67 research outputs found

    Brief Announcement: Fast Aggregation in Population Protocols

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    The coalescence protocol plays an important role in the population protocol model. The conceptual structure of the protocol is for two agents holding two non-zero values a, b respectively to take a transition (a,b) -> (a+b, 0), where + is an arbitrary commutative binary operation. Obviously, it eventually aggregates the sum of all initial values. In this paper, we present a fast coalescence protocol that converges in O(sqrt(n) log^2 n) parallel time with high probability in the model with an initial leader (equivalently, the model with a base station), which achieves an substantial speed-up compared with the naive implementation taking Omega(n) time

    Time-Optimal Loosely-Stabilizing Leader Election in Population Protocols

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    We consider the leader election problem in the population protocol model. In pragmatic settings of population protocols, self-stabilization is a highly desired feature owing to its fault resilience and the benefit of initialization freedom. However, the design of self-stabilizing leader election is possible only under a strong assumption (i.e., the knowledge of the exact size of a network) and rich computational resource (i.e., the number of states). Loose-stabilization is a promising relaxed concept of self-stabilization to address the aforementioned issue. Loose-stabilization guarantees that starting from any configuration, the network will reach a safe configuration where a single leader exists within a short time, and thereafter it will maintain the single leader for a long time, but not necessarily forever. The main contribution of this paper is giving a time-optimal loosely-stabilizing leader election protocol. The proposed protocol with design parameter ? ? 1 attains O(? log n) parallel convergence time and ?(n^?) parallel holding time (i.e., the length of the period keeping the unique leader), both in expectation. This protocol is time-optimal in the sense of both the convergence and holding times in expectation because any loosely-stabilizing leader election protocol with the same length of the holding time is known to require ?(? log n) parallel time

    A Surprisingly Non-attractiveness of Commercial Poison Baits to Newly Established Population of White-Footed Ant, Technomyrmex brunneus (Hymenoptera: Formicidae), in a Remote Island of Japan

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    The white-footed ant, Technomyrmex brunneus, was newly introduced and established in a remote island of Japan and has caused unacceptable damage to the daily life of residents. To establish proper control measures, the present study investigated whether T. brunneus is effectively attracted to commercially available poison baits used to exterminate common household pest ants and the Argentine ant in Japan. Cafeteria experiments using three types of nontoxic baits and eight types of commercial poison baits for ants were conducted in the field, and the attractiveness was compared among the baits. The liquid poison bait “Arimetsu,” which consists of 42.6% water, 55.4% sugar, and 2.0% borate, and nontoxic 10% (w/v) sucrose water showed the highest attractiveness. On the other hand, other commercial poison baits were not as attractive. Therefore, sucrose liquid is the most effective attractive component to use in poison baits for T. brunneus

    Partial Gathering of Mobile Agents in Dynamic Tori

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    Study Protocol for Assessing the Efficacy of Compression Therapy Using Stockings and Sleeves to Prevent Docetaxel-Induced Peripheral Neuropathy in Breast Cancer Patients

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    Taxanes are key drugs for patients with breast cancer. A major adverse effect associated with the administration of the taxane docetaxel is chemotherapy-induced peripheral neuropathy (CIPN). We are conducting a singlecenter, single-arm, open-label historical control trial to evaluate the ability of compression therapy using stockings or sleeves to prevent CIPN due to docetaxel treatment. The primary endpoint is the incidence of all-grade CIPN according to patients’ records until 3 weeks after the fourth docetaxel administration. This study’s results will clarify whether compression therapy using stockings or sleeves can prevent CIPN in breast cancer patients

    An Evaluation of the Efficacy of Compression Therapy Using Sleeves and Stockings to Prevent Docetaxel-induced Peripheral Neuropathy in Breast Cancer Patients

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    Taxanes are key drugs for patients with breast cancer. A major adverse effect of taxanes is peripheral neuropathy (PN). To investigate the ability of compression therapy using sleeves and stockings to prevent PN due to the taxane docetaxel, we conducted a single-center historical control trial. Patients receiving docetaxel at 75 mg/m2 every 3 weeks for 4 cycles as first-line chemotherapy for breast cancer were eligible. PN was evaluated using the common terminology criteria for adverse events version 4.0. The primary endpoint was the incidence of allgrade PN until 3 weeks after the fourth docetaxel administration. We evaluated 26 patients in the intervention group and compared their data to those collected retrospectively from 52 patients treated with docetaxel without compression. Neither the incidence of all-grade PN until 3 weeks after the fourth docetaxel administration (63.5% in the control group vs. 76.9% in the intervention group, p=0.31) nor that of PN grade ≥ 2 (13.5% vs. 15.4%, p=0.99) differed between the groups. In this study, the efficacy of compression therapy using sleeves and stockings to prevent PN induced by docetaxel was not demonstrated. Further clinical studies including medications or intervention are needed to reduce the incidence and severity of PN induced by chemotherapy

