109 research outputs found

    IterCQR: Iterative Conversational Query Reformulation with Retrieval Guidance

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    Conversational search aims to retrieve passages containing essential information to answer queries in a multi-turn conversation. In conversational search, reformulating context-dependent conversational queries into stand-alone forms is imperative to effectively utilize off-the-shelf retrievers. Previous methodologies for conversational query reformulation frequently depend on human-annotated rewrites. However, these manually crafted queries often result in sub-optimal retrieval performance and require high collection costs. To address these challenges, we propose Iterative Conversational Query Reformulation (IterCQR), a methodology that conducts query reformulation without relying on human rewrites. IterCQR iteratively trains the conversational query reformulation (CQR) model by directly leveraging information retrieval (IR) signals as a reward. Our IterCQR training guides the CQR model such that generated queries contain necessary information from the previous dialogue context. Our proposed method shows state-of-the-art performance on two widely-used datasets, demonstrating its effectiveness on both sparse and dense retrievers. Moreover, IterCQR exhibits superior performance in challenging settings such as generalization on unseen datasets and low-resource scenarios

    Direct relation between the low-energy spin excitations and superconductivity of overdoped high-TcT_c superconductors

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    The dynamic spin susceptibility, χ(ω)\chi''(\omega), has been measured over the energy range of 2ω102 \leq \omega \leq 10 meV for overdoped La2x_{2-x}Srx_{x}CuO4_{4}. Incommensurate (IC) spin excitations are observed at 8 K for all superconducting samples for 0.25x0.280.25 \leq x \leq 0.28 with χ\chi'' peaking at 6\sim 6 meV. The IC peaks at 6 meV become smaller in intensity with increasing xx and, finally, become unobservable for a sample with x=0.30x=0.30 which has no bulk superconductivity. The maximum χ\chi'' decreases linearly with TcT_c(onset) in the overdoped region, implying a direct cooperative relation between the spin fluctuations and the superconductivity.Comment: 4 pages, 4 figure

    Dialogizer: Context-aware Conversational-QA Dataset Generation from Textual Sources

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    To address the data scarcity issue in Conversational question answering (ConvQA), a dialog inpainting method, which utilizes documents to generate ConvQA datasets, has been proposed. However, the original dialog inpainting model is trained solely on the dialog reconstruction task, resulting in the generation of questions with low contextual relevance due to insufficient learning of question-answer alignment. To overcome this limitation, we propose a novel framework called Dialogizer, which has the capability to automatically generate ConvQA datasets with high contextual relevance from textual sources. The framework incorporates two training tasks: question-answer matching (QAM) and topic-aware dialog generation (TDG). Moreover, re-ranking is conducted during the inference phase based on the contextual relevance of the generated questions. Using our framework, we produce four ConvQA datasets by utilizing documents from multiple domains as the primary source. Through automatic evaluation using diverse metrics, as well as human evaluation, we validate that our proposed framework exhibits the ability to generate datasets of higher quality compared to the baseline dialog inpainting model.Comment: Accepted to EMNLP 2023 main conferenc

    Magnetic properties of the overdoped superconductor La2x_{2-x}Srx_{x}CuO4_{4} with and without Zn impurities

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    The magnetic properties of the Zn-substituted overdoped high-TcT_c superconductor La2x_{2-x}Srx_{x}Cu1y_{1-y}Zny_{y}O4_{4} have been studied by magnetization measurements and neutron scattering. Magnetization measurements reveal that for Zn-free samples with x0.22x \geq 0.22 a Curie term is induced in the temperature dependence of the magnetic susceptibility implying the existence of local paramagnetic moments. The induced Curie constant corresponds to a moment of 0.5 μB\mu_B per additional Sr2+^{2+} ion that exceeds x=0.22x=0.22. Zn-substitution in the overdoped \lsco also induces a Curie term that corresponds to 1.2 μB\mu_B per Zn2+^{2+} ion, simultaneously suppressing TcT_c. The relationship between TcT_c and the magnitude of the Curie term for Zn-free \lsco with x0.22x \geq 0.22 and for Zn-substituted \lsco with x=0.22x = 0.22 are closely similar. This signifies a general competitive relationship between the superconductivity and the induced paramagnetic moment. Neutron scattering measurements show that Zn-substitution in overdoped \lsco anomalously enhances the inelastic magnetic scattering spectra around the (π,π)(\pi, \pi) position, peaking at ω7\omega \sim 7 meV. These facts are discussed on the basis of a "swiss-cheese" model of Zn-substituted systems as well as a microscopic phase separation scenario in the overdoped region indicated by muon-spin-relaxation measurements.Comment: 10 pages, 8 figure

    Treatment Using a Long Pulsed Nd:Yag Laser with a Pulsed Dye Laser for Four Cases of Blebbed Port Wine Stains

