Original Orientation Research Articles

The synovial microenvironment suppresses chondrocyte hypertrophy and promotes articular chondrocyte differentiation

During the development of the appendicular skeleton, the cartilaginous templates undergo hypertrophic differentiation and remodels into bone, except for the cartilage most adjacent to joint cavities where hypertrophic differentiation and endochondral bone formation are prevented, and chondrocytes instead form articular cartilage. The mechanisms that prevent hypertrophic differentiation and endochondral bone formation of the articular cartilage have not been elucidated. To explore the role of the synovial microenvironment in chondrocyte differentiation, osteochondral allografts consisting of articular cartilage, epiphyseal bone, and growth plate cartilage from distal femoral epiphyses of inbred Lewis rats expressing enhanced green fluorescent protein from a ubiquitous promoter were transplanted either in inverted or original (control) orientation to matching sites in wildtype littermates, thereby allowing for tracing of transplanted cells and their progenies. We found that no hypertrophic differentiation occurred in the growth plate cartilage ectopically placed at the joint surface. Instead, the transplanted growth plate cartilage, with time, remodeled into articular cartilage. This finding suggests that the microenvironment at the articular surface inhibits hypertrophic differentiation and supports articular cartilage formation. To explore this hypothesis, rat chondrocyte pellets were cultured with and without synoviocyte-conditioned media. Consistent with the hypothesis, hypertrophic differentiation was inhibited and expression of the articular surface marker lubricin (Prg4) was dramatically induced when chondrocyte pellets were exposed to synovium- or synoviocyte-conditioned media, but not to chondrocyte- or osteoblast-conditioned media. Taken together, we present evidence for a novel mechanism by which synoviocytes, through the secretion of a factor or factors, act directly on chondrocytes to inhibit hypertrophic differentiation and endochondral bone formation and promote articular cartilage formation. This mechanism may have important implications for articular cartilage development, maintenance, and regeneration.

Massive crossover suppression by CRISPR-Cas-mediated plant chromosome engineering.

Recent studies have demonstrated that not only genes but also entire chromosomes can be engineered using clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPER-associated protein 9 (Cas9)1-5. A major objective of applying chromosome restructuring in plant breeding is the manipulation of genetic exchange6. Here we show that meiotic recombination can be suppressed in nearly the entire chromosome using chromosome restructuring. We were able to induce a heritable inversion of a >17 Mb-long chromosome fragment that contained the centromere and covered most of chromosome 2 of the Arabidopsis ecotype Col-0. Only the 2 and 0.5 Mb-long telomeric ends remained in their original orientation. In single-nucleotide polymorphism marker analysis of the offspring of crosses with the ecotype Ler-1, we detected a massive reduction of crossovers within the inverted chromosome region, coupled with a shift of crossovers to the telomeric ends. The few genetic exchanges detected within the inversion all originated from double crossovers. This not only indicates that heritable genetic exchange can occur by interstitial chromosome pairing, but also that it is restricted to the production of viable progeny.

Modulation of polar dynamics with oxygen vacancies in Zn doped BaZr0.1Ti0.9O3

Zinc modified barium zirconium titanate ceramics have been fabricated by the solid-state reaction method. Crystallographic analysis shows that the ceramics exhibit tetragonal crystal structure with P4mm symmetry. The polar behavior of Zn doped BaZr0.1Ti0.9O3 [BZT] differs from the pure BZT compound, as observed from ferroelectric analysis. As a result of doping, the P-E loops become pinched and linear in the low field region as well as P-E loop characteristics transformed from single hysteresis to double hysteresis behavior. Double hysteresis behavior emerging in BZT ferroelectrics validates the leading characteristic of defective dipoles. The defect dipoles provide restoring force to the spontaneous dipoles and ease the recovery of domain towards its original orientation. To validate the role of defects dipoles in the synthesized ceramics, we performed P-E hysteresis measurement under field cooling protocol. P-E loops of field cooled doped-ceramics transformed into single hysteresis curve and shifts on field scale, which further confirms that the double hysteresis feature is associated with defects dipoles rather than antiferroelectric ordering. The normalized entropy curves, ΔS(E,T,x)/ΔSmax(E,TC,x), for x = 0–6%, follow the scheme of master curve with two reference temperatures and consistent with second-order phase transition theory. The dielectric spectroscopy and Arrott plot approach collectively reveal that Zn doping causes sharpening of Landau free energy profiles and doping increases the depth of double-well potential and lowers the polar dynamics. The room temperature energy storage efficiency (η∼83,x=6%) of BZT is significantly modified. Our study reveals that the interplay between ferroelectric dipoles and point defects opens a novel route toward the realization of efficient energy storage performance.

