits and prognostic factors of conversion surgery (CS) in UPC patients.MethodsWe retrospectively enrolled patients with UPC who had received CS following first-line systemic treatment in our center between 2014 to 2022. Treatment response, safety of the surgical procedure and clinicopathological data were collected. We analyzed the prognostic factors for postoperative survival among UPC patients who had CS.ResultsSixty-seven patients with UPC were enrolled (53 with locally advanced pancreatic cancer (LAPC) and 14 with metastatic pancreatic cancer (MPC)). The duration of preoperative systemic treatment was 4.17 months for LAPC patients and 6.52 months for MPC patients. All patients experienced a partial response (PR) or had stable disease (SD) preoperatively according to imaging. Tumor resection was unsuccessful in four patients and, finally, R0 resection was obtained in 81% of cases. Downstaging was determined pathologically in 87% of cases; four patients achieved a complete pathological response. Median postoperative-progression-free survival (PO-PFS) was 9.77 months and postoperative overall survival (PO-OS) was 31.2 months. Multivariate logistic regression analyses revealed that the resection margin and postoperative changes in levels of tumor markers were significant prognostic factors for PO-PFS. No factors were associated significantly with PO-OS according to multivariate analyses.ConclusionsCS is a promising strategy for improving the prognosis of UPC patients. The resection margin and postoperative change in levels of tumor markers are the most important prognostic factors for prolonged PFS. Multidisciplinary treatment in high-volume centers is strongly recommended. Prospective studies must be undertaken to resolve the various problems regarding optimal regimens, the duration of treatment, and detailed criteria for CS.

Use of Computed Tomography in Evaluation and Management of Shell Fracture in a Red Eared Slider Turtle ( Trachemys scripta elegans) A Case report

Traumatic lesions of the shell are common problems in chelonians. Lesions of the shell vary in severity from a simple superficial abrasion (with a loss of the external skin layer and exposure of the bone) to complicated fractures of the carapace with exposure of internal organs of the coelom and injury of the soft tissues (Barten, 2006). In most shell or skeletal injuries in the turtle, plain radiographic data do not reveal the extent of complex fractures due to superimposed bone structures (Abou-Madi et al., 2002). In Comparison with conventional radiography, computed tomography (CT) allows better distinction of specific tissue densities and discrete changes in organ size, shape, margin, contour and position (Gaudron et al., 2001). Computed tomography is a non-invasive, cross-sectional diagnostic imaging technique that offers significant advantages for detection of pathologies in chelonians, and is ideal for diagnosing skeletal and soft tissue abnormalities (Gumpenberger and Henninger, 2001). The aim of the present work was to evaluate the three dimensional computed tomography (CT) for clinical examination of shell lesions in a red eared slider turtle.

Unusual Breast Malignancies—Going A Step Ahead of Breast Imaging Reporting and Data System

AbstractWith the advent of the Breast Imaging Reporting and Data System (BIRADS), the categorization of the entire gamut of breast lesions has been simplified. However, there are many unusual breast lesions, both benign and malignant, which cannot be categorized accurately using the BIRADS descriptors due to the overlap of features. Carcinomas such as medullary, papillary, and mucinous (colloid) types, may be difficult to recognize as malignant because they may have relatively benign-appearing morphologic features. Well-circumscribed, small, and hyperechoic lesions may not be benign in all cases, and the presence of any microlobulations in margin, vascularity, heterogeneity, round shape, or interval change in size or appearance should raise suspicion of a sinister etiology. Therefore, it is important to be aware of the imaging features of such malignancies so that any mismanagement or undue delay in the diagnosis of any sinister etiology can be avoided.

