Differential Shift Research Articles

Large Range Curvature Measurement Using FBGs in Two-Core Fiber with Protective Coating

In this work, we propose a fiber Bragg grating (FBG)-based sensor for curvature measurements. Two gratings are inscribed through the protective coating in a specialty optical fiber using focused femtosecond laser pulses and point-by-point direct writing technology. One grating is inscribed on the central core adjacent to an air channel, while the other is inscribed on the eccentric core. The bending characteristics of the two-core fiber strongly depend on the bending direction due to the asymmetry of the fiber cores. A bending sensitivity of 58 pm/m−1 is achieved by the FBG in the eccentric fiber core over the curvature range of 0–50 m−1 . Temperature and humidity cross-sensitivity could be significantly reduced by analyzing the differences in peak shifts between the two gratings. The sensor features a large sensing range and good robustness due to the presence of its protective buffer coating, which makes it a good candidate for curvature sensing in engineering fields.

STAD: Ship trajectory anomaly detection in ocean with dynamic pattern clustering

With the continuous increase of maritime traffic, developing an efficient and accurate model for ship trajectory anomaly detection has become crucial for ensuring maritime transportation safety. The high complexity and variability of the marine environment lead to diverse ship trajectory patterns, making it challenging to learn effective trajectory representations for accurately identifying anomalies. We thus proposed an unsupervised deep learning model called STAD for ship trajectory anomaly detection in ocean to address this challenge. Concretely, STAD leverages offset reconstruction-based representation learning and a deep Gaussian Mixture Model (GMM) estimation network to learn the underlying complex clustering patterns of ship trajectories and utilize the learned patterns to enhance trajectory anomaly detection. Extensive experiments on multiple AIS datasets indicate that our model significantly outperforms existing methods in detecting multiple representative types of ship trajectory anomalies, including shift deviation, abnormal heading, and abnormal speeding. This study could help closely monitor the status of ship movement and detect abnormal behaviors in advance, thus benefiting maritime safety.

Anionic N-Heterocyclic Carbenes from Mesoionic Imidazolium-4-pyrrolides: The Influence of Substituents, Solvents, and Charge on their 77Se NMR Chemical Shifts.

Mesoionic compounds are the starting material for the synthesis of unique anionic N-heterocyclic carbenes. Herein, mesoionic imidazolium pyrrolides synthesized from pyrrole-2-carbaldehyde via various N-alkyl-4-pyrroyl-imidazoles are described. These were converted into nine new 4-(pyrrol-2-yl)-substituted imidazolium salts and transformed into the mesoionic title compounds using an anion exchange resin. The DFT-calculated (B3LYP/6-311++G**) CREF values indicate a great potential for the formation of anionic N-heterocyclic carbenes by deprotonation, which were generated and reacted with selenium to obtain selenoureas. The 77Se NMR shifts investigated under systematic variation of conditions are dependent on the substitution pattern (ΔδSe = 133 ppm) and the steric demand of the substituents. Solvent dependencies of the 77Se NMR shifts were investigated applying toluene-d8, THF-d8, CDCl3, CD2Cl2, pyridine-d5, acetone-d6, DMSO-d6, CD3CN, AcOD, and MeOD. The influences of the referencing method on the 77Se shifts using external or internal Me2Se or Ph2Se2 and solvent can add up to ΔδSe = ca. 80 ppm. In addition, we observed a temperature dependence of both the selenoureas and the reference reagent Ph2Se2 as well as a 77Se shift difference of the analyte caused by interaction with internally added Ph2Se2. The negative charge of deprotonated selenoureas shifts the values by an additional -20 ppm.

Triantaspirols A-C and Paraphaeolactone Cs from Paraphaeosphaeria sp. KT4192: Sensitivity of CP3 in Distinguishing Close NMR Signals.

Hybridized spirobisnaphthalene derivatives, triantaspirols A-C (1-3) and paraphaeolactones C1 and C2 (4 and 5), were identified from the culture broth of the fungus Paraphaeosphaeria sp. KT4192. The NMR spectra of 2 and 3, as well as 4 and 5, closely resembled each other, indicating that these were pairs of diastereomers. Although this NMR spectral resemblance made it challenging to distinguish their relative configurations, detailed analysis of the electronic circular dichroism (ECD) spectra and NOE correlations allowed us to deduce them. The CP3 metric with the DFT-based NMR chemical shifts was found to distinguish configurations of diastereomers in a highly sensitive and accurate manner that DP4 could not account for because of the very close chemical shift differences in the experimental NMR spectra. The reliability of this method was assessed using 23 published examples which could not be distinguished by DP4 protocol.

