bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient Intrusion Detection System Data Preprocessing Using Deep Sparse Autoencoder with Differential Evolution
Authors: N. Saranya , Haldorai Anandakumar
Published: August 2024

A great amount of data is generated by the Internet and communication areas’ rapid technological improvement, which expands the size of the network. These cutting‐edge technologies could result in unique network attacks that present security risks. This intrusion launches many attacks on the communication network which is to be monitored. An intrusion detection system (IDS) is a tool to prevent from intrusions by inspecting the network traffic and to make sure the network integrity, confidentiality, availability, and robustness. Many researchers are focused to IDS with machine and deep learning approaches to detect the intruders. Yet, IDS face challenges to detect the intruders accurately with reduced false alarm rate, feature selection, and detection. High dimensional data affect the feature selection methods effectiveness and efficiency. Preprocessing of data to make the dataset as balanced, normalized, and transformed data is done before the feature selection and classification process. Efficient data preprocessing will ensure the whole IDS performance with improved detection rate (DR) and reduced false alarm rate (FAR). Since datasets are required for the various feature dimensions, this article proposes an efficient data preprocessing method that includes a series of techniques for data balance using SMOTE, data normalization with power transformation, data encoding using one hot and ordinal encoding, and feature reduction using a proposed deep sparse autoencoder (DSAE) with differential evolution (DE) on data before feature selection and classification. The efficiency of the transformation methods is evaluated with recursive Pearson correlation‐based feature selection and graphical convolution neural network (G‐CNN) methods.
Two black widow pulsars in the optical and X-rays
Authors: Bobakov A. V. , Kirichenko A. Yu. , Zharikov S. V. , Karpova A. V. , Zyuzin D. A. , Shibanov Yu. A. , Mennickent R. E. , Garcia-Álvarez D.
Published: August 2024

Context. Two millisecond pulsars, PSR J1513−2550 and PSR J2017−1614, with spin periods of about 2.1 and 2.3 ms were recently discovered in the radio and γ-rays and classified as black widow pulsars in tight binary stellar systems with orbital periods of about 4.3 and 2.3 h.

Aims. Our goals are to reveal the fundamental parameters of both systems and their binary components using multi-wavelength observations.

Methods. We carried out the first time-series multi-band optical photometry of the objects with the 2.1-m telescope of the Observatorio Astronómico Nacional San Pedro Mártir, the 6.5-m Magellan-1 telescope, and the 10.4-m Gran Telescopio Canarias. To derive the parameters of both systems, we fitted the obtained light curves with a model assuming heating of the companion by the pulsar. We also analysed archival X-ray data obtained with the XMM-Newton observatory.

Results. For the first time, we firmly identified J1513−2550 in the optical and both pulsars in X-rays. The optical light curves of both systems have a single peak per orbital period with a peak-to-peak amplitude of ≳2 magnitudes. The J2017−1614 light curves are symmetric, while J1513−2550 demonstrates strong asymmetry whose nature remains unclear.

Conclusions. We constrained the orbital inclinations, pulsar masses, companion temperatures and masses, and the distances to both systems. We also conclude that J2017−1614 may contain a massive neutron star of 2.4 ± 0.6 M⊙. The X-ray spectra of both sources can be fitted by power laws with parameters typical of black widow systems.
Vorticity and magnetic dynamo from subsonic expansion waves
Authors: Elias-López Albert , Del Sordo Fabio , Viganò Daniele
Published: August 2024

Context. The amplification of astrophysical magnetic fields takes place via dynamo instability in turbulent environments. Vorticity is usually present in any dynamo, but its role is not yet fully understood.

Aims. This work is an extension of previous research on the effect of an irrotational subsonic forcing on a magnetized medium in the presence of rotation or a differential velocity profile. We aim to explore a wider parameter space in terms of Reynolds numbers, the magnetic Prandtl number, the forcing scale, and the cooling timescale in a Newtonian cooling. We studied the effect of imposing that either the acceleration or the velocity forcing function be curl-free and evaluated the terms responsible for the evolution vorticity.

Methods. We used direct numerical simulations to solve the fully compressible, resistive magnetohydrodynamic equations with the Pencil Code. We studied both isothermal and non-isothermal regimes and addressed the relative importance of different vorticity source terms.

Results. We report no small-scale dynamo for the models that do not include shear. We find a hydro instability, followed by a magnetic one, when a shearing velocity profile is applied. The vorticity production is found to be numerical in the purely irrotational acceleration case. Non-isothermality, rotation, shear, and density-dependent forcing, when included, contribute to increasing the vorticity.