Clinical Features of Lid Margin, Meibomian Gland and Tear Film Changes in Patients with Primary Pterygium

Abstract Introduction: The aim of this study was to clinically evaluate lid margin abnormality, meibomian glands expression and tear function changes in patients with primary pterygium. Methods: Fifty normal and 50 primary pterygia participants without other ocular pathologies were randomly selected from patients who attended an ophthalmology visit. The lid margin abnormality, meibomian gland expression, tear break-up time, Schirmer's test results and ocular surface disease index (OSDI) were evaluated. Multiple tear meniscus values include the lower tear meniscus height (TMH), tear meniscus depth (TMD) and tear meniscus area (TMA) were also measured using time-domain ocular coherence tomography. Comparative analyses between groups were performed for all parameters. A statistical significance level of P < 0.05 was considered. Association of ocular surface disease index with lid margin abnormality scores, meibomian gland expression and tear break-up time were evaluated. Results: Ocular surface disease index, lid margin abnormality and meibomian gland expression scores were significantly higher in primary pterygium patients than in normals (P < 0.001). Tear break-up time, Schirmer's test results, lower TMH, TMD and TMA values donot differ between the two groups (P > 0.05). Correlation analysis demonstrated that lid margin abnormality, meibomian gland expression and tear break-up time were significantly correlated with ocular surface disease index (P < 0.05). Conclusions: Primary pterygium may cause alteration of lid margin and meibomian glands expressions, which is associated with ocular discomfort. Early detection of lid margin and meibomian gland changes seem to be important to understand the relationship between pterygium, tear film functions and changes of the ocular surface.

Study on plant generator scheduling based on mixed integer model

Due to the outbreak of the new crown epidemic, the production plans of most factories have been affected to a certain extent, and there may be some changes in the production machinery and manpower arrangements of the factories. In this paper, we study how to arrange the dispatch strategy of generators under the condition of power demand in a specified time. Based on the minimum cost, a mixed integer model was established, which provided a solution for some factories to control the scheduling of machines on time during the outbreak of the epidemic. According to the established model, a factory is programmed to solve the problem, and the minimum power generation cost in a week is given 1589130 CNY. In special cases, the working generator set must set aside 20% of the power generation capacity margin to cope with the unexpected situation. At this time, the generator’s daily production cost is as small as 239870 CNY while giving the corresponding generator scheduling scheme. Finally, this paper does a sensitivity analysis of the total daily power generation cost when the power generation margin changes, and finds that the total daily cost of the generator is sensitive to the power generation margin.

Accurate gingival recession quantification using 3D digital dental models

ObjectivesTo develop and validate a method for accurate quantitative assessment of gingival recessions based on superimposition of serial 3D digital models.Materials and methodsGingival recessions of mild (0.5–2 mm) and increased (3–7 mm) severity were simulated on stone casts and surface models were created. The outlines of the gingival margins of the mild (A) and severe recessions (B) were compared to the original gingival margins following 3D best fit superimposition through a gold standard technique (GS), which used intact adjacent structures, and the tested method (CC), which used single tooth crowns at the position of recessions, as superimposition reference. The primary outcome was the distance between the most apical point of each corresponding gingival margin along the respective tooth long axis.ResultsFor mild recessions, the median difference of the test methods (CC_A) from the reference method (GS_A) was 0.008 mm (IQR: 0.093; range: − 0.143, 0.147). For severe recessions, the median difference of the test method (CC_B) from the reference method (GS_B) was 0.009 mm (IQR: 0.091; range: − 0.170, 0.198). The proposed method (CC) showed very high intra- and inter-operator reproducibility (median: 0.025 and 0.033 mm, respectively).ConclusionsThe suggested method offers highly accurate monitoring of gingival margin changes and diagnosis of gingival recessions using 3D digital dental models. The method is applicable irrespective of changes in tooth position or form, allowing for assessments over any time span.Clinical relevanceThe accurate detection and visualization of gingival margin changes in 3D will enhance diagnosis and patient-doctor communication.

Novel surgical procedure for preventing anastomotic leakage following colorectal cancer surgery: A propensity score matching study.

