Direct Response Research Articles

Simulation research on the characteristics of a minitype neutron reference radiation field

In order to research the characteristics of minitype neutron reference radiation field regulated by ISO 8529 series standards, Monte Carlo simulation method was applied to calculate the ratio of room-scattered neutron response to the direct neutron response, neutron fluence and energy spectra in the radiation field. Firstly, the characteristics of the field were investigated from the four physical factors as shielding materials, field sizes, shielding thicknesses and borated polyethylene with different boron contents. Secondly, the response of sphere instrument with different diameters in the field and the influence of instrument on the field were analyzed. The results showed that minitype neutron reference radiation field with a size of 2 m × 2 m × 2 m, a shielding material of 5 % borated polyethylene and a shielding thickness of 10 cm was expected to be used for the calibration of neutron measuring instrument.

Toward enhancing web privacy on HTTPS traffic: A novel SuperLearner attack model and an efficient defense approach with adversarial examples

Web privacy-enhancing technologies have been grown to preserve the users' privacy against sophisticated traffic analysis attacks aimed at inferring sensitive information. An especially concerning form of traffic analysis attacks is website fingerprinting attacks, allowing local eavesdroppers to identify a user's visited websites over encrypted connections. Leveraging recent advances in AI methods and aligned with the principle of adversarial thinking (think like an adversary), our objective is to better understand privacy vulnerabilities of HTTPS traffic against ever-evolving traffic analysis attacks. Therefore, as a novel contribution, we propose an HTTPS website fingerprinting attack model called Super-Learner Attack, an ensemble of base learners to exploit the strengths and diminish the weaknesses of the individual base learners, including LogisticRegression, DecisionTreeClassifier, Gaussian Naive Bayes, KNeighborsClassifier, AdaboostClassifier, BaggingClassifier, RandomForestClassifier, and ExtraTreeClassifier. The SuperLearner aims to learn fusion weights in a data-adaptive manner to obtain the optimal combination of the base learners. The proposed attack attains a high accuracy of over 97% on HTTPS traffic, outperforming existing attack models. Furthermore, responding to the challenge of website fingerprinting attacks and in direct response to the SuperLearner Attacker, we propose HTTPS Obfuscation Defender. This is a novel and highly effective defense strategy rooted in deception. This strategy disrupts classification by skillfully introducing fake packets into real flows, obfuscating patterns, and disrupting classification. Unlike previous methods, our approach leverages adversarial example algorithms originally designed for image analysis, to generate maximal obfuscation in encrypted HTTPS traffic. It generates perturbations for encrypted HTTPS traffic through the utilization of three well-established adversarial example algorithms. Our experimental results demonstrate that HTTPS Obfuscation Defender significantly reduces the accuracy of website fingerprinting from 97.2% to 2.89%, even when an attacker attempts to adapt to the defense and retrain a classifier using defended traffic. Moreover, our proposed defense ensures a minimal impact on time and bandwidth, making it a highly practical and resource-efficient defense approach.

ANALISIS KUALITAS LAYANAN PERUSAHAAN DAERAH AIR MINUM PADA PELAYANAN AIR BERSIH DI KECAMATAN TIRAWUTA KABUPATEN KOLAKA TIMUR

The research aims to analyze the quality of PDAM Tirta Simbune services in East Kolaka Regency, with a focus on clean water services in Tirawuta District. East Kolaka Regency has abundant water resource potential, but there are still various challenges in providing quality and adequate drinking water to the community. This research uses secondary data analysis methods and customer surveys to identify existing problems and increase understanding of customer needs and expectations for PDAM services. Data was collected from PDAM, the local government, and through a survey involving several PDAM customers in Tirawuta District. The research results illustrate that the service quality of PDAM Tirta Simbune is quite good when seen from direct evidence, reliability, responsiveness, assurance and empathy, but there is still a need for improvements in facilities and infrastructure. Meanwhile, factors that influence service quality are external influences and also internal influences. Internal influences can relatively be controlled by the company, for example, facilities and infrastructure, discipline, employee responsibility, employee ability, politeness, speed of response, ease of service procedures, suitability of procedures, clarity of service, and thoroughness of transactions, while external influences such as building relationships with customers, flow Dry season, rainy season flow and professionalism in resolving customer complaints.

