Academic literature on the topic 'SURROGATE CURBS'

The paper presents a microsimulation approach for assessing the safety performance of turbo-roundabouts where Cooperative Autonomous Vehicles “CAVs” have been introduced into the traffic mix alongside conventional vehicles “CVs”. Based on the analysis of vehicle trajectories from VISSIM and subsequent analysis of traffic conflicts through the Surrogate Safety Assessment Model (SSAM), the research aims to evaluate the safety benefits of turbo-roundabouts where the lanes are physically separated by raised curbs, compared to roundabouts without such curbs. The paper will then describe the methodological path followed to build VISSIM models of turbo-roundabouts with and without raised curbs in order to calibrate the simulation models and estimate the potential conflicts when a higher percentage of CAVs are introduced into the traffic mix. A criterion has been also proposed for setting properly the principal SSAM filters. The results confirmed both higher safety levels for turbo-roundabouts equipped with raised lane dividers compared to turbo-roundabout solutions without curbs, and better safety conditions under the traffic mix of CVs and CAVs. Therefore, it follows that, in absence of crash data including CAVs, the surrogate measures of safety are the only approach in which the safety performance of any roundabout or road entity can be evaluated.

The word surrogacy has its origin among the Latin term “surrogatus” which suggests a lady acts as a substitute for a pregnant woman. Surrogacy has been in practice form last thirty years. The surrogacy regulated by business can be classified as then, altruistic surrogacy and commercial surrogacy. The paper aim to conduct systematic review on surrogacy. The literature review was conducted using PubMed and alternative search engines. Further, additional information concerning the constitutional articles was collected from search engines like legal service of India, prsinndia.org, icmr.nic.in, Press Information Bureau, Wikipedia, IJCM and Indiankanoon. In India, surrogacy is legally recognised since 2002. This paper looks into various aspects of surrogacy. Factors faced by the surrogate mother such as exploitation, psychological conditions, human rights, dignity and respect, feminism and religious issues are explored. The paper discuss the economic benefit is mostly enjoyed by the medical practitioners. The Indian government tried to curb the problems by updating the law to overcome the challenges but with time government introduce the surrogacy bill in 2016 which addressed many issues and still in 2020 it address various aspects of surrogacy to prevent the exploitation.

Abstract If globalisation has led to a greater mobility of people specific issues have emerged with the current coronavirus pandemic. Consequently, extreme measures have been taken worldwide to flatten the curb of the virus. From lockdowns to several levels of isolation these measures have worked undoubtedly for some situations. Nonetheless, these same measures have sown chaos in other situations. One good example is surrogacy especially when this practice is undergone overseas, revealing the legal insecurity of the use of surrogacy whether for the intended parents, the surrogate born child or the surrogate mother for whom the risks have heightened.

In 2011, the United Nations Road Safety Collaboration (UNRSC) developed a Global Plan for the Decade of Action for Road Safety 2011–2020. Among the categories or “pillars” of activities, is the improvement of road safety for infrastructures. Furthermore, this plan is aligned by the UN Sustainable Development Goals that included even traffic safety. In this regard, this study estimates safety improvements achieved by converting a standard roundabout into an egg turbo roundabout. In particular, turbo roundabouts have become very popular in Northern Europe for both their safety and their capacity. Many studies have shown these advantages thanks to their features: preventive separation of entering flows, limited lane changing and low speeds due to curbs. Given the absence of existing turbo roundabouts in Italy, this research studied and compared a “virtual” roundabout with spiraling circular carriageways to an existing multi-lane roundabout in order to assess its significant reduction in terms of potential collisions. This study relied on traffic conflicts in micro-simulation by using VISSIM software and then Surrogate Safety Assessment Model (SSAM). The research is based on the traffic process observed at a standard roundabout in Cosenza (Italy) marked by a high level of congestion and safety problems. Speeds, critical gaps, queue lengths, and floating car data, obtained from video observations, have been used as input data for the calibration procedure of the first scenario (case study roundabout). Then, the turbo roundabout solution was built and simulated by using the previously derived parameters. Finally, the two roundabout scenarios were compared in terms of spatial distribution of the potential conflicts determined by SSAM. The results could help to measure the performance and safety impact of these two roundabout configurations.

