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The light-gated cation channel Channelrhodopsin-2 (ChR2), a retinylidene protein found in the eye-spot of Chlamydomonas reinhardtii, became an optogenetic tool to trigger neurophysiological responses by light and, thus, revolutionized spatio-temporal studies of such processes. The reaction mechanism still remains elusive but recent vibrational spectroscopic experiments started to resolve details of the associated structural changes during the photocycle. Large alterations in the polypeptide backbone were observed by FT-IR spectroscopy that precede and succeed the opening and closing of the channel, respectively. However, the molecular switch that controls gating is still unknown. Here, we present difference spectra of the D156E mutant of ChR2 and assign the observed vibrational bands to crucial hydrogen bonding changes of this residue in various intermediate states of the photoreaction. By comparison with spectra of wild-type ChR2 and the C128T mutant and correlation to electrophysiological studies, we propose the DC gate as a crucial hydrogen-bonding interaction between D156 and C128 which may represent the valve of the channel. [ABSTRACT FROM AUTHOR]

The introduction of time-resolved Fourier transform infrared (FT-IR) spectroscopy to biochemistry opened the possibility of monitoring the catalytic mechanism of proteins along their reaction pathways. The infrared approach is very fruitful, particularly in the application to membrane proteins where NMR and X-ray crystallography are challenged by the size and protein hydrophobicity, as well as by their limited time-resolution. Here, we summarize the principles and experimental realizations of time-resolved FT-IR spectroscopy developed in our group and compare with aspects emerging from other laboratories. Examples of applications to retinal proteins and energy transduction complexes are reviewed, which emphasize the impact of time-resolved FT-IR spectroscopy on the understanding of protein reactions on the level of single bonds. [ABSTRACT FROM AUTHOR]

Many important biochemical processes occur on the time-scales of nanoseconds and microseconds. The introduction of the laser temperature-jump (T-jump) to biophysics more than a decade ago opened these previously inaccessible time regimes up to direct experimental observation. Since then, laser T-jump methodology has evolved into one of the most versatile and generally applicable methods for studying fast biomolecular kinetics. This perspective is a review of the principles and applications of the laser T-jump technique in biophysics. A brief overview of the T-jump relaxation kinetics and the historical development of laser T-jump methodology is presented. The physical principles and practical experimental considerations that are important for the design of the laser T-jump experiments are summarized. These include the Raman conversion for generating heating pulses, considerations of size, duration and uniformity of the temperature jump, as well as potential adverse effects due to photo-acoustic waves, cavitation and thermal lensing, and their elimination. The laser T-jump apparatus developed at the NIH Laboratory of Chemical Physics is described in detail along with a brief survey of other laser T-jump designs in use today. Finally, applications of the laser T-jump in biophysics are reviewed, with an emphasis on the broad range of problems where the laser T-jump methodology has provided important new results and insights into the dynamics of the biomolecular processes. [ABSTRACT FROM AUTHOR]

Remote Measurement Technologies (RMTs) could revolutionise management of chronic health conditions by providing real-time symptom tracking. However, the promise of RMTs relies on user engagement, which at present is variably reported in the field. This review aimed to synthesise the RMT literature to identify how and to what extent engagement is defined, measured, and reported, and to present recommendations for the standardisation of future work. Seven databases (Embase, MEDLINE and PsycINFO (via Ovid), PubMed, IEEE Xplore, Web of Science, and Cochrane Central Register of Controlled Trials) were searched in July 2020 for papers using RMT apps for symptom monitoring in adults with a health condition, prompting users to track at least three times during the study period. Data were synthesised using critical interpretive synthesis. A total of 76 papers met the inclusion criteria. Sixty five percent of papers did not include a definition of engagement. Thirty five percent included both a definition and measurement of engagement. Four synthetic constructs were developed for measuring engagement: (i) engagement with the research protocol, (ii) objective RMT engagement, (iii) subjective RMT engagement, and (iv) interactions between objective and subjective RMT engagement. The field is currently impeded by incoherent measures and a lack of consideration for engagement definitions. A process for implementing the reporting of engagement in study design is presented, alongside a framework for definition and measurement options available. Future work should consider engagement with RMTs as distinct from the wider eHealth literature, and measure objective versus subjective RMT engagement. Registration: This review has been registered on PROSPERO [CRD42020192652]. [ABSTRACT FROM AUTHOR]

