A Contrastive Study on Korean and Cia-Cia Language Vowels Based on an Acoustic Experiment

The Cia-Cia language, which is spoken by around 79.000 people in the Bau-Bau area of Buton Island, does not have its own writing system. In 2009, the Korean alphabet, Hangeul, was approved by the Bau-Bau city government for transcribing Cia-Cia, owing to the similarity of phonemes in Korean to those in Cia-Cia. This research aimed to compare the acoustics of monophthongs in the Korean and Cia-Cia languages with an experimental phonetic approach and to discuss writing system problems in Cia-Cia when adopting the Korean writing system. Based on the classification, the Cia-Cia vowels /i, e, a, u, and o/ are equivalent to the Korean vowels /이 ([i]), 에 ([e]), 아 ([a]), 우 ([u]), 오 ([o])/. However, there are two Korean vowels that have no Cia-Cia equivalents namely, /으/ ([ɨ]) and /어/ ([ə]). In general, the vowel equivalents between the two languages have significant differences in terms of their acoustic characteristics. Nonetheless, unlike other vowel equivalents, the Cia-Cia vowel /u/ and Korean vowel /우/ ([u]) when pronounced show similar phonetic features in terms of position and oral cavity opening level. In contrast, the Cia-Cia vowel /a/ and Korean vowel /아/ ([a]) when pronounced is shown to have the same oral cavity opening level, but different tongue positions. The use of the vowel /으/ ([ɨ]) in Hangeul's writing in transcribing particular Cia-Cia words is a unique feature of Korean grammar. This renders some transcriptions different from the pronunciation of the source Cia-Cia word. This is because of the limitations of Korean syllables, which, unlike Cia-Cia words, are not able to be written as double consonants.

Energy penalties enhance flexible receptor docking in a model cavity

Protein flexibility remains a major challenge in library docking because of difficulties in sampling conformational ensembles with accurate probabilities. Here, we use the model cavity site of T4 lysozyme L99A to test flexible receptor docking with energy penalties from molecular dynamics (MD) simulations. Crystallography with larger and smaller ligands indicates that this cavity can adopt three major conformations: open, intermediate, and closed. Since smaller ligands typically bind better to the cavity site, we anticipate an energy penalty for the cavity opening. To estimate its magnitude, we calculate conformational preferences from MD simulations. We find that including a penalty term is essential for retrospective ligand enrichment; otherwise, high-energy states dominate the docking. We then prospectively docked a library of over 900,000 compounds for new molecules binding to each conformational state. Absent a penalty term, the open conformation dominated the docking results; inclusion of this term led to a balanced sampling of ligands against each state. High ranked molecules were experimentally tested by Tm upshift and X-ray crystallography. From 33 selected molecules, we identified 18 ligands and determined 13 crystal structures. Most interesting were those bound to the open cavity, where the buried site opens to bulk solvent. Here, highly unusual ligands for this cavity had been predicted, including large ligands with polar tails; these were confirmed both by binding and by crystallography. In docking, incorporating protein flexibility with thermodynamic weightings may thus access new ligand chemotypes. The MD approach to accessing and, crucially, weighting such alternative states may find general applicability.

Effects of Receiver Parameters on Solar Flux Distribution for Triangle Cavity Receiver in the Fixed Linear-Focus Fresnel Lens Solar Concentrator

The objective of the study is to investigate and optimize the solar flux uniformity of a fixed linear-focus Fresnel lens solar concentrator using a triangle cavity receiver. The effects of receiver parameters including the vertical distance from the cavity opening plane to the Fresnel lens f, receiver internal surface absorptivity αab, end reflection plane reflectivity ρr, solar declination angle δ and solar angle ω on the uniformity factor (UF) of a triangle cavity receiver were carried out. The effects of receiver parameters are evaluated with a significance test of critical factors. The results showed that the increase in f and δ would result in an increase in the UF. The average UF with f = 600, 625, 650, 675 and 700 mm, respectively, are 0.5030, 0.5858, 0.6337, 0.6576 and 0.6784 for ω in range of 0–60°. Moreover, the UF increases as αab decreases when other receiver parameters are constant for the δ of 0–8°. The ρr has a limited effect on the UF until δ becomes relatively larger and ω becomes relatively smaller. Furthermore, ω effects are most significant on the UF, followed by δ, f and αab. Setting a suitable f is the most economical and effective way to improve the UF.

