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The aim of this study was to examine the relationship between suicidal behavior and gonadotropins, gonadal hormones, and cortisol in females.The study included 3 groups of 23 females each, aged 18-45 years; one group comprising those who had attempted suicide, another group of females matched for age, menstrual phase, and body mass index, with depression but no suicidal tendencies, and a control group of 23 healthy females. For all participants, a sociodemographic information form was completed, and the Beck Depression Inventory, the Beck Anxiety Inventory, and the Beck Hopelessness Scale were used. Blood samples were taken at 8 am (in the attempted-suicide group, within 24 hours of the attempt), and follicle-stimulating hormone, luteinizing hormone, estradiol, testosterone, progesterone, and cortisol levels were measured.No statistically significant differences were observed between the groups with respect to gonadotropin and gonadal hormone levels. There were statistically significant differences in the cortisol levels between the attempted suicide and control groups and between the depression and control groups (Studies on suicidal patients should pay more attention to the potential role of hypocortisolism. More studies with larger samples are needed to investigate the relationship between gonadotropins, gonadal hormones, and suicidal behavior.

Since the introduction of the MELD-based allocation system, women are now 30% less likely than men to undergo liver transplant (LT) and have 20% higher waitlist mortality. These disparities are in large part due to height differences in men and women though no national policies have been implemented to reduce sex disparities. Patients were identified using the Scientific Registry of Transplant Recipients (SRTR) from 2014 to 2019. Patients were categorized into five groups by first dividing into thirds by height then dividing the shortest third into three groups to capture more granular differences in the most disadvantaged patients (166 cm). We then used LSAM to model waitlist outcomes in five versions of awarding additional MELD points to shorter candidates compared to current policy. We identified two proposed policy changes LSAM scenarios that resulted in improvement in LT and death percentage for the shortest candidates with the least negative impact on taller candidates. In conclusion, awarding an additional 1-2 MELD points to the shortest 8% of LT candidates would improve waitlist outcomes for women. This strategy should be considered in national policy allocation to address sex-based disparities in LT.

The Importance of Considering System Congestion When Acquiring Used Items for Remanufacturing The condition of used items obtained by remanufacturers often varies widely and may only be truly known after an inspection. In “Technical Note–Optimal Procurement in Remanufacturing Systems with Uncertain Used-Item Condition,” Nadar, Akan, Debo, and Scheller-Wolf study the procurement problem by taking into account this pre-inspection uncertainty as well as the quantities of available used items of different quality levels. The authors provide a novel optimal policy structure for a Markov decision process representation of this problem. They prove that the optimal acquisition decision depends on the system congestion level — the total remanufacturing load weighted by the quality levels. Their results show that it becomes less desirable to acquire a used item as the number of available items or the quality level of any available item increases. To prove their results, the authors introduce a new functional characterization that is a relaxation of supermodularity and discrete convexity.

In this chapter, the authors present a simple model to determine the optimal choice of vaccination scheduling for a society composed of two groups of individuals in order to minimize the economic loss only, assuming herd immunity. First, a simple classical SIR model is presented to form the basis of the analysis; second, the model is revised to include the effects of vaccination which in turn will be extended to include two heterogeneous groups of individuals forming a society. The solutions of relevant differential equations will then be used to calculate the total economic cost of each scenario presented.

The use of cocaine, which is a stimulant substance that can quickly develop addiction, is increasing in Europe and Turkey. Cocaine use can cause psychiatric and physical diseases in the individual, but it can also cause social and legal problems. Genetic, sociocultural and pharmacological factors, some factors related to learning and conditioning have an important role in the etiology of cocaine addiction. Cocaine exerts its psychoactive and addictive effects through the limbic system in the brain, which regulates pleasure and motivation. The nucleus accumbens, which is a part of the limbic system, is the most important region that mediates the effect of cocaine. Cocaine use can often be seen together with other psychiatric diseases, and it can also cause damage by affecting other system organs, especially the central nervous system. In this article, the neurochemical effects of cocaine, related psychiatric/physical diseases and treatment options are presented in the light of current information.