Dose-dependent effects of transcranial photobiomodulation on brain temperature in patients with major depressive disorder: a spectroscopy study.

This study aimed to evaluate the dose-dependent brain temperature effects of transcranial photobiomodulation (t-PBM). Thirty adult subjects with major depressive disorder were randomized to three t-PBM sessions with different doses (low: 50 mW/cm2, medium: 300 mW/cm2, high: 850 mW/cm2) and a sham treatment. The low and medium doses were administered in continuous wave mode, while the high dose was administered in pulsed wave mode. A 3T MRI scanner was used to perform proton magnetic resonance spectroscopy (1H-MRS). A voxel with a volume of 30 × 30 × 15 mm3 was placed on the left prefrontal region. Brain temperature (°C) was derived by analyzing 1H-MRS spectrum chemical shift differences between the water (~ 4.7 ppm) and N-acetyl aspartate (NAA) (~ 2.01 ppm) peaks. After quality control of the data, the following group numbers were available for both pre- and post-temperature estimations: sham (n = 10), low (n = 11), medium (n = 10), and high (n = 8). We did not detect significant temperature differences for any t-PBM-active or sham groups post-irradiation (p-value range = 0.105 and 0.781). We also tested for potential differences in the pre-post variability of brain temperature in each group. As for t-PBM active groups, the lowest fluctuation (variance) was observed for the medium dose (σ2 = 0.29), followed by the low dose (σ2 = 0.47), and the highest fluctuation was for the high dose (σ2 = 0.67). t-PBM sham condition showed the overall lowest fluctuation (σ2 = 0.11). Our 1H-MRS thermometry results showed no significant brain temperature elevations during t-PBM administration.

Neural net analysis of NMR spectra from strongly-coupled spin systems

Extracting parameters such as chemical shifts and coupling constants from proton NMR spectra is often a first step in using spectra for compound identification and structure determination. This can become challenging when scalar couplings between protons are comparable in size to chemical shift differences (strongly coupled), as is often the case with low-field (bench top) spectrometers. Here we explore the potential utility of AI methods, in particular neural networks, for extracting parameters from low-field spectra. Rather than seeking large experimental sets of spectra for training a network, we chose quantum mechanical simulation of sets, something that is possible with modern software packages and computer resources. We show that application of a network trained on 2-D J-resolved spectra and applied to a spectrum of iduronic acid, shows some promise, but also meets with some obstacles. We suggest that these may be overcome with improved pulse sequences and more extensive simulations.

Dual-comb source with a reconfigurable repetition frequency difference using intracavity Brillouin lasers

A Brillouin-assisted 80-GHz-spaced dual-comb source with a reconfigurable repetition frequency difference ranging from 48 MHz to 1.486 GHz is demonstrated. Two pairs of dual-pump seeds with an interval offset produce the corresponding dual Brillouin lasers in two fiber loops, and then the Brillouin lasers give rise to dual combs via the cavity-enhanced cascaded four-wave mixing effect. The repetition frequency difference is determined by the interval offset of the dual-pump seeds, which is induced by the Brillouin frequency shift difference between different fibers in a frequency shifter. Each comb provides 22 lasing lines, and the central 10 lines in a 20-dB power deviation feature high optical signal-to-noise ratios exceeding 50 dB. The linewidths of the dual-comb beating signals are less than 300 Hz, and the absolute linewidths of the comb lines are around 1.5 kHz. The dual-comb source enables substantial repetition frequency differences from 48 MHz to 1.486 GHz by changing the pluggable fibers in the frequency shifter.

The essential synergy of MD simulation and NMR in understanding amorphous drug forms.

Molecular dynamics (MD) simulations and chemical shifts from machine learning are used to predict 15N, 13C and 1H chemical shifts for the amorphous form of the drug irbesartan. The local environments are observed to be highly dynamic well below the glass transition, and averaging over the dynamics is essential to understanding the observed NMR shifts. Predicted linewidths are about 2 ppm narrower than observed experimentally, which is hypothesised to largely result from susceptibility effects. Previously observed differences in the 13C shifts associated with the two tetrazole tautomers can be rationalised in terms of differing conformational dynamics associated with the presence of an intramolecular interaction in one tautomer. 1H shifts associated with hydrogen bonding can also be rationalised in terms of differing average frequencies of transient hydrogen bonding interactions.