Use of landmarks for nest site choice and small-scale navigation to the nest in birds

Nest sites of animals are often concealed to keep vulnerable offspring from being detected by predators. Parents may use landmarks near the nest to relocate it quickly. We allowed blue tits (Cyanistes caeruleus) to choose between two nest boxes fixed on the same tree with either none, the same, or different white painted markings. Surprisingly, the female brought material to both boxes and sometimes laid eggs in both. In a second experiment, we let pied flycatchers (Ficedula hypoleuca) and great tits (Parus major) become familiar with a marking on the initial nest box and then let them choose between two new nest boxes erected on different, nearby trees. Neither species preferred the box with the matching mark. In nature, the birds may locate the correct entrance of a cavity using other landmarks near the nest opening, like branches and the height of the cavity opening above the ground.

Energy Penalties Enhance Flexible Receptor Docking in a Model Cavity

Protein flexibility remains a major challenge in library docking due to difficulties in sampling conformational ensembles with accurate probabilities. Here we use the model cavity site of T4 Lysozyme L99A to test flexible receptor docking with energy penalties from molecular dynamics (MD) simulations. Crystallography with larger and smaller ligands indicates that this cavity can adopt three major conformations, open, intermediate, and closed. Since smaller ligands typically bind better to the cavity site, we anticipate an energy penalty for cavity opening. To estimate its magnitude, we calculate conformational preferences from MD simulations. We find that including a penalty term is essential for retrospective ligand enrichment, otherwise high-energy states dominate the docking. We then prospectively docked a library of over 900,000 compounds for new molecules binding to each conformational state. Absent a penalty term, the open conformation dominated the docking results; inclusion of this term led to a balanced sampling of ligands against each state. High ranked molecules were experimentally tested by Tm-upshift and X-ray crystallography. From 33 selected molecules, we identified 18 new ligands and determined 13 crystal structures. Most interesting were those bound to the open cavity, where the buried site opens to bulk solvent. Here, highly unusual ligands for this cavity had been predicted, including large ligands with polar tails; these were confirmed both by binding and by crystallography. In docking, incorporating protein flexibility with thermodynamic weightings may thus access new ligand chemotypes. The MD approach to accessing and, crucially, weighting such alternative states may find general applicability.

Measuring the Reduction of the Confinement along the Evolution of a Burn Cut

We provide an analysis of a tunnel opening cut in a tunnel face. In particular, we focus on the effect of a “burn cut,” which is a typical parallel hole cut. As the evolution of the opening consists of an increase in the volume of the cut prism and the consequent reduction of confinement of the holes along the initiation sequence, we analyze such an evolution using photographic documentation, as well as evaluating the reduction of confinement by measuring the energy transferred from the explosive charge to the rock mass. The energy was estimated by monitoring and analyzing the vibrations induced by the blasting at three different points. We adopted low-cost shock sensors for monitoring the effect of the detonation times at short distance from the blast (about 10 m). The results show an evident reduction of the shock transfer to the rock mass (i.e., a reduction of confinement) with the increase of the cavity opening. Nevertheless, when only the response of the piezometric sensors was considered, a disparity in behavior among the sensors was noted. On the other hand, when the sensor response was integrated over time, the behavior of all sensors normalized, showing the need to focus both on the oscillation and the duration to properly address the shock effect.