Understanding active matter has led to new perspectives on biophysics and non-equilibrium dynamics. However, the development of numerical tools for simulating active fluids capable of incorporating non-trivial boundaries or inclusions has lagged behind. Active particle-based methods, which typically excel at this, suffer from large density fluctuations that affect the dynamics of inclusions. To this end, we advance the Active-Nematic Multi-Particle Collision Dynamics algorithm, a particle-based method for simulating active nematics, by addressing the large density fluctuations that arise from activity. This paper introduces three activity formulations that mitigate the coupling between activity and local density. Local density fluctuations are decreased to a level comparable to the passive limit while retaining active nematic phenomenology and increasing the active turbulence regime four-fold in two dimensions. These developments extend the technique into a flexible tool for modeling active systems, including solutes and inclusions, with broad applications for the study of biophysical systems. Particle-based models of soft active matter are known to exhibit large density fluctuations, which may be problematic for considering homogeneous systems. Through considering the coupling of activity to local density, we reduce density fluctuations while retaining active turbulent dynamics. [ABSTRACT FROM AUTHOR]

The degree of DNA compaction in various regions of the cell nucleus determines whether the corresponding genes should be expressed and other crucial cellular processes, such as DNA replication and repair, should occur. Therefore, the development of approaches to the experimental assessment of DNA compactness in cell nuclei, as well as its indicator, dynamic disorder which determines the degree of thermal fluctuation in the position and mutual orientation of molecular fragments, is highly relevant. In this paper, using single-stranded guanine and cytosine oligonucleotides, as well as their double-stranded combination as an example, it is shown that dynamic disorder in DNA can be assessed based on low-frequency Raman scattering (RS) spectroscopy data. For the first time, Raman spectra of oligonucleotides have been measured over a wide frequency range, including the low-frequency (10–200 cm ) and high-frequency (200–2000 cm ) regions. It was found that the low-frequency Raman intensity is maximal in single-stranded oligocytosine and minimal in the double-stranded oligonucleotide, which is in full agreement with the magnitude of dynamic disorder estimated from molecular dynamics simulations. The obtained results indicate the promising application of low-frequency Raman spectroscopy for assessing dynamic disorder and DNA compactness. The use of such a technique is expected to contribute to the understanding of key cellular processes and the physical mechanisms that underlie them, which is necessary for the development of advanced methods in molecular biophysics and cell biology. [ABSTRACT FROM AUTHOR]

Presents a list of papers presented at the Australian Biophysical Society Annual Meeting in November 2000, published in the March 2002 issue of 'European Biophysical Journal.'

The article presents information for the contributors of the journal "Khimiko Farmatsevticheskii Zhurnal". The papers submitted to the journal should reflect new, previously unreported investigations performed at the modern scientific and technological level and advanced commercial experience, in the fields of molecular biology and biochemistry. Papers presenting the results of experiments on the synthesis of new compounds and their characterization should contain separate chemical and biological experimental parts. Papers presenting new medicinal products should provide data on the chemical and physical properties; molecular and structural formulas; main results of the biological tests and clinical investigations.

The European Biophysics Journal Prizes awarded at the European Biophysical Societies Association (EBSA) Congress in Stockholm in the Summer of 2023 recognised papers published in 2020 and 2021 which made use of multiple complementing experimental, theoretical and computational approaches. One of the winning papers addressed the specific role of arginine residues within antimicrobial and cell-penetrating peptides, in promoting membrane defect stabilisation and pore formation. The other winning paper described the influence of atomic force microscopy probe geometry on the measurement of surface deformability, assessed for investigation of the differing viscoelastic properties of non-malignant and cancerous cells. These papers showcase biophysical science; the importance of combining different experimental, modelling and molecular dynamics methods; and how researchers need to understand the theoretical basis and the limitations of the techniques they use. EBSA warmly congratulates the authors on their work and its subsequent recognition. Publication of these papers also demonstrates the ongoing commitment of the European Biophysics Journal to molecular scale and to systems biophysics, and to support of the international biophysical community. [ABSTRACT FROM AUTHOR]