BUILDING A STRATEGIC PARTNERSHIP: TURNING CHALLENGES INTO OPPORTUNITIES

Abstract The University of North Georgia’s Institute for Healthy Aging (IHA) and the Georgia Department of Human Services, Division of Aging Services (DAS), have partnered to address critical workforce needs in the program areas of Elder Abuse, Neglect and Exploitation and Public Guardianship. Working together they have aligned requirements a new University System of Georgia degree, the Nexus degree, with the educational and experiential requirements of employment in these DAS program areas. The University System of Georgia’s Nexus Degree, a new academic credential and the first new degree program in the United States since the 1890s when the associate’s degree was added, was designed to help more Georgians access careers in high demand areas. Creation of this degree is in direct response to talent demand analysis with employers in high demand career areas. The Division of Aging Services faces many challenges that hamper finding and retaining the right workers for the difficult but rewarding roles in Adult Protective Services and Public Guardianship. This presentation will outline the DAS needs and UNG academic program, and how working together to meet the needs of at-risk elders, a direct pipeline to employment has been developed. This paper will discuss and provide insight into this unique collaboration and newly created training approach.

Living with Cerebrotendinous Xanthomatosis: Patient, Caregiver, and Expert Perspectives.

In this article, patients with cerebrotendinous xanthomatosis (CTX) and caregivers detail their experience with lifelong symptoms, diagnosis, treatment and efficacy, and ongoing disease management. One patient and four caregivers describe the challenges associated with pursuing a correct diagnosis for years before testing confirmed a CTX diagnosis. They also detail their ongoing struggles and desire for greater access to physicians with CTX knowledge and to reliable online resources to continue their education about the disease and strategies for symptom management. The expert perspective is a direct response by three CTX researchers, including physicians who are treating patients with CTX in the United States and experts whose laboratories provide genetic and biochemical testing for CTX. They respond to many of the patient and caregiver concerns, including steps that are being taken to identify CTX earlier and provide access to confirmatory diagnostic testing sooner, and suggest the best online resources for CTX-related information and access to webinars and support groups. While the expert perspective is a direct response to the patient and caregiver authors' CTX journeys, it should be beneficial to any patient with CTX or their caregivers.

Preclinical assessment of an anti-HTLV-1 heterologous DNA/MVA vaccine protocol expressing a multiepitope HBZ protein

BackgroundHuman T-lymphotropic virus 1 (HTLV-1) is associated with the development of several pathologies and chronic infection in humans. The inefficiency of the available treatments and the challenge in developing a protective vaccine highlight the need to produce effective immunotherapeutic tools. The HTLV-1 basic leucine zipper (bZIP) factor (HBZ) plays an important role in the HTLV-1 persistence, conferring a survival advantage to infected cells by reducing the HTLV-1 proteins expression, allowing infected cells to evade immune surveillance, and enhancing cell proliferation leading to increased proviral load.MethodsWe have generated a recombinant Modified Virus Vaccinia Ankara (MVA-HBZ) and a plasmid DNA (pcDNA3.1(+)-HBZ) expressing a multiepitope protein based on peptides of HBZ to study the immunogenic potential of this viral-derived protein in BALB/c mice model. Mice were immunized in a prime-boost heterologous protocol and their splenocytes (T CD4+ and T CD8+) were immunophenotyped by flow cytometry and the humoral response was evaluated by ELISA using HBZ protein produced in prokaryotic vector as antigen.ResultsT CD4+ and T CD8+ lymphocytes cells stimulated by HBZ-peptides (HBZ42–50 and HBZ157–176) showed polyfunctional double positive responses for TNF-α/IFN-γ, and TNF-α/IL-2. Moreover, T CD8+ cells presented a tendency in the activation of effector memory cells producing granzyme B (CD44+High/CD62L−Low), and the activation of Cytotoxic T Lymphocytes (CTLs) and cytotoxic responses in immunized mice were inferred through the production of granzyme B by effector memory T cells and the expression of CD107a by CD8+ T cells. The overall data is consistent with a directive and effector recall response, which may be able to operate actively in the elimination of HTLV-1-infected cells and, consequently, in the reduction of the proviral load. Sera from immunized mice, differently from those of control animals, showed IgG-anti-HBZ production by ELISA.ConclusionsOur results highlight the potential of the HBZ multiepitope protein expressed from plasmid DNA and a poxviral vector as candidates for therapeutic vaccine.