Urban design of inner courtyards and road traffic noise: Influence of façade characteristics and building orientation on perceived noise annoyance

Residents of densely populated urban areas are often exposed to high road traffic noise. While noise control measures help mitigating road traffic noise exposure in residential areas (e.g., inner courtyards), their psychoacoustic impacts on residents have not been well explored. In this study, effects of façade surface material (sound reflecting, absorbing or diffusing) and building rotation (parallel vs. nonparallel walls) on perceived noise annoyance were investigated in laboratory experiments. To that aim, a virtual acoustic environment within a residential area was designed. Moving passenger cars were artificially generated by convolving synthesised car emission sound signals with position-specific impulse responses and simulating sound propagation for static receiver locations along different vehicle trajectories. A method to interpolate the impulse responses was developed to generate receiver audio signals of a continuously passing vehicle. The resulting stimuli were spatially reproduced using loudspeakers. The laboratory experiments revealed that absorbing façades were associated with lower noise annoyance than reflecting or diffusing façades due to reduced sound pressure level. However, at the same level, the absorbing façades were perceived as more annoying than the reflecting or diffusing façades, indicating somewhat unfavourable acoustical quality. Building rotation (resulting in nonparallel walls) was associated with lower noise annoyance compared to the original parallel-wall building orientation. While this was due to reduced sound level as well, the positive effect also tended to remain when the level was the same for rotated and parallel buildings. Our experiments show that façade characteristics and building orientation may be important architectural features to optimize the sound environment of inner courtyards.

Art for Whose Sake? Audience Relational Orientation Work in the “Porcelain Capital” of China

This study examines whether and how occupational members adjust their relational orientation toward their audience in the face of a disruptive event. Drawing on interviews, observation, and photographs from an ethnographic field study, I investigate how 67 porcelain artists in Jing De Zhen responded to disintermediation in the art market, which resulted in artists interacting directly with their customers. I found that while some artists held onto or even strengthened their original relational orientation towards their customers, other artists constructed (to a greater or lesser extent) a new relational orientation. Analyzing these divergent responses to the market shift reveals that artists who constructed a new audience relational orientation experienced a misalignment between their occupational prototypes (beliefs around what constituted an exemplary occupational member) and their own personal considerations (e.g., aspirations, financial considerations, etc.), which led them to question their previous way of working and gave rise to innovations in their work. In contrast, artists who experienced alignment between their occupational prototypes and personal considerations moralized their existing orientation toward their audience and reinforced or even amplified previous ways of working. My study highlights the importance of audience relational orientation work for how occupational members see themselves and accomplish their work.

Antenna movements as a function of odorants’ biological value in honeybees (Apis mellifera L.)

In honeybees, the antennae are highly mobile sensory organs that express scanning movements in various behavioral contexts and toward many stimuli, especially odorants. The rules underlying these movements are still unclear. Using a motion-capture system, we analyzed bees’ antennal responses to a panel of pheromonal and other biologically relevant odorants. We observed clear differences in bees’ antennal responses, with opposite movements to stimuli related to opposite contexts: slow backward movements were expressed in response to alarm pheromones, while fast forward movements were elicited by food related cues as well as brood and queen related pheromones. These responses are reproducible, as a similar pattern of odor-specific responses was observed in bees from different colonies, on different years. We then tested whether odorants’ attractiveness for bees, measured using an original olfactory orientation setup, may predict antenna movements. This simple measure of odorants’ valence did however not correlate with either antennal position or velocity measures, showing that more complex rules than simple hedonics underlie bees’ antennal responses to odorants. Lastly, we show that newly-emerged bees express only limited antennal responses compared to older bees, suggesting that a significant part of the observed responses are acquired during bees’ behavioral development.