Deep brain stimulation (DBS) in thalamic reticular nucleus (TRN) neuron provides a novel treatment for drug-resistant epilepsy via the induced electrical field (EFs). However, the mechanisms underlying EF effects remain unclear. This paper investigated how EFs regulate low-threshold dendritic Ca2+ (dCa) response and thus contribute to the input–output relationship of TRN cell. Our results showed that EFs modulate firing modes differently in a neuronal state-dependent manner. At the depolarized state, EFs only regulate the spike timing of a somatic stimulus-evoked single action potential (AP) with less contribution in the regulation of dCa response but could induce the transition between a dendritic stimulus-evoked single AP and a tonic burst of APs via the moderate regulation of dCa response. At the hyperpolarized state, EFs have significant effects on the dCa response, which modulate the large dCa response-dependent burst discharge and even cause a transition from this type of burst discharge to a single AP with less dCa response. Moreover, EF effects on stimulation threshold of somatic spiking prominently depend on EF-regulated dCa responses and the onset time differences between the stimulus and EF give rise to the distinct effect in the EF regulation of dCa responses. Finally, the larger neuronal axial resistance tends to result in the dendritic stimulus-evoked dCa response independent of somatic state. Interestingly, in this case, the EF application could reproduce the similar somatic state-dependent dCa response to dendritic stimulus which occurs in the case of lower axial resistance. These results suggest that the influence of EF on neuronal activities depends on neuronal intrinsic properties, which provides insight into understanding how DBS in TRN neuron modulates epilepsy from the point of view of biophysics. [ABSTRACT FROM AUTHOR]

The results reported in the papers on protein crystallography entering this issue were obtained with the aid of synchrotrons. B.K. Vainshtein was a pioneer of protein crystallography in Russia: he organized a protein crystallography laboratory at the Institute of Crystallography of the USSR Academy of Sciences in 1958 (now the Federal Scientific Research Centre (FSRC) "Crystallography and Photonics" of the Russian Academy of Sciences (RAS)). X-ray diffraction analysis of proteins (or protein crystallography), which was originated in the 1950s, holds the leading position until now. [Extracted from the article]

Multidisciplinary work is necessary for the development and improvement of techniques for the diagnosis and treatment of diseases, with physics playing a prominent role. For example, in-depth knowledge of the interaction of electromagnetic (ionizing and non-ionizing) and mechanical (sound and ultrasound) waves with biological tissues is important for the development of protocols for the management of skin cancer. In this paper, we review the developments carried out at the São Carlos Institute of Physics that resulted in new technologies and protocols for the diagnosis and treatment of non-melanoma skin lesions. Photodynamic therapy (PDT), a technique that combines light and a photosensitive molecule, was improved, and more than 2000 patients were directly treated in our clinical trials. Our research group pioneered the technique in Brazil, and we developed several fundamental studies involving cell culture and animal studies that demonstrated the effectiveness of this technique in treating cancer. Based on these results, multicenter clinical studies in Brazil have been implemented for the treatment of non-melanoma skin cancer. These studies generated commercial prodrugs and irradiation devices that are currently being considered for incorporation into the Brazilian public health system. In addition, nine countries in Latin America have implemented our technique. In this paper, we also show the physical fundamentals of PDT, the new developments that will allow us to overcome current challenges such as the use of ultrasound to treat cancer. Developments in the diagnosis of cancer will also be discussed. [ABSTRACT FROM AUTHOR]