Electrochemiluminescence Sensor Based on CeO2 Nanocrystalline for Hg2+ Detection in Environmental Samples.

The excessive concentration of heavy-metal mercury ions (Hg2+) in the environment seriously affects the ecological environment and even threatens human health. Therefore, it is necessary to develop rapid and low-cost determination methods to achieve trace detection of Hg2+. In this paper, an Electrochemiluminescence (ECL) sensing platform using a functionalized rare-earth material (cerium oxide, CeO2) as the luminescent unit and an aptamer as a capture unit was designed and constructed. Using the specific asymmetric matching between Hg2+ and thymine (T) base pairs in the deoxyribonucleic acid (DNA) single strand, the "T-Hg-T" structure was formed to change the ECL signal, leading to a direct and sensitive response to Hg2+. The results show a good linear relationship between the concentration and the response signal within the range of 10 pM-100 µM for Hg2+, with a detection limit as low as 0.35 pM. In addition, the ECL probe exhibits a stable ECL performance and excellent specificity for identifying target Hg2+. It was then successfully used for spiked recovery tests of actual samples in the environment. The analytical method solves the problem of poor Hg2+ recognition specificity, provides a new idea for the efficient and low-cost detection of heavy-metal pollutant Hg2+ in the environment, and broadens the prospects for the development and application of rare-earth materials.

Evidence of an intracellular creatine-sensing mechanism that modulates creatine biosynthesis via AGAT expression in human HAP1 cells

Cellular homeostasis of creatine (CT), integral part of the energy buffering and transducing system connecting intracellular sites of ATP production and utilization, comprises of mechanisms that increase CT, i.e., biosynthesis and cellular uptake, and CT-lowering processes, such as export and non-enzymatic conversion to creatinine. The biosynthesis of CT is controlled by negative feedback loop via suppression of the rate-limiting enzyme arginine:glycine amidinotransferase (AGAT). Although the regulatory mechanism involved is not well understood, AGAT suppression is successfully used in patients with guanidinoacetate methyltransferase (GAMT) deficiency to reduce the neurotoxic accumulation of the AGAT-mediated guanidinoacetate production by supplementing patients with CT. Utilizing the CT-dependent feedback loop for the upregulation of AGAT expression may well represent a therapeutic target for an additional CT deficiency syndrome, the CT transporter (CrT) defect, for which no effective treatment option is available so far. We have used CRISPR to tag the C-terminus of AGAT with a nanoluc luciferase (NLuc) reporter in HAP1 cells. A biphasic decay of AGAT-NLuc in response to increasing extracellular CT was observed, whereas the decrease in AGAT-NLuc expression was directly proportional to the rise in intracellular CT levels with an approximate IC50 of 1–2 mM. CRISPR generated HAP1 CrT null cells and HAP1 CrT null cells stably expressing a CrT-GFP fusion protein further demonstrated that the biphasic response to extracellular CT is mediated by a high-affinity (Km 9–10 µM) CrT dependent, saturable mechanism and a CrT independent, unsaturable uptake process. The direct response to intracellular CT suggests the existence of an intracellular CT sensing system enabling a dynamic cell response to changing CT concentration that is relevant for cellular CT homeostasis.