Effect of Microstructure on Fatigue-Crack Propagation of 18CrNiMo7-6 High-Strength Steel

The effect of microstructure on fatigue crack propagation of 18CrNiMo7-6 high-strength steel was studied by scanning electron microscopy and electron backscatter diffraction techniques. The crack propagation path was related to the microstructure of the original austenite grain boundary, lath martensite and crystal orientation. The crack path was tortuous and many small cracks or extrusions appeared on both sides of the main crack, with most of the extrusions parallel to the martensite lath. When the crack propagation encountered a high-angle boundary or passed through different crystal orientations, the crack was deflected, and when it encountered a low-angle boundary, the crack expanded.

Paper 17: Optimal Tibial Tunnel Placement for Medial and Lateral Meniscal Root Repair in the Setting of Multiligament Reconstructions of the Knee

Objectives:Although the risk of tibial tunnel convergence in the setting of multiligament reconstruction has been reported in the literature, the risk of tunnel convergence in the setting of posterior cruciate ligament (PCL), anterior cruciate ligament (ACL), and medial and lateral meniscal root repair has not been defined. The purpose of this study was to examine the risk of tunnel convergence and to determine optimal tunnel placement for ACL and PCL reconstruction performed in conjunction with posterior medial and lateral meniscal root repairs in the proximal tibia.Methods:Three-dimensional tibial models were created using computed tomography scans of twenty cadaveric specimens. After determining optimal tunnel entry and exit points for ACL and PCL reconstructions, and medial and lateral meniscal root repair on the models, Mimics software was used to create root tunnels. The meniscal root repair tunnels were then re-oriented to be parallel to the ACL tunnel. The initial and re-oriented configurations are illustrated in Figure 1. Tunnel convergence risk was analyzed with single and double tunnel techniques in both case scenarios.Results:There were no cases of convergence between the ACL and medial meniscal root tunnels in any of the configurations. The greatest distance between the tunnels was achieved with the single tunnel technique in parallel orientation (12.09 ± 2.78 mm). All specimens demonstrated convergence between the ACL and lateral meniscal root tunnels when the sagittal plane entry was not taken into consideration and only the anatomic root attachment was accounted for, for single and double tunnel techniques, but no convergence was seen between these tunnels with the parallel orientation in the sagittal plane. Figure 2 illustrates the reduction in the convergence risk when the meniscal root tunnels are reoriented as parallel to the ACL tunnel. There were no cases of convergence between the PCL and medial meniscal root tunnels in the original orientation, but 2/20 specimens demonstrated convergence in the parallel orientation with the double tunnel technique and no cases of convergence in the single tunnel technique. The PCL and lateral meniscal root tunnels did not demonstrate convergence in any configuration. Table 1 demonstrates the mean, minimum and maximum distances of each tunnel configuration as well as the number of cases where the distance between tunnels was <2mm. A summary of the preferred tunnel configurations for each setting, ranked by greatest tunnel distance conferred and cases of convergence, is reported in Table 2.Conclusions:There is a high risk of convergence between ACL and posterior meniscus root tunnels. Re-orienting meniscal root tunnels parallel to ACL tunnels may help reduce this risk. When PCL reconstruction is performed with ACL reconstruction and medial and lateral meniscal root repair, the single tunnel root repair technique may pose less risk over the double tunnel technique to prevent tunnel convergence between the meniscal root repair and PCL tunnels in the tibia.Figure 1. Illustration of the reconstruction of the tunnels. (A) Initial orientation where the meniscal root tunnels’ entry points on the anteromedial aspect of the tibia were created above the ACL tunnel. (B) The meniscal root tunnels re-orientated and were placed parallel to that of the ACL and aimed to exit at the anatomic attachment of the posterior roots of the meniscus. (Gold guide for the creation of the ACL tunnel and silver guide for the creation of the meniscal root tunnel)

Gel‐like inclusions of C‐terminal fragments of TDP‐43 sequester stalled proteasomes in neurons