In Brazil, the CNPq (National Council for Scientific and Technological Development) provides grants, funds and fellowships to productive scientists to support their investigations. They are ranked and categorized into four hierarchical levels ranging from PQ 1A (the highest) to PQ 1D (the lowest). Few studies, however, report and analyse scientific productivity in different sub-fields of Biomedical Sciences (BS), e.g., Biochemistry, Pharmacology, Biophysics and Physiology. In fact, systematic comparisons of productivity among the PQ 1 categories within the above sub-fields are lacking in the literature. Here, the scientific productivity of 323 investigators receiving PQ 1 fellowships (A to D levels) in these sub-fields of BS was investigated. The Scopus database was used to compile the total number of articles, citations, h-index values and authorship positions (first-, co- or last-listed author) in the most cited papers by researchers granted CNPq fellowships. We found that researchers from Pharmacology had the best performance for all of the parameters analysed, followed by those in Biochemistry. There was great variability in scientific productivity within the PQ 1A level in all of the sub-fields of BS, but not within the other levels (1B, 1C and 1D). Analysis of the most cited papers of PQ 1(A–D) researchers in Pharmacology revealed that the citations of researchers in the 1C and 1D levels were associated with publications with their senior supervisors, whereas those in the 1B level were less connected with their supervisors in comparison to those in 1A. Taken together, these findings suggest that the scientific performance of PQ 1A researchers in BS is not homogenous. In our opinion, parameters such as the most cited papers without the involvement of Ph.D. and/or post-doctoral supervisors should be used to make decisions regarding any given researcher's fellowship award level. [ABSTRACT FROM AUTHOR]

Dear Editors, I am writing to add my voice to those making I BLANCO-80 i contributions to the I Journal of Membrane Biology i to celebrate the birthday of Professor Stephen H. White of the University of California-Irvine and his long career of discovery in membrane biophysics. Papers from this era included no less than 5 on alkane-bilayer interactions (White [29]; White et al. [30]; Jacobs and White [13], [14]; King et al. [17]). This period of his career culminated in the classic Wiener and White paper on the dynamics structure of lipid bilayers (Wiener and White [36]). [Extracted from the article]

This research delves into a comprehensive exploration of exact solutions for the time-space fractional phi-four equation through the implementation of both the unified method and the modified Khater method. The Phi-four equation, rooted in the Klein-Gordon model, holds significance in diverse scientific realms, such as biological and nuclear physics, making it imperative to unravel its solutions. Leveraging a well-suited wave transformation, the governing equation is transformed into an ordinary differential equation, laying the groundwork for an in-depth analysis. The proposed methodologies yield a rich spectrum of solutions, encompassing trigonometric, hyperbolic, and rational forms. These solutions manifest as Kink, bright singular, dark, combo dark bright, periodic and singular periodic solutions, each characterized by explicit conditions defining their validity. The versatility and computational robustness of these methods establish a robust framework for soliton research. To provide a comprehensive assessment, a comparative analysis is conducted, contrasting the outcomes obtained through the proposed methodologies with those derived from earlier approaches. A key fact of this study is the visual representation of a subset of these solutions through carefully crafted graphical illustrations. Parameter values are judiciously selected to elucidate the nuanced characteristics of the solutions, enhancing our understanding of the model's physical behavior. It is noteworthy that all computations are meticulously executed with Mathematica software, underscoring the precision and computational efficiency integral to this research. The novelty of this paper lies in the identification of new solutions through the application of the unified and modified Khater methods. These solutions are not previously documented in existing literature. The visual depictions of dynamic behaviors through two and three-dimensional figures further contribute to the originality of our findings. [ABSTRACT FROM AUTHOR]

[FeFe]-hydrogenases are gas-processing metalloenzymes that catalyze H2 oxidation and proton reduction (H2 release) in microorganisms. Their high turnover frequencies and lack of electrical overpotential in the hydrogen conversion reaction has inspired generations of biologists, chemists, and physicists to explore the inner workings of [FeFe]-hydrogenase. Here, we revisit 25 years of scientific literature on [FeFe]-hydrogenase and propose a personal account on 'must-read' research papers and review article that will allow interested scientists to follow the recent discussions on catalytic mechanism, O2 sensitivity, and the in vivo synthesis of the active site cofactor with its biologically uncommon ligands carbon monoxide and cyanide. Focused on—but not restricted to—structural biology and molecular biophysics, we highlight future directions that may inspire young investigators to pursue a career in the exciting and competitive field of [FeFe]-hydrogenase research. [ABSTRACT FROM AUTHOR]

