Optimal strategies to protect a sub-population at risk due to an established epidemic

Epidemics can particularly threaten certain sub-populations. For example, for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the elderly are often preferentially protected. For diseases of plants and animals, certain sub-populations can drive mitigation because they are intrinsically more valuable for ecological, economic, socio-cultural or political reasons. Here, we use optimal control theory to identify strategies to optimally protect a ‘high-value’ sub-population when there is a limited budget and epidemiological uncertainty. We use protection of the Redwood National Park in California in the face of the large ongoing state-wide epidemic of sudden oak death (caused by Phytophthora ramorum ) as a case study. We concentrate on whether control should be focused entirely within the National Park itself, or whether treatment of the growing epidemic in the surrounding ‘buffer region’ can instead be more profitable. We find that, depending on rates of infection and the size of the ongoing epidemic, focusing control on the high-value region is often optimal. However, priority should sometimes switch from the buffer region to the high-value region only as the local outbreak grows. We characterize how the timing of any switch depends on epidemiological and logistic parameters, and test robustness to systematic misspecification of these factors due to imperfect prior knowledge.

Optimal strategies to protect a sub-population at risk due to an established epidemic

Epidemics can particularly threaten certain sub-populations. For example, for SARS-CoV-2, the elderly are often preferentially protected. For diseases of plants and animals, certain sub-populations can drive mitigation because they are intrinsically more valuable for ecological, economic, socio-cultural or political reasons. Here we use optimal control theory to identify strategies to optimally protect a “high value” sub-population when there is a limited budget and epidemiological uncertainty. We use protection of the Redwood National Park in California in the face of the large ongoing state-wide epidemic of sudden oak death (caused by Phytophthora ramorum) as a case study. We concentrate on whether control should be focused entirely within the National Park itself, or whether treatment of the growing epidemic in the surrounding “buffer region” can instead be more profitable. We find that, depending on rates of infection and the size of the ongoing epidemic, focusing control on the high value region is often optimal. However, priority should sometimes switch from the buffer region to the high value region only as the local outbreak grows. We characterise how the timing of any switch depends on epidemiological and logistic parameters, and test robustness to systematic misspecification of these factors due to imperfect prior knowledge.

Efficiency Comparison of Public Hospitals under Different Administrative Affiliations in China: A Pilot City Case

This study seeks to measure the efficiency disparity and productivity change of tertiary general public hospitals in Wuhan city, central China from the perspective of administrative affiliations by using panel data from 2013 to 2017. Sample hospitals were divided into three categories, namely provincial hospitals, municipal hospitals, and other levels of hospitals. Data envelopment analysis with bootstrapping technique was used to estimate efficiency scores, and a sensitive analysis was performed by varying the specification of model by considering undesirable outputs to test robustness of estimation, and efficiency evolution analysis was carried out by using the Malmquist index. The results indicated that the average values of provincial hospitals and municipal hospitals have experienced efficiency improvement over the period, especially after the initiation of Pilot Public Hospital Reform, but hospitals under other affiliations showed an opposite trend. Meanwhile, differences of administrative subordination in technical efficiency of public hospitals emerged, and the disparity was likely to grow over time. The higher efficiency of hospitals affiliated with municipality, as compared with those governed by province and under other administrative affiliations, may be attributed to better governance and organization structure.

Market Volatility and Investors’ View of Firm-Level Risk: A Case of Green Firms

Do investors believe that firm-level (i.e., idiosyncratic) risk of green (i.e., environmentally responsible) firms is relatively lower? How does high market volatility affect the investors’ view on the firm-level risk of green firms? This paper addresses these questions by investigating the relationship between firm-level (idiosyncratic) risk and firms’ environmental performance. Further, we examine the effect market volatility has on the relationship. We estimate fixed-effect panel models using 8036 firm-year observations across 793 firms. We test robustness of the results with difference-in-difference (DiD), propensity score matching (PSM) and dynamic panel with the generalized method of moments (GMM) estimations. We find that investors generally associate firms that perform well on the environmental front to be of lower risk. However, during periods of high market volatility, just performing better than the industry does not make the investors see the firms’ risk as being significantly lower. How well the firms perform in relation to the industry performance is associated with the investors believing that the firm’s risk is significantly lower.