Aggregation of the multifunctional RNA‐binding protein TDP‐43 defines large subgroups of amyotrophic lateral sclerosis and frontotemporal dementia and correlates with neurodegeneration in both diseases. In disease, characteristic C‐terminal fragments of ~25 kDa ("TDP‐25") accumulate in cytoplasmic inclusions. Here, we analyze gain‐of‐function mechanisms of TDP‐25 combining cryo‐electron tomography, proteomics, and functional assays. In neurons, cytoplasmic TDP‐25 inclusions are amorphous, and photobleaching experiments reveal gel‐like biophysical properties that are less dynamic than nuclear TDP‐43. Compared with full‐length TDP‐43, the TDP‐25 interactome is depleted of low‐complexity domain proteins. TDP‐25 inclusions are enriched in 26S proteasomes adopting exclusively substrate‐processing conformations, suggesting that inclusions sequester proteasomes, which are largely stalled and no longer undergo the cyclic conformational changes required for proteolytic activity. Reporter assays confirm that TDP‐25 impairs proteostasis, and this inhibitory function is enhanced by ALS‐causing TDP‐43 mutations. These findings support a patho‐physiological relevance of proteasome dysfunction in ALS/FTD.

A novel in-situ stress measurement method incorporating non-oriented core ground re-orientation and acoustic emission: A case study of a deep borehole

The measurement of in-situ stress is a critical prerequisite for the mining design and the stability analysis of surrounding rock in deep mining engineering. In this study, a novel re-oriented core acoustic emission (RCAE) method incorporating the non-oriented core ground re-orientation and AE techniques was proposed for in-situ stress measurement. First, the principle of non-oriented core ground re-orientation is established according to the spatial coupling relationship between the drilling trajectory and the core surface characteristics. Then, an innovative apparatus was designed for recovering the original spatial orientation of non-oriented cores. Furthermore, the measurement procedures of RCAE method are described in detail, involving suitability analysis, outdoor operations, core re-orientation, specimen preparation, AE test and stress calculation. Using this method, a case study for in-situ stress measurement was performed in an ultra-deep borehole (2360 m) of the Sanshandao gold mine, China. Meanwhile, the verifications of measurement accuracy were conducted based on the tectonic stress inversion and the underground overcoring method. The results show that the measurement accuracy of RCAE method is acceptable, especially the horizontal maximum principal stress and its azimuth measured are well matched with those measured by other methods. In addition, the field applications indicate that the in-borehole procedure of RCAE method only requires drilling trajectory measurement without excessive complex operations, and the adequate measuring depth of this method in the case area is up to 3841 ± 521 m according to the damage stress threshold analysis. Therefore, the RCAE method could break through the challenges caused by the restricted measuring space and large measuring depth when no deep underground access exists. Moreover, the non-oriented cores can be rapidly re-oriented on the ground, which could expand the application value of ordinary geological boreholes in the field of deep geostress and tectonic measurement.

Optimal Tibial Tunnel Placement for Medial and Lateral Meniscus Root Repair on the Anteromedial Tibia in the Setting of Anterior and Posterior Cruciate Ligament Reconstruction of the Knee