Earth observation from satellites offers the possibility to monitor our planet with unprecedented accuracy. Radiative transfer models (RTMs) encode the energy transfer through the atmosphere, and are used to model and understand the Earth system, as well as to estimate the parameters that describe the status of the Earth from satellite observations by inverse modeling. However, performing inference over such simulators is a challenging problem. RTMs are nonlinear, non-differentiable and computationally costly codes, which adds a high level of difficulty in inference. In this paper, we introduce two computational techniques to infer not only point estimates of biophysical parameters but also their joint distribution. One of them is based on a variational autoencoder approach and the second one is based on a Monte Carlo Expectation Maximization (MCEM) scheme. We compare and discuss benefits and drawbacks of each approach. We also provide numerical comparisons in synthetic simulations and the real PROSAIL model, a popular RTM that combines land vegetation leaf and canopy modeling. We analyze the performance of the two approaches for modeling and inferring the distribution of three key biophysical parameters for quantifying the terrestrial biosphere. [ABSTRACT FROM AUTHOR]

The anterolateral ligament (ALL) was first described in 1879 in the context of Segond fractures, which correlate with a 75–100% chance of an anterior cruciate ligament (ACL) tear or a 66–75% chance of a meniscal tear. The purpose of this paper is to provide an updated comprehensive review on the anterolateral ligament complex of the knee focusing on the: (1) anatomy of the ALL/ALC; (2) associated biomechanics/function; and (3) important surgical considerations in contemporary anterior cruciate ligament (ACL) reconstruction and total knee arthroplasty (TKA). A systematic review of studies on ALL was conducted on Pubmed/MEDLINE and Cochrane databases (May 7th, 2020 to February 1st, 2022), with 20 studies meeting inclusion/exclusion criteria. Studies meeting inclusion criteria were anatomical/biomechanical studies assessing ALL function, cadaveric and computer simulations, and comparative studies on surgical outcomes of ALLR (concomitant with ACL reconstruction). Eight studies were included and graded by MINOR and Newcastle–Ottawa scale to identify potential biases. The anatomy of the ALL is part of the anterolateral ligament complex (ALC), which includes the superficial/deep iliotibial band (including the Kaplan fiber system), iliopatellar band, ALL, and anterolateral capsule. Multiple biomechanical studies have characterized the ALC as a secondary passive stabilizer in resisting tibial internal rotation. Given the role of the ALC in resisting internal tibial rotation, lateral extra-articular procedures including ALL augmentation may be considered for chronic ACL tears, ACL revisions, and a high-grade pivot shift test. In the context of TKA, in the event of injury to the ALC, a more constrained implant or soft-tissue reconstruction may be necessary to restore appropriate knee stability. [ABSTRACT FROM AUTHOR]

Bacterial swarms are a highly-researched example of natural active matter. In particular, the interplay between biological interactions and the physics underlying the swarming dynamics is of both biological and physical interest. In this paper, we study mixed swarms of Bacillus subtilis and Pseudomonas aeruginosa. We find intricate interactions between the species, showing both cooperation and segregation across different spatial and temporal scales. On one hand, even though axenic colonies grow on disparate time scale, an order of magnitude apart, the two-species swarm together, forming a single, combined colony. However, the rapidly moving populations are locally segregated, with different characteristic speeds and lengths (or cluster sizes) that depend on the ratio between the species. Comparison with controlled mutant strains suggest that both the physical and known biological differences in species characteristics may not be enough to explain the segregation between the species in the mixed swarm. We hypothesize that the heterogeneous spatial distribution is due to some mechanism that enables bacteria to recognize their own kind, whose precise origin we could not identify. [ABSTRACT FROM AUTHOR]

Focuses on the 5th European Biophysical Societies Association (EBSA) and the 15th International Union of Pure and Applied Biophysics International Biophysics Congress which will be held in Montpellier, France on August 27-September 1, 2005. Significance of the congress; Organizing committee of the congress; Relationship of the "European Biophysics Journal" with EBSA.

Editorial. Deals with the European Biophysics Journal and the European Biophysics Societies Association (EBSA) 3rd European Biophysics Congress. Relationship between Biophysics Journal and the EBSA; Development of the journal; Overview of the EBSA Congress.