Semisynthesis, Structure Elucidation and Anti-Mycobacterium marinum Activity of a Series of Marine-Derived 14-Membered Resorcylic Acid Lactones with Interesting Ketal Groups.

The incidence of Mycobacterium marinum infection is on the rise; however, the existing drug treatment cycle is lengthy and often requires multi-drug combination. Therefore, there is a need to develop new and effective anti-M. marinum drugs. Cochliomycin A, a 14-membered resorcylic acid lactone with an acetonide group at C-5' and C-6', exhibits a wide range of antimicrobial, antimalarial, and antifouling activities. To further explore the effect of this structural change at C-5' and C-6' on this compound's activity, we synthesized a series of compounds with a structure similar to that of cochliomycin A, bearing ketal groups at C-5' and C-6'. The R/S configuration of the diastereoisomer at C-13' was further determined through an NOE correlation analysis of CH3 or CH2 at the derivative C-13' position and the H-5' and H-6' by means of a 1D NOE experiment. Further comparative 1H NMR analysis of diastereoisomers showed the difference in the chemical shift (δ) value of the diastereoisomers. The synthetic compounds were screened for their anti-microbial activities in vitro. Compounds 15-24 and 28-35 demonstrated promising activity against M. marinum, with MIC90 values ranging from 70 to 90 μM, closely approaching the MIC90 of isoniazid. The preliminary structure-activity relationships showed that the ketal groups with aromatic rings at C-5' and C-6' could enhance the inhibition of M. marinum. Further study demonstrated that compounds 23, 24, 29, and 30 had significant inhibitory effects on M. marinum and addictive effects with isoniazid and rifampicin. Its effective properties make it an important clue for future drug development toward combatting M. marinum resistance.

Study on the role of alkali halides on the mutarotation and dehydration of d-xylose in aqueous solution

Although the xylose mutarotation and transformation have been investigated largely separately, their relationship has been rarely systematically elaborated. The effect of several factors such as xylose concentration, temperature, and salt concentration, affecting the mutarotation of xylose are discussed. Nine alkali halides (LiCl, NaCl, KCl, LiBr, NaBr, KBr, LiI, NaI, and KI) are used to test salt effects. The relationship between xylose rotation rate constant (kM), specific optical rotation at equilibrium ([α]eqm), α/β ratio, H chemical shift difference (ΔΔδ), Gibbs free energy difference (ΔG), hydrogen ion or hydroxide ion concentration ([H+] or [OH−]), and xylose conversion is discussed. Different salts dissolved in water result in different pH of the solutions, which affect the mutarotation of xylose, with the nature of both cation and anion. Shortly, the smaller the cation radius is and the larger the anion radius is, the greater the mutarotation rate is. In the dehydration of xylose to furfural in salty solutions, xylose conversion is positively correlated to mutarotation rate, H+ or OH− concentration, and the energy difference between α-xylopyranose and β-xylopyranose. Although the [α]eqm of xylose is positively correlated with α/β configuration ratio, there is no obvious correlation with xylose dehydration. The conversion to furfural in chlorides is superior to that in bromines and iodides, which is due to the fact that the pH of chloride salts is smaller than that of the corresponding bromide and iodized salts. Higher H+ concentration prefers to accelerate the formation of furfural. In basic salt solutions, the xylulose selectivity is higher than that of furfural at the initial stage of reaction. The furfural selectivity and carbon balance are better in acidic condition rather than in basic condition. In H2O-MTHF (2-Methyltetrahydrofuran) biphasic system, the optimal furfural selectivity of 81.0 % is achieved at 190 °C in 1 h with the assistance of LiI and a little HCl (0.2 mmol, 8 mmol/L in aqueous phase). A high mutarotation rate represents rapid xylose conversion, but a high furfural selectivity prefers in acidic solutions, which would be perfect if organic solvents were available to form biphasic systems.