Fabrication, Evaluation, and Multiscale Simulation of Piezoelectric Composites Reinforced Using Unidirectional Carbon Fibers for Flexible Motion Sensors.

Piezoelectric composite materials can convert mechanical energy into electrical energy, thus promoting battery-free motion-sensing systems. However, their substandard mechanical performance limits the capability of sensors developed using flexible piezoelectric materials. This study introduces a novel design strategy for preparing high-strength flexible piezoelectric composite materials comprising unidirectional carbon fiber-reinforced potassium sodium niobate (K0.5Na0.5NbO3) nanoparticle-filled epoxy resin (UDCF/KNN-EP). The fibers significantly improve the Young's modulus of UDCF/KNN-EP along the fiber direction, which reaches 282.5MPa. Moreover, the composite exhibits excellent stretchability and piezoelectric response ( ) in the cross-fiber direction under cyclic tensile loading. Multiscale finite element analysis is performed via simulation, which allows theoretical examination of the experimental results and the material's mechanical response mechanism. Finally, UDCF/KNN-EP is seamlessly incorporated into athletic gear and used to measure the impact caused by baseball catching and track footfall patterns. This study harnesses the superior strength of carbon fibers to enhance the durability and dependability of self-powered sensors without compromising flexibility in specific directions.

Tailoring the Direct Current Modulation Response of Electrically Pumped Semiconductor Nano-Laser Arrays

Semiconductor nano-lasers have been a topic of interest from the perspective of advancing the capabilities of photonic integration. Nano-lasers are perceived as the means to achieve improved functionality in photonic integrated circuits. The properties and performance of nano-lasers have been examined by means of simulations and laboratory measurements. Nano-lasers lend themselves to integration to form dense arrays in both one and two dimensions. In a recent work, a theoretical treatment was presented for the dynamic behaviour of stand-alone electrically pumped nano-laser arrays. In this work, the response of nano-laser arrays to direct current modulation is examined. As in previous works, attention is given to two prototype array geometries: a linear three-element linear array and an equilateral triangular array. Large one-dimensional arrays can be built by repeating this elementary linear array. Two-dimensional photonic integrated circuits can incorporate the triangular arrays studied here. Such prototypical configurations offer opportunities to tailor the modulation response of the nano-laser arrays. The principal factors which provide that capability are the coupling strengths between lasers in the arrays and the direct modulation parameters. The former are fixed at the design and manufacture stage of the array whilst the latter can be chosen. In addition, the enhancement of the spontaneous emission rate via the so-called Purcell effect in nano-lasers offers a device-specific means for accessing a range of modulation responses. Two-dimensional portraits of the regimes of differing modulation responses offer a convenient means for determining the dynamics that may be accessed by varying the laser drive current. It is shown by these means that a rich variety of modulation responses can be accessed in both linear and triangular arrays.

A colorimetric detection of Hg2+ based on gold nanoparticles synthesized oxidized N-methylpyrrolidone as a reducing agent

In this study, a gold nanoparticles colorimetric probe (AuNPs) with direct response to mercury ions (Hg2+) were developed using treated N-methylpyrrolidone (NMP) and chloroauric acid (HAuCl4) as precursors. NMP showed good reducibility after high temperature hydrolysis and could be used as reducing and stabilizing agent to synthesize AuNPs. The prepared AuNPs have obvious characteristic absorption peaks and appear wine-red. At the same time, it was found that the presence of Hg2+ can cause the aggregation of AuNPs, increased the absorbance at 700 nm, and changed the color of the solution into blue-gray. This method is capable of sensitive and specific determination of Hg2+ ranging from 1 to 30 μM, with the limit of detection (LOD) at 0.3 μM. The method showed good specificity for the determination of Hg2+ and has the potential to be applied to Hg2+ detection in sewage samples in the environment.

