bluuebunny/crossref_metadata_2025 huggingface dataset:
Coloring and fusing architectural sketches by combining a Y‐shaped generative adversarial network and a denoising diffusion implicit model
Authors: Zhao Liang , Song Dexuan , Chen Weizhen , Kang Qi
Published: October 2023

Sketch‐based architectural design tasks require considerable time and effort. However, developing an artificial intelligence agent to color and fuse architectural sketches is challenging due to the imaginative nature of the task and technical limitations. Here, we first introduce Y‐shaped generative adversarial networks (GANs), which can color sketches on the basis of temporarily specified reference images by embedding an attention mechanism model that can match spatial and color information and by maintaining a type of triangular equilibrium state. Then, we develop practicable methods for coloring and fusing the given sketches simultaneously using a combination of our Y‐shaped GANs and the denoising diffusion implicit model, yielding results with high quality and veracity. A novel interpolation process is developed as a necessary trick for realizing the fusion function. The testing results indicate that this method works better than the existing methods for the tasks of coloring and fusing architectural sketches.
Task communicative function and oral fluency of L1 and L2 speakers
Authors: Morrison Astrid , Tavakoli Parvaneh
Published: October 2023

To respond to recent calls for examining oral fluency from a broader social and communicative perspective, the current study aimed at investigating the effects of task communicative function on second language (L2) and first language (L1) speakers’ fluency. Designing tasks that represent three different communicative functions (congratulations, bad news, and complaint), we collected data from 40 Spanish L2 learners of English, 20 L1 English speakers, and 20 L1 Spanish speakers. The data were analysed for a range of measures of speed, composite, breakdown, and repair fluency. Results of the statistical analyses (descriptive, Multivariance Analysis of Variance (MANOVA), and two‐way mixed Analysis of Variance (ANOVAs)) suggested that task communicative function had an impact on the speakers’ performance, with bad news eliciting the slowest speech and most mid‐clause pauses, and complaint the fastest with fewest end‐clause pauses. Significant differences were observed across the tasks for speech rate and end‐clause pauses in the L1 English group, but the results were nonsignificant for task effects in the L1 Spanish and L2 English groups. The three language groups’ fluency was statistically different, highlighting (a) cross‐linguistic differences between L1 Spanish and L1 English speakers and (b) differences between L1 and L2 English speakers.
Plasmodesmal connectivity in C4Gynandropsis gynandra is induced by light and dependent on photosynthesis
Authors: Schreier Tina B. , Müller Karin H. , Eicke Simona , Faulkner Christine , Zeeman Samuel C. , Hibberd Julian M.
Published: October 2023

In leaves of C4 plants, the reactions of photosynthesis become restricted between two compartments. Typically, this allows accumulation of C4 acids in mesophyll (M) cells and subsequent decarboxylation in the bundle sheath (BS). In C4 grasses, proliferation of plasmodesmata between these cell types is thought to increase cell‐to‐cell connectivity to allow efficient metabolite movement. However, it is not known whether C4 dicotyledons also show this enhanced plasmodesmal connectivity and so whether this is a general requirement for C4 photosynthesis is not clear. How M and BS cells in C4 leaves become highly connected is also not known.

We investigated these questions using 3D‐ and 2D‐electron microscopy on the C4 dicotyledon Gynandropsis gynandra as well as phylogenetically close C3 relatives.

The M–BS interface of C4 G. gynandra showed higher plasmodesmal frequency compared with closely related C3 species. Formation of these plasmodesmata was induced by light. Pharmacological agents that perturbed photosynthesis reduced the number of plasmodesmata, but this inhibitory effect could be reversed by the provision of exogenous sucrose.

We conclude that enhanced formation of plasmodesmata between M and BS cells is wired to the induction of photosynthesis in C4 G. gynandra.
Shoot‐to‐root communication via GmUVR8‐GmSTF3 photosignaling and flavonoid biosynthesis fine‐tunes soybean nodulation under UV‐B light
Authors: Chen Jiansheng , Xu Huifang , Liu Qiulin , Ke Meiyu , Zhang Zhongqin , Wang Xu , Gao Zhen , Wu Ruimei , Yuan Qiao , Qian Chongzhen , Huang Laimei , Chen Jiaomei , Han Qingqing , Guan Yuefeng , Yu Xiaomin , Huang Xi , Chen Xu
Published: October 2023

Legume nodulation requires light perception by plant shoots and precise long‐distance communication between shoot and root. Recent studies have revealed that TGACG‐motif binding factors (GmSTFs) integrate light signals to promote root nodulation; however, the regulatory mechanisms underlying nodule formation in changing light conditions remain elusive.

Here, we applied genetic engineering, metabolite measurement, and transcriptional analysis to study soybean (Glycine max) nodules.

We clarify a fine‐tuning mechanism in response to ultraviolet B (UV‐B) irradiation and rhizobia infection, involving GmUVR8‐dependent UV‐B perception and GmSTF3/4‐GmMYB12‐GmCHS‐mediated (iso)flavonoid biosynthesis for soybean nodule formation. GmUVR8 receptor‐perceived UV‐B signal triggered R2R3‐MYB transcription factors GmMYB12‐dependent flavonoid biosynthesis separately in shoot and root. In shoot, UV‐B‐triggered flavonoid biosynthesis relied on GmUVR8a, b, c receptor‐dependent activation of GmMYB12L‐GmCHS8 (chalcone synthase) module. In root, UV‐B signaling distinctly promotes the accumulation of the isoflavones, daidzein, and its derivative coumestrol, via GmMYB12B2‐GmCHS9 module, resulting in hypernodulation. The mobile transcription factors, GmSTF3/4, bind to cis‐regulatory elements in the GmMYB12L, GmMYB12B2, and GmCHS9 promoters, to coordinate UV‐B light perception in shoot and (iso)flavonoid biosynthesis in root.

