DNAを利用した反応拡散システムのプログラミング

Tohoku University村田智課

Catch more to catch less: Estimation of fishing timing choice as bycatch avoidance behavior in the Bering Sea Pollock fishery

This study develops a dynamic model of the harvesters’ choice of when to use individual fishing quota (IFQ), considering time-varying rates of potentially limiting bycatch, and a time-varying outside opportunity. The temporal allocation of IFQ over a season by harvesters has not been well-studied empirically due to complexity of the dynamic problem. In this paper, we focus on participation and target species as the harvester’s margin, which is flexibly chosen under IFQ management. To explore the incentive, we theoretically model harvesters’ seasonal profit maximizing behavior under constraints provided by regulations in the target, bycatch, and alternative fisheries. The solution motivates us to incorporate the dynamic quota use in a simple discrete choice model to estimate the harvesters’ choice. To link the shadow cost of quota in our theoretical model and harvester behavior in the data, we construct a variable which is the speed of quota usage relative to the remaining season weighted by the revenue opportunity and captures the harvesters’ forward-looking decision. The application of this empirical model is implemented with the AFA Alaskan pollock catcher-processor fleet. The result indicates that the harvesters are less likely to participate in the pollock fishery when the quota usage is too fast relative to the remaining time, suggesting that the dynamic planning plays a role, and the estimates of the coefficients on bycatch rate supports the dynamic avoidance behavior of bycatch

Harvesters’ Dynamic Decision on Fishing Trip Duration

This study investigates harvesters’ effort in terms of days at using dynamic discrete choice model. Fishing effort as a form of time has been analyzed with trip level data, in which only averaged daily catch is available. On the other hand, daily level data enables us to have the variation of daily catch within a trip. Such variation provides more information than averaged daily catch in two ways. Firstly, it can capture how the harvesters update the expectation of future catch. Secondly, it also captures the daily change in the state variables such as total weight and freshness of caught fish. This study incorporates these factors in a dynamic discrete choice model of a fishing trip. We suggest freshness as a critical factor in determining fishing trip duration. Using daily logbook data from a Japanese-based longline fishery, we find the effect of freshness on trip length. The result shows that the catch older than 15 days significantly decreases the probability of a trip continuation. Our use of daily data resolves the endogeneity present in this related work and identifies the tradeoff between freshness and increased catch, capturing the intra-trip variation that drives the marginal decision to remain at sea or return to port.

Optimal Spatial Strategy of the Fishing Efforts for Heterogeneous Fishing Grounds

This study explores the optimal spatial strategy for fishing efforts for subdivided on fishing grounds for different economic performance. We analyze the Japanese off-shore longline fishing vessel groups targeting swordfish and blue shark in the North Pacific. The seasonal dynamic optimal spatial strategy to maximize the economic performance is explored with identified fishing grounds by the cluster analysis. This study carries out the sensitivity analysis to see how the optimal strategy changes when the input parameters (e.g., ex-vessel price), objective functions and benefit allocation scheme between vessel owners and crews are varied. The results suggest that the robust optimal spatial strategy is to minimize the days per trip to maintain flexibility of destination of fishing grounds

Exploring Optimum Economic Efficiency of Fishing: Shall We Move from the Tradition in the Post-Tsunami Fishery?

An empirically-estimated production function for a Japanese off-shore longline fishing vessel for swordfish fishery is integrated with a demand model and operating costs. This integrated model is used to explore optimal fishing efforts, a combination of days for (a) searching fishing grounds and (b) actual longline fishing operations.  The results demonstrate explicit differences between the optimizing combination of two fishing efforts to maximize economic efficiency and fishing efforts resulted from a traditional revenue share scheme under limited- open access situation. Our result suggests that this group of vessels operates close to the open access equilibrium which is not optimal for the economic maximization, and encourage them to move new revenue share scheme to induce optimal fishing efforts to rationalize their operation.

Dynamic Target Choice Model In Multi-Fisheries

This study estimates the harvesters’ dynamic target fishery choice by building an empirical model incorporating dynamic quota use with the insight from a theoretical model. The harvesters’ behavior, which purposes to maximize seasonal profit under constraints of the regulations, are theoretically modeled and solved using a dynamic optimization method. The solution motivates us to incorporate the dynamic quota use in a simple discrete choice model to estimate the harvesters’ choice. Choice behavior of fisheries has been analyzed using a discrete choice models. The application of this model is implemented with an offshore fleet in Alaskan groundfish fishery, which has appropriate feature to apply the model such as multiple target choices and individual quota. The result indicates that the dynamic variable, quota use, adjusts the incentive to catch pollock for revenue, and it largely lessened the avoidance behavior. We run a simulation of a policy alternative that opens fishing season earlier using the parameter estimates and evaluate the potential effect of the policy on bycatch reduction induced by the change in harvesters’ fishery choice behavior.