Seismogram Synthesis of Multi-Scale Layered Transversely Isotropic Saturated Half-Space Using a Revised Stiffness Matrix Method

Seismogram synthesis for a multi-scale transversely isotropic (TI) saturated layered half-space subjected to seismic dislocation source is studied by a revised stiffness matrix method in this paper. First, based on Biot’s theory of wave propagation in a fluid-saturated porous solid, the governing equations of motion in TI saturated medium are transformed by Fourier–Hankel integral transform. Next, the contribution of the seismic dislocation source can be imposed in the form of body forces. Then, the global stiffness matrix with well-conditioned properties is obtained by assembling each layer’s exact stiffness matrix, which can avoid accumulating errors in the matrix transmission. By extracting the divergence exponent terms of the stiffness matrix concerning thickness and wavenumber, the bottleneck of simulating the wave propagation process in multi-scale half-space, where the layer thickness and velocity vary sharply from the near-surface region to the crustal zone, could be overcome, and a fast and accurate seismogram synthesis could be achieved. The accuracy of the proposed method is verified by comparing the calculated results with those of published literature. Finally, the method is applied to the multi-scale system with realistic superficial fine layers. Numerical examples regarding thickness, TI properties and porosity are presented to illustrate the effects of superficial layers on ground motion. The numerical results show that the surface properties affect the wave propagation and energy distribution, leading to variable impacts on the surface response in different directions; this phenomenon is more pronounced in the case of high-frequency ground motions.

Enhanced vibration control using non-reciprocal piezoelectric beam having sensing and actuating bimorph: Spectral element formulation

A unique strategy of low-frequency wideband vibration control by harnessing the concept of feedback control between the piezoelectric bimorph sub-cells which are acting as sensors and actuators is conceptualized in this paper. In the unit cell, voltages from the sensing bimorph are fed back to actuate another bimorph through operational amplifier-based gain circuits. The prime novelty of the paper is the non-trivial formulation of the spectral element of the non-reciprocal piezoelectric beam (NRPB), having electro-mechanically coupled sensing and actuating bimorph in the unit cell, derived from the exact solution of the governing differential equations. The analytical formulation employing the spectral element method enables the elementary assembling of the NRPB units to simulate different boundary conditions and various configurations arising due to the alteration of the position of the sensing and actuating bimorph. The direct frequency responses for various configurations are obtained for a cantilevered and a simply-supported beam with varying feedback gain. The feedback gain induced damping to the system, hence sharp peaks and drops are flattened. Most promisingly, the amplitude of the displacement response for the entire frequency range can be brought down below its corresponding static deformation with the application of positive gain for certain configurations. Hence, the proposed system could potentially be used for application in the field of vibration and acoustics.

Spatio-temporal distribution characteristics and influencing factors of protoporphyrin IX in the estuarine-coastal ecosystems

Protoporphyrin IX (PPIX), a key precursor for the synthesis of chlorophyll and heme, is fundamental to photosynthetic eukaryotic cells and participates in light absorption, energy transduction, and numerous other cellular metabolic activities. Along with the application of genetic and biochemical techniques over the past few years, our understanding of the formation of PPIX has been largely advanced, especially regarding possible metabolic pathways. However, the ecological role and function of PPIX in natural ecosystems remains unclear. We have previously established a method for quantifying PPIX in marine ecosystems. Here, our results provide evidence that PPIX is not only subtly linked to nutrient uptake but also triggers phytoplankton productivity. PPIX and its derivatives are dynamic spatiotemporally in direct response to increased nutrient availability. Using 16 S rRNA gene amplicon sequencing, PPIX was revealed to interact strongly with many microorganisms, indicating that PPIX serves as a critical metabolite in maintaining microbial metabolism and community development. In summary, we observed that PPIX is linearly related to nutrient availability and microbial diversity. The levels of microbial PPIX reflect ecological health, and the availability of PPIX and nutrients jointly affect microbial community composition.

