bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Interaction of Oscillatory Neurons Coupled with Reciprocally Inhibitory Synapses Acts to Stabilize the Rhythm Period
Authors: Mamiya Akira , Nadim Farzan
Published: June 2004

In the rhythmically active pyloric circuit of the spiny lobster, the pyloric dilator (PD) neurons are members of the pacemaker group of neurons that make inhibitory synapses onto the follower lateral pyloric (LP) neuron. The LP neuron, in turn, makes a depressing inhibitory synapse to the PD neurons, providing the sole inhibitory feedback from the pyloric network to its pacemakers. This study investigates the dynamic interaction between the pyloric cycle period, the two types of neurons, and the feedback synapse in biologically realistic conditions. When the rhythm period was changed, the membrane potential waveform of the LP neuron was affected with a consistent pattern. These changes in the LP neuron waveform directly affected the dynamics of the LP to PD synapse and caused the postsynaptic potential (PSP) in the PD neurons to both peak earlier in phase and become larger in amplitude. Using an artificial synapse implemented in dynamic clamp, we show that when the LP to PD PSP occurred early in phase, it acted to speed up the pyloric rhythm, and larger PSPs also strengthened this trend. Together, these results indicate that interactions between these two types of neurons can dynamically change in response to increases in the rhythm period, and this dynamic change provides a negative feedback to the pacemaker group that could work to stabilize the rhythm period.
Neuronal Avalanches Are Diverse and Precise Activity Patterns That Are Stable for Many Hours in Cortical Slice Cultures
Authors: Beggs John M. , Plenz Dietmar
Published: June 2004

A major goal of neuroscience is to elucidate mechanisms of cortical information processing and storage. Previous work from our laboratory (Beggs and Plenz, 2003) revealed that propagation of local field potentials (LFPs) in cortical circuits could be described by the same equations that govern avalanches. Whereas modeling studies suggested that these “neuronal avalanches” were optimal for information transmission, it was not clear what role they could play in information storage. Work from numerous other laboratories has shown that cortical structures can generate reproducible spatiotemporal patterns of activity that could be used as a substrate for memory. Here, we show that although neuronal avalanches lasted only a few milliseconds, their spatiotemporal patterns were also stable and significantly repeatable even many hours later. To investigate these issues, we cultured coronal slices of rat cortex for 4 weeks on 60-channel microelectrode arrays and recorded spontaneous extracellular LFPs continuously for 10 hr. Using correlation-based clustering and a global contrast function, we found that each cortical culture spontaneously produced 4736 ± 2769 (mean ± SD) neuronal avalanches per hour that clustered into 30 ± 14 statistically significant families of spatiotemporal patterns. In 10 hr of recording, over 98% of the mutual information shared by these avalanche patterns were retained. Additionally, jittering analysis revealed that the correlations between avalanches were temporally precise to within ±4 msec. The long-term stability, diversity, and temporal precision of these avalanches indicate that they fulfill many of the requirements expected of a substrate for memory and suggest that they play a central role in both information transmission and storage within cortical networks.
A Novel Mechanism for the Facilitation of Theta-Induced Long-Term Potentiation by Brain-Derived Neurotrophic Factor
Authors: Kramár Enikö A. , Lin Bin , Lin Ching-Yi , Arai Amy C. , Gall Christine M. , Lynch Gary
Published: June 2004

Brain-derived neurotrophic factor (BDNF) contributes to the induction of long-term potentiation (LTP) by theta-pattern stimulation, but the specific processes underlying this effect are not known. Experiments described here, using BDNF concentrations that have minor effects on baseline responses, show that the neurotrophin both reduces the threshold for LTP induction and elevates the ceiling on maximal potentiation. The enhanced LTP proved to be as stable and resistant to reversal as that recorded under control conditions. BDNF markedly increased the facilitation of burst responses that occurs within a theta train. This suggests that the neurotrophin acts on long-lasting events that (1) are set in motion by the first burst in a train and (2) regulate the amplitude of subsequent bursts. Whole-cell recordings established that BDNF causes a rapid reduction in the size of the long-lasting afterhyperpolarization (AHP) that follows individual theta bursts. Apamin, an antagonist of type 2 small-conductance Ca2+-activated potassium (SK2) channels, also reduced hippocampal AHPs and closely reproduced the effects of BDNF on theta-burst responses and LTP. The latter results were replicated with a newly introduced, highly selective inhibitor of SK2 channels. Immunoblot analyses indicated that BDNF increases SK2 serine phosphorylation in hippocampal slices. These findings point to the conclusion that BDNF-driven protein kinase cascades serve to depress the SK2 component, and possibly other constituents, of the AHP. It is likely that this mechanism, acting with other factors, promotes the formation and increases the magnitude of LTP.
Identification of Motifs Involved in Endoplasmic Reticulum Retention–Forward Trafficking of the GLT-1 Subtype of Glutamate Transporter
Authors: Kalandadze Avtandil , Wu Ying , Fournier Keith , Robinson Michael B.
Published: June 2004