Zimbabwe has experienced an economic meltdown dating back to 2000, which created perennial economic woes such as a liquidity crisis that continued haunting the country to date. Various possible solutions were explored but did not yield the desired results. Amongst the explored solutions was an introduction of surrogate currency specifically to curb the liquidity crisis. This paper sought to explore the effects of using "surrogate currency" to address the liquidity crisis in Zimbabwe by employing a desk review. Currently, there is a dearth of literature on using surrogate currency in African countries. Hence this study contributes to the existing literature on the use of such currency. The review established that the surrogate currency led to the emergence of bad money as propounded by Gresham’s law of currency systems. Moreover, the surrogate currency rapidly lost its value, whereas the introduction of the surrogate currency failed to address the liquidity crisis, leading to other socio-economic challenges. Finally, financial reporting under the surrogate currency became a challenge as well. This study recommends the withdrawal of the surrogate currency and the use of multicurrency along with the promotion of products for export to attract more foreign currency into the economy.

In this paper, a multi-disciplinary optimization frame considering weld fatigue constraints is constructed based on kriging surrogate model in order to improve the fatigue reliability of vehicle structures. Under this frame, kriging surrogate model is used to construct weight, strength, stiffness, frequency, fatigue life responses for optimization, which improves effectively the computing efficiency. For weld fatigue analysis, master S-N curve method in AMSE criterion is used for reliable fatigue life. The curb girders of a high-speed train are taken as an example, a light-weight optimization model considering static strengthen and weld fatigue constrains is constructed and solved by use of submodelling technology under the proposed optimization frame. After optimization, the weight of the curb girders is reduced about 33% from 1.73 ton to 1.16 ton. These results show the proposed optimization method is effective, and provide the preference for the light-weight design of high-speed trains.

Returning orphan bear cubs to the wild can benefit bear welfare and conservation but is hindered in Asia by the scarcity of documented experience. We experimented with rehabilitation of two Asiatic Black Bear cubs in Thailand using the assisted method of soft-release. We raised the 5-month old cubs for 11 months with minimal human contact in a remote enclosure in high quality habitat, letting cubs out periodically to walk with caretakers in the forest. The caretakers acted as surrogate mothers, allowing cubs to safely acquire foraging skills and familiarity with the forest. Supplementary feeding resulted in the cubs’ rapid weight gain (average 157g/day), faster than would occur in the wild. Faster growth allowed the cubs to be released sooner, reducing the likelihood of long-term habituation. After three months of rehabilitation, the bear cubs started showing signs of being wary of the caretakers (e.g., cautious when we approached their enclosure) and their focus during walks switched from play to foraging. After seven months they began to spend nights away from their enclosure, thus declining the supplemental food. This sequence and timing of increasing separation and independence from people matched other assisted soft releases in the region. The cubs went missing in month 12, shortly before planned collaring and release. They were seen together 2.5 months later on a fruiting tree and ran away when approached. Assisted soft releases might be a promising option for bear rehabilitation in Asia but more data are needed to evaluate their effectiveness relative to other methods. This method affords direct observations of bears in the wild that can augment our knowledge of bear behavior and ecology.

Abstract Background: Overall survival (OS) remains the definitive primary efficacy endpoint to evaluate previously untreated acute myeloid leukemia (AML) therapies, but it requires prolonged follow-up. An earlier endpoint assessed post-treatment would expedite clinical trial conduct and accelerate patient access to effective new therapies. Our objective was to formally evaluate event-free survival (EFS) as a surrogate endpoint for OS in untreated AML. Methods: Individual patient data were analyzed from 2,475 patients (pts) from 4 multicenter, randomized controlled phase III trials of active treatment in previously untreated AML using anthracycline and cytarabine induction chemotherapy as the concurrent control (CALGB 10201, n=506, enrollment period 2003-2006, age 60-88 years (y); CALGB 10603, n=717, enrollment period 2008-2015, age 18-60 y, FLT3-mutated pts only; SWOG 0106, n=595, enrollment period 2004-2009, age 18-60 y; ECOG-ACRIN 1900, n=657, enrollment period 2002-2008, age 17-60 y). Individual patient-level surrogacy examines the association between the individual patients' EFS and OS time after adjusting for treatment effect, and was assessed using the copula bivariate survival model (Kendall's tau). Trial-level surrogacy measures how precisely the treatment effect on OS can be predicted on the basis of observed treatment effect on EFS, and was evaluated using both linear regression (R2WLS) weighted by trial size and Copula bivariate (R2Copula) models. Pre-specified criteria for surrogacy required either R2WLS or R2Copula ≥0.80, neither below 0.7, with either lower bound 95% Confidence Interval (CI) >0.60. Sensitivity analyses were conducted using different EFS definitions (Table 1). Results: With a median follow-up of 50.2 months for the 896 patients still alive, the median OS and EFS across all four trials were 20.9 months (95% CI: 19.0-22.7) and 5.6 months (95% CI: 4.5-6.4), respectively. Trial-level surrogacy for EFS was strong (R2WLS=0.79; R2Copula=0.89), indicating a high correlation of treatment effect between EFS and OS. At the individual patient-level, however, EFS showed weak association with OS (tau= 0.52), compared to the strength of trial-level surrogacy. The discrepancy between patient-level EFS and OS was greatest among patients who did not achieve a CR, followed by those who achieved a CR but relapsed (Figure 1). Sensitivity analysis on alternative EFS definitions showed that the trial-level surrogacy was similar, but individual patient-level surrogacy varied across different EFS definitions (Table 1). This is consistent with what we previously reported (ASH 2016): EFS estimates differed considerably based on the definition of induction failure (IF) in a single arm setting, but this had minimal impact on the estimation of the treatment effect using EFS in randomized trials. In addition, when considering only relapse and death as events (definition 4), both individual patient- and trial-level correlations were high. Conclusions: Correlation between EFS and OS was impacted by patients not achieving CR during induction. Despite the lack of patient-level correlation, a strong correlation between hazard ratios for treatment effects was observed between EFS and OS on the trial level. Hence, it remains debatable whether EFS represents a clinical benefit in itself for patient with untreated AML considering the strong correlation in treatment effects. Further validation is needed due to the small number of trials included and the heterogeneity across trials. Acknowledgment: We gratefully acknowledge the important contributions of the late Dr. Stephen H. Petersdorf, SWOG S0106 Study Chair. Support: U10CA180821, U10CA180882, U10CA180794, U10CA180820, U10CA180888; Clinicaltrials.gov Identifiers: NCT00085124 (10201), NCT00651261 (10603), NCT01253070 (11001), NCT00085709 (SWOG S0106), and NCT00049517 (ECOG-ACRIN E1900) Disclosures Uy: Curis: Consultancy; GlycoMimetics: Consultancy. Larson:Pfizer: Consultancy, Research Funding; BristolMyers Squibb: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Ariad/Takeda: Consultancy, Research Funding.