A full-length SSU rRNA-based workflow for high-resolution monitoring of nematode communities reveals direct and indirect responses to plant-based manipulations

Agricultural intensification has resulted in a decline in soil biodiversity, and concerns about the deterioration of the biological condition of soils prompted the development of measures to restore soil life. Due to the overwhelming biodiversity of soils, evaluation of such measures is not straightforward, and proxies are used to assess soil health. Because of their trophic diversity, high abundance, and relatively well-characterized ecologies, nematodes are often used as soil health indicators. However, the scarcity of informative morphological characters hampers the upscaling of this proxy. Here we present a community analysis approach that uses nanopore sequencing to generate full-length sequences of small subunit ribosomal DNAs (SSU rDNA). Cover cropping is a common agricultural practice that stimulates soil life, and we mapped the effects of ten cover crop treatments on nematode communities in a field experiment. These analyses included the monitoring of a high-impact plant-parasite, Meloidogyne chitwoodi. In total, 132 nematode samples were analyzed, and 65 nematode taxa were detected, mostly at the species level, including representatives of all trophic groups. As a validation, all samples were analyzed microscopically for M. chitwoodi, and a comparison of count and DNA read data revealed highly similar results. Treatments did not only affect plant-parasitic nematodes but also free-living nematodes in a cover crop-specific manner. Free-living nematodes from the same trophic group, and even congeneric species, responded differentially to plant-mediated manipulations of the soil microbiome. Hence, nanopore-based SSU rDNA sequencing could facilitate a substantial refinement of the use of nematodes as indicators for soil health.

Pesticides vs. Biopesticides: From Pest Management to Toxicity and Impacts on the Environment and Human Health.

The environmental pollution that occurs in direct response to the widespread use of man-made/conventional pesticides results from many chemicals that require a long period of time, often decades, to degrade. The synthetic nature of pesticides also harms animals, beneficial insects, microorganisms, and plants, as well as humans. Fortunately, however, there are many natural pesticides, the so-called biopesticides, that are also effective against pests and more importantly, do not interfere with the well-being of ecosystems. Consequently, most biopesticides are safer for use around people and pets than man-made pesticides because, for example, they can be easily washed away from fruits and vegetables. The natural habitat is a rich resource with a wide selection of plants, many of which are also used to treat diseases in humans, animals, and plants. Out of concern for public health, environmental safety, and the stringent regulation of pesticide residues in agricultural commodities, the use of biopesticides is becoming increasingly important, but questions regarding potential pest resistance to these products may arise, just as is the case with conventional pesticides. Therefore, the performance and potential role of biopesticides in the management of plant pests should be prioritized due to their sustainability and importance to human and environmental welfare. In this review, we propose to highlight a scenario in which we discuss in detail the main constraints posed by the use of pesticides compared to biopesticides, starting with issues regarding their definition and continuing on to issues related to their toxicity and their impact on the environment and human health.

A new time integration method based on state formulations for dynamic analysis of nonviscously damped systems

The mode superposition method (MSM), which is used for dynamic response calculations of nonviscously damped systems, requires state–space eigensolutions, which incur a high computational cost. This study proposed an alternative symmetric formulation-based time integration method for analyzing structural dynamic systems. An anelastic displacement field (ADF) model was introduced to capture damping mechanisms in nonviscous systems. The differential equation describing the ADF model was transformed into an augmented coupled system via the introduction of dissipative variables. Two symmetric state formulations based on coupled augmented systems were derived for nonviscous systems. Consequently, alternative asymmetric state formulations were derived for nonviscous systems involving the ADF model. Thereafter, a new method was developed based on these state–space formulations by assuming linear approximations. A numerical implementation of the new method for dynamic systems was demonstrated. Three benchmark examples of discrete and continuous systems were considered to evaluate the asymmetric formulation and the computational efficiency, accuracy, stability, and time-step-size sensitivity of the new method. Further, the response of the new method was validated using MSM and precise time integration (PTI) methods. An asymmetric state formulation was also validated against MSM and direct frequency response methods. The results revealed that the new method accurately matched the MSM and PTI methods at various time steps. The results also showed that the new method was more efficient than the MSM and PTI methods, rendering it suitable for solving large-scale structural dynamics problems.