Two-dimensional refractive index distribution using polarization phase shifting interferometry and total internal reflection

An effective method to measure the 2-D refractive index distribution of homogeneous liquids: acetic acid and glycerol- water mixture at different concentration and a non- homogeneous mixture of liquids: water, acetic acid, acetone and glycerin but not limited to these liquids is presented. In the present setup a combination of polarization phase shifting interferometry (PPSI) and total internal reflection (TIR) is used. The s-polarized light strikes the boundary of a right angle prism and a tested liquid droplet. When TIR occurs on the interface, the incident light has a phase variation which depends on the refractive index of adhered liquid on prism surface. Two-dimensional index distributions can be easily calculated using the relation among reflection phase shift difference and the liquid index. The results of the tested mixed liquid by proposed technique show the refractive index and its distribution in range 1.433 ± 0.031 to 1.433 ± 0.124.

Highly sensitive intensity-type polarization chiral sensor with reference light.

Optical rotation is a special phenomenon in which the plane of polarization of polarized light is rotated after passing through a chiral medium. This work first, to our knowledge, presents and optimizes a polarization chiral sensor with a reference light on the basis of a weak measurement light path. The influences of phase shift and polarization angle difference on sensitivity were theoretically optimized and verified experimentally. The introduction of a reference light further reduced the impact of light source fluctuations on the detection signal, improving the signal-to-noise ratio and reducing the optical rotation resolution to 2 × 10-5 rad. This method has the characteristics of low cost, high sensitivity, and real-time rapid detection, making it potentially applicable in the field of chemical analysis, such as chiral molecule detection.

Latitudinal Dependence of Variations in the Frequencies of Solar Oscillations Above the Acoustic Cut-Off

At high frequencies beyond the acoustic cut-off, a peak-like structure is visible in the solar power spectrum. Known as the pseudo-modes, their frequencies have been shown to vary in anti-phase with solar magnetic activity. In this work, we determined temporal variations in these frequencies across the solar disc, with the aim of identifying any potential latitudinal dependence of pseudo-mode frequency shifts. We utilised nearly 22 years of spatially resolved GONG data for all azimuthal orders, m\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$\ extit{m}$\\end{document}, for harmonic degrees 0≤l≤200\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$0\\leq l\\leq 200$\\end{document}, and determined shifts using the resampled periodogram method. Periodogram realisations were created from overlapping, successive 216 day-long segments in time, and cropped to 5600 – 6800 μHz. Cross-correlation functions were then repeatedly generated between these realisations to identify any variation in frequency and the uncertainty. We categorised each mode by its latitudinal sensitivity and used this categorisation to produce average frequency shifts for different latitude bands (15∘ and 5∘ in size) which were compared to magnetic proxies, the F10.7\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$F_{\\mathrm{10.7}}$\\end{document} index and GONG synoptic maps. Morphological differences in the pseudo-mode shifts between different latitudes were found, which were most pronounced during the rise to solar maximum where shifts reach their minimum values. At all latitudes, shift behaviour was strongly in anti-correlation with the activity proxy. Additionally, periodicities shorter than the 11-year cycle were observed. Wavelet analysis was used to identify a periodicity of four years at all latitudes.

It is challenging to reproduce both anatomical and functional aspects of anterolateral reconstruction: postoperative 3D-CT analysis of the femoral tunnel position

BackgroundThis study aimed to evaluate the femoral tunnel position and fiber length of the anterolateral ligament (ALL) reconstruction compared with the natural anatomy of the ALL. We also evaluated whether the femoral tunnel position would affect residual pivot shift.MethodsThis study was a retrospective review of 55 knees that underwent ALL reconstruction considering the anatomical and functional aspects, during primary anterior cruciate ligament (ACL) reconstruction in the presence of a high-grade pivot shift or revisional ACL reconstruction. We determined the position of the femoral tunnel and the length of graft using a three-dimensional (3D)-computed tomography (CT) model after ALL reconstruction. We also measured graft excursion during surgery and examined pivot shift 2 years after surgery. We conducted a subgroup analysis of femoral tunnel position, fiber length, isometricity, and residual pivot shift depending on whether the tunnel was anterior or posterior to the lateral epicondyle (LE). We also performed a subgroup analysis depending on whether the ACL reconstruction was primary or revisional.ResultsThe mean femoral tunnel position was 2.04 mm posterior and 14.5 mm proximal from the center of the LE. The mean lengths of the anterior and posterior fibers were 66.6 and 63.4 mm, respectively. The femoral tunnel was positioned more proximally than the anatomical position, and both anterior and posterior ALL fibers were longer than the natural anatomy. The anteroposterior femoral tunnel position was significantly correlated with anterior (p = 0.045) and posterior (p = 0.037) fiber excursion. In the subgroup analysis, there was no significant difference in the residual pivot shift between the posterior and anterior tunnel positions. However, there were significant differences for proximal position (p < 0.001) and fiber length (p = 0.006). There was no significant difference between primary and revisional ACL regarding femoral tunnel position and fiber lengths.ConclusionIt is challenging to reproduce both anatomical and functional aspects of ALL reconstruction in both primary and revision ACL reconstruction. Especially for functional reconstruction, the femoral tunnel tended to be positioned more proximally than the anatomical position. However, the femoral tunnel position did not affect functional clinical outcomes at the 2-year follow-up.Level of evidenceLevel IV Case series.