Hypoperfusion is the main cause of anastomotic leakage (AL) following colorectal surgery. The conventional method for evaluating anastomotic perfusion is to observe color change and active bleeding of the resection margin of the intestine and the pulsation of mesenteric vessels. However, the accuracy of this method is low, which may be due to insufficient observation time. A novel surgical procedure that separates the mesentery in advance at the intended transection site can delay the observation of anastomotic perfusion, and can potentially detect more anastomotic sites with insufficient vascular supply and reduce the rate of AL. This study aimed to investigate the effects of a novel surgical procedure on AL following sigmoid colon and rectal cancer surgeries. A total of 343 patients who underwent rectal and sigmoid colon cancer surgeries were included in the study. From August 2021 to June 2022, patients with sigmoid colon or rectal cancer underwent a new surgical procedure of pre-division of the mesentery (PDM) at the intended transection site (PDM group). Patients with colorectal cancer who underwent conventional surgical procedures from August 2018 to July 2021 were categorized as the non-PDM group. Symptomatic AL (SAL) within 30 days and other outcomes were retrospectively analyzed using propensity score matching and compared between the two groups. The incidences of SAL were 1.3% and 11.3% in the PDM and non-PDM groups, respectively. PDM significantly reduced the SAL rate in sigmoid colon and rectal cancer surgeries (P = 0.009). The incidence of total postoperative complications (P < 0.05) was significantly lower in the PDM group than that in the non-PDM group. There were no significant differences between the two groups for operative time (P = 0.662), intraoperative blood loss (P = 0.651), intraoperative blood transfusion (P = 0.316), and intensive care rate (P = 1). The length of postoperative hospital stay (P = 0.010) and first exhaust (P = 0.001) and defecation time (P < 0.05) were shorter in the PDM group than in the non-PDM group. PDM can effectively prevent AL, and this procedure can be safely performed in sigmoid colon and rectal cancer surgeries.

Towards sustainability and affordability of expensive cell and gene therapies? Applying a cost-based pricing model to estimate prices for Libmeldy and Zolgensma

Background aimsDrug prices are regarded as one of the most influential factors in determining accessibility and affordability to novel therapies. Cell and gene therapies such as OTL-200 (brand name: Libmeldy) and AVXS-101 (brand name: Zolgensma) with (expected) list prices of 3.0 million EUR and 1.9 million EUR per treatment, respectively, spark a global debate on the affordability of such therapies. The aim of this study was to use a recently published cost-based pricing model to calculate prices for cell and gene therapies, with OTL-200 and AVXS-101 as case study examples. MethodsUsing the pricing model proposed by Uyl-de Groot and Löwenberg, we estimated a price for both therapies. We searched the literature and online public sources to estimate (i) research and development (R&D) expenses adjusted for risk of failure and cost of capital, (ii) the eligible patient population and (iii) costs of drug manufacturing to calculate a base-case price for OTL-200 and AVXS-101. All model input parameters were varied in a stepwise, deterministic sensitivity analysis and scenario analyses to assess their impact on the calculated prices. ResultsPrices for OTL-200 and AVXS-101 were estimated at 1 048 138 EUR and 380 444 EUR per treatment, respectively. In deterministic sensitivity analyses, varying R&D estimates had the greatest impact on the price for OTL-200, whereas for AVXS-101, changes in the profit margin changed the calculated price substantially. Highest prices in scenario analyses were achieved when assuming the lowest number of patients for OTL-200 and highest R&D expenses for AVXS-101. The lowest R&D expenses scenario resulted in lowest prices for either therapy. ConclusionsOur results show that, using the proposed model, prices for both OTL-200 and AVXS-101 lie substantially below the currently (proposed) list prices for both therapies. Nevertheless, the uncertainty of the used model input parameters is considerable, which translates in a wide range of estimated prices. This is mainly because of a lack of transparency from pharmaceutical companies regarding R&D expenses and the costs of drug manufacturing. Simultaneously, the disease indications for both therapies remain heavily understudied in terms of their epidemiological profile. Despite the considerable variation in the estimated prices, our results may support the public debate on value-based and cost-based pricing models, and on “fair” drug prices in general.

The effects of physical and temporal certainty on human locomotion with discrete underfoot perturbations.

Foot placement can be selected to anticipate upcoming perturbations, but it is unclear how this anticipatory strategy is influenced by available response time or precise knowledge of the perturbation's characteristics. This study investigates anticipatory and reactive locomotor strategies for repeated underfoot perturbations with varying levels of temporal certainty, physical certainty, and available response time. Thirteen healthy adults walked with random underfoot perturbations from a mechanized shoe. Temporal certainty was challenged by presenting the perturbations with or without warning. Available response time was challenged by adjusting the timing of the warning before the perturbation. Physical certainty was challenged by making perturbation direction (inversion or eversion) unpredictable for certain conditions. Linear-mixed effects models assessed the effect of each condition on the percentage change of margin of stability and step width. For perturbations with one stride or less of response time, we observed few changes to step width or margin of stability. As response time increased to two strides, participants adopted wider steps in anticipation of the perturbation (P=0.001). Physical certainty had little effect on gait for the step of the perturbation, but participants recovered normal gait sooner when the physical nature of the perturbation was predictable (P<0.001). Despite having information about the timing and direction of upcoming perturbations, individuals do not develop perturbation-specific feedforward strategies. Instead, they use feedback control to recover normal gait after a perturbation. However, physical certainty appears to make the feedback controller more efficient and allows individuals to recover normal gait sooner.