Background: Although the risk of tibial tunnel convergence in the setting of multiligamentous reconstruction has been reported in the literature, the risk of tunnel convergence in the setting of posterior cruciate ligament (PCL), anterior cruciate ligament (ACL) reconstruction and medial and lateral meniscus root repair has not been defined. Purpose: To examine the risk of tunnel convergence and to determine optimal tunnel placement for ACL and PCL reconstruction performed in conjunction with posterior medial and lateral meniscus root repairs on the anteromedial proximal tibia. Study Design: Descriptive laboratory study. Methods: Three-dimensional (3D) tibial models were created using computed tomography scans of 20 cadaveric specimens. After determining optimal tunnel entry and exit points for ACL and PCL reconstructions, and medial and lateral meniscus root reattachment to the anatomic footprints, we used image processing software to create root tunnels over the anteromedial tibia on the tibial models. ACL and PCL tunnels were kept constant. The meniscus root repair tunnels were then reoriented to match the angle of the ACL tunnel, making both tunnels parallel in the sagittal plane. Tunnel convergence risk was analyzed by identifying the shortest 3D distance between tunnel axes and subtracting the radius of each tunnel from this distance for single- and double-tunnel repair techniques in both case scenarios. Results: All specimens demonstrated convergence between the ACL and lateral meniscus root tunnels when the root tunnel’s entry was created proximal to the ACL tunnel’s entry for single- and double-tunnel techniques, but no convergence was seen between these tunnels using the parallel orientation in the sagittal plane. There were no cases of convergence between the ACL and medial meniscus root tunnels in any of the configurations. The greatest distance between the ACL and medial meniscus root tunnels was achieved using the single-tunnel technique in parallel orientation (12.1 ± 2.8 mm). There were no cases of convergence between the PCL and medial meniscus root tunnels in the original orientation; however, 2 of 20 specimens demonstrated convergence using the parallel orientation with the double-tunnel technique, and there were no cases of convergence using the single-tunnel technique. The PCL and lateral meniscus root tunnels did not demonstrate convergence in any configuration. Conclusion: There was a high risk of convergence between ACL and posterior meniscus root tunnels when all the tunnels were created on the anteromedial tibia. Reorienting meniscus root tunnels parallel to ACL tunnels may help reduce this risk. There is increased risk of tunnel convergence with root repairs in cases of bicruciate reconstructions, and therefore a double-tunnel root repair technique should be used with caution. Clinical Relevance: To avoid tibial tunnel convergence when performing ACL and PCL reconstruction with medial and lateral meniscus root repair, surgeons should reorient the meniscus root repair tunnels to be parallel on the sagittal plane to the ACL tunnel to decrease the risk of convergence. In cases of bicruciate ligament reconstruction, use of the double-tunnel technique requires caution to avoid convergence risk with the PCL tunnel.

Numerical Assessment of the Immersion Process of a Ceramic Foam Filter in a Steel Melt

Visualization of the melt immersion process at time step t = 1.2 s in the XSITE CAVE. The image shows the upper half of the filter in its original orientation. Entrapped gas bubbles are visualized as blue blobs on the surfaces of the filter and inside pores. Photo credit: Amjad Asad, article number 2100753, Institute of Mechanics and Fluid Dynamics, Henry Lehmann, Virtual Reality and Multimedia Group, TU Bergakademie Freiberg.

A numerical study of effect of cold temperature on growth orientation of horizontal fractures using displacement discontinuity method

We study the effect of temperature change in the fracture on the orientation of fracture propagation in the hydraulic fracturing process. Hydraulic fracturing technologies have been employed in many industries to increase operation products or reduce operation risks. In the hydraulic fracturing process with double fractures, the fractures propagate away from the original orientation under the influence of fluid pressure. It was found recently that cold fluid temperature in the fractures causes the fractures to propagate in the opposite direction from that caused by fluid pressure. Therefore, it seems that cold temperature of the fluid in the fractures could reduce the curvature of the fractures. In this study, we use FRACOD3D code, which employs combined displacement discontinuity method for fracture propagation and an indirect boundary element method for thermal conduction in rocks, to simulate propagation of fractures in three-dimension under fluid pressure and thermal conditions. Particularly we focus on the effect of cold temperature of the fluid on the growth orientation of fractures in hydraulic fracturing.

Analysis of Electro-Optical Behavior in Liquid Crystal Cells with Asymmetric Anchoring Strength

Liquid crystal director distributions have been numerically analyzed between asymmetric anchoring surfaces, that is, infinitely strong and very weak anchoring strength interfaces. In a hybrid aligned nematic (HAN) cell and a twisted nematic (TN) cell, HAN and TN orientations turn to a homogeneous orientation when the weak anchoring strength is lower than a critical one. Relationships between the anchoring strength and elastic constants of the liquid crystal were analyzed to be of a quasi-homogeneous orientation. The quasi-homogeneous orientation returned to the original HAN and TN orientations under voltage application. Low-driving electro-optical properties with no threshold voltage can be obtained in a quasi-homogeneous HAN cell. A unique voltage–transmission curve of 0–100–0% appeared in a quasi-homogeneous TN cell between the crossed polarizers.

One size may not fit all: patient-specific computational optimization of locking plates for improved proximal humerus fracture fixation.