Distinct chemical degradation pathways of AAV1 and AAV8 under thermal stress conditions revealed by analytical anion exchange chromatography and LC-MS-based peptide mapping

Adeno-associated virus (AAV)-based gene therapy is experiencing a rapid growth in the field of medicine and holds great promise in combating a wide range of human diseases. For successful development of AAV-based products, comprehensive thermal stability studies are often required to establish storage conditions and shelf life. However, as a relatively new modality, limited studies have been reported to elucidate the chemical degradation pathways of AAV products under thermal stress conditions. In this study, we first presented an intriguing difference in charge profile shift between thermally stressed AAV8 and AAV1 capsids when analyzed by anion exchange chromatography. Subsequently, a novel and robust peptide mapping protocol was developed and applied to elucidate the underlying chemical degradation pathways of thermally stressed AAV8 and AAV1. Compared to the conventional therapeutic proteins, the unique structure of AAV capsids also led to some key differences in how modifications at specific sites may impact the overall charge properties. Finally, despite the high sequency identity, the analysis revealed that the opposite charge profile shifts between thermally stressed AAV8 and AAV1 could be mainly attributed to a single modification unique to each serotype.

China and the Australia-New Zealand alliance: the importance of loyal opposition

ABSTRACT The Australia-New Zealand alliance is a critical element of New Zealand foreign and defence policy. It is especially important in a region that is becoming less stable and more competitive. This commentary asks how the alliance influences New Zealand’s China policy. Australia and New Zealand both enjoy significant trade relations with China, and both have sought to manage relations to maximise economic opportunities. Following decades of economic growth, China has led a regionwide increase in defence spending, becoming a more powerful, consequential and at times disruptive regional actor. This shift has complicated China policy in both countries and further underlined the importance of the alliance partnership for New Zealand. Both countries have recalibrated their China policies and strengthened the cohesion of the alliance. This is shown by shared assessments of opportunity and risk, of synchronised shifts due to changes in China and joint actions to shape China’s behaviour and the regional order. Temporal differences in policy shifts, notably in security settings and public diplomacy, follow a tradition of loyal opposition that ultimately strengthens the alliance response to a rejuvenated China.

Demonstration of a tunable interface between Rydberg atoms and superconducting microwave circuits with differential polarizability nulling

Microwave-dressed Rydberg atoms in pairs of states that are optically accessible and engineered so that the frequency of the transition between them is tunable while exhibiting a low sensitivity to stray electric fields have been interfaced with a superconducting coplanar waveguide (CPW) microwave resonator. This was achieved with helium atoms in triplet Rydberg states with principal quantum numbers n=55 and 56. The atoms were dressed with two strong microwave fields—a control field and a differential polarizability nulling field. The control field allowed the atoms to be coupled to the resonator using the two-color two-photon transition between the equal parity 1s55sS13≡|55s〉 and 1s56sS13≡|56s〉 Rydberg states, with one photon supplied by it and the other provided by the resonator. The nulling field was detuned from the field-free 1s55sS13→1s55pPJ3≡|55p〉 transition to admix |55p〉 character into the |55s〉 state and eliminate the differential static electric dipole polarizability of the |55s〉 and |56s〉 states. The experiments were performed with atoms located ∼300µm above a λ/4 niobium nitride superconducting CPW resonator operated at temperatures between 3.59 and 3.73K. The measured ac and dc Stark shifts of the Rydberg states at this atom-circuit interface in the presence of the dressing fields are in good quantitative agreement with the results of Floquet calculations. The differential polarizability nulling fields used in the experiments allowed the difference in the Stark shifts of the |55s〉 and |56s〉 states over the range of dc fields offset from the residual stray field by ±65 mV/cm to be reduced from 2π×2.1 MHz to 2π×125 kHz. Published by the American Physical Society 2024