Conclusions. As in our previous study, we find that turbulence driven by subsonic expansion waves can amplify the vorticity and magnetic field only in the presence of a background shearing profile. The presence of a cooling function makes the instability occur on a shorter timescale. We estimate critical Reynolds and magnetic Reynolds numbers of 40 and 20, respectively.
Birth and evolution of fast radio bursts: Strong population-based evidence for a neutron-star origin
Authors: Wang Yuyang , van Leeuwen Joeri
Published: August 2024

While the appeal of their extraordinary radio luminosity to our curiosity is undiminished, the nature of fast radio bursts (FRBs) has remained unclear. The challenge has been due in part to small sample sizes and limited understanding of telescope selection effects. We here present the first inclusion of the entire set of one-off FRBs from CHIME/FRB Catalog 1 in frbpoppy. Where previous work had to curate this data set, and fit for few model parameters, we have developed full multi-dimensional Markov chain Monte Carlo (MCMC) capabilities for frbpoppy – the comprehensive, open-science FRB population synthesis code – that allow us to include all one-off CHIME bursts. Through the combination of these two advances we now find the best description of the real, underlying FRB population, with higher confidence than before. We show that 4 ± 3 × 103 one-off FRBs go off every second between Earth and z = 1; and we provide a mock catalog based on our best model, for straightforward inclusion in other studies. We investigate CHIME side-lobe detection fractions, and FRB luminosity characteristics, to show that some bright, local FRBs are still being missed. We find strong evidence that FRB birth rates evolve with the star formation rate of the Universe, even with a hint of a short (0.1−1 Gyr) delay time. The preferred contribution of the hosts to the FRB dispersion agrees with a progenitor birth location in the host disk. This population-based evidence solidly aligns with magnetar-like burst sources, and we conclude FRBs are emitted by neutron stars.
Bedeutung neuer Alkoholbiomarker in der Eignungsbegutachtung von
Verkehrsteilnehmern
Authors: Musshoff Frank
Published: August 2024

Die direkten Alkoholkonsummarker Ethylglucuronid (EtG) in Urin und Haaren sowie
Phosphatidylethanol (PEth) im Blut sind die Biomarker der Wahl bei einer
Überprüfung einer Eignung gerade auch im Straßenverkehr. Die Bestimmung von EtG
im Urin kann nur für unvorhersehbar anberaumte Abstinenzkontrollen eingesetzt
werden, erlaubt aber keine weiterführende Interpretation bzgl. eines
Konsumverhaltens. Die Bestimmung von EtG im Haar kann bei einem Cutoff von
5 pg/mg als Abstinenzkontrolle erfolgen, bis unter 30 pg/mg kann man ansonsten
von einem moderaten, sozial angepasstem Konsumverhalten ausgehen. PEth im Blut
eignet sich mit einem Cutoff von 20 ng/mL ebenfalls für Abstinenzkontrollen,
Werte ab 210 ng/mL sprechen für einen übermäßigen Alkoholkonsum. PEth, das viel
schneller auf Änderungen des Konsumverhaltens reagiert, als die Konzentration
von EtG im Haar, wird auch eingesetzt in der analytischen Begleitung des
Kontrollierten Trinkens nach Körkel. Der derzeitig dafür propagierte Cutoff von
100 ng/mL ist ggf. noch nach unten zu korrigieren. Möglichkeiten und Grenzen
dieser Alkoholkonsummarker werden vorgestellt und diskutiert.
Synthesis, Characterization, and Biological Applications of Tetramethylpiperidinyl Triazolopyridazine Derivatives
Authors: Varkolu Mohan , Keesara Srinivasa Reddy , Bolla Ratnasekhar , Bharathkumar Hanumantharayappa , Andugulapati Sai Balaji , Gundekari Sreedhar
Published: August 2024

We have synthesized a series of tetramethylpiperidinyl triazolopyridazine derivatives and screened the molecules for their biological activity against a cancer (NCI-H460) cell line. Among the tested molecules, 2-[3-(2,2,6,6-tetramethylpiperidin-4-yl)-3H-[1,2,3]triazolo[4,5-c]pyridazin-6-yl]-5-(2H-1,2,3-triazol-2-yl)phenol significantly inhibited cell growth with an IC50 value of 5.2 μM. We hope that this study will help in the development of better candidates for the treatment of lung cancer.
Comparison of the Effects of Stirring and Standing on Chemical Reactions
Authors: Huang Xianting , Zhao Jianyou , Wang Qingxu , Liu Zhong-Quan , Fang Pengkai , Xie Wei , Chen Meng , Han Hongliang , Zhang Lanlan , Zhang Jiatai , Wang Fan
Published: August 2024

For hundreds of years, it seems that people have needed stirring to conduct chemical experiments. This operation can be seen everywhere in chemical, pharmaceutical, and materials laboratories and factories. People generally believe that stirring helps with processes such as material dispersion, dissolution, and collision, thereby enabling more-efficient reactions. However, why do chemical reactions that occur in Nature not require stirring? What are the facts? For this purpose, we investigated a total of 329 organic chemical reactions in eight categories and 25 types, including 26 chemical reactions magnified to gram or even kilogram levels. Under the same conditions of temperature, humidity, pressure, and reaction time, we compared the reaction yields under stirring and standing conditions. More than 600 results showed that stirring or not stirring had almost no effect on the efficiency of chemical reactions in solution. If most chemists performing reactions turned off the agitator, it would not be difficult to imagine how much electricity could be saved!
Rare Case of Twin Reversed Arterial Perfusion Acardius Acephalus Subtype Seen in a Community-Based Hospital
Authors: Reguero Cadilla Laura , Villafuerte Santana Carlos , Centazzo Nicolle , Faustin Daniel
Published: August 2024

Background TRAP sequence occurs in monochorionic pregnancies consisting of one normal fetus and a non-viable fetus. The pump twin has an increased risk of developing high-output cardiac failure.