Glutamate transporters may exist as homomultimers, but little is known about the mechanisms that ensure proper assembly and surface expression. In the present study, we investigated the mechanisms that contribute to posttranslational processing of the GLT-1 subtype of glutamate transporter. An extracellular leucine-based motif was identified that after mutation to alanine (6L/6A GLT-1) prevented export of GLT-1 from the endoplasmic reticulum (ER) to the plasma membrane and displayed a glycosylation pattern characteristic of “immature” transporter. This 6L/6A variant had a selective dominant-negative effect on wild-type GLT-1 expression and formed coimmunoprecipitable complexes with GLT-1. Mutation of two downstream arginine residues to alanine partially restored maturation and functional activity of the 6L/6A variant. The fact that this additional mutation rescued maturation of GLT-1 essentially excludes the possibility that the 6L/6A mutant variant is not appropriately processed because of simple misfolding. When the domain containing these motifs was introduced into a topologically similar location in the interleukin 2α receptor subunit (Tac protein), the mutations had a similar effect on protein maturation. Topological models place at least the leucine-based motif in an extracellular domain, which would face the lumen of the ER during assembly. On the basis of these data, we suggest that an evolutionarily conserved arginine-based motif functions as an ER retention signal and a lumenal leucine motif is required for suppression of this signal. Interestingly, a high percentage of variably spliced GLT-1 mRNAs lacking parts of this domain are found in the CNS, suggesting that GLT-1 expression may be regulated during assembly.
Single-Channel Analysis of KCNQ K+Channels Reveals the Mechanism of Augmentation by a Cysteine-Modifying Reagent
Authors: Li Yang , Gamper Nikita , Shapiro Mark S.
Published: June 2004

The cysteine-modifying reagentN-ethylmaleimide (NEM) is known to augment currents from native M-channels in sympathetic neurons and cloned KCNQ2 channels. As a probe for channel function, we investigated the mechanism of NEM action and subunit specificity of cloned KCNQ2–5 channels expressed in Chinese hamster ovary cells at the whole-cell and single-channel levels. Biotinylation assays and total internal reflection fluorescence microscopy indicated that NEM action is not caused by increased trafficking of channels to the membrane. At saturating voltages, whole-cell currents of KCNQ2, KCNQ4, and KCNQ5 but not KCNQ3 were augmented threefold to fourfold by 50 μmNEM, and their voltage dependencies were negatively shifted by 10–20 mV. Unitary conductances of KCNQ2 and KCNQ3 (6.2 and 8.5 pS, respectively) were much higher that those of KCNQ4 and KCNQ5 (2.1 and 2.2 pS, respectively). Surprisingly, the maximal open probability (Po) of KCNQ3 was near unity, much higher than that of KCNQ2, KCNQ4, and KCNQ5. NEM increased thePoof KCNQ2, KCNQ4, and KCNQ5 by threefold to fourfold but had no effect on their unitary conductances, suggesting that the increase in macroscopic currents can be accounted for by increases inPo. Analysis of KCNQ3/4 chimeras determined the C terminus to be responsible for the differential maximalPo, channel expression, and NEM action between the two channels. To further localize the site of NEM action, we mutated three cysteine residues in the C terminus of KCNQ4. The C519A mutation alone ablated most of the augmentation by NEM, suggesting that NEM acts via alkylation of this residue.
Presynaptic Mechanism Underlying cAMP-Dependent Synaptic Potentiation
Authors: Kaneko Masahiro , Takahashi Tomoyuki
Published: June 2004