The appropriateness of test vehicles specified in NCHRP Report 350 was assessed, including ( a) whether the 2000-kg, three-quarter-ton pickup truck should continue to be used as a test vehicle, and if not, what replacement vehicle would be appropriate; ( b) whether the 820-kg passenger car should continue to be used as a test vehicle, and if not, what replacement vehicle would be appropriate; and ( c) whether another test vehicle should be added to the matrix—for example, an intermediate-sized passenger car. From the analysis, the following conclusions and recommendations were drawn: ( a) The three-quarter-ton pickup truck appears to be a good surrogate for the light truck subclasses. The recommendation is to keep the 2000-kg, three-quarter-ton pickup truck as one of the design test vehicles in the update of the guidelines for NCHRP Report 350. ( b) A potential problem is the availability of three-quarter-ton pickup trucks with standard cabs. An alternative design test vehicle may be an intermediate-sized sport utility vehicle, ( c) The availability of the 820-kg passenger car design test vehicle will be a problem within the next few years. The recommendation is to keep the current test vehicle as long as it is still readily available, or until the NCHRP Report 350 guidelines are updated, and to increase the curb weight to a level consistent with the curb weights of the two smallest passenger cars with reasonably high sales volume. ( d) The addition of a third design vehicle—for example, a 1500-kg intermediate-sized passenger car—to ensure that a roadside feature performs satisfactorily across the entire vehicle spectrum is highly desirable but cost-prohibitive. The addition of an intermediate-sized design test vehicle is therefore not recommended except in situations in which there is a perceived concern that the device may not function properly when impacted by an intermediate-sized vehicle.

Decoding stem cell metabolism has implicated a tight linkage between energy metabolism and cell fate regulation, a dynamic interplay vital in the execution of developmental and differentiation programs. The inherent plasticity in energy metabolism enables prioritisation of metabolic pathways in support of stage-specific demands. Beyond traditional support of energetic needs, intermediate metabolism may also dictate cell fate choices through regulation of cellular signalling and epigenetic regulation of gene expression. The notion of a ‘metabolism-centric’ control of stem cell differentiation has been informed by developmental embryogenesis based upon an on-demand paradigm paramount in defining diverse developmental behaviours, from a post-fertilisation nascent zygote to complex organogenesis leading to adequate tissue formation and maturation. Monitored through natural or bioengineered stem cell surrogates, nutrient-responsive metabolites are identified as mediators of cross-talk between metabolic flux, cell signalling and epigenetic regulation charting, collectively, whether a cell will self-renew to maintain progenitor pools, lineage specify to ensure tissue (re)generation or remain quiescent to curb stress damage. Thus, bioenergetics are increasingly recognised as integral in governing stemness and associated organogenic decisions, paving the way for metabolism-defined targets in control of embryology, stem cell biology and tissue regeneration.