Objective: In this article, we aimed to evaluate patients with Parkinson’ s disease (PD) in terms of psychiatric diseases and related clinical features. Methods: 101 patients diagnosed with PD and 101 randomly selected control cases who applied to general internal medicine and endocrine outpatient clinics were included in the study. All subjects were administered a questionnaire including questions about their sociodemographic and clinical features, and were evaluated by the psychiatrist. Results: The rate of psychiatric disease (42.6%) in the PD group was significantly higher than the control group. Anxiety disorders and depression were the most common among these diseases. Also the use of antidepressant in the PD group was higher than the control group. Conclusion: Psychiatric disorders are seen more frequently in patients with PD than in patients with other physical diseases. Considering that quality of life in patients with PD is associated with psychiatric well-being, psychiatric symptoms in patients are of high clinical importance. The physician’ s awareness of psychiatric symptoms and taking necessary precautions will contribute positively to the treatment of the disease.

We present new spectroscopic observations of the double-lined eclipsing binary V850 Cyg. The long-cadence photometric observations obtained by Kepler were analysed and combined with the analysis of radial velocities for deriving the absolute parameters of the components. Masses and radii were determined as M p =1.601 ± 0.076 M ⊙ and R p =4.239 ± 0.076 R ⊙ , M s =0.851 ± 0.053 M ⊙ and R s =5.054 ± 0.087 R ⊙ for the components of V850 Cyg. We estimate an interstellar reddening of 0.28 ± 0.12 mag and a distance of 1040 ± 160 pc for the system. The measured rotational velocity of the secondary appears to lower than that of synchronize rotation. However its spectral lines are too weak to be measured the rotational velocity with reasonable accuracy. We have extracted the synthetic light curve from the observations and excluded the data within the eclipses for the frequency analysis. We obtained at least nine frequencies in the γ Dor regime. It seems that the primary component oscillates with a dominant period of about 1.152549 ± 0.000009 days. We also compare pulsational properties of the primary star of V850 Cyg with the γ Dor type pulsating components in other binaries.

We provide a new method for solving a very general model of an assemble-to-order system: multiple products, multiple components that may be demanded in different quantities by different products, batch production, random lead times, and lost sales, modeled as a Markov decision process under the discounted cost criterion. A control policy specifies when a batch of components should be produced and whether an arriving demand for each product should be satisfied. As optimal solutions for our model are computationally intractable for even moderately sized systems, we approximate the optimal cost function by reformulating it on an aggregate state space and restricting each aggregate state to be represented by its extreme original states. Our aggregation drastically reduces the value iteration computational burden. We derive an upper bound on the distance between aggregate and optimal solutions. This guarantees that the value iteration algorithm for the original problem initialized with the aggregate solution converges to the optimal solution. We also establish the optimality of a lattice-dependent base-stock and rationing policy in the aggregate problem when certain product and component characteristics are incorporated into the aggregation/disaggregation schemes. This enables us to further alleviate the value iteration computational burden in the aggregate problem by eliminating suboptimal actions. Leveraging all of our results, we can solve the aggregate problem for systems of up to 22 components, with an average distance of 11.09% from the optimal cost in systems of up to 4 components (for which we could solve the original problem to optimality). The e-companion is available at https://doi.org/10.1287/opre.2017.1710 .

Investment behavior of a price regulated service firm facing fluctuating demand is investigated with a Cobb-Douglas type of production function using optimal control theoretic model. Both machinery and labor are assumed to be capital goods. Rates of change of demand, attrition rate of labor and the depreciation rate of capital are the primary parameters determining optimal investment behavior. Switching times between four phases of investment where (1) both labor and capital investment are positive, (2) capital investment is zero but labor investment is positive,(3) capital investment is zero but labor investment is positive and (4) where both investments are zero are identified. The same analysis is repeated using Constant Elasticity of Substitution (CES) type of production function.

Two dynamic profit maximizing models of a pension fund company are developed and solved using calculus of variations techniques. Starting with a low portfolio management fee and increasing it gradually to a level of interest rate of Government paper is shown to be the optimal strategy which is contrary to the observed behavior of such companies. Thus, this result should lead the managers of such funds to review their pricing strategies.