Presented is a brief summary of recent developments of topics addressed by the reviews and original papers of this volume related to non-equilibrium phenomena in various (especially mesoscopic) systems, the foundations of quantum physics, quantum optics and related fields of physics including biophysics, cosmology, gravitation and astrophysics. [ABSTRACT FROM AUTHOR]

Cutting-edge X-ray sources have enabled the structural dynamics of proteins to be tracked during biochemical processes, but the findings have been questioned. Two experts discuss the implications of a study that digs into this issue.Absorption of multiple photons alters structural dynamics of proteins. [ABSTRACT FROM AUTHOR]

Communications Physics is 2 years old. To celebrate, we look back at our achievements and put together a collection of our editors' favourite papers. We will renew this collection over the months to share with our community what we like the most. [ABSTRACT FROM AUTHOR]

This paper presents a proposal to a source-filter theory of voice production, more precisely related to voiced sounds. It is a proposal of a model to generate signal using linear and time-invariant systems and takes into account the phonation biophysics and the cyclostationary characteristics of the voice signal, related to the vibrational behavior of the vocal cords. The model suggests that the oscillation frequency of the vocal cords is a function of its mass and length, but controlled by the longitudinal tension applied to them. The mathematical description of the model of glottal excitation is presented, along with a mathematical closed expression for the power spectral density of the signal that excites the glottis. The voice signal, whose parameters can be adjusted for detection and classification of glottis pathologies, is also present. As a result, the output of each block diagram that represents the proposed model is analysed, including a power spectral density comparison between emulated voice, original voice, and classic source-filter model. The Log Spectral Distortion is computed, providing values below 1.40 dB, indicating an acceptable distortion for all cases. [ABSTRACT FROM AUTHOR]

Abstract: The Anthropocene imposes new challenges for governments, demanding capabilities for dealing with complexity and uncertainty. In this paper we examine how effective governing of social-biophysical dynamics is constrained by current processes and systems of government. Framing choices and structural determinants combine to create governance deficits in multiple domains, particularly in relation to the governing of complex larger-scale social-biophysical systems. Attempts to build capability for governing ‘wicked problems’ are relevant to sustainability science and Anthropocene governance, but these have mostly failed to become institutionalised. Two cases studies are reported to elucidate how the systemic dynamics of governing operate and fail in relation to espoused purpose. In the UK attempts to enact ‘joined-up’ government’ during the years of New Labour government reveal systemic flaws and consistent praxis failures. From Australia we report on water governance reforms with implications for a wide range of complex policy issues. We conclude that innovations are needed to build capacity for governing the unfolding surprises and inherent uncertainties of the Anthropocene. These include institutionalising, or structural incorporation, of cyber-systemic thinking/practices that can also enhance empowerment and creativity that underpins sustainability science.Graphical abstract: [ABSTRACT FROM AUTHOR]

In this paper, we introduce a special device, in which the topological rejection effect in the study of biomacromolecule translocation competes with the entropic tensile force. The expected results for the translocation of the polymer chain given by these two different theories do not coincide with each other, so we call this problem the "translocation paradox". The dynamics of the polymer chain and the preference translocation in such device are studied using computer simulation method. Surprisingly, these results do not completely satisfy all these hypothesis. We provide a plausible explanation which coincides our simulation results perfectly. Meanwhile, this explanation provides a possible solution to the design of translocation device in biophysics field. [ABSTRACT FROM AUTHOR]

The following paper presents the history of the Climate and Human Health Commission at the International Society of Biometeorology after more than one decade since its creation. A brief history of the origins of the human biometeorology is revealed through some of the main research topics and publications of the founders of the society in this field. Secondly, it is presented as a brief review of the activities of the commission in the last 10 years, based on the reports that have periodically been submitted by members of the commission to the Bulletin of the society. A summary of the topics of interest on human biometeorology and the most frequent research topics are also described. Thirdly, the need of adapting human biometeorology contents, methods and techniques to a changing world is articulated according to some of the new environmental threats in the XXI century. Finally, a list of future actions and research lines collected through a form from members of the commission is presented. The paper concludes with the existence of great challenge for human biometeorology in order to transform biometeorological knowledge into specific services to improve the wellbeing of human beings. [ABSTRACT FROM AUTHOR]