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    Port wine stains (PWS) are congenital capillary malformations consisting of ectasia of capillaries and venules. At birth,lesions are flat and relatively uniform in color, but evolve with age to become raised, thickened, irregularly surfaced, and deeply colored. Therefore, it is considered optimal to begin treatment of patients at an early age. Conventional treatment modalities, such as electrocautery or excision, require considerable effort and may be cosmetically unsatisfactory. We have performed treatment of blebbed PWS of four patients using a 1,064 nm long pulsed Nd:YAG laser with a contact cooling device. According to their size, most blebs required three or fewer treatment sessions at 8-week intervals. Treatments were well tolerated by all subjects and patients showed moderate to good improvement of blebs. A 1,064 nm long pulsed Nd:YAG laser with contact cooling may be considered as a promising therapeutic option for treatment of blebbed PWS

    PHF7 Modulates BRDT Stability and Histone-to-Protamine Exchange during Spermiogenesis

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    Chang Rok Kim, Taichi Noda, Hyunkyung Kim, Gibeom Kim, Seongwan Park, Yongwoo Na, Seiya Oura, Keisuke Shimada, Injin Bang, Jun-Yeong Ahn, Yong Ryoul Kim, Se Kyu Oh, Hee-Jung Choi, Jong-Seo Kim, Inkyung Jung, Ho Lee, Yuki Okada, Masahito Ikawa, Sung Hee Baek, PHF7 Modulates BRDT Stability and Histone-to-Protamine Exchange during Spermiogenesis, Cell Reports, Volume 32, Issue 4, 2020, 107950, ISSN 2211-1247, https://doi.org/10.1016/j.celrep.2020.107950

    Micafungin prophylaxis for acute leukemia patients undergoing induction chemotherapy

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    Background Micafungin is a well-tolerated and effective prophylactic antifungal agent used in hematologic diseases. In this prospective trial, we evaluated the efficacy and safety of prophylactic micafungin during first induction chemotherapy in patients with acute leukemia. We also compared outcomes of prophylactic micafungin with those of prophylactic posaconazole in acute myeloid leukemia (AML). Methods Medically fit patients with newly diagnosed acute leukemia received 50 mg micafungin intravenously once daily from the initiation of first induction chemotherapy to recovery of neutrophil count, suspected fungal infection, or unacceptable drug-related toxicity (Clinicaltrials.gov number, NCT02440178). The primary end point was incidence of invasive fungal infection, and the secondary end points were adverse events of prophylactic micafungin and mortality during induction therapy. Results The 65 patients (median age = 51 years, male:female = 34:31) enrolled in this study had diagnoses of AML (33, 50.8%), acute lymphoblastic leukemia (31, 47.7%), and acute biphenotypic leukemia (1, 1.5%). Median duration of micafungin treatment was 24 days (range 1–68), with proven invasive fungal disease in one patient (1.5%) and possible fungal infection in two patients (3.1%). Three of the patients (4.6%) experienced the following adverse events, but all events were tolerable: liver function abnormality (Grade 2, n = 1; Grade 3, n = 1) and allergic reaction (Grade 2, n = 1). Three patients died during induction therapy, and invasive aspergillosis pneumonia was the cause of death for one of those patients. Overall, 19 patients (29.2%) discontinued prophylactic micafungin, and 18 (27.7%) patients switched to another antifungal agent. We observed no fungal infections caused by amphotericin B-resistant organisms. In AML patients, outcomes of prophylactic micafungin during induction chemotherapy did not differ significantly with those of prophylactic posaconazole with regard to incidence of fungal infections, rate of discontinuation, or safety. Conclusions Our study demonstrates that prophylactic micafungin is safe and effective in patients with acute leukemia undergoing induction chemotherapy. Outcomes in patients with AML were similar to those of prophylactic posaconazole, indicating the usefulness of micafungin as a prophylactic antifungal agent during induction chemotherapy for AML. Trial registration Clinicaltrials.gov NCT02440178, registered May 12th 2015.This study was funded by Astellas Pharma Korea, Inc. Funding source had no role in the study design, data collection, data analysis or data interpretation

    Uv To Soft X-Ray Continuum Characteristics Of Bright Quasars 3c 273 And 1e1821+643

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    1821+643 were taken from Kolman et al. (1993). We then empirically characterize the shape of the UV continuum of 3C 273 and 1E1821+643. We model the continuum as a power-law curve and all the identified emission and absorption features in the observed spectrum as Gaussian profiles. We use the program SPECFIT (Kriss 1994) to fit the observed spectrum. SPECFIT runs in IRAF and determines best-fit parameters by simplex or Marquardt non-linear minimization of Ø 2 . As shown in Fig. 1a (the dot-dashed curve represents the best-fit continuum), the HUT spectrum of 3C 273 shows a distinct break in the continuum slope just longward of the redshifted Lyman edge (marked as L.E.). The continuum shape of 3C 273 is empirically well characterized by a broken power law in F . This continuum break may be a signature of the Lyman edge in the thermal spectrum of an accretion disk (Lee 1995). The combined HUT and HST=FOS&lt
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