Case 32-year-old G4P2012 with TRAP syndrome in current pregnancy presented to triage at 26 weeks with contractions and spotting. She had undergone RFA for selective reduction at another facility. Placental abruption was suspected and patient underwent a cesarean section. Twin A was delivered alive although she subsequently succumbed due to complications of prematurity.

Conclusion This case highlights the importance of early detection and consistent prenatal care in the management of TRAP sequence. Further research of interventions associated with improved outcomes should be encouraged.
Free Latissimus Dorsi Flaps in Head and Neck Reconstruction at a Modern High-Volume Microsurgery Center
Authors: Shyaka Ian , Su Chun-Lin , Wei Fu-Chan
Published: August 2024

Background Over the past two decades, with the introduction of the perforator flap concept and advances in flap dissections, lower extremities have emerged as the preferred soft tissue flap donor sites. As a modern and high-volume microsurgical center, and the senior author being one of the pioneers and advocates for the use of lower extremity flap donor sites, we aim to investigate the role of latissimus dorsi (LD) free flap in head and neck reconstruction within our current practice.

Methods All free LD flaps used for head and neck reconstruction performed by a single surgeon between January 2010 and June 2023 were reviewed for their indications and immediate and short-term outcomes.

Results A total of 1,586 head and neck free flap reconstructions were performed, and 33 free LD flaps were identified. The patients' median age was 53 (interquartile range [IQR] 48.5–63.5) years. Twenty-nine (87.9%) flaps were used to reconstruct oro-maxillo-facial and four (12.1%) flaps were used to reconstruct scalp defects. Most patients had prior radiation (n = 28, 84.8%), neck dissection (n = 24, 72.7%), and multiple previous head and neck flap reconstructions with a median of 3.0 (IQR 3.0–3.5) previous flaps. Six (18.2%) LD flaps were used to replace failed flaps from other donor sites. No major complications such as total flap failure or takebacks, and no need for vein grafts but three (9.1%) had flap marginal necrosis. Other complications included one flap dehiscence (3.0%), one orocutaneous fistula (3.0%), two wound infections (6.1%), three plate exposures (9.1%), and three patients who developed local recurrence (9.1%). The median patient follow-up time was 16 (IQR 5–27) months.

Conclusion This retrospective study demonstrates the role of LD free flap in head and neck reconstruction as a reliable and versatile backup soft tissue flap when workhorse flaps from lower extremity donor sites are either unavailable or unsuitable.
A Case Report of Fetal Split Hand Foot Malformation Syndrome: A Rare Congenital Limb Anomaly
Authors: Roy Prasanna , Dey Shankar
Published: August 2024

Fetal split hand foot malformation (SHFM) syndrome is a rare congenital disorder characterized by developmental abnormalities of fingers and/or toes, resulting in a split appearance. SHFM is sporadic and shows mainly autosomal dominant inheritance with variable clinical presentation. Prenatal diagnosis plays a crucial role in the management and in counseling of affected families. In this case report, we present the diagnosis of SHFM through ultrasound imaging and genetic testing in a primigravida, along with post abortal fetal findings. The aim was to highlight the importance of early detection during routine ultrasound and genetic counseling for appropriate understanding and management of this rare limb condition.
Midterm Clinical Outcomes of a Resurfacing Capitate Pyrocarbon Implant: A Case Series
Authors: Andrews Steve A. , Mayo Andrew , Hope Ben , Al Hakim Wisam , Couzens Greg B. , Jha Bhavana , Lee Louise , Peters Susan E. , Ross Mark
Published: August 2024

Purpose Scaphoid nonunion advanced collapse (SNAC), scapholunate advanced collapse (SLAC), and Kienbock's disease are some of the most common pathologies to result in arthritis of the wrist in patients with a relatively high functional demand. An option for treatment where there are not two cartilage surfaces suitable for articulation to allow either a proximal row carpectomy (PRC) or partial fusion is to perform a PRC combined with resurfacing of the capitate using a pyrocarbon implant (RCPI). The purpose of this study was to examine the medium-term survivorship, clinical-, and patient-reported outcomes of the RCPI in a case series of patients.

Methods Survivorship was assessed in 46 patients at approximately 21 months or greater (range = 21–144, median follow-up = 67). Of these, 36 patients completed patient-reported outcome measures (Visual Analogue Scales, Disabilities of the Arm, Shoulder and Hand–short form, Patient-Rated Wrist Evaluation, Global Rating of Change) at 21 months or greater. Patient population was 42% (n = 16) female, average age was 59 (range = 25–79), and majority had the operation on their right hand (78%, n = 35).

Results Implant survival can be confirmed until most recent follow-up at a median of 60 months (range = 21–144), with Kaplan–Meier analysis indicating an 83% survival probability at 10 years. Complications at 21 months or greater were observed in 11 patients (24%), with 9 (20%) patients receiving further surgery (7 wrist fusions, 1 ulnar nerve decompression, and 1 distal radioulnar joint replacement [RCPI in situ]). Time to revision was a mean of 20 months (range = 4–39). Comparison between passive range of motion at 21 months to 4 years and >5 years showed no significance (p > 0.5), suggesting 2- to 4-year outcomes are maintained midterm.

Conclusions The RCPI extends the indications for PRC where there is unsatisfactory cartilage on the proximal capitate, the lunate facet of the radius, or both. It provides a safe and effective treatment for pain relief and improved functional use of the hand for SLAC and SNAC arthritis without the increased morbidity of more complex arthroplasty or total wrist arthrodesis.