Our findings establish a novel shoot‐to‐root communication module involved in soybean nodulation and reveal an adaptive strategy employed by soybean roots in response to UV‐B light.
Can philosophy benefit nurses and/or nursing? Heidegger and Strauss, problems of knowledge and context
Authors: Lipscomb Martin
Published: October 2023

When researchers and scholars claim their work is based on a philosophical idea or a philosopher's corpus of ideas (and theory/theorist can be substituted for philosophy/philosopher), and when ‘basing’ signifies something significant rather than subsidiary or inconsequential, what level of understanding and expertise can readers reasonably expect authors to possess? In this paper, some of the uses to which philosophical ideas and named philosophers (Martin Heidegger and Leo Strauss) are put in exegesis is critiqued. Considering problematic instances of idea‐name use may enable the question: ‘Can philosophy benefit nurses and/or nursing?’ to be better understood if not answered.
Enhanced transformation efficiency in Treponema denticola enabled by SyngenicDNA‐based plasmids lacking restriction–modification target motifs
Authors: Johnston Christopher D. , Goetting‐Minesky M. Paula , Kennedy Kelly , Godovikova Valentina , Zayed Sara M. , Roberts Richard J. , Fenno J. Christopher
Published: October 2023

Oral spirochetes are among a small group of keystone pathogens contributing to dysregulation of tissue homeostatic processes that leads to breakdown of the tissue and bone supporting the teeth in periodontal disease. Additionally, our group has recently demonstrated that Treponema are among the dominant microbial genera detected intracellularly in tumor specimens from patients with oral squamous cell carcinoma. While over 60 species and phylotypes of oral Treponema have been detected, T. denticola is one of the few that can be grown in culture and the only one in which genetic manipulation is regularly performed. Thus, T. denticola is a key model organism for studying spirochete metabolic processes, interactions with other microbes, and host cell and tissue responses relevant to oral diseases, as well as venereal and nonvenereal treponematoses whose agents lack workable genetic systems. We previously demonstrated improved transformation efficiency using an Escherichia coli–T. denticola shuttle plasmid and its utility for expression in T. denticola of an exogenous fluorescent protein that is active under anaerobic conditions. Here, we expand on this work by characterizing T. denticola Type I and Type II restriction–modification (R–M) systems and designing a high‐efficiency R–M‐silent “SyngenicDNA” shuttle plasmid resistant to all T. denticola ATCC 35405 R–M systems. Resequencing of the ATCC 33520 genome revealed an additional Type I R–M system consistent with the relatively low transformation efficiency of the shuttle plasmid in this strain. Using SyngenicDNA approaches, we optimized shuttle plasmid transformation efficiency in T. denticola and used it to complement a defined T. denticola ΔfhbB mutant strain. We further report the first high‐efficiency transposon mutagenesis of T. denticola using an R–M‐silent, codon‐optimized, himarC9 transposase‐based plasmid. Thus, use of SyngenicDNA‐based strategies and tools can enable further mechanistic examinations of T. denticola physiology and behavior.
Clinical Outcomes of Minimally Invasive Fixation with Pre‐Bent Elastic Stable Intramedullary Nails for the Treatment of Distal Radius Metaphyseal Diaphysis Junction Fractures in Children
Authors: Yang Limeng , Wang Shuqin , Xu Jindi , Deng Changzong , Wang Kai , Li Qing , Zhou Hua , Ruan Hongfeng , Zhuang Wei
Published: October 2023

Objective

Although mini‐plate fixation is an attractive treatment option for distal radius metaphyseal diaphysis junction (DRMDJ) fractures in children, the benefits of minimally invasive fixation (MIF) with pre‐bent elastic stable intramedullary nails (MIF) remain underexplored. Therefore, this study aimed to evaluate the clinical efficacy of MIF administration in children with DRMDJ fractures.

Methods

This retrospective study enrolled 40 patients with DRMDJ fractures who underwent MIF or mini‐plate fixation from January 2016 to January 2021. Radiographic parameters, such as palmar inclination and ulnar deflection angle, were examined postoperatively to assess the anatomical reduction of the wrist joint. Clinical outcomes, including the range of wrist flexion and back extension, were examined to analyze the recovery of the wrist range of motion. Additionally, the Gartland–Werley scoring system was used to assess the recovery status of wrist function and healing condition. The student t‐test and χ2 test were used to compare differences among groups.

Results

All included patients successfully underwent the operation and were followed up for 12–24 months. Patients in the MIF group had a smaller surgical incision length (0.49 ± 0.06 cm) compared to those in the mini‐plate fixation group (4.41 ± 0.73 cm) (t = 22.438, p = 0.000). Palmar inclination and ulnar deflection were within the normal range in patients of both groups, and the fractures were successfully anatomically reduced. Moreover, wrist flexion and back extension in the MIF group and mini‐plate group were (72.50° ± 0.64° vs. 70.18° ± 0.56°) and (59.55° ± 1.75° vs. 60.04° ± 1.37°), and differences were statistically significant (t = 2.708, p = 0.010 and t = 0.885, p = 0.382, respectively). Furthermore, MIF treatment resulted in a higher proportion of excellent Gartland–Werley scores (94.44%) than mini‐plate fixation (86.36%) (p = 0.390). In addition, one case in the mini‐plate fixation group experienced re‐fracture following the removal of the internal fixation, and the fracture healed after reduction and cast fixation. All patients achieved satisfactory bone healing without other complications.

