Gaussianization of peculiar velocities and bulk flow measurement

The line-of-sight peculiar velocities are good indicators of the gravitational fluctuation of the density field. Techniques have been developed to extract cosmological information from the peculiar velocities in order to test cosmological models. These techniques include measuring cosmic flow, measuring two-point correlation and power spectrum of the peculiar velocity fields, and reconstructing the density field using peculiar velocities. However, some measurements from these techniques are biased due to the non-Gaussianity of the estimated peculiar velocities. Therefore, we rely on the 2MTF survey to explore a power transform that can Gaussianize the estimated peculiar velocities. We find a tight linear relation between the transformation parameters and the measurement errors of log-distance ratio. To show an example for the implementation of Gaussianized peculiar velocities in cosmology, we develop a bulk flow estimator and estimate bulk flow from the Gaussianized peculiar velocities. We use 2MTF mocks to test the algorithm, and we find the algorithm yields unbiased measurements. We also find this technique gives smaller measurement errors compared to other techniques. In Galactic coordinates, at the depth of 30 h −1 Mpc, we measure a bulk flow of 332 ± 27 km s−1 in the direction (l,b) = (293° ± 5°, 13° ± 4°). The measurement is consistent with the ΛCDM prediction.

Terahertz Nano-Imaging with s-SNOM

Spectroscopy and imaging with terahertz radiation propagating in free space suffer from the poor spatial resolution which is a consequence of the comparatively large wavelength of the radiation (300 μm at 1 THz in vacuum) in combination with the Abbe diffraction limit of focusing. A way to overcome this limitation is the application of near-field techniques. In this chapter, we focus on one of them, scattering-type Scanning Near-field Optical Microscopy (s-SNOM) which − due to its versatility − has come to prominence in recent years. This technique enables a spatial resolution on the sub-100-nm length scale independent of the wavelength. We provide an overview of the state-of-the-art of this imaging and spectroscopy modality, and describe a few selected application examples in more detail.

The diversity of edible plants traded in Ir. Soekarno Market, a traditional market in Sukoharjo District, Indonesia

Deanova AK, Pristiawati CM, Aprilia D, Solikah I, Nurcahyati M, Liza N, Partasasmita R, Setyawan AD. 2021. Title. Biodiversitas 22: 4095-4105. Market is one of the most important economic sectors in a country. One type of market is a traditional market that is synonymous with squalid, overcrowded and slum conditions. However, traditional markets provide essential commodities that are relatively cheaper and fresher than modern markets. The purpose of this research was to record the diversity of species and varieties of edible plants traded in Ir. Soekarno Market, a traditional market in Sukoharjo District. Plant commodities observed were vegetables, spices, fruits, and staples sold by the sellers in this market. The method used in this research was qualitative based on the ethnobotany approach. Meanwhile, to collect primary data, several field techniques were used, namely direct observation such as market commodity surveys, trader observations, and trader interviews. The direct survey results showed that the edible plant commodities consisted of 105 plant species representing 28 families. The variations found included 9 types of rice, 4 types of onions, 7 types of bananas, and 9 types of beans. The decline in the number of traded commodities and the lack of visitors was due to the increase in COVID-19 cases in Sukoharjo and disputes between traders and local government. Thus until recently, Ir. Soekarno Market, which was originally the main market full of visitors, became a market that was empty of visitors and traders.

Images in Space and Time

Medical imaging diagnosis is mostly subjective, as it depends on medical experts. Hence, the service provided is limited by expert opinion variations and image complexity as well. However, with the increasing advancements in deep learning field, techniques are developed to help in the diagnosis and risk assessment processes. In this article, we survey different types of images in healthcare. A review of the concept and research methodology of Radiomics will highlight the potentials of integrated diagnostics. Convolutional neural networks can play an important role in next generations of automated imaging biomarker extraction and big data analytics systems. Examples are provided of what is already feasible today and also describe additional technological components required for successful clinical implementation.

An Overview of Acoustic Impedance Measurement Techniques and Future Prospects

In order to progress in the area of aeroacoustics, experimental measurements are necessary. Not only are they required for engineering applications in acoustics and noise engineering, but also they are necessary for developing models of acoustic phenomenon around us. One measurement of particular importance is acoustic impedance. Acoustic Impedance is the measure of opposition of acoustical flow due to the acoustic pressure. It indicates how much sound pressure is generated by the vibration of molecules of a particular acoustic medium at a given frequency and can be a characteristic of the medium.The aim of the present paper is to give a synthetic overview of the literature on impedance measurements and to discuss the advantage and disadvantage of each measurement technique. In this work, we investigate the three main categories of impedance measurement techniques, namely reverberation chamber techniques, impedance tube techniques, and far-field techniques. Theoretical principles for each technique are provided along with a discussion on historical development and recent advancements for each technique.

Two-loop helicity amplitudes for gg → ZZ with full top-quark mass effects

We calculate the two-loop QCD corrections to gg → ZZ involving a closed top-quark loop. We present a new method to systematically construct linear combinations of Feynman integrals with a convergent parametric representation, where we also allow for irreducible numerators, higher powers of propagators, dimensionally shifted integrals, and subsector integrals. The amplitude is expressed in terms of such finite integrals by employing syzygies derived with linear algebra and finite field techniques. Evaluating the amplitude using numerical integration, we find agreement with previous expansions in asymptotic limits and provide ab initio results also for intermediate partonic energies and non-central scattering at higher energies.

Using Crayfish Burrows to Illustrate Simple Ecological Field Techniques

Ecological field techniques such as transect surveys are long-used, integral means of immersing students in field exercises to illustrate ecological measures. Many species of crayfish create conspicuous burrows within or near aquatic habitats. Such burrows can easily be identified and measured by students during an ecological field exercise. In this article, we describe a field activity we developed as part of a college-level course in which students utilized transects and calipers to collect counts and measurements of crayfish burrows in order to evaluate their distribution and size among different substratum types along a small stream. This field exercise could be incorporated, with or without modification, into an applicable high school or introductory/intermediate college biology course as a means of illustrating ecological concepts, sampling technique, and/or behavioral biology.