Knowledge regarding the 3D structure of a protein provides useful information about the protein's functional properties. Particularly, structural similarity between proteins can be used as a good predictor of functional similarity. One method that uses the 3D geometrical structure of proteins in order to compare them is the similarity value (SV). In this paper, we introduce a new definition of the SV measure for comparing two proteins. To this end, we consider the mass of the protein's atoms and concentrate on the number of protein's atoms to be compared. This defines a new measure, called the weighted similarity value (WSV), adding physical properties to geometrical properties. We also show that our results are in good agreement with the results obtained by TM-SCORE and DALILITE. WSV can be of use in protein classification and in drug discovery. [ABSTRACT FROM AUTHOR]

The article presents the texts of welcome addresses for the 7th EBSA European Biophysics Congress to be held in Genoa, Italy from July 11 to 15, 2009 is presented.

In this paper, we reject commonly accepted views on fundamentality in science, either based on bottom-up construction or top-down reduction to isolate the alleged fundamental entities. We do not introduce any new scientific methodology, but rather describe the current scientific methodology and show how it entails an inherent search for foundations of science. This is achieved by phrasing (minimal sets of) metaphysical assumptions into falsifiable statements and define as fundamental those that survive empirical tests. The ones that are falsified are rejected, and the corresponding philosophical concept is demolished as a prejudice. Furthermore, we show the application of this criterion in concrete examples of the search for fundamentality in quantum physics and biophysics. [ABSTRACT FROM AUTHOR]

INTRODUCTION BY ANA-NICOLETA BONDAR, BIOPHYSICS SECTION HEAD EDITOR: This issue of the Journal of Membrane Biology inaugurates Up-and-Coming Scientist, in which investigators at early career stages are invited to present recent research in the broad context of their discipline. We inaugurate Up-and-Coming Scientist with the essay by Dr. Elena Lesca of the ETH Zürich and the Paul Scherrer Institut, Switzerland. Dr. Lesca has completed her doctoral degree at the Technical University München, Germany, in 2014, and pursued postdoctoral research at the ETH Zürich and Paul Scherrer Institut, where she is Senior Assistant since 2019. Two recent papers by Dr. Lesca et al. (references 33 and 39) have used X-ray crystallography and experimental biophysics approaches to shed light on the mechanism of action of a membrane receptor from the G Protein-Coupled Receptor (GPCR) family, Jumping Spider Rhodopsin-1 (JSR-1). JSR-1 is a visual rhodopsin activated upon absorption of light by its covalently bound retinal chromophore. Unlike the better-understood bovine rhodopsin GPCR, which is monostable, JSR-1 is bistable (i.e., in JSR-1 the Schiff base that binds retinal to the protein stays protonated throughout the reaction cycle), and absorption of a second photon resets the retinal ligand to the resting state configuration. In her essay, Dr. Lesca discusses the implications of her work on JSR-1 and, more broadly, GPCR research, for state-of-the-art applications in optogenetics and drug design. [ABSTRACT FROM AUTHOR]

The leaf area index (LAI) is a key biophysical parameter that determines the state of plant growth. A global LAI has been routinely produced by the Moderate Resolution Imaging Spectro-radiometer (MODIS) and Advanced Very High Resolution Radiometer (AVHRR). However, the MODIS and AVHRR LAI products cannot be synchronized with the same spatial and temporal resolution. The LAI features are not discernible when a global LAI product is implemented at the regional scale because it has low resolution and different land cover types. To obtain high spatial and temporal resolution of LAI products, an empirical model based on the pixel scale was developed. The approach to generate a long (multi-decade) time series of a 1-km spatial resolution LAI normally integrates both AVHRR and MODIS datasets for different land cover types. In this paper, a regression-based model for generating a vegetation LAI was developed using the AVHRR Global Inventory Modelling and Mapping Studies Normalized Difference Vegetation Index (NDVI), MODIS LAI and land cover as input data; the model was evaluated by using relevant data from the same period data from 2000 to 2006. The results of this method show a good consistency in LAI values retrieved from the AVHRR NDVI and MODIS LAI. This simple method has no specific-limited data requirements and can provide improved spatial and temporal resolution in a region without ground data. [ABSTRACT FROM AUTHOR]