Optimal treatment options for proximal humerus fractures (PHFs) are still debated because of persisting high fixation failure rates experienced with locking plates. Optimization of the implants and development of patient-specific designs may help improve the primary fixation stability of PHFs and reduce the rate of mechanical failures. Optimizing the screw orientations in locking plates has shown promising results; however, the potential benefit of subject-specific designs has not been explored yet. The purpose of this study was to evaluate by means of finite element (FE) analyses whether subject-specific optimization of the screw orientations in a fixed-angle locking plate can reduce the predicted cutout failure risk in unstable3-part fractures. FE models of 19 low-density proximal humeri were generated from high-resolution computed tomographic images using a previously developed and validated computational osteosynthesis framework. The specimens were virtually osteotomized to simulate unstable malreduced 3-part fractures and fixed with the PHILOS plates using 6 proximal locking screws. The average principal compressive strain in cylindrical bone regions around the screw tips-a biomechanically validated surrogate for the risk of cyclic screw cutout failure-was defined as the main outcome measure. The angles of the 6 proximal locking screws were optimized via parametric analysis for each humerus individually, resulting in subject-specific screw orientations (SSO). The average peri-implant strains of the SSO were statistically compared with the previously reported cohort-specific (CSO) and original PHILOS screw orientations (PSO) for females vs. males. The optimized SSO significantly reduced the peri-screw bone strain vs. CSO (6.8% ± 4.0%, P = .006) and PSO (25.24% ± 7.93%, P < .001), indicating lower cutout risk for subject-specific configurations. The benefits of SSO vs. PSO were significantly higher for women than men. The findings of this study suggest that subject-specific optimization of the locking screw orientations could lead to lower cutout risk and improved PHF fixation. These computer simulation results require biomechanical and clinical corroboration. Further studies are needed to evaluate whether the potential benefit in stability could justify the increased efforts related to implementation of individualized implants. Nevertheless, computational exploration of the biomechanical factors influencing the outcome of fracture fixations could help better understand the fixation failures and reduce their incidence.

Prospect of Level of thermal Comfort within Public Office Buildings in Addis Ababa (Case of Prototype Government Office Buildings)

Office buildings are where individuals spend 7.7 hour to 9hr of their time daily, and it should be comfortable under all circumstances. This place could be comfortable for the occupants in every in every condition. Comfort ability or uncomfortable work behavior of workplace have significant influence on the productivity of worker and health of employee. Most government sector offices in Ethiopia built with similar prototype and standard in different site and orientation. This duplicating the similar office building affects the thermal and visual comfort as well as productivity of occupants. This study assesses the thermal comfort level of selected Addis Ababa government standard and prototype buildings. The study sample sampled three site similar buildings and two from each site which found in different orientations and has different characteristics. The study based on field survey measurement of five sequent days in the warmest month of January 2021. Also it includes the literature review and use of secondary data. The occupants asked about the thermal level, their preference through the primary data collection. The major indoor thermal comfort variables air temperature and relative humidity in each case offices measured in these five days to compare and analyze with the standard office operational temperature. The data obtained and analyzed by the supporting software like SPSS, ArchiCAD, Revit and excel. The result from data analysis indicated that almost half of the people asked are not comfortable with the thermal environment. The temperature of some selected case buildings are at the expected and standard level while others are exceeding the level due to characteristics in each office. These factors include the green infrastructure integration, orientation, number of occupants, the thermal regulation measures in each office. In this study the buildings those with original design, similar with original design orientation and engaged in maintenance have good thermal comfort when compared to others.

Curved, expanded and inclined patterns of dynamic double slit/cross‐double slit/grating experiments

Young's 1D-double-slit experiments have been extended to 2D-cross-double-slit experiments, in which more than one 1D-double-slits are crossed at the same spot and each 1D-double-slit creates the interference pattern independently. In this article, the varieties of the double-slit/cross-double-slit/grating experiments are presented. The universal novel phenomena are: (1) the interference/diffraction patterns (hereafter referred as “patterns”) are curved; (2) the patterns are expanded; and (3) the patterns created by the tilt-double slits are inclined to the axis perpendicular to the axis the diaphragm rotates around. The directions of the patterns curved towards are determined by whether the diaphragm rotates clockwise or counter-clockwise. To determine the directions, right-hand rule and left-hand rule are proposed. The degrees of the expansions depend on both the original orientation of the double slit and the angle of the diaphragm rotates. The formulars to calculate the expansion and the inclination of the patterns are derived. The experimental observations support the formulars. The novel phenomena not only make the Feynman's mystery more mysterious, but also provide the comprehensive data/information to theoretical study of the mystery of double slit experiments. Furthermore, the novel phenomena may have potential applications, for example, in antenna system. The phenomenon of the expanded Airy pattern is presented.