We consider an assemble-to-order (ATO) system with multiple products, multiple components which may be demanded in different quantities by different products, possible batch ordering of components, random lead times, and lost sales. We model the system as an infinite-horizon Markov decision process under the average cost criterion. A control policy specifies when a batch of components should be produced, and whether an arriving demand for each product should be satisfied. Previous work has shown that a lattice-dependent base-stock and lattice-dependent rationing (LBLR) policy is an optimal stationary policy for a special case of the ATO model presented here (the generalized M-system). In this study, we conduct numerical experiments to evaluate the use of an LBLR policy for our general ATO model as a heuristic, comparing it to two other heuristics from the literature: a state-dependent base-stock and state-dependent rationing (SBSR) policy, and a fixed base-stock and fixed rationing (FBFR) policy. Remarkably, LBLR yields the globally optimal cost in each of more than 22,500 instances of the general problem, outperforming SBSR and FBFR with respect to both objective value (by up to 2.6% and 4.8%, respectively) and computation time (by up to three orders and one order of magnitude, respectively) in 350 of these instances (those on which we compare the heuristics). LBLR and SBSR perform significantly better than FBFR when replenishment batch sizes imperfectly match the component requirements of the most valuable or most highly demanded product. In addition, LBLR substantially outperforms SBSR if it is crucial to hold a significant amount of inventory that must be rationed.

Akan, Mustafa (Dogus Author) -- Conference full title: 1st International Annual Meeting of Sosyoekonomi Society, October 29-30, 2015, Munich / Germany An analysis of optimal investments in technical capacity, goodwill and financial portfolios to maximize the long term profit of a nonlife company is conducted using Optimal Control Theory. Technical capacity affects both the claim ratio and the number of policies while goodwill affects only the number of policies. Financial portfolio is assumed to be optimally managed hence it is not analysed. Mathematically technical capacity (T) is assumed to obey the following differential equation; T ' = dT / dt = q - T Therefore, technical capacity increases by the investments (q) made in underwriting personnel, their education, software and hardware for technical analysis and decreases by the obsolescence of technical methods and the depreciation of hardware at a rate . Goodwill (G) is assumed by to obey the following differential equation; G' = a - G where, (a) denotes the investment made in quality and advertising and denotes the exponential rate of decline of goodwill. In a competitive insurance market (where price is constant), the profit of a company at any time t is expressed as; П=p.N(G,T)-p.N(G,T).H(T)-q-w(a) N represents number of policies sold. H(T) represents the claim ratio. q and a represents the investments made in technical capacity and goodwill respectively. w(a) represents the convex cost function of goodwill expenditures. The objective of the company is to maximize discounted profits over the infinite horizon. Analysis of the differential equations representing the necessary conditions for the solution of the problem gives the following results: 1. The company with lower than required goodwill at the beginning should increase the expenditures in both goodwill and the technical capacity at an increasing rate if the impact of technical capacity on claim ratio is greater than its impact on the number of customers. 2. The company should first invest heavily in goodwill to increase the number of customers and then increase the investment in technical capacity to decrease the claim ratio if impact of technical capacity on claim ratio is less than its impact on the number of customers. 3. A sudden drop in the level of goodwill can be increased by investment quality and advertising. Reinsurance is not included in the model since this function is a partnership function. Other expenses are assumed to be constant and hence they do affect the solution.

We study the portfolio selection problem in a new product development setting with many projects in parallel, each lasting several stages, in the face of uncertainty. Each stage of the process performs an experiment on a selected number of projects in the stage, depending on the amount of (scarce) budget allocated to the stage. Projects become differentiated through their experimental results, and all available results for a project determine its category.We model the problem as a Markov decision process. We seek an optimal policy that specifies, for every configuration of projects in categories, which projects to test and/or terminate. For two special cases we characterize the optimal project promotion policy as following a new type of strategy, state-dependent non-congestive promotion (SDNCP). SDNCP implies that a project with the highest expected reward in any stage is advanced to the next stage if and only if the number of projects in each successor category is below a congestion-dependent threshold. For the general problem, numerical experiments reveal the outstanding performance of SDNCP (optimal in 72 of 77 instances with maximum deviation from optimal of 0.67%), highlighting when and how a fixed non-congestive promotion policy, which is easier to implement, may fall short.

The speed of the application of current economic policies that are being followed in Turkey is a very important question. This paper uses the results of the solutions of optimal control theoretic inventory and production problems for companies to offer opinions on this question under various assumptions on interest rates. The most important result of the paper is that the rate of decline of interest rates is as important as the absolute level of interest rates for investors to start investing in inventories (consequently in machinery and other production infrastructure) which, in turn, implies growth of the economy.