Level of Evidence IV, case series
Rare Liraglutide-Induced Dermatological Adverse Reaction in the Treatment of Obesity
Authors: Alam Muhammad Masoud , Rivero-Navea Giselle , Rivero-Jimenez Rene Antonio
Published: August 2024

Liraglutide is a glucagon-like peptide-1 (GLP-1) agonist widely used for managing type 2 diabetes mellitus and obesity. Although allergic reactions to the drug have been documented, skin-related adverse effects remain underreported. We present a case of a 43-year-old woman undergoing subcutaneous liraglutide injections for obesity treatment. Approximately 3 weeks into the treatment regimen, the patient experienced a distinctive reaction characterized by oval, red erythema accompanied by swelling, itchiness, and skin warmth around the injection site shortly after drug administration. This reaction recurred with each subsequent dose over the next 3 days, prompting the patient to discontinue treatment. A dermatology consultant suggested oral antihistamines in conjunction with topical methylprednisolone. Over the course of several days, the intensity of the skin lesions gradually decreased, ultimately resolving completely within 1 month. This case highlights the rarity of skin adverse reactions associated with liraglutide and underscores the importance of recognizing and managing injection site erythema as a potential side effect of this medication. Further research is needed to better understand and document such reactions for improved patient care and safety.
Rotational motion of skyrmion driven by optical vortex in frustrated magnets
Authors: Lei Y. M. , Yang Q. Q. , Tang Z. H. , Tian G. , Hou Z. P. , Qin M. H.
Published: August 2024

Effective control of skyrmion rotation is of significant importance in designing skyrmion-based nano-oscillators. In this work, we numerically study the optical vortex-driven skyrmion rotation in frustrated magnets using the Landau–Lifshitz–Gilbert simulations. The skyrmion rotation is induced by the orbital angular momentum (OAM) transfer from the optical vortex to the skyrmion, which is regardless of the sign of the OAM quantum number m due to the helicity degree of freedom of the frustrated skyrmion. This property highly broadens the parameter range of the optical vortex in controlling the skyrmion rotation. The direction of the rotation is determined by the sign of m, and the radius and angular velocity depend on the magnitude of m, light polarization, and intensity. Interestingly, the helicity oscillation induced by the linearly polarized beam is much slower than that driven by the circularly polarized beam with a same intensity, resulting in a faster rotation of the skyrmion. This phenomenon demonstrates the advantage of the linearly polarized beam in controlling the dynamics of the frustrated skyrmion, benefiting energy-saving and high-efficient device design.
Relativistic and quantum electrodynamics effects on NMR shielding tensors of TlX (X = H, F, Cl, Br, I, At) molecules
Authors: Kozioł Karol , Aucar I. Agustín , Gaul Konstantin , Berger Robert , Aucar Gustavo A.
Published: August 2024

The results of relativistic calculations of nuclear magnetic resonance shielding tensors (σ) for the thallium monocation (Tl+), thallium hydride (TlH), and thallium halides (TlF, TlCl, TlBr, TlI, and TlAt) are presented as obtained within a four-component polarization propagator formalism and a two-component linear response approach within the zeroth-order regular approximation. In addition to a detailed analysis of relativistic effects performed in this work, some quantum electrodynamical (QED) effects on those nuclear magnetic resonance shieldings and other small contributions are estimated. A strong dependence of σ(Tl) on the bonding partner is found, together with a very weak dependence of QED effects with them. In order to explain the trends observed, the excitation patterns associated with relativistic ee (or paramagnetic-like) and pp (or diamagnetic-like) contributions to σ are analyzed. For this purpose, the electronic spin-free and spin-dependent contributions are separated within the two-component zeroth-order regular approximation, and the influence of spin–orbit coupling on involved molecular orbitals is studied, which allows for a thorough understanding of the underlying mechanisms.
Evaluating the energy storage performance of polymer blends by phase-field simulation
Authors: Ma Zhe , Shen Zhong-Hui , Liu Run-Lin , Chen Xiao-Xiao , Shen Yang , Chen Long-Qing , Nan Ce-Wen
Published: August 2024

Polymer blends are regarded as a straightforward and effective method to enhance the energy storage performance of dielectric film capacitors. However, how the components and structures within the blend systems affect the energy density and efficiency remains insufficiently explored in-depth. In this discourse, employing a polymer blend of ferroelectric and linear dielectric phases as a paradigm, we perform phase-field simulations to elucidate the effects of ferroelectric phase volume fractions, geometrical dimensions, and the dielectric constant of the linear phase on the energy storage capabilities. Concurrently, we have devised six divergent blending microstructures to probe the ramifications of structural variances on the overarching performance metrics. We also analyze the domain configurations and switching dynamics under varying electric fields to understand the performance variations and delineate the determinants conducive to superior energy density and efficiency. This paper theoretically establishes the component–content–structure–performance relationships of different polymer blend systems, which is expected to better guide the innovative design of new polymer blend dielectrics.
Inverse scattering for repulsive potential and strong singular interactions
Authors: Ishida Atsuhide
Published: August 2024