Geochemistry of the Permian–Triassic boundary strata in the southwest margin of the North China Craton: Provenance and tectonic implications

The Late Permian Sunjiagou Formation and Early Triassic Liujiagou Formation were studied to understand the palaeoclimatic and palaeoenvironmental changes in the southwest margin of the North China Craton across the Permian–Triassic boundary, as well as the tectonic evolution of their provenance sediment. Major, trace, and rare earth elements in 20 clastic rock samples from the strata above and below the boundary were analysed. Overall, the Sunjiagou Formation samples showed an average index of compositional variability (ICV) and chemical index of alteration (CIA) of 1.53 and 73.59, respectively, indicating high‐maturity sediments in a warm and humid environment with moderate chemical weathering, whereas Liujiagou Formation samples had an average ICV and CIA of 2.40 and 70.1, respectively, indicating low‐maturity sediments in a cold and dry environment with mild chemical weathering. These strata were composed of first‐cycle sediments in a tectonically active area. The provenance of the Sunjiagou Formation was dominated by quartz‐rich sedimentary rocks, whereas that of Liujiagou Formation had both quartz‐rich sedimentary rocks and intermediate volcanic rocks. The provenance tectonic settings were mainly the continental island arc and active continental margin. Thus, the study area was in a terrestrial, freshwater sedimentary environment from the Late Permian to Early Triassic, and the climate gradually changed from warm and humid to dry and hot, with multiple small‐scale periodic evolutions. Taken together, these findings further confirm that the entire study area was in an oxidizing environment and the oxidation degree in the Early Triassic was higher than that in the Late Permian.

VOICE PROFILING IN YOUNGSTERS FOLLOWING CLUB PARTY

Introduction. Club parties are becoming very common among youngsters at present days. They tend to shout, yell, scream and indulge in other vocally abusive behaviors beyond their vocal range and for a long period during club parties. Vocal abuse in presence of high background noise with poor vocal hygiene and various other environmental factors have a disastrous effect on one's voice. The present study aimed to show and correlate theObjective. effect of vocal abuse (during vocally demanding situations like club parties) on the perceptual and objective vocal features of youngsters. This study included a total of 20 youngsters with equal gender distribution, age range 18-23 years.Methodology. Pre-test and post-test research designs were applied. Perceptual scales such as GRBAS, Video laryngoscopic examination(otopront 1CCD), and Acoustic voice analysis (CSL-4500) were used for all the candidates. Appropriate statistic analysis was done for the values obtained to measure and compare pre and post-club-party effects on samples. TheResult. post-party effect represented vocal effects on the GRBAS scale, VLS examination, and acoustic values on CSL. However, changes that were more prominent and statistically signicant for Females (P&lt;0.05- SPI, jitter, shimmer, APQ) may be due to laryngeal precipitating factors in female vocal cords. Changes in vocal margins were evident on VLS examination with are correlated with CSL. However, the non-signicance on a few parameters was also found, concluding that few parameters were less suspectable to the temporary effects on vocal function. Youngsters who shout very loudly during club partiesConclusion. have throat pain, hoarseness, and breathiness following the party in our present study. Females have more prominent changes as compared to boys may be due to boys having more hyaluronic acid which prevents vocal folds from scarring. However, any signicant changes are not reported in just one day of exposure but if such a situation persists it may lead to permanent change altering their vocal range. It is thought that attending club parties once in a while may not be altering vocal symptoms but youngsters must abstain from continuing such activities in the long run, to avoid permanent vocal pathologies. Meanwhile, youngsters should follow vocal hygiene to avoid such vocal conditions.