Effect of Thermal Radiation on Accuracy of Restricted Domain Approach in a Square Open Cavity

To reduce computational time for simulation of natural convection in open cavities, it is quite common to use a domain restricted to the cavity with approximate boundary conditions at the cavity opening. It had been shown that such approach leads to quite accurate solutions for high Rayleigh number (Ra) flows. Such approach has been extended to flows involving radiative heat transfer as well. However, it is important to note that the effect of radiation on the accuracy of restricted domain approach has not been evaluated. In the present work, a comparison of Nusselt numbers is obtained by restricted domain approach with those obtained by using extended domain approach. The convective as well as radiative Nusselt numbers are considered for comparison for various values of Ra and radiation conduction parameter (Nr). It is observed that the accuracy of the restricted domain approach varies with the radiation conduction parameter as well and the approach is found to be quite accurate for high values of Nr.

Initial development of Prochilodus hartii (Pisces: Prochilodontidae) submitted to induced reproduction

SummaryThe Prochilodontidae prepare for reproduction in captivity, but neither ovulation nor spawning occurs, thus requiring induced reproduction for breeding and restocking. This study analyzed for the first time the embryogenesis and larval ontogeny of P. hartii submitted to induced reproduction by hypophysation with crude common carp pituitary extract. The extrusion of oocytes and sperm was performed manually and fertilization was done using the dry method. After fertilization, the eggs were kept in incubators at 23°C. A stereomicroscope was used to measure egg diameter and to monitor embryo development. Samples of larvae were collected daily for 7 days for histological and biometric analyses. The recently extruded oocytes, non-hydrated, are spherical, grey, and non-adhesive with a diameter of 1480 ± 39 μm and after hydration, have a diameter of 2860 ± 120 μm. The positive response to hypophysation was 100% for females and 80% for males. Spawning occurred 7 h after the third hormonal dosage. The fertilization rate was 77% at 23°C. Blastopore closure occurred at 6 h 45 min and embryonic development was completed 36 h 10 min after fertilization. After 204 h post fertilization (hpf) the larvae reached a standard length of 6.56 ± 0.14 mm with the yolk sac completely resorbed. In P. hartii, the oral cavity opening occurred 132 hpf. The results of this study provide knowledge to better understand induced reproduction, breeding, and management of P. hartii, a species with a high potential for pisciculture, and which is commercially important in the Jequitinhonha River basin.

Interannual variability of glacier basal pressure from a 20 year record

Basal pressure has been recorded at the Svartisen Subglacial Laboratory, northern Norway, for 20 years, and is measured by load cells installed at the ice–rock interface under ~200m of glacier ice. Synchronous pressure variations between load cells are investigated as evidence of stress redistribution and hydrological bed connectivity. A running Pearson correlation is used to study the temporal variation in the response of several sensors. By studying the nature of this correlation as well as the correlation between sensor pairs, it is possible to investigate the evolution of the degree of synchronous response, and to some extent basal connectivity, at the glacier bed. Persistent seasonal variations associated with the melt season are observed throughout the measurement period, indicating dependence on surface hydrological forcing. Overlying this pattern, specific years with longer periods of positive and negative correlation of pressure between sensors are presented to show contrasting interannual variability in basal pressure. An anticorrelated connectivity is associated with a local increase in the rate of daily subglacial discharge, and is caused by load transfer or passive cavity opening. Stable weather appears to enhance connectivity of the sensors, which is attributed to the development of a persistent drainage system and stress redistribution.

Shear Layer Driven Acoustic Modes in a Cylindrical Cavity

This paper describes the interior acoustic pressure of a cylindrical cavity driven by a shear layer. Existing cavity flow literature is generally focused on rectangular cavities, where the resonance is either longitudinal or the result of excited depth modes inside the cavity. The design of the present circular cavity is such that azimuthal duct modes can be excited in various combinations with depth modes depending on free stream velocity. An acoustic simulation of the system was used to identify the modes as a function of frequency when the system is driven by an acoustic point source. With appropriate manipulation of the free stream flow, abrupt mode switching and mode oscillation were both observed, and a condition with a dominant azimuthal mode was found. The strength of the lock-on was documented for the various resonance conditions, and the effects of the cavity opening size and location were studied.