Conclusion

Compared with mini‐plate fixation, MIF has the advantages of small incision length, superior range of motion of thr wrist joint, and better maintenance of the physiological radian, providing a promising approach for clinical and surgical treatment of DRMDJ fractures.
Deep learning and targeted metabolomics‐based monitoring of chewing insects in tea plants and screening defense compounds
Authors: Chen Yifan , Wang Zhenyu , Gao Tian , Huang Yipeng , Li Tongtong , Jiang Xiaolan , Liu Yajun , Gao Liping , Xia Tao
Published: October 2023

Tea is an important cash crop that is often consumed by chewing pests, resulting in reduced yields and economic losses. It is important to establish a method to quickly identify the degree of damage to tea plants caused by leaf‐eating insects and screen green control compounds. This study was performed through the combination of deep learning and targeted metabolomics, in vitro feeding experiment, enzymic analysis and transient genetic transformation. A small target damage detection model based on YOLOv5 with Transformer Prediction Head (TPH‐YOLOv5) algorithm for the tea canopy level was established. Orthogonal partial least squares (OPLS) was used to analyze the correlation between the degree of damage and the phenolic metabolites. A potential defensive compound, (‐)‐epicatechin‐3‐O‐caffeoate (EC‐CA), was screened. In vitro feeding experiments showed that compared with EC and epicatechin gallate, Ectropis grisescens exhibited more significant antifeeding against EC‐CA. In vitro enzymatic experiments showed that the hydroxycinnamoyl transferase (CsHCTs) recombinant protein has substrate promiscuity and can catalyze the synthesis of EC‐CA. Transient overexpression of CsHCTs in tea leaves effectively reduced the degree of damage to tea leaves. This study provides important reference values and application prospects for the effective monitoring of pests in tea gardens and screening of green chemical control substances.
UGT89AC1‐mediated quercetin glucosylation is induced upon herbivore damage and enhances Camellia sinensis resistance to insect feeding
Authors: Jing Tingting , Du Wenkai , Qian Xiaona , Wang Kai , Luo Lanxin , Zhang Xueying , Deng Yanni , Li Bo , Gao Ting , Zhang Mengting , Guo Danyang , Jiang Hao , Liu Yuantao , Schwab Wilfried , Sun Xiaoling , Song Chuankui
Published: October 2023

Quercetin is a key flavonol in tea plants (Camellia sinensis (L.) O. Kuntze) with various health benefits, and it often occurs in the form of glucosides. The roles of quercetin and its glucosylated forms in plant defense are generally not well‐studied, and remain unknown in the defense of tea. Here, we found higher contents of quercetin glucosides and a decline of the aglucone upon Ectropis grisescens (E. grisescens) infestation of tea. Nine UGTs were strongly induced, among which UGT89AC1 exhibited the highest activity toward quercetin in vitro and in vivo. The mass of E. grisescens larvae that fed on plants with repressed UGT89AC1 or varieties with lower levels of UGT89AC1 was significantly lower than that of larvae fed on controls. Artificial diet supplemented with quercetin glucoside also reduced the larval growth rate, whereas artificial diet supplemented with free quercetin had no significant effect on larval growth. UGT89AC1 was located in both the cytoplasm and nucleus, and its expression was modulated by JA, JA‐ILE, and MeJA. These findings demonstrate that quercetin glucosylation serves a defensive role in tea against herbivory. Our results also provide novel insights into the ecological relevance of flavonoid glycosides under biotic stress in plants.
Habitat aging and degradation in terrestrialized floodplains: a need to rejuvenate processes for sustaining freshwater mussel populations
Authors: Nagayama Shigeya , Harada Morihiro , Negishi Junjiro N. , Kitamura Jyun‐ichi , Mori Terutaka , Mori Seiichi
Published: October 2023

Progressive floodplain terrestrialization leads to the deterioration of floodplain ecosystems. Although the importance of hydrological connectivity between floodplain habitats and river channels for floodplain‐dependent organisms has been emphasized, less attention has been paid to the temporal relationship between habitat degradation and aquatic organisms. In this study, we examined temporal changes in mussel population structures and the hydrological connectivity of pond‐like floodplain water bodies (FWBs) in the terrestrialized floodplains of a lowland river in Japan. We tested the hypothesis that FWB habitats for mussels degrade over time, while newly formed FWBs contribute to providing recruitment sites for mussels. The habitat age for 53 FWBs was determined as of 2018, using historical aerial photographs. Inundation frequency, mussel abundance, and size structures (shell length) were also investigated in the FWBs in 2007 and 2018. Mussel abundance decreased with FWB aging (6–36 years), which coincided with a decrease in inundation frequency. In most existing FWBs, mussel abundance in all size classes decreased over the decade (2007–2018). In contrast, small individuals occurred in the newly formed FWBs at age 6, and in the existing FWBs where inundation frequency slightly increased over the decade (2007–2018), such FWBs were rare. In conclusion, the “young” and “rejuvenated” FWBs were found to be critically important for the recruitment and persistence of mussel populations. This suggests that the floodplain management strategy of “cyclic floodplain rejuvenation” could be applicable for mussel conservation in terrestrialized floodplains of lowland rivers.
Hidden in Plain Sight: “Neutral” Enclosures for High‐Skilled Immigrants During COVID‐191
Authors: Purkayastha Bandana , Roy Rianka
Published: October 2023