In a previous work of 2014 on a quantum system governed by the repulsive Hamiltonian, the author proved uniqueness for short-range interactions described by a scattering operator consisting of regular and singular parts. In this paper, the singular part is assumed to have much stronger singularities and the same uniqueness theorem is proved. By applying the time-dependent method invented by Enss and Weder [J. Math. Phys. 36(8), 3902–3921 (1995)], the high-velocity limit for a wider class of the scattering operator with stronger singularities also uniquely determines the interactions of a multi-dimensional system.
Forte: A suite of advanced multireference quantum chemistry methods
Authors: Evangelista Francesco A. , Li Chenyang , Verma Prakash , Hannon Kevin P. , Schriber Jeffrey B. , Zhang Tianyuan , Cai Chenxi , Wang Shuhe , He Nan , Stair Nicholas H. , Huang Meng , Huang Renke , Misiewicz Jonathon P. , Li Shuhang , Marin Kevin , Zhao Zijun , Burns Lori A.
Published: August 2024

Forte is an open-source library specialized in multireference electronic structure theories for molecular systems and the rapid prototyping of new methods. This paper gives an overview of the capabilities of Forte, its software architecture, and examples of applications enabled by the methods it implements.
First principles study of electronic structure of x-form phthalocyanine crystals doped with one-dimensional iodine atomic chains
Authors: Inaoka Takeshi
Published: August 2024

The x-form phthalocyanine (Pc) crystal is composed of a square-lattice arrangement of one-dimensional and double-period molecular chains with molecular planes normal to the stacking direction, and doped iodine (I) atomic chains between these molecular chains are known to induce the insulator-metal transition. Using the van der Waals density functional method, we investigate the electronic structure of a single x-form silicon Pc (x-SiPc) chain and the x-SiPc crystal undoped and doped with I atomic chains in a comparative manner. Although a SiPc molecule has a Si pz derived orbital just above the LUMO, the aligned Si atoms in x-crystals, each of which is at the center of the molecular plane, dimerize in the stacking direction, which prevents formation of a Si metallic band. In a single SiPc chain, two molecules in each primitive unit cell are stacked face-to-face with a staggering angle of 45°. However, when these molecular chains aggregate to create x-crystals, the staggering angle deviates from 45° to about 40° to form H–H bonding orbitals like H2 molecules between neighboring molecular planes in the lateral direction. Doping of the I atomic chains converts half-filling of the doubly degenerate bands to a lower band occupancy, which corresponds to the insulator-metal transition observed experimentally. The equally spaced I atomic chains create a metallic band due to pz-orbital overlapping with an effective-mass ratio of 0.15. Although the SiPc chains operate to create equally spaced I atomic chains, the effect of I atoms trying to trimerize is larger. This trimerization prevents pz orbitals of I atoms from making a metallic band.
Prediction of specific cutting energy consumption in eco-benign lubricating environment for biomedical industry applications: Exploring efficacy of GEP, ANN, and RSM models
Authors: Sen Binayak , Bhowmik Abhijit , Prakash Chander , Ammarullah Muhammad Imam
Published: August 2024

This study emphasizes the criticality of measuring specific cutting energy in machining Hastelloy C276 for biomedical industry applications, offering valuable insights into machinability and facilitating the optimization of tool selection, cutting parameters, and process efficiency. The research employs artificial intelligence-assisted meta-models for cost-effective and accurate predictions of specific cutting energy consumption. Comparative analyses conducted on Hastelloy C276, utilizing a TiAlN-coated solid carbide insert across various media (dry, MQL, LN2, and MQL+LN2), reveal the superiority of hybrid LN2+MQL in reducing specific cutting energy consumption. Subsequently, the analysis of variance underscores the cutting speed as the most influential parameter as compared to other inputs. Finally, a statistical evaluation compares the Gene Expression Programming (GEP) model against the Artificial Neural Network (ANN), and Response Surface Methodology model, demonstrating the superior predictive performance of the GEP meta-model. The GEP model demonstrates validation results with an error range of 0.25%–1.52%, outperforming the ANN and RSM models, which exhibit an error range of 0.49%–8.33% and 2.68%–10.18%, respectively. This study suggests the potential integration of contemporary intelligent methodologies for sustainable superalloy machining in biomedical industry applications, providing a foundation for enhanced productivity and reduced environmental impact of surgical instrument and biomedical device machining.
Long-wavelength infrared upconversion time-stretch spectroscopy
Authors: He Linzhen , Wu Han , Wang Weizhe , Hu Bo , Yang Xuemei , Liang Houkun
Published: August 2024

High-speed spectroscopy in the molecular fingerprint spectral region (≈6–12 μm) is essential for the detection of ultrafast molecular dynamic processes, rapid combustion analysis, and biological diagnostics. However, ultrafast spectroscopy in the long-wavelength infrared (LWIR) region remains a challenge due to the limitations of laser sources and the lack of ultrafast and sensitive detectors in this wavelength region. Here, we demonstrate broadband LWIR time-stretch spectroscopy, which can realize a single-shot high-speed spectral measurement in a 8–10 μm region, by combining the LWIR femtosecond (fs) light generation and upconversion time-stretching detection with specific dispersive fiber. Broadband tunable fs light generated in the 8–10 μm region is upconverted to the 1.1–1.2 μm near-infrared wavelength via difference-frequency generation with the 1 μm chirped pump pulse. Time-stretch detection of the upconverted light can then be realized by adopting dispersion shifted fiber, which has a superior dispersion-to-loss ratio in the 1.1–1.2 μm wavelength region, as the dispersive medium. As a result, we experimentally demonstrate LWIR time-stretch spectroscopy in the 8–10 μm region with a spectral resolution of 1.07 cm−1, at a rate of 200 kSpectra s−1, which is only limited by the repetition rate of the 1 μm pump source. The demonstration of high-speed time-stretch spectroscopy in the LWIR region would open the possibility in exploring the transient dynamics of molecular fingerprint spectroscopy.
Interaction of inertia and magnetic force in the liquid metal flow past a magnetic obstacle
Authors: Solano-Olivares V. , Cuevas S. , Figueroa A. , Domínguez-Lozoya D. R.
Published: August 2024