The adenylyl cyclase activator forskolin presynaptically facilitates synaptic transmission at many synapses, but the exact intracellular mechanism underlying this effect is not known. We studied this issue at the calyx of Held, where it is possible to make simultaneous presynaptic and postsynaptic whole-cell recordings. Bath application of forskolin or intracellular application of cAMP into presynaptic terminals strongly potentiated EPSCs. The forskolin-induced synaptic potentiation was associated with increases in release probability (P) and number of releasable synaptic vesicles (N). Forskolin had no effect on the peak amplitudes of presynaptic Ca2+currents or K+currents, suggesting that the main target of cAMP resides in downstream of Ca2+influx. Intracellular application of the selective Epac agonist 8-(4-chlorophenylthio)-2′-O-methyl-cAMP into presynaptic terminals potentiated EPSCs, suggesting that Epac is the main target of cAMP-induced synaptic potentiation. We conclude that an increase in cAMP concentration in the nerve terminal facilitates transmitter release by increasing both release probability and number of releasable vesicles via activating the Epac pathway at the calyx of Held.
Dopamine–Glutamate Interactions Controlling Prefrontal Cortical Pyramidal Cell Excitability Involve Multiple Signaling Mechanisms
Authors: Tseng Kuei Y. , O'Donnell Patricio
Published: June 2004

Although the importance of dopamine (DA) for prefrontal cortical (PFC) cognitive functions is widely recognized, the nature of DA actions in the PFC remains controversial. A critical component in DA actions is its modulation of glutamate transmission, which can be different when specific receptors are activated. To obtain a clear picture of cellular mechanisms involved in these interactions, we studied the effects of DA–glutamate coactivation on pyramidal cell excitability in brain slices obtained from developmentally mature rats using whole-cell patch-clamp recordings. Bath application of NMDA, AMPA, and the D1 agonistSKF38393induced concentration-dependent excitability increases, whereas bath application of the D2 receptor agonist quinpirole induced a concentration-dependent excitability decrease. The NMDA-mediated response was potentiated bySKF38393. This NMDA–D1 synergism required postsynaptic intracellular Ca2+and protein kinase A (PKA) and was independent of membrane depolarization. On the other hand, the excitatory effects of both NMDA and AMPA were attenuated by a D2 agonist. Surprisingly, the D2–NMDA interaction was also blocked by the GABAAantagonists bicuculline and picrotoxin, suggesting that the inhibitory action of D2 receptors on NMDA-induced responses in the PFC may be mediated by GABAergic interneurons. In contrast, the D2–AMPA interaction involves inhibition of PKA and activation of phospholipase lipase C–IP3and intracellular Ca2+at a postsynaptic level. Thus, the modulatory actions of D1 and D2 receptors on PFC pyramidal cell excitability are mediated by multiple intracellular mechanisms and by activation of GABAAreceptors, depending on the glutamate receptor subtypes involved.
Removal of AMPA Receptors (AMPARs) from Synapses Is Preceded by Transient Endocytosis of Extrasynaptic AMPARs
Authors: Ashby Michael C. , De La Rue Sarah A. , Ralph G. Scott , Uney James , Collingridge Graham L. , Henley Jeremy M.
Published: June 2004

AMPA receptors (AMPARs) are dynamically regulated at synapses, but the time course and location of their exocytosis and endocytosis are not known. Therefore, we have used ecliptic pHluorin-tagged glutamate receptor 2 to visualize changes in AMPAR surface expression in real time. We show that synaptic and extrasynaptic AMPARs respond very differently to NMDA receptor activation; there is a rapid internalization of extrasynaptic AMPARs that precedes the delayed removal of synaptic AMPARs.
Distinct Roles of Gαqand Gα11for Purkinje Cell Signaling and Motor Behavior
Authors: Hartmann J. , Blum R. , Kovalchuk Y. , Adelsberger H. , Kuner R. , Durand G. M. , Miyata M. , Kano M. , Offermanns S. , Konnerth A.
Published: June 2004