Politicians and mainstream media in the EU, UK, and US regularly emphasize the need for highly skilled migrants, but, over the last few decades, the terms and conditions for these highly skilled migrants have changed drastically. As part of the neoliberal migrant control regime, highly skilled migrants are brought to countries under very restrictive conditions. They work and contribute taxes but have few to no political rights. Based on data on highly skilled Indian migrants in the US during the pandemic, we argue that highly skilled “nonimmigrants” are placed within a thicket of laws and policies that act as enclosures, but these seemingly neutral enclosures remain “hidden in plain sight” because of the silence about their near‐indentured life conditions.
Smooth Lagrangian Crack Band Model Based on Spress-Sprain Relation and Lagrange Multiplier Constraint of Displacement Gradient
Authors: Tay Nguyen Anh , Xu Houlin , Matouš Karel , Bažant Zdeněk P.
Published: October 2023

A preceding 2023 study argued that the resistance of a heterogeneous material to the curvature of the displacement field is the most physically realistic localization limiter for softening damage. The curvature was characterized by the second gradient of the displacement vector field, which includes the material rotation gradient, and was named the “sprain” tensor, while the term “spress” is here proposed as the force variable work-conjugate to “sprain.” The partial derivatives of the associated sprain energy density yielded in the preceeding study, sets of curvature resisting self-equilibrated nodal sprain forces. However, the fact that the sprain forces had to be applied on the adjacent nodes of a finite element greatly complicated the programming and extended the simulation time in a commercial code such as abaqus by almost two orders of magnitude. In the present model, Smooth Lagrangian Crack Band Model (slCBM), these computational obstacles are here overcome by using finite elements with linear shape functions for both the displacement vector and for an approximate displacement gradient tensor. A crucial feature is that the nodal values of the approximate gradient tensor are shared by adjacent finite elements. The actual displacement gradient tensor calculated from the nodal displacement vectors is constrained to the approximate displacement gradient tensor by means of a Lagrange multiplier tensor, either one for each element or one for each node. The gradient tensor of the approximate gradient tensor then represents the approximate third-order displacement curvature tensor, or Hessian of the displacement field. Importantly, the Lagrange multiplier behaves as an externally applied generalized moment density that, similar to gravity, does not affect the total strain-plus-sprain energy density of material. The Helmholtz free energy of the finite element and its associated stiffness matrix are formulated and implemented in a user’s element of abaqus. The conditions of stationary values of the total free energy of the structure with respect to the nodal degrees-of-freedom yield the set of equilibrium equations of the structure for each loading step. One- and two-dimensional examples of crack growth in fracture specimens are given. It is demonstrated that the simulation results of the three-point bend test are independent of the orientation of a regular square mesh, capture the width variation of the crack band, the damage strain profile across the band, and converge as the finite element mesh is refined.
Parks Visitation, Physical Activity Engagement, and Older People’s Motivation for Visiting Local Parks
Authors: Levinger Pazit , Dreher Bronwyn L. , Dunn Jeremy , Garratt Stephanie , Abfalter Emma , Dow Briony , Batchelor Frances , Hill Keith D.
Published: October 2023

Despite the health benefits of parks and outdoor recreational spaces, small numbers of older people visit parks. This study identified older park visitors’ perceptions of their local parks, visit motivation, health, and physical activity level in six parks in Victoria, Australia. Characteristics of general community park visitors and their physical activity engagement were also recorded. Fifty-five older people were surveyed onsite; 92.7% lived within a 5-km distance from the park. Walking was the most common reason for visiting (36.4%), followed by walking the dog (36.4%) and exercise (23.6%). Most older visitors (77.8%) were determined as being sufficiently active. Observation of parks visitors over 1 week recorded 3,770 park visitors, with <5% being older people. Half of all park visitors were inactive, and half of older people visitors (50.5%) engaged in walking. This study supports the importance of parks, park features, and their potential in helping older people to achieve levels of physical activity required for good health.
Nonaccidental Violence Among Elite Athletes in Finland: Associations With Sport Conditions and Mental Well-Being and Ill-Being
Authors: Kaski Satu , Kinnunen Ulla
Published: October 2023

The aim of this research was to study the prevalence of nonaccidental violence among elite athletes in Finland, the predisposing factors to violence, and its consequences for mental well-being and ill-being. A total of 2,045 Finnish athletes participated in the study. Logistic and linear regression analyses were used to analyze the associations. The results indicated that 38.8% had experienced psychological abuse, 14.7% bullying, 13.3% gender-based harassment, and 5.5% sexual harassment. Female and younger athletes reported more violent experiences than male and older athletes. A team’s safe atmosphere and readiness to act protected athletes from nonaccidental violence, whereas the coach did not play a role. Nonaccidental violence, particularly psychological abuse, was associated with reduced mental well-being and increased ill-being. Our results suggest that it is worth investing in the team’s mutual relationships and safe cooperation when ensuring appropriate behavior and preventing nonaccidental violence among athletes.
Demographic and hormonal evidence for menopause in wild chimpanzees
Authors: Wood Brian M. , Negrey Jacob D. , Brown Janine L. , Deschner Tobias , Thompson Melissa Emery , Gunter Sholly , Mitani John C. , Watts David P. , Langergraber Kevin E.
Published: October 2023