A compact, portable and improved blood flow measurement system for an extracorporeal circuit having a rotating permanent magnetic excitation scheme is described in this paper. The system consists of a set of permanent magnets rotating near blood or any conductive fluid to create high-intensity alternating magnetic field in it and inducing a sinusoidal varying voltage across the column of fluid. The induced voltage signal is acquired, conditioned and processed to determine its flow rate. Performance analysis shows that a sensitivity of more than 250 mV/lpm can be obtained, which is more than five times higher than conventional flow measurement systems. Choice of rotating permanent magnet instead of an electromagnetic core generates alternate magnetic field of smooth sinusoidal nature which in turn reduces switching and interference noises. These results in reduction in complex electronic circuitry required for processing the signal to a great extent and enable the flow measuring device to be much less costlier, portable and light weight. The signal remains steady even with changes in environmental conditions and has an accuracy of greater than 95%. This paper also describes the construction details of the prototype, the factors affecting sensitivity and detailed performance analysis at various operating conditions. [ABSTRACT FROM AUTHOR]

Precise measurement of magnetic fields is essential for various applications, such as fundamental physics, space exploration, and biophysics. Although recent progress in quantum engineering has assisted in creating advanced quantum magnetometers, there are still ongoing challenges in improving their efficiency and noise resistance. This study focuses on using symmetric graph state resources for quantum magnetometry to enhance measurement precision by analyzing the estimation theory under time-homogeneous and time-inhomogeneous noise models. The results show a significant improvement in estimating both single and multiple Larmor frequencies. In single Larmor frequency estimation, the quantum Fisher information spans a spectrum from the standard quantum limit to the Heisenberg limit within a periodic range of the Larmor frequency, and in the case of multiple Larmor frequencies, it can exceed the standard quantum limit for both noisy cases. This study highlights the potential of graph state-based methods for improving magnetic field measurements under noisy environments. [ABSTRACT FROM AUTHOR]

Biophysics has been either an independent discipline or an element of another discipline in the United States, but it has always been recognized as a stand-alone discipline in the People's Republic of China (PRC) since 1949. To inquire into this apparent divergence, this paper investigates the formational history of biophysics in China by examining the early institutional history of one of the best-known and prestigious science and technology universities in the PRC, the University of Science and Technology of China (USTC). By showing how the university and its biophysics program co-evolved with national priorities from the school's founding in 1958 to the eve of the Cultural Revolution in 1966, the purpose of this paper is to assess the development of a scientific discipline in the context of national demands and institutional politics. Specific materials for analysis include the school's admission policies, curricula, students' dissertations, and research program. To further contextualize the institutional setting of Chinese biophysics, this paper begins with a general history of proto-biophysical institutions in China during the Nationalist-Communist transitional years. This paper could be of interest to historians wanting to know more about the origin of the biophysics profession in China, and in particular how research areas that constitute biophysics changed in tandem with socio-political contingencies. [ABSTRACT FROM AUTHOR]

Scenario analysis constitutes a valuable deployment method for scientific models to inform environmental decision-making, particularly for evaluating land degradation mitigation options, which are rarely based on formal analysis. In this paper we demonstrate such an assessment using the PESERA-DESMICE modeling framework with various scenarios for 13 global land degradation hotspots. Starting with an initial assessment representing land degradation and productivity under current conditions, options to combat instances of land degradation are explored by determining: (1) Which technologies are most biophysically appropriate and most financially viable in which locations; we term these the 'technology scenarios'; (2) how policy instruments such as subsidies influence upfront investment requirements and financial viability and how they lead to reduced levels of land degradation; we term these the 'policy scenarios'; and (3) how technology adoption affects development issues such as food production and livelihoods; we term these the 'global scenarios'. Technology scenarios help choose the best technology for a given area in biophysical and financial terms, thereby outlining where policy support may be needed to promote adoption; policy scenarios assess whether a policy alternative leads to a greater extent of technology adoption; while global scenarios demonstrate how implementing technologies may serve wider sustainable development goals. Scenarios are applied to assess spatial variation within study sites as well as to compare across different sites. Our results show significant scope to combat land degradation and raise agricultural productivity at moderate cost. We conclude that scenario assessment can provide informative input to multi-level land management decision-making processes. [ABSTRACT FROM AUTHOR]