G-protein-coupled metabotropic glutamate group I receptors (mGluR1s) mediate synaptic transmission and plasticity in Purkinje cells and, therefore, critically determine cerebellar motor control and learning. Purkinje cells express two members of the G-protein Gqfamily, namely Gqand G11. Althoughin vitrocoexpression of mGluR1 with either Gα11or Gαqproduces equally well functioning signaling cascades, Gαq- and Gα11-deficient mice exhibit distinct alterations in motor coordination. By using whole-cell recordings and Ca2+imaging in Purkinje cells, we show that Gαqis required for mGluR-dependent synaptic transmission and for long-term depression (LTD). Gα11has no detectable contribution for synaptic transmission but also contributes to LTD. Quantitative single-cell RT-PCR analyses in Purkinje cells demonstrate a more than 10-fold stronger expression of Gαqversus Gα11. Our findings suggest an expression level-dependent action of Gαqand Gα11for Purkinje cell signaling and assign specific roles of these two Gqisoforms for motor coordination.
Modular Premotor Drives and Unit Bursts as Primitives for Frog Motor Behaviors
Authors: Hart Corey B. , Giszter Simon F.
Published: June 2004

Spinal cord modularity impacts on our understanding of reflexes, development, descending systems in normal motor control, and recovery from injury. We used independent component analysis and best-basis or matching pursuit wavepacket analysis to extract the composition and temporal structure of bursts in hindlimb muscles of frogs. These techniques make minimala prioriassumptions about drive and motor pattern structure. We compared premotor drive and burst structures in spinal frogs with less reduced frogs with a fuller repertoire of locomotory, kicking, and scratching behaviors. Six multimuscle drives explain most of the variance of motor patterns (∼80%). Each extracted drive was activated with pulses at a single time scale or common duration (∼275 msec) burst structure. The data show that complex behaviors in brainstem frogs arise as a result of focusing drives to smaller core groups of muscles. Brainstem drives were subsets of the muscle groups from spinal frogs. The 275 msec burst duration was preserved across all behaviors and was most precise in brainstem frogs. These data support a modular decomposition of frog behaviors into a small collection of unit burst generators and associated muscle drives in spinal cord. Our data also show that the modular organization of drives seen in isolated spinal cord is fine-tuned by descending controls to enable a fuller movement repertoire. The unit burst generators and their associated muscle synergies extracted here link the biomechanical “primitives,” described earlier in the frog, rat, and cat, and to the elements of pattern generation examined in fictive preparations.
Berlin Walls: Dahlhaus Knepler, and Ideologies of Music History
Authors: Shreffler Anne C.
Published: May 2004

As exemplified in writings by Carl Dahlhaus and Georg Knepler, a debate about music historiography took place in East and West Germany in the 1960s and 1970s. A comparison between two books, Dahlhaus's Grundlagen der Musikgeschichte (Foundations of Music History) and Knepler's Geschichte als Weg zum Musikverständnis (History as a Means of Understanding Music), both published in 1977, is instructive as a measure of the two poles of the Methodenstreit: the one centered around music as autonomous work, the other around music as a human activity. The central questions raised prove uncannily current. The two scholars, who knew each other and respected each other's work, were both based in Berlin; but with Dahlhaus in the West and Knepler in the East, they represented the two different political systems that existed in the divided city between 1945 and 1989. In their work, and especially in these two books, Dahlhaus and Knepler defended their own positions and sought to point out weaknesses in the other side. While Dahlhaus's work is well known in English-speaking musicology, Knepler's is not. His contribution to music history and historiography was comparable to Dahlhaus's in importance, however, and his ideas anticipate many tenets of the "new musicology."
From Invention to Interpretation: The Prologues of the First Court Operas Where Oral and Written Cultures Meet
Authors: Hansen Jette Barnholdt
Published: May 2004