Among mammals, post-reproductive life spans are currently documented only in humans and a few species of toothed whales. Here we show that a post-reproductive life span exists among wild chimpanzees in the Ngogo community of Kibale National Park, Uganda. Post-reproductive representation was 0.195, indicating that a female who reached adulthood could expect to live about one-fifth of her adult life in a post-reproductive state, around half as long as human hunter-gatherers. Post-reproductive females exhibited hormonal signatures of menopause, including sharply increasing gonadotropins after age 50. We discuss whether post-reproductive life spans in wild chimpanzees occur only rarely, as a short-term response to favorable ecological conditions, or instead are an evolved species-typical trait as well as the implications of these alternatives for our understanding of the evolution of post-reproductive life spans.
Room-temperature wavelike exciton transport in a van der Waals superatomic semiconductor
Authors: Tulyagankhodjaev Jakhangirkhodja A. , Shih Petra , Yu Jessica , Russell Jake C. , Chica Daniel G. , Reynoso Michelle E. , Su Haowen , Stenor Athena C. , Roy Xavier , Berkelbach Timothy C. , Delor Milan
Published: October 2023

The transport of energy and information in semiconductors is limited by scattering between electronic carriers and lattice phonons, resulting in diffusive and lossy transport that curtails all semiconductor technologies. Using Re
6
Se
8
Cl
2
, a van der Waals (vdW) superatomic semiconductor, we demonstrate the formation of acoustic exciton-polarons, an electronic quasiparticle shielded from phonon scattering. We directly imaged polaron transport in Re
6
Se
8
Cl
2
at room temperature, revealing quasi-ballistic, wavelike propagation sustained for a nanosecond and several micrometers. Shielded polaron transport leads to electronic energy propagation lengths orders of magnitude greater than in other vdW semiconductors, exceeding even silicon over a nanosecond. We propose that, counterintuitively, quasi-flat electronic bands and strong exciton–acoustic phonon coupling are together responsible for the transport properties of Re
6
Se
8
Cl
2
, establishing a path to ballistic room-temperature semiconductors.
A dirigent protein complex directs lignin polymerization and assembly of the root diffusion barrier
Authors: Gao Yi-Qun , Huang Jin-Quan , Reyt Guilhem , Song Tao , Love Ashley , Tiemessen David , Xue Pei-Ying , Wu Wen-Kai , George Michael W. , Chen Xiao-Ya , Chao Dai-Yin , Castrillo Gabriel , Salt David E.
Published: October 2023

Functionally similar to the tight junctions present in animal guts, plant roots have evolved a lignified Casparian strip as an extracellular diffusion barrier in the endodermis to seal the root apoplast and maintain nutrient homeostasis. How this diffusion barrier is structured has been partially defined, but its lignin polymerization and assembly steps remain elusive. Here, we characterize a family of dirigent proteins (DPs) essential for both the localized polymerization of lignin required for Casparian strip biogenesis in the cell wall and for attachment of the strip to the plasma membrane to seal the apoplast. We reveal a Casparian strip lignification mechanism that requires cooperation between DPs and the Schengen pathway. Furthermore, we demonstrate that DPs directly mediate lignin polymerization as part of this mechanism.
Multiplicative enhancement of stereoenrichment by a single catalyst for deracemization of alcohols
Authors: Wen Lu , Ding Jia , Duan Lingfei , Wang Shun , An Qing , Wang Hexiang , Zuo Zhiwei
Published: October 2023

Stereochemical enrichment of a racemic mixture by deracemization must overcome unfavorable entropic effects as well as the principle of microscopic reversibility; recently, photochemical reaction pathways unveiled by the energetic input of light have led to innovations toward this end, most often by ablation of a stereogenic C(sp
3
)–H bond. We report a photochemically driven deracemization protocol in which a single chiral catalyst effects two mechanistically different steps, C–C bond cleavage and C–C bond formation, to achieve multiplicative enhancement of stereoinduction, which leads to high levels of stereoselectivity. Ligand-to-metal charge transfer excitation of a titanium catalyst coordinated by a chiral phosphoric acid or bisoxazoline efficiently enriches racemic alcohols that feature adjacent and fully substituted stereogenic centers to enantiomeric ratios up to 99:1. Mechanistic investigations support a pathway of sequential radical-mediated bond scission and bond formation through a common prochiral intermediate and reveal that, although the overall stereoenrichment is high, the selectivity in each individual step is moderate.
Quantum walk comb in a fast gain laser
Authors: Heckelmann Ina , Bertrand Mathieu , Dikopoltsev Alexander , Beck Mattias , Scalari Giacomo , Faist Jérôme
Published: October 2023

Synthetic lattices in photonics enable the exploration of light states in new dimensions, transcending phenomena common only to physical space. We propose and demonstrate a quantum walk comb in synthetic frequency space formed by externally modulating a ring-shaped semiconductor laser with ultrafast recovery times. The initially ballistic quantum walk does not dissipate into low supermode states of the synthetic lattice; instead, the state stabilizes in a broad frequency comb, unlocking the full potential of the synthetic frequency lattice. Our device produces a low-noise, nearly flat broadband comb (reaching 100 per centimeter bandwidth) and offers a promising platform to generate broadband, tunable, and stable frequency combs.
Observation and control of hybrid spin-wave–Meissner-current transport modes
Authors: Borst M. , Vree P. H. , Lowther A. , Teepe A. , Kurdi S. , Bertelli I. , Simon B. G. , Blanter Y. M. , van der Sar T.
Published: October 2023