Extension of unemployment benefits and changes in job search margins

Abstract Unemployment insurance benefits are often extended during recessions. Existing research shows that this policy increases the unemployment rate and the duration of unemployment. But less is known about why these changes occur. I construct a job search model with an endogenous participation decision to quantify the contributions of (i) search effort, (ii) job selectivity, and (iii) labor market participation, to changes in unemployment outcomes. In a model calibrated to the US economy, I show that the increased participation accounts for a large fraction of the increase in the unemployment rate following a permanent extension of benefits. This finding indicates the importance of changes in the participation decision of workers facing extended benefits for the unemployment rate—a mechanism that is understudied and frequently overlooked in the quantitative labor market research exploring the impact of UI policies.

Unravelling the long-term, locally heterogenous response of Greenland glaciers observed in archival photography

Abstract. We present an approach for extracting quantifiable information from archival aerial photographs to extend the temporal record of change over a region of the central eastern Greenland Ice Sheet. The photographs we use were gathered in the 1930s as part of a surveying expedition, and so they were not acquired with photogrammetric analysis in mind. Nevertheless, we are able to make opportunistic use of this imagery, as well as additional, novel datasets, to explore changes at ice margins well before the advent of conventional satellite technology. The insights that a longer record of ice margin change bring is crucial for improving our understanding of how glaciers are responding to the changing climate. In addition, our work focuses on a series of relatively small and little studied outlet glaciers from the eastern margin of the ice sheet. We show that whilst air and sea surface temperatures are important controls on the rates at which these ice masses change, there is also significant heterogeneity in their responses, with non-climatic controls (such as the role of bathymetry in front of calving margins) being extremely important. In general, there is often a tendency to focus either on changes of the Greenland Ice Sheet as a whole, or on regional variations. Here, we suggest that even this approach masks important variability, and full understanding of the behaviour and response of the ice sheet requires us to consider changes that are taking place at the scale of individual glaciers.

Long Term Time-Lapse Imaging of Geographic Atrophy: A Pilot Study.

Geographic atrophy (GA), the late stage of age-related macular degeneration, is a major cause of visual disability whose pathophysiology remains largely unknown. Modern fundus imaging and histology revealed the complexity of the cellular changes that accompanies atrophy. Documenting the activity of the disease in the margins of atrophy, where the transition from health to disease occurs, would contribute to a better understanding of the progression of GA. Time-lapse imaging facilitates the identification of structural continuities in changing environments. In this retrospective pilot study, we documented the long-term changes in atrophy margins by time-lapse imaging of infrared scanning laser ophthalmoscopy (SLO) and optical coherence tomography (OCT) images in 6 cases of GA covering a mean period of 32.8 months (range, 18–72). The mean interval between imaging sessions was 2.4 months (range, 1.4–3.8). By viewing time-lapse sequences we observed extensive changes in the pattern of marginal hyperreflective spots, which associated fragmentation, increase and/or disappearance. Over the entire span of the follow-up, the most striking changes were those affecting hyperreflective spots closest to margins of atrophy, on the non-atrophic side of the retina; a continuum between the successive positions of some of the hyperreflective spots was detected, both by SLO and OCT. This continuum in their successive positions resulted in a subjective impression of a centrifugal motion of hyperreflective spots ahead of atrophy progression. Such mobilization of hyperreflective spots was detected up to several hundred microns away from atrophic borders. Such process is likely to reflect the inflammatory and degenerative process underlying GA progression and hence deserves further investigations. These results highlight the interest of multimodal time-lapse imaging to document cell-scale dynamics during progression of GA.Clinical Trial Registrationclinicaltrials.gov, identifier: NCT04128150 and NCT04129021.

Productivity and trade dynamics in sudden stops

This paper proposes a framework to jointly study productivity and trade dynamics during financial crises. The persistent output loss caused by crises is driven by lower productivity growth, which is determined by changes in product entry and exit margins in domestic and export markets. We calibrate and validate the model using unique data on firms’ product portfolios, finding they closely match the behavior of various margins during Chile's 1998 sudden stop. We decompose the sources of the welfare cost of sudden stops, finding that 30% is due to a decline in productivity growth. Lower productivity growth, in turn, is due mostly to slower firm and product entry into the domestic market, while a persistent real exchange rate depreciation induces surviving firms to tilt their product portfolios toward export markets, driving the productivity recovery in the aftermath of the crisis.