In this paper, we present a numerical study of the three-dimensional behavior of a liquid metal flow in an insulating rectangular duct of narrow cross section past a localized magnetic field (i.e., a magnetic obstacle) produced by two parallel square magnets arranged externally on the walls of the duct. A series of simulations are conducted focused mainly on describing the interplay between inertial and magnetic forces in a wide range of interaction parameters (1.8<N<48) by varying the Reynolds number while the Hartmann number is kept fixed (Ha = 75). The analyzed configuration coincides with that studied experimentally by Domínguez et al. [“Experimental and theoretical study of the dynamics of wakes generated by magnetic obstacles,” Magnetohydrodynamics 51(2), 215–224 (2015)] and, as a first step, experimental data from local variables (streamwise velocity component) and global parameters (oscillation frequency and kinetic energy of the wake) are consistently replicated by the numerical model. Furthermore, to complement the flow phenomenology, the transition to different flow structures as the interaction parameter varies is explored. It is found that when the magnetic forces predominate over inertia, stationary vortex patterns with two, four, and six vortices appear while, unlike the hydrodynamic flow past a bluff body, the increase in inertial effects leads to a reduction in the number of vortices and eventually to their disappearance, reaching a state in which the magnetic obstacle becomes imperceptible to the flow. The existence of a critical value of the interaction parameter that maximizes the kinetic energy of the wake is confirmed numerically and corroborated from the experimental data.
Monolithically integrated mode converter from terahertz substrateless silicon guide to conductive slotline
Authors: Headland Daniel , Dechwechprasit Panisa , Withayachumnankul Withawat
Published: August 2024

Although substrateless micro-scale silicon waveguides are a useful and versatile platform for terahertz waves, the fact that modal fields occupy the volume of the core limits the potential to dynamically manipulate guided waves. To address this, we introduce an aperiodic lattice structure to enable the monolithic co-integration of a Vivaldi antenna-like mode converter with a substrateless silicon waveguide. This broadband transition is experimentally confirmed to exhibit ∼2.5 dB average loss for two couplers, from 220 GHz to 330 GHz, and enables a photoexcited variable attenuator as proof-of-concept demonstration. This is an important enabling step to incorporate general-purpose dynamic reconfigurability, sensing, and modulation functionality into terahertz-range silicon-based integrated circuits, which are currently limited to primarily all-passive structures.
Lattice Boltzmann simulation of counter-current imbibition of oil and water in porous media at the equivalent capillarity
Authors: Cheng Zhilin , Tong Shaokai , Shang Xiongtao , Yu Jinzhu , Li Xiaohang , Dou Liangbin
Published: August 2024

The characterization of oil and water displacement in porous media often relies on the capillary number (Ca = μv/σ cos θ). However, limited investigations have been conducted to explore the relative significance of interfacial tension and wettability in determining oil recovery, particularly under the imbibition mode. To address this research gap, the modified color gradient lattice Boltzmann method has been employed. This study aims to systematically investigate the transient imbibition characteristics, pore-scale events, and morphological features of the two-phase distribution in the matrix, all under the same capillarity but varying capillary numbers. The obtained results indicate that, for a given capillary number, a more water–wet condition generally leads to a higher imbibition recovery. Conversely, the influence of capillary number on oil recovery is complex and contingent upon the capillarity value, i.e., the interfacial tension between oil and water. Additionally, the oil recovery data from all cases have been effectively fitted using the Minkowski functionals, demonstrating a linear correlation. Moreover, an attempt has been made to elucidate the mechanism behind the varying oil recovery observed in different capillarity combinations. This analysis considers factors such as energy conversion, the transient change of the ratio of viscous force over capillarity, and the capillary valve effect. The findings of this study contribute to our understanding of the use of chemical agents to enhance oil recovery and provide valuable insights for determining key two-phase parameters in reservoir simulations.
Hot spot localization in the field of view of the Kirkpatrick–Baez microscope
Authors: Wu Yankang , Yang Pin , Zhang Xing , Dong Jianjun , Xu Jie , Li Mingtao , Chen Zhongjing , Li Yingjie , Jiang Wei , Sun Chuankui , Chen Liang , Li Wenjie , Yan Ji , Pu Yudong , Dong Yunsong , Yang Dong , Wang Feng , Mu Baozhong , Zhao Zongqing
Published: August 2024