The dynamic progression from orality to literacy is embodied in the notation of the prologues to the first court operas. This transition is influenced by the proliferation of printed scores at the beginning of the 17th century and has profound rhetorical consequences for vocal performance. In the first prologues, where the written arie are formulaic, the singer is the creator and authority; s/he controls the musical performance and makes the connection between words and music by means of variation, ornamentation, and improvisation as part of a persuasive dialogue with listeners. In the later prologues, however, the composer rather than the singer is in control of the discourse. Because of a new and more elaborate way of writing out the prologues, where all stanzas are set to music, the singer is now turned into an interpreter of the composer's rhetorical realization of the words, a realization fixed in the score by musical notation and capable of being brought to life in performance. The prologue can profitably be discussed as a genre in the context of the oral tradition of the late Renaissance, and is illuminated by a number of 16th- and 17th-century Italian sources dealing with lyric poetry, linguistic theory, vocal performance, sound, and listening. In this regard, the edition of Jacopo Peri's Euridice by Howard Mayer Brown (1981) is open to criticism, because all stanzas of the prologue are written out, which is not in accordance with Peri's original score (Florence, 1600). The editorial realization of the strophes, therefore, seems to run contrary to the principles of orality according to which the prologue was originally composed.
Gonadotropin requirements for dominant follicle selection in GnRH agonist-treated cows
Authors: Hampton J H , Bader J F , Lamberson W R , Smith M F , Youngquist R S , Garverick H A
Published: June 2004

A study was conducted to examine the effects of gonadotropins on ovarian follicular development and differentiation in GnRH agonist (GnRHa)-treated cattle. Holstein cows were allotted into two pre-treatment groups: controls (n = 5) and GnRHa-treated (n = 9). Ovaries were removed from control cows on day 5 following a synchronized estrus. Treatment with GnRHa resulted in follicular arrest at <5 mm. Following follicular arrest, GnRHa-treated cows received a constant infusion of FSH for 96 h (GnRHa/FSH), with a randomly selected subset receiving hourly pulses of LH in addition to FSH during the last 48 h of infusion (GnRHa/FSH + LH). At the end of infusion, ovaries were removed, follicles were counted and measured, and follicular fluid samples were collected from large follicles (>10 mm). Differences in expression of mRNA for LH receptor, FSH receptor, cytochrome P450 side-chain cleavage, 3β-hydroxysteroid dehydrogenase, cytochrome P450 17α-hydroxylase (P450c17) and cytochrome P450 aromatase were determined in large follicles using in situ hybridization. The number of large follicles did not differ between GnRHa/FSH-treated and GnRHa/FSH + LH-treated cows (P = 0.64), but was greater than control animals (P ≤ 0.004). Follicular fluid concentrations of estradiol-17β and androstenedione were highest in GnRHa/FSH + LH-treated cows (P ≤ 0.04), intermediate in control cows, and lowest in GnRHa/FSH-treated cows. Hybridization intensity of P450c17 was greater in GnRHa/FSH + LH-treated versus control or GnRHa/FSH-treated cows (P ≤ 0.03). These results indicate that while FSH can support bovine follicular growth >10 mm, LH increases androgen production and expression of P450c17.
Offspring produced from heterotopic ovarian allografts in male and female recipient mice
Authors: Waterhouse Tracey , Cox Shae-Lee , Snow Melanie , Jenkin Graham , Shaw Jill
Published: June 2004

Studies on human ovarian xenografts and mouse allografts indicate that the male hormonal milieu and exogenous gonadotrophin administration stimulate antral follicle growth. However, it is not known whether oocytes produced under these conditions are developmentally competent. The objective of our study was to evaluate the developmental competence of oocytes produced in heterotopic mouse ovarian grafts placed in male and female recipient mice. Gonadotrophins were 7.5 IU pregnant mare serum gonadotrophin (PMSG) alone or 7.5 IU PMSG and 7.5 IU human chorionic gonadotrophin or were not given prior to oocyte collection. The developmental competence of oocytes was assessed by performing in vitro fertilisation and embryo transfer to recipients. When no gonadotrophins were given the cleavage rate was similar for oocytes collected from ovarian grafts in male and female recipients. Gonadotrophin treatment significantly (P < 0.05) increased two-cell formation by oocytes grown in female graft recipients but not in male recipients. Implantation rates, fetal development and the birth of live young were unaffected by the sex of the graft recipient or gonadotrophin treatment. Live offspring were produced from oocytes collected from ovarian grafts in male and female recipients treated with or without gonadotrophins. In conclusion, this work has shown that the hormonal environment of male mice can support the growth of oocytes in ovarian allografts and that these oocytes can produce live offspring.
Cloning of a buffalo (Bubalus bubalis) prostaglandin F2α receptor: changes in its expression and concentration in the buffalo cow corpus luteum
Authors: Verma-Kumar Shalu , Srinivas S V , Muraly P , Yadav Vijay K , Medhamurthy R
Published: June 2004