Seeing Parochially and Acting Locally

Why some communities have greater rates of social entrepreneurship in similar domains is a question of importance to scholars and practitioners alike. Much of the literature in social entrepreneurship begins with a social problem that has been identified, and then analyzes the antecedents of the entrepreneurial process that lead to organizational solutions emerging for those problems. However, why some problems gain traction as being worthy of time and effort in solving, has garnered little attention. I argue that particular problems are more or less salient triggers of action by prospective social entrepreneurs based on the distribution of such problems in the local social environment, rather than aggregate levels of need. Yet, even problems widely experienced as shared, salient, and generally worthy of action might lack the emergence of solutions in fragmented communities, such as those with high levels of residential segregation by race and income. We study this in the context of founding of advocacy and support organizations in the domain of healthcare, and find support for our predictions. We also conducted additional tests to better characterize the findings and test robustness to alternative sources of influence, such as the local pool of potential social entrepreneurs, the role of local ecology, and geographic spillovers from neighboring areas.

UV SPECTROPHOTOMETRIC METHOD FOR QUANTITATIVE DETERMINATION OF AGOMELATINE IN COATED TABLETS

UV spectrophotometry is an analytical technique used routinely for qualitative and quantitative assay due the low cost and reliability during analysis. In this work, it was validated a quantitative UV method for determination of agomelatine in coated tablets. The parameters specificity, linearity, precision, accuracy and robustness were evaluated according to official guidelines. Methanol was selected as solvent and the maximum wavelength for drug analysis was 230 nm. The purposed assay showed to be specific and the linearity was proved in a range of 0.5 - 2.5 µg/mL. The RSD values obtained during precision assay (inter-day RSD = 1.75%) indicated the method reproducibility, and the accuracy testing showed good results from recovery test. Robustness assay was complementary and showed that the purposed method is adequate for drug quantitation in commercial samples, being a reliable alternative to chromatographic assay.

Temporary Redundant Transmission Mechanism for SCTP Multihomed Hosts

In SCTP’s Concurrent Multipath Transfer, if data is sent to the destined IP(s) without knowledge of the paths condition, packets may be lost or delayed. This is because of the bursty nature of IP traffic and physical damage to the network. To offset these problems, network path status is examined using our new mechanism Multipath State Aware Concurrent Multipath Transfer using redundant transmission (MSACMT-RTv2). Here the status of multiple paths is analyzed, initially and periodically thereafter transmitted. After examination, paths priority is assigned before transmission. One path is temporarily employed as redundant path for the failure-expected path (FEP); this redundant path is used for transmitting redundant data. At the end of predefined period, reliability of the FEP is confirmed. If FEP is ensured to be reliable, temporary path is transformed into normal CMT path. MSACMT-RTv2 algorithm is simulated using the Delaware University ns-2 SCTP/CMT module (ns-2; V2.29). We present and discuss MSACMT-RTv2 performance in asymmetric path delay and with finite receiver buffer (rbuf) size. We extended our experiment to test robustness of this algorithm and inferred exhaustive result. It is inferred that our algorithm outperforms better in terms of increasing the throughput and reducing the latency than existing system.

Spatial network generation tool for water distribution network design and performance analysis

The research presented in this paper aims at the support tool for generation of multiple networks with preset or randomised properties. To explore particular phenomena, water distribution analysis may require a coherent set of cases. Readily available in the literature are simple synthetic networks used for benchmarking, either real-life cases that are too diverse in size and configuration. The network generation tool (NGT) developed on the principles of graph theory connects any seed of nodes prepared in EPANET modelling software, by avoiding pipe crossings or unnecessary duplications. The pipe properties can be assigned by specifying a range of arbitrary lengths and diameters, by using coordinates to calculate the lengths, or by genetic algorithm optimisation of initial diameters. Equally, the nodal elevations and demands are arbitrarily assigned when not predefined in EPANET. Several sets of networks have been generated, up to 200 junctions. To test robustness of the tool, 13,000 layouts of a 50-junction seed have been generated using different settings. NGT has been proven to be capable of executing this task mostly within a few minutes, producing network layouts that resemble those from practice.