    The Efficacy of Software to Help Patients Understand Drug for Adjuvant Treatment for Breast Cancer: A Pilot Randomized Controlled Trial

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    We assessed the usefulness of ChemoCalc, a software package for calculating drug costs, in helping patients understand these costs. We randomly assigned, in a 1 : 1 ratio, 20 women who had undergone surgery for early breast cancer to a group that discussed adjuvant treatment with their physicians using the ChemoCalc software (ChemoCalc group) or a group that discussed adjuvant treatment without ChemoCalc (Usual Explanation group). The participants completed a five-grade evaluation questionnaire after these discussions. The primary endpoint was the intergroup comparison of the questionnaire scores regarding participants’ understanding of their treatment-associated drug costs. Median age was not significantly different between the ChemoCalc group and Usual Explanation group (57 vs. 50, respectively; p=0.27). Patients in the ChemoCalc group had a significantly higher perceived level of understanding of the drug cost than those in the Usual Explanation group (5 [4-5] vs. 2.5 [1-5], respectively; p=0.002). Scores related to the patients’ perception that understanding drug costs is an important part of breast cancer treatment were also higher in the ChemoCalc group than the Usual Explanation group (5 [2-5] vs. 3 [1-5], respectively; p=0.049). ChemoCalc was found to be useful for understanding drug costs

    Tumor-Infiltrating Lymphocytes and Macrophages as a Significant Prognostic Factor in Biliary Tract Cancer

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    Background: The impact of tumor-infiltrating lymphocytes (TILs) and tumor-associated macrophages (TAMs) on the prognosis of biliary tract cancer (BTC) is not completely understood. Therefore, in our study, we investigated the effects of the various immune cells infiltration in tumor microenvironment (TME). Methods: A total of 130 patients with BTC who underwent surgical treatment at our institution were enrolled in this study. We retrospectively evaluated TILs and TAMs with immunohistochemical staining. Results: With CD8-high, CD4-high, FOXP3-high, and CD68-low in TME as one factor, we calculated Immunoscore according to the number of factors. The high Immunoscore group showed significantly superior overall survival (OS) and recurrence-free survival (RFS) than the low Immunoscore group (median OS, 60.8 vs. 26.4 months, p = 0.001; median RFS not reached vs. 17.2 months, p \u3c 0.001). Also, high Immunoscore was an independent good prognostic factor for OS and RFS (hazards ratio 2.05 and 2.41 and p = 0.01 and p = 0.001, respectively). Conclusions: High Immunoscore group had significantly superior OS and RFS and was an independent good prognostic factor for OS and RFS

    Lymphedema After Axillary Lymph Node Dissection in Breast Cancer: Prevalence and Risk Factors—A Single-Center Retrospective Study

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    Background: Lymphedema may develop when axillary lymph node dissection (ALND) injures and obstructs the lymph ducts in the upper limb. In patients with breast cancer, lymphedema is difficult to treat and can cause arm swelling, heaviness, and restricted movement. We aimed to identify the prevalence and risk factors for lymphedema after ALND in patients with breast cancer.Methods and Results: This retrospective study included 175 patients with breast cancer who underwent ALND in the Nagasaki University Hospital, Japan, between 2005 and 2018. Lymphedema was defined as symptomatic arm swelling with a >2-cm difference in the arm circumference between the affected and contralateral arms. Patients were divided into two groups according to the presence or absence of lymphedema. Surgical and pathological findings were compared between the two groups. Univariate and multivariate analyses were performed, including the chi-square test, Student’s t-test, and logistic regression analysis. Lymphedema was prevalent in 20% of the study participants, and the mean time interval from surgery to development of lymphedema was 479 days. In the univariate analysis, a body mass index of >26 kg/m2, smoking, radiotherapy (RT), and dissection of >18 axillary lymph nodes (ALNs) significantly increased the risk of lymphedema. In the multivariate analysis, smoking, RT, and dissection of >18 ALNs significantly increased the risk of lymphedema.Conclusions: The prevalence of lymphedema in our study was 20%. Our findings suggest that smoking, RT, and dissection of >18 ALNs are risk factors for lymphedema. Aggressive and empiric ALND might be associated with axillary lymph duct damage
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