The Kirkpatrick–Baez (KB) microscope is an effective instrument for x-ray imaging of hot spot. However, the non-uniform distribution of response efficiency in the field of view is a drawback of the KB microscope. A more accurate hot spot image requires the correction of the measured image by combining the hot spot position and the response efficiency distribution. Here, we describe a method to locate the position of the hot spot in the field of view during hot spot imaging with a KB microscope. The position of the hot spot in the field of view can be obtained by measuring the grazing incidence angle change during hot spot imaging. In the experiment of hot spot self-emission imaging with a four-channel KB microscope, the location of the hot spot with an accuracy of 15 μm was realized, and the intensity corrected hot spot image was obtained. This will solve the problem of the non-uniform distribution of the response efficiency of the KB microscope and enable quantitative measurement of hot spot radiation intensity.
Expansion wave-reinforced initiation of the oblique detonation wave
Authors: Qin Qiongyao , Li Longgang , Han Feng , Yao Qian , Liu Yidong , Yuan Mingze , Li Xiafei , Ji Tianyong , Li Jianzhong
Published: August 2024

Efficient initiation of oblique detonation waves (ODWs) is crucial for optimizing the performance of oblique detonation wave engines. A novel approach is proposed for enhancing ODW initiation through expansion waves in this research. Validation of the expansion wave-reinforced initiation method is conducted via numerical simulations employing multi-species reactive Euler equations and a pressure-dependent reaction mechanism. Results demonstrate a significant reduction in the initiation length of ODWs with the addition of an expansion wave ahead of the wedge, contrasting with the absence of detonation wave initiation on a wedge lacking an expansion wave. A theoretical model, based on expansion wave and shock wave relations, along with constant volume combustion theory, elucidates the underlying mechanism of reinforcement. The model reveals that crossing the expansion wave elevates the fluid's Mach number and locally enlarges the flow deflection angle on the wedge surface, without altering the wedge's structure. Furthermore, post-shock temperature increases and pressure decreases compared to the wedge not encountering an expansion wave. The heightened temperature predominantly triggers ODW initiation, thus reinforcing the process. Theoretical analyses indicate the reinforcement's greater efficacy at lower inflow temperatures and lower inflow Mach numbers, suggesting the expansion wave's suitability for initiation in the early flight stages of an aircraft equipped with oblique detonation wave engines.
Analysis on dual Fano resonance in a coupled-resonator waveguide
Authors: Wei Zhiwei , Yuan Tingge , Wu Jiangwei , Chen Chengyu , Chen Yuping , Chen Xianfeng
Published: August 2024

Dual Fano resonance was demonstrated in a compact coupling system without additional large footprint tunable devices consisting of a grating-coupled waveguide and a micro-racetrack resonator on thin film lithium niobate. A multimode interference model was proposed for the dual Fano resonance system. The inverse design method was used to realize model fitting, validate our model, and analyze our model. Based on the parameters obtained by the inverse design, we further analyzed the influence of different parameters. Our research also shows that through the interaction of two Fano resonance modes, tunable line shape and enhanced extinction ratio can be realized in the transmission spectrum, which has potential applications in optical sensing.
A narrative review of factors affecting the welfare of dairy cows in larger Australasian pasture-based production systems
Authors: Verdon Megan , Beggs David S.
Published: August 2024

On the basis of current growth trajectories, pasture-based dairies of the future are likely to be bigger, have higher stocking rates and feed more concentrate to cows. This review uses the five-domains framework to consider risks to the welfare of dairy cows in these larger intensified pasture-based production systems. The factors considered in this review can be broadly categorised as (1) emerging welfare risks that can be managed, (2) emerging welfare risks that require research to be managed, or (3) persisting and/or exacerbated welfare risks. First, large herds could be subject to welfare risks associated with more stock per labour unit, longer milking times and longer distances walked to and from the dairy. To counter this, the time that cows in large herds spend off pasture can be reduced by splitting the herd into several more manageable groups, and animal-monitoring technologies can help identify health challenges with a reduced stockperson to animal ratio. Cow body condition and productivity can be maintained at high stocking rates by improving pasture production and feeding a higher proportion of concentrate. The risk of ruminal acidosis may then be reduced by appropriate transition feeding regimes and rumen buffers. Second, ensuring social stability and reducing competition may become difficult as herd sizes increase and feeding becomes more intensive. The resulting variability in feed intake, increased agonistic behaviour and social stress present emerging risks to cow welfare. Research is needed to better understand the social behaviour of cows in large intensive pasture-based herds, and how the design of the pre-milking area, the feeding pad and pasture feeding regimes (i.e. quantity and timing of pasture allocation) can improve accessibility for more vulnerable animals. Finally, intensive pasture-based dairies of the future will continue to face welfare challenges relating to lameness, mastitis and cull-cow management, whereas risks due to environmental exposure may be exacerbated by the removal of shelterbelts to facilitate irrigation. These require continued efforts in research (e.g. ways of incorporating shelter into intensive grazing systems), development (e.g. pathway to market for aged beef) and extension (e.g. improved record keeping and benchmarking of lameness and mastitis).
GPT is an effective tool for multilingual psychological text analysis
Authors: Rathje Steve , Mirea Dan-Mircea , Sucholutsky Ilia , Marjieh Raja , Robertson Claire E. , Van Bavel Jay J.
Published: August 2024