Detection of Suicidal Ideation in Clinical Interviews for Depression Using Natural Language Processing and Machine Learning: Cross-Sectional Study.

Assessing patients' suicide risk is challenging, especially among those who deny suicidal ideation. Primary care providers have poor agreement in screening suicide risk. Patients' speech may provide more objective, language-based clues about their underlying suicidal ideation. Text analysis to detect suicide risk in depression is lacking in the literature. This study aimed to determine whether suicidal ideation can be detected via language features in clinical interviews for depression using natural language processing (NLP) and machine learning (ML). This cross-sectional study recruited 305 participants between October 2020 and May 2022 (mean age 53.0, SD 11.77 years; female: n=176, 57%), of which 197 had lifetime depression and 108 were healthy. This study was part of ongoing research on characterizing depression with a case-control design. In this study, 236 participants were nonsuicidal, while 56 and 13 had low and high suicide risks, respectively. The structured interview guide for the Hamilton Depression Rating Scale (HAMD) was adopted to assess suicide risk and depression severity. Suicide risk was clinician rated based on a suicide-related question (H11). The interviews were transcribed and the words in participants' verbal responses were translated into psychologically meaningful categories using Linguistic Inquiry and Word Count (LIWC). Ordinal logistic regression revealed significant suicide-related language features in participants' responses to the HAMD questions. Increased use of anger words when talking about work and activities posed the highest suicide risk (odds ratio [OR] 2.91, 95% CI 1.22-8.55; P=.02). Random forest models demonstrated that text analysis of the direct responses to H11 was effective in identifying individuals with high suicide risk (AUC 0.76-0.89; P<.001) and detecting suicide risk in general, including both low and high suicide risk (AUC 0.83-0.92; P<.001). More importantly, suicide risk can be detected with satisfactory performance even without patients' disclosure of suicidal ideation. Based on the response to the question on hypochondriasis, ML models were trained to identify individuals with high suicide risk (AUC 0.76; P<.001). This study examined the perspective of using NLP and ML to analyze the texts from clinical interviews for suicidality detection, which has the potential to provide more accurate and specific markers for suicidal ideation detection. The findings may pave the way for developing high-performance assessment of suicide risk for automated detection, including online chatbot-based interviews for universal screening.

Readings on Evolution and the Nature of Science: One Christian’s Perspective

Readings on Evolution and the Nature of Science: One Christian’s Perspective

A study on constructing arbitrary directivity of sound sources by fitting the spherical harmonics coefficients

We attempt to obtain room impulse responses by sound sources with arbitrary directional characteristics by directivity synthesis in the spherical harmonic domain. For this purpose, we use directional room impulse responses measured with a general loudspeaker pointed in multiple directions. Specifically, we attempt to synthesize the directivity from measurements in 24 directions, including the horizontal and elevation angles of 45 degrees each and the case where the loudspeaker was pointed directly above and below. This enables us to construct an omnidirectional sound source that strictly meets ISO standards or a more flexible directional that reflects musical instruments' directivity. For the omnidirectional case, we are also considering how much we can reduce the number of measurement directions and propose a practical index. In addition, because the proposed method uses a commercially available coaxial loudspeaker with enough sound quality and performs frequency spectrum correction at the same time as directional synthesis, it is possible to synthesize room impulse responses that can be used for auralization.