Superconductors are materials with zero electrical resistivity and the ability to expel magnetic fields, which is known as the Meissner effect. Their dissipationless diamagnetic response is central to magnetic levitation and circuits such as quantum interference devices. In this work, we used superconducting diamagnetism to shape the magnetic environment governing the transport of spin waves—collective spin excitations in magnets that are promising on-chip signal carriers—in a thin-film magnet. Using diamond-based magnetic imaging, we observed hybridized spin-wave–Meissner-current transport modes with strongly altered, temperature-tunable wavelengths and then demonstrated local control of spin-wave refraction using a focused laser. Our results demonstrate the versatility of superconductor-manipulated spin-wave transport and have potential applications in spin-wave gratings, filters, crystals, and cavities.
Menopause in chimpanzees
Authors: Cant Michael
Published: October 2023

Signs of menopause in wild chimpanzees provide insights into human evolution
Leveraging investment in agricultural science, technology, and innovation in Latin America and the Caribbean
Authors: Saini Eugenia
Published: October 2023

Climate change poses severe impacts on and risks to agriculture, food, and nutrition, particularly for smallholders. Agricultural researchers are tasked with deciphering interconnected variables—from soil characteristics and nutrient cycles to water and biodiversity—to create a robust framework for technological advancements. Increasing sustainability, resilience, and productivity is an urgent need that requires approaches to research and innovation tailored to both regional and country-specific challenges. One compelling model of regional collaboration is
FONTAGRO
, the Regional Fund for Agricultural Technology, which for 25 years has combined public and private institutions in supporting science, technology, and innovation within the agrifood sector in Latin American and the Caribbean. The science-based evidence that emerges is strategic not only for its local application but also for its potential in other regions of the world and capacity to accelerate the transformation of agrifood systems.
Pharmacokinetics and safety of first-line tuberculosis drugs rifampin, isoniazid, ethambutol, and pyrazinamide during pregnancy and postpartum: results from IMPAACT P1026s
Authors: Van Schalkwyk Marije , Bekker Adrie , Decloedt Eric , Wang Jiajia , Theron Gerhard B. , Cotton Mark F. , Eke Ahizechukwu C. , Cressey Tim R. , Shapiro David E. , Bacon Kira , Knowles Kevin , George Kathleen , Browning Renee , Chakhtoura Nahida , Rungruengthanakit Kittipong , Wiesner Lubbe , Capparelli Edmund V. , Stek Alice M. , Mirochnick Mark , Best Brookie M. ,   on behalf of the IMPAACT P1026s Protocol Team
Published: October 2023

Physiological changes during pregnancy may alter the pharmacokinetics (PK) of antituberculosis drugs. The International Maternal Pediatric Adolescent AIDS Clinical Trials Network P1026s was a multicenter, phase IV, observational, prospective PK and safety study of antiretroviral and antituberculosis drugs administered as part of clinical care in pregnant persons living with and without HIV. We assessed the effects of pregnancy on rifampin, isoniazid, ethambutol, and pyrazinamide PK in pregnant and postpartum (PP) persons without HIV treated for drug-susceptible tuberculosis disease. Daily antituberculosis treatment was prescribed following World Health Organization-recommended weight-band dosing guidelines. Steady-state 12-hour PK profiles of rifampin, isoniazid, ethambutol, and pyrazinamide were performed during second trimester (2T), third trimester (3T), and 2–8 of weeks PP. PK parameters were characterized using noncompartmental analysis, and comparisons were made using geometric mean ratios (GMRs) with 90% confidence intervals (CI). Twenty-seven participants were included: 11 African, 9 Asian, 3 Hispanic, and 4 mixed descent. PK data were available for 17, 21, and 14 participants in 2T, 3T, and PP, respectively. Rifampin and pyrazinamide AUC
0–24
and
C
max
in pregnancy were comparable to PP with the GMR between 0.80 and 1.25. Compared to PP, isoniazid AUC
0–24
was 25% lower and
C
max
was 23% lower in 3T. Ethambutol AUC
0–24
was 39% lower in 3T but limited by a low PP sample size. In summary, isoniazid and ethambutol concentrations were lower during pregnancy compared to PP concentrations, while rifampin and pyrazinamide concentrations were similar. However, the median AUC
0–24
for rifampin, isoniazid, and pyrazinamide met the therapeutic targets. The clinical impact of lower isoniazid and ethambutol exposure during pregnancy needs to be determined.
Diversity at single nucleotide to pangenome scales among sulfur cycling bacteria in salt marshes
Authors: Pérez Castro Sherlynette , Peredo Elena L. , Mason Olivia U. , Vineis Joseph , Bowen Jennifer L. , Mortazavi Behzad , Ganesh Anakha , Ruff S. Emil , Paul Blair G. , Giblin Anne E. , Cardon Zoe G.
Published: October 2023