The social and behavioral sciences have been increasingly using automated text analysis to measure psychological constructs in text. We explore whether GPT, the large-language model (LLM) underlying the AI chatbot ChatGPT, can be used as a tool for automated psychological text analysis in several languages. Across 15 datasets (
n
= 47,925 manually annotated tweets and news headlines), we tested whether different versions of GPT (3.5 Turbo, 4, and 4 Turbo) can accurately detect psychological constructs (sentiment, discrete emotions, offensiveness, and moral foundations) across 12 languages. We found that GPT (
r
= 0.59 to 0.77) performed much better than English-language dictionary analysis (
r
= 0.20 to 0.30) at detecting psychological constructs as judged by manual annotators. GPT performed nearly as well as, and sometimes better than, several top-performing fine-tuned machine learning models. Moreover, GPT’s performance improved across successive versions of the model, particularly for lesser-spoken languages, and became less expensive. Overall, GPT may be superior to many existing methods of automated text analysis, since it achieves relatively high accuracy across many languages, requires no training data, and is easy to use with simple prompts (e.g., “is this text negative?”) and little coding experience. We provide sample code and a video tutorial for analyzing text with the GPT application programming interface. We argue that GPT and other LLMs help democratize automated text analysis by making advanced natural language processing capabilities more accessible, and may help facilitate more cross-linguistic research with understudied languages.
AlphaFold2-based prediction of the co-condensation propensity of proteins
Authors: Zhang Shengyu , Lim Christine M. , Occhetta Martina , Vendruscolo Michele
Published: August 2024

The process of protein phase separation into liquid condensates has been implicated in the formation of membraneless organelles (MLOs), which selectively concentrate biomolecules to perform essential cellular functions. Although the importance of this process in health and disease is increasingly recognized, the experimental identification of proteins forming MLOs remains a complex challenge. In this study, we addressed this problem by harnessing the power of AlphaFold2 to perform computational predictions of the conformational properties of proteins from their amino acid sequences. We thus developed the CoDropleT (co-condensation into droplet transformer) method of predicting the propensity of co-condensation of protein pairs. The method was trained by combining experimental datasets of co-condensing proteins from the CD-CODE database with curated negative datasets of non-co-condensing proteins. To illustrate the performance of the method, we applied it to estimate the propensity of proteins to co-condense into MLOs. Our results suggest that CoDropleT could facilitate functional and therapeutic studies on protein condensation by predicting the composition of protein condensates.
Conservation of kinetic stability, but not the unfolding mechanism, between human transthyretin and a transthyretin-related enzyme
Authors: Jäger Marcus , Kelly Jeffery W. , Gruebele Martin
Published: August 2024

Kinetic stability is thought to be an attribute of proteins that require a long lifetime, such as the transporter of thyroxine and holo retinol-binding protein or transthyretin (TTR) functioning in the bloodstream, cerebrospinal fluid, and vitreous humor. TTR evolved from ancestral enzymes known as TTR-related proteins (TRPs). Here, we develop a rate-expansion approach that allows unfolding rates to be measured directly at low denaturant concentration, revealing that kinetic stability exists in the
Escherichia coli
TRP (EcTRP), even though the enzyme structure is more energetically frustrated and has a more mutation-sensitive folding mechanism than human TTR. Thus, the ancient tetrameric enzyme may already have been poised to mutate into a kinetically stable human transporter. An extensive mutational study that exchanges residues at key sites within the TTR and EcTRP dimer–dimer interface shows that tyrosine 111, replaced by a threonine in TTR, is the gatekeeper of frustration in EcTRP because it is critical for function. Frustration, virtually absent in TTR, occurs at multiple sites in EcTRP and even cooperatively for certain pairs of mutations. We present evidence that evolution at the C terminus of TTR was a compensatory event to maintain the preexisting kinetic stability while reducing frustration and sensitivity to mutation. We propose an “overcompensation” pathway from EcTRPs to functional hybrids to modern TTRs that is consistent with the biophysics discussed here. An alternative plausible pathway is also presented.
Insights into the interaction between UGGT, the gatekeeper of folding in the ER, and its partner, the selenoprotein SEP15
Authors: Williams Robert V. , Guay Kevin P. , Hurlbut Lesk Owen A. , Clerico Eugenia M. , Hebert Daniel N. , Gierasch Lila M.
Published: August 2024

The enzyme UDP-glucose: glycoprotein glucosyltransferase (UGGT) is the gatekeeper of protein folding within the endoplasmic reticulum (ER). One-third of the human proteome traverses the ER where folding and maturation are facilitated by a complex protein homeostasis network. Both glycan modifications and disulfide bonds are of key importance in the maturation of these ER proteins. The actions of UGGT are intimately linked to the glycan code for folding and maturation of secretory proteins in the ER. UGGT selectively glucosylates the N-linked glycan of misfolded proteins so that they can reenter the lectin-folding chaperone cycle and be retained within the ER for further attempts at folding. An intriguing aspect of UGGT function is its interaction with its poorly understood cochaperone, the 15 kDa selenoprotein known as SELENOF or SEP15. This small protein contains a rare selenocysteine residue proposed to act as an oxidoreductase toward UGGT substrates. AlphaFold2 predictions of the UGGT1/SEP15 complex provide insight into this complex at a structural level. The predicted UGGT1/SEP15 interaction interface was validated by mutagenesis and coimmunoprecipitation experiments. These results serve as a springboard for models of the integrated action of UGGT1 and SEP15.