Prospection des eaux souterraines dans la région de Niellé (Nord de la Côte d’Ivoire): Efficience de la méthode de résistivité électrique

The National Office of Drinking Water (ONEP) has initiated a study at Niellé to strengthen the drinking water production capacity of this locality. The aim of this study is to identify cracks aquifers for the choice of highflowrate drill sites. The study consists in an analysis previous drilling, a prospective study by geophysics and selection of drilling sites. This work shows that the hydraulically active fractures in the region is optimal in the upper part of the fissured horizon located in the first thirty meters under saprolites. The electrical method was used to locate and characterize fractures in various directions including those oriented N164 °, N100 ° and N86 °. They were selected for the drilling site choice. A drilling was carried out with an hourly flow rate of 10.2 m3 / h. This work also showed that the fracture- geomorphological combination the combined study of fracking and geomorphological analysis allows precise selection of drilling sites

Accurate interpretation of genetic variants in sudden unexpected death in infancy by trio-targeted gene-sequencing panel analysis

In sudden unexpected death in infancy cases, postmortem genetic analysis with next-generation sequencing potentially can extract candidate genes associated with sudden death. However, it is difficult to accurately interpret the clinically significant genetic variants. The study aim was to conduct trio analysis of cases of sudden unexpected death in infancy and their parents to more accurately interpret the clinically significant disease-associated gene variants associated with cause of death. From the TruSight One panel targeting 4813 genes we extracted candidate genetic variants of 66 arrhythmia-, 63 inherited metabolic disease-, 81 mitochondrial disease-, and 6 salt-losing tubulopathy-related genes in 7 cases and determined if they were de novo or parental-derived variants. Thirty-four parental-derived variants and no de novo variants were found, but none appeared to be related to the cause of death. Using trio analysis and an in silico algorithm to analyze all 4813 genes, we identified OBSCN of compound heterozygous and HCCS of hemizygous variants as new candidate genetic variants related to cause of death. Genetic analysis of these deceased infants and their living parents can provide more accurate interpretation of the clinically significant genetic variants than previously possible and help confirm the cause of death

Effects of psychotherapy for middle-aged individuals with anxiety disorders in a general medicine practice

Background: Anxiety disorders are mental disorders that cause somatic symptoms for which patients may seek care from generalmedicine departments. We focused on anxiety disorders in middle-aged patients and examined the effect of a psychotherapeuticintervention.Materials and Methods: The participants were 14 middle-aged patients diagnosed with an anxiety disorder. Patients receivedpretreatment assessments and were randomly assigned to a pharmacotherapy group (n = 8) or a pharmacotherapy and psychotherapygroup (n = 6). The duration of the study was three months. Pre-and post-treatment, the Medical Outcomes Study 36-ItemShort-Form Health Survey (SF-36), State-Trait Anxiety Inventory (STAI), and a visual analog scale (VAS) were administered. Inthe pharmacotherapy and psychotherapy group, salivary cortisol was collected pre- and post-psychotherapy at the first and finalpsychotherapy sessions.Result: Four patients in the pharmacotherapy group withdrew from the study. There were no significant differences in the totalscores of the SF-36 or STAI between groups. Improvement was seen in the pharmacotherapy and psychotherapy group pre- andpost- treatment. SF-36 subscales of bodily pain (p = 0.02) and mental health (p = 0.04) were significantly higher than posttreatment.The state anxiety score on the STAI improved post-treatment (p = 0.03). On the VAS, the pharmacotherapy and psychotherapygroup’s symptoms were significantly improved (p = 0.02).Conclusion: This suggests that psychotherapy for middle-aged individuals contributes to the improvement of anxiety states andHRQoL in general medicine departments. It promotes the recognition of curative effects and prevents doctor shopping

Enteropathy-Type Intestinal T-Cell Lymphoma Showing Jejunoileal Fistula: Report of a Case

Jejunoileal fistula is an extremely rare complication in patients with intestinal lymphoma. Here, we report a Japanese male patient with enteropathy-type intestinal T-cell lymphoma presenting abdominal pain and weight loss. A jejunoileal fistula was discovered during colonoscopy and pathological diagnosis was performed preoperatively by forceps biopsy. After elective surgery for partial resections of jejunum, ileum, and sigmoid colon, eight cycles of cyclophosphamide, doxorubicin, vincristine and prednisolone chemotherapy led complete remission of the disease