Sulfur-cycling microbial communities in salt marsh rhizosphere sediments mediate a recycling and detoxification system central to plant productivity. Despite the importance of sulfur-cycling microbes, their biogeographic, phylogenetic, and functional diversity remain poorly understood. Here, we use metagenomic data sets from Massachusetts (MA) and Alabama (AL) salt marshes to examine the distribution and genomic diversity of sulfur-cycling plant-associated microbes. Samples were collected from sediments under
Sporobolus alterniflorus
and
Sporobolus pumilus
in separate MA vegetation zones, and under
S. alterniflorus
and
Juncus roemerianus
co-occuring in AL. We grouped metagenomic data by plant species and site and identified 38 MAGs that included pathways for sulfate reduction or sulfur oxidation. Phylogenetic analyses indicated that 29 of the 38 were affiliated with uncultivated lineages. We showed differentiation in the distribution of MAGs between AL and MA, between
S. alterniflorus
and
S. pumilus
vegetation zones in MA, but no differentiation between
S. alterniflorus
and
J. roemerianus
in AL. Pangenomic analyses of eight ubiquitous MAGs also detected site- and vegetation-specific genomic features, including varied sulfur-cycling operons, carbon fixation pathways, fixed single-nucleotide variants, and active diversity-generating retroelements. This genetic diversity, detected at multiple scales, suggests evolutionary relationships affected by distance and local environment, and demonstrates differential microbial capacities for sulfur and carbon cycling in salt marsh sediments.

IMPORTANCE

Salt marshes are known for their significant carbon storage capacity, and sulfur cycling is closely linked with the ecosystem-scale carbon cycling in these ecosystems. Sulfate reducers are key for the decomposition of organic matter, and sulfur oxidizers remove toxic sulfide, supporting the productivity of marsh plants. To date, the complexity of coastal environments, heterogeneity of the rhizosphere, high microbial diversity, and uncultured majority hindered our understanding of the genomic diversity of sulfur-cycling microbes in salt marshes. Here, we use comparative genomics to overcome these challenges and provide an in-depth characterization of sulfur-cycling microbial diversity in salt marshes. We characterize communities across distinct sites and plant species and uncover extensive genomic diversity at the taxon level and specific genomic features present in MAGs affiliated with uncultivated sulfur-cycling lineages. Our work provides insights into the partnerships in salt marshes and a roadmap for multiscale analyses of diversity in complex biological systems.
Biofilm formation and cell plasticity drive diazotrophy in an anoxygenic phototrophic bacterium
Authors: Fernández-Juárez Víctor , Hallstrøm Søren , Pacherres Cesar O. , Wang Jiaqi , Coll-Garcia Guillem , Kühl Michael , Riemann Lasse
Published: October 2023

Non-cyanobacterial diazotrophs (NCDs) are widespread and active in marine waters. The carbon and low-oxygen (O
2
) conditions required for their N
2
fixation may be encountered on marine particles, while a putative role of light remains uninvestigated. This study explored factors that regulate N
2
fixation in
Rhodopseudomonas
sp. BAL398—a anoxygenic phototrophic bacterium isolated from low-salinity surface waters. Light (250 µmol photons m
−2
s
−1
) and anoxia (0 µM O
2
) stimulated growth and N
2
fixation; however, diazotrophy in light was dependent on high organic carbon levels (35 mM, glucose:succinate). Immunolabeling revealed that cellular nitrogenase levels increased with light, decreasing inorganic nitrogen (N) and ambient O
2
(250 µM). Light and O
2
stimulated motility and biofilm formation on surfaces, and N
2
fixation rates increased compared to the control treatment. N
2
fixation rates were positively correlated with the formation of rosette-like cellular structures, and an increased concentration of nitrogenase was observed toward the center of these structures, which increased their occurrence 600 times when cultures reached maximum N
2
fixation rates vs when they had low rates. Interestingly, N
2
fixation was not completely inhibited under oxic conditions and was accompanied by increased formation of capsules and cysts. Rosettes, as well as capsules and cysts, may thus serve as protection against O
2
. Our study reveals the physiological adaptations that underlie N
2
fixation in an anoxygenic phototroph, emphasizing the significance of biofilm formation for utilizing light and fixing N
2
under oxic conditions, and underscores the need for deciphering the importance of light for marine NCDs.

IMPORTANCE

The contribution of non-cyanobacterial diazotrophs (NCDs) to total N
2
fixation in the marine water column is unknown, but their importance is likely constrained by the limited availability of dissolved organic matter and low O
2
conditions. Light could support N
2
fixation and growth by NCDs, yet no examples from bacterioplankton exist. In this study, we show that the phototrophic NCD,
Rhodopseudomonas
sp. BAL398, which is a member of the diazotrophic community in the surface waters of the Baltic Sea, can utilize light. Our study highlights the significance of biofilm formation for utilizing light and fixing N
2
under oxic conditions and the role of cell plasticity in regulating these processes. Our findings have implications for the general understanding of the ecology and importance of NCDs in marine waters.
Bladder-draining lymph nodes support germinal center B cell responses during urinary tract infection in mice
Authors: Hawas Sophia , Vagenas Dimitrios , Haque Ashraful , Totsika Makrina
Published: October 2023