Investigation of the State of Hydration of a Non-Stoichiometric Hydrate in a Low Dose Formulation Using 19F Solid-State NMR

A variable or non-stoichiometric hydrate of GDC-4379 was developed into a formulated capsule with a 1% drug loading. The water content of this hydrate varied from 0-0.7 moles over the relative humidity (RH) range of 0-98% (25°C). Since a variable state of hydration coupled with rapid equilibration of lattice water with the environmental RH can lead to challenges in formulation development, an analytical method to directly and accurately determine the state of hydration of the active in such a low dose formulation was deemed necessary. Owing to its high selectivity and fast acquisition times, 19F solid-state NMR was effectively utilized to directly determine the lattice water content of the active in the formulated capsule. By correlating Δδ, the chemical shift difference between the isotropic peaks, with the relative humidity and ultimately the lattice water content, the state of hydration of GDC-4379 in the formulated capsule was experimentally determined as 0.63 moles of water/mole of anhydrate.

Feeding Habits of Scomber japonicus Inferred by Stable Isotope and Fatty Acid Analyses

Scomber japonicus is widely distributed off the coast of Japan and in the northwestern Pacific. It is an important target for fisheries. To reveal the differences in diet shifts and niche changes of S. japonicus, we collected samples in the high seas of the northwest Pacific (38°59′ N–43°00′ N, 150°30′ E–161°48′ E) from June to August 2021. We utilized stable isotope and fatty acid analyses to study the differences in body length and sex of S. japonicus. The results showed no significant differences in stable isotope values and fatty acid composition between male and female individuals (p &gt; 0.05). Differences in δ13C and δ15N values among different body length groups were also not significant (p &gt; 0.05). Both δ13C and δ15N values showed a trend of increasing and then decreasing across different body length groups. The niche width of S. japonicus in different body length groups first increased and then decreased, with niche overlap among the groups exceeding 60%. Principal component analysis (PCA) results showed that the main fatty acids in S. japonicus were C14:0, C16:0, C18:0, C16:1n-7, C18:1n-9, C18:3n-6, C20:5n-3, C20:4n-6 and 22:6n-3. Except for C18:0 and C20:4n-6, the content of the other fatty acids showed significant differences among different body length groups (p &lt; 0.05). The results of the similarity analysis (ANOSIM) indicated that the fatty acid compositions of the 100–130 mm length group were significantly different from those of the 131–160 mm and 161–190 mm length groups (p &lt; 0.05). However, there were no significant differences among the other size groups (p &gt; 0.05). During the growth and development of S. japonicus, the proportion of krill in their diet gradually decreased. Meanwhile, their consumption of zooplankton, diatoms and fish significantly increased. Additionally, S. japonicus also consumed crustaceans, but their intakes of planktonic bacteria and green algae were relatively low. We suggested that there were no significant differences between male and female individuals of S. japonicus. As they grew and developed, the ecological niche and feeding habits of S. japonicus continuously changed.

The Influence of Variations in Shape and Placement Sliding Walls on The Behavior of Multi-Story Building Structures to Withstand Earthquake Loads (Case Study: Building Pasar Raya Inpres Block)

System the structure of Building a Pasar Raya Inpres Padang Block IV, namely system double that uses wall shift as retainer lateral load and SRPMK as retainer style gravity, but cold sliding on the building the only there is on the 1st floor only if wall shifts No continuously until building roof floor so can influence behavior structure building the like mark style shift basis, displacement, deviation between the floor and p-delta influence. The study this aims to compare mark style shift basis, displacement, and deviation between which floor and p-delta later will compared against 4 variation models shape and placement wall shift. The method used that is method comparative with analysis uses response spectrum using ETABS software. Results of the study show model 2 structure has a mark base shear namely 3658,658 kN. Model 2 has a mark displacement the smallest in the x direction is 3,766 mm and Model 4 has a mark displacement the smallest in the y direction is 2,347 mm. Model 2 has a mark deviation atar floor smallest namely 8,019 mm for the X direction and 4,015 for the Y direction. All models are confirmed safe at the moment checking the P-Delta effect, with model 2 having the mark lowest for the X direction and Y direction.