Through the eyes of a descriptor: Constructing complete, invertible descriptions of atomic environments

In this work we apply methods for describing three-dimensional images to the problem of encoding atomic environments in a way that is invariant to rotations, translations, and permutations of the atoms and, crucially, can be decoded back into the original environment modulo global orientation without the need for training a model. From the point of view of decoding, the descriptor is optimally complete and can be extended to arbitrary order, allowing for a systematic convergence of the fidelity of the description. In experiments on molecules ranging from 3 to 29 atoms in size, we demonstrate that positions can be decoded with a 97% success rate and positions plus species with a 70% rate of success, rising to 95% if a second fingerprint is used. In all cases, consistent recovery is observed for molecules with 17 or fewer atoms. Additionally, we evaluate the descriptor's performance in predicting the energies and forces of bulk Ni, Cu, Li, Mo, Si, and Ge by means of a neural network model trained on DFT data. When comparing to six machine learning interaction potential methods that use various descriptors and regression schemes, our descriptor is found to be competitive, in several cases outperforming well established methods. The combined ability to both decode and make property predictions from a representation that does not need to be learned lays the foundations for a novel way of building generative models that are tasked with solving the inverse problem of predicting atomic arrangements that are statistically likely to have certain desired properties.

The Electrostatic Model of Homeopathy: The Mechanism of Physicochemical Activities of Homeopathic Medicines.

This paper attempts to propose a model, called the electrostatic model of homeopathy, to explain a mechanism for the physicochemical activities of highly diluted homeopathic medicines (HMs). According to this proposed model, the source of HMs' action is dipole orientations as electrostatic imprints of the original molecules carried by diluent molecules (such as sugar molecules) or potentization-induced aqueous nanostructures. The nanoscale domains' contact charging and dielectric hysteresis play critical roles in the aqueous nanostructures' or sugar molecules' acquisition of the original molecules' dipole orientations. The mechanical stress induced by dynamization (vigorous agitation or trituration) is a crucial factor that facilitates these phenomena. After dynamization is completed, the transferred charges revert to their previous positions but, due to dielectric hysteresis, they leave a remnant polarization on the aqueous nanostructures or sugar molecules' nanoscale domains. This causes some nanoscale domains of the aqueous nanostructures or sugar molecules to obtain the original substance molecules' dipole orientations. A highly diluted HM may have no molecule of the original substance, but the aqueous nanostructures or sugar molecules may contain the original substance's dipole orientations. Therefore, HMs can precisely aim at the biological targets of the original substance molecules and electrostatically interact with them as mild stimuli.

The palaeoinclination of the ancient lunar magnetic field from an Apollo 17 basalt

Palaeomagnetic studies of Apollo samples indicate that the Moon generated a magnetic field for at least 2 billion years1,2. However, the geometry of the lunar magnetic field is still largely unknown because the original orientations of essentially all Apollo samples have not been well constrained. Determining the direction of the lunar magnetic field over time could elucidate the mechanism by which the lunar dynamo was powered and whether the Moon experienced true polar wander. Here we present measurements of the lunar magnetic field 3.7 billion years ago as recorded by Apollo 17 mare basalts 75035 and 75055. We find that 75035 and 75055 record a mean palaeointensity of ~50 μT. Furthermore, we could infer from the magnetization direction of 75055 and the layering of its parent boulder that the inclination of the magnetic field at the time was 34 ± 10°. Our recovered inclination is consistent with, but does not require, a selenocentric axial dipole (SAD) field geometry: a dipole in the centre of the Moon and aligned along the spin axis. Additionally, although true polar wander is not required by our data, true polar wander paths inferred from some independent studies of lunar hydrogen deposits and crustal magnetic anomalies4,5,6 are consistent with our measured paleoinclination.