Bacterial urinary tract infections (UTIs) are both common and exhibit high recurrence rates in women. UTI healthcare costs are increasing due to the rise of multidrug-resistant (MDR) bacteria, necessitating alternative approaches for infection control. Here, we directly observed host adaptive immune responses in acute UTI. We employed a mouse model in which wild-type C57BL/6J mice were transurethrally inoculated with a clinically relevant MDR UTI strain of uropathogenic
Escherichia coli
(UPEC). Firstly, we noted that

rag1
−/−

C57BL/6J mice harbored larger bacterial burdens than wild-type counterparts, consistent with a role for adaptive immunity in UTI control. Consistent with this, UTI triggered in the bladders of wild-type mice early increases of myeloid cells, including CD11c
hi
conventional dendritic cells, suggesting possible involvement of these professional antigen-presenting cells. Importantly, germinal center B cell responses developed by 4 weeks post-infection in bladder-draining lymph nodes of wild-type mice and, although modest in magnitude and transient in nature, could not be boosted with a second UTI. Thus, our data reveal for the first time in a mouse model that UPEC UTI induces local B cell immune responses in bladder-draining lymph nodes, which could potentially serve to control infection.
The
P. falciparum
alternative histones Pf H2A.Z and Pf H2B.Z are dynamically acetylated and antagonized by PfSir2 histone deacetylases at heterochromatin boundaries
Authors: Azizan Suffian , Selvarajah Shamista A. , Tang Jingyi , Jeninga Myriam D. , Schulz Danae , Pareek Kapil , Herr Tamara , Day Karen P. , De Koning-Ward Tania F. , Petter Michaela , Duffy Michael F.
Published: October 2023

The
Plasmodium falciparum
alternative histones Pf H2A.Z and Pf H2B.Z are enriched in the same nucleosomes in intergenic euchromatin but depleted from heterochromatin. They occupy most promoters but are only dynamically associated with expression at
var
genes. In other organisms, acetylation of H2A.Z is important for its functions in gene expression and chromatin structure. Here, we show that acetylated Pf H2A.Z and Pf H2B.Z are dynamically associated with gene expression at promoters. In addition, acetylated Pf H2A.Z and Pf H2B.Z are antagonized by the sirtuin class III histone deacetylases (HDAC) PfSir2A and B at heterochromatin boundaries and encroach upon heterochromatin in parasites lacking PfSir2A or B. However, the majority of acetylated Pf H2A.Z and Pf H2B.Z are deacetylated by class I or II HDACs. Acetylated Pf H2A.Z and Pf H2B.Z are also dynamically associated with promoter activity of both canonical upstream
var
gene promoters and
var
gene introns. These findings suggest that both acetylated Pf H2A.Z and Pf H2B.Z play critical roles in gene expression and contribute to maintenance of chromatin structure at the boundaries of subtelomeric, facultative heterochromatin, critical for the variegated expression of genes that enable rapid adaptation to altered host environments.

IMPORTANCE

The malaria parasite
Plasmodium falciparum
relies on variant expression of members of multi-gene families as a strategy for environmental adaptation to promote parasite survival and pathogenesis. These genes are located in transcriptionally silenced DNA regions. A limited number of these genes escape gene silencing, and switching between them confers variant fitness on parasite progeny. Here, we show that PfSir2 histone deacetylases antagonize DNA-interacting acetylated alternative histones at the boundaries between active and silent DNA. This finding implicates acetylated alternative histones in the mechanism regulating
P. falciparum
variant gene silencing and thus malaria pathogenesis. This work also revealed that acetylation of alternative histones at promoters is dynamically associated with promoter activity across the genome, implicating acetylation of alternative histones in gene regulation genome wide. Understanding mechanisms of gene regulation in
P. falciparum
may aid in the development of new therapeutic strategies for malaria, which killed 619,000 people in 2021.
The transcription factor DksA exerts opposing effects on cell division depending on the presence of ppGpp
Authors: Anderson Sarah E. , Vadia Stephen E. , McKelvy Jane , Levin Petra Anne
Published: October 2023

Bacterial cell size is a multifactorial trait that is influenced by variables including nutritional availability and the timing of cell division. Prior work revealed a negative correlation between concentration of the alarmone (p)ppGpp (ppGpp) and cell length in
Escherichia coli
, suggesting that ppGpp may promote assembly of the division machinery (divisome) and cytokinesis in this organism. To clarify this counterintuitive connection between a starvation-induced stress response effector and cell proliferation, we undertook a systematic analysis of growth and division in
E. coli
cells defective in ppGpp synthesis and/or engineered to overproduce the alarmone. Our data indicate that ppGpp acts indirectly on divisome assembly through its role as a global mediator of transcription. Loss of either ppGpp (ppGpp
0
) or the ppGpp-associated transcription factor DksA led to increased average length, with ppGpp
0
mutants also exhibiting a high frequency of extremely long filamentous cells. Using heat-sensitive division mutants and fluorescently labeled division proteins, we confirmed that ppGpp and DksA are cell division activators. We found that ppGpp and DksA regulate division through their effects on transcription, although the lack of known division genes or regulators in available transcriptomics data strongly suggests that this regulation is indirect. We also found that DksA inhibits division in ppGpp
0
cells, contrary to its role in a wild-type background. We propose that the ability of ppGpp to switch DksA from a division inhibitor to a division activator helps tune cell length across different concentrations of ppGpp.

IMPORTANCE

Cell division is a key step in the bacterial lifecycle that must be appropriately regulated to ensure survival. This work identifies the alarmone (p)ppGpp (ppGpp) as a general regulator of cell division, extending our understanding of the role of ppGpp beyond a signal for starvation and other stress. Even in nutrient-replete conditions, basal levels of ppGpp are essential for division to occur appropriately and for cell size to be maintained. This study establishes ppGpp as a “switch” that controls whether the transcription factor DksA behaves as a division activator or inhibitor. This unexpected finding enhances our understanding of the complex regulatory mechanisms employed by bacteria to coordinate division with diverse aspects of cell growth and stress response. Because division is an essential process, a better understanding of the mechanisms governing the assembly and activation of the division machinery could contribute to the development of novel therapeutics to treat bacterial infections.