Acting primarily through its specific G protein-coupled receptor termed FPr, prostaglandin (PG) F2αinduces regression of the corpus luteum (CL) at the end of a non-fertile oestrous cycle. This study was aimed at cloning a full-length cDNA for FPr and determining its expression and protein concentrations during different stages of CL development in the water buffalo. Serum progesterone and StAR expression were determined to establish temporal relationships between indices of steroidogenesis and changes in FPr expression at different stages of CL development. In contrast to the dairy cow, the stage IV CL (day 20 of the oestrous cycle) did not appear to be functionally regressed in the buffalo. Molecular cloning of a cDNA encoding the buffalo FPr yielded a full length 2193 bp FPr cDNA containing a single open reading frame encoding a 362 amino acid protein with seven putative membrane-spanning domains. The deduced buffalo FPr amino acid sequence possesses a high degree of identity with the other mammalian homologues. Steady state concentration of buffalo FPr transcript increased (P> 0.05) from stage I to stage II/III, and declined at 18 h post PGF2αinjection. The FPr concentration expressed as fmol/μg of plasma membrane protein showed an increase (P> 0.05) from stage I (1.98 ± 0.10), through stage II/III (2.42 ± 0.48) to stage IV (2.77 ± 0.18). High affinity FPr was observed in stage I (Kd4.86 nmol) and stage II/III (Kd6.28 nmol) while low affinity FPr (Kd19.44 nmol) was observed in stage IV. In conclusion, we have cloned a full length FPr cDNA from buffalo cow CL and observed that FPr mRNA expression, receptor number and affinity did not vary significantly (P> 0.05) within the luteal phase of the oestrous cycle.
The consequences of nuclear transfer for mammalian foetal development and offspring survival. A mitochondrial DNA perspective
Authors: St John Justin C , Lloyd Rhiannon E I , Bowles Emma J , Thomas Emma C , El Shourbagy Shahinaz
Published: June 2004

The introduction of nuclear transfer (NT) and other technologies that involve embryo reconstruction require us to reinvestigate patterns of mitochondrial DNA (mtDNA) transmission, transcription and replication. MtDNA is a 16.6 kb genome located within each mitochondrion. The number of mitochondria and mtDNA copies per organelle is specific to each cell type. MtDNA is normally transmitted through the oocyte to the offspring. However, reconstructed oocytes often transmit both recipient oocyte mtDNA and mtDNA associated with the donor nucleus. We argue that the transmission of two populations of mtDNA may have implications for offspring survival as only one allele might be actively transcribed. This could result in the offspring phenotypically exhibiting mtDNA depletion-type syndromes. A similar occurrence could arise when nucleo–cytoplasmic interactions fail to regulate mtDNA transcription and replication, especially as the initiation of mtDNA replication post-implantation is a key developmental event. Furthermore, failure of the donor somatic nucleus to be reprogrammed could result in the early initiation of replication and the loss of cellular mtDNA specificity. We suggest investigations should be conducted to enhance our understanding of nucleo–cytoplasmic interactions in order to improve NT efficiency.
Prevalence of Technology-Facilitated Abuse Among Sexual and Gender Minority Youths
Authors: Turner Heather A. , Finkelhor David , Mitchell Kimberly , Colburn Deirdre
Published: February 2024

Importance

Digital communication and imaging technologies have created new opportunities for technology-facilitated abuse (TFA) and necessitate a better understanding of how and why the risk for TFA varies across different groups of youths.

Objectives

To compare the prevalence of TFA among youths across 5 different sexual and gender identity groups, and to identify risk factors that may explain variations in TFA risk.

Design, Setting, and Participants

A US nationally representative online survey was conducted among 2639 young adults recruited from the KnowledgePanel online panel from November 19 to December 29, 2021. Individuals aged 18 to 28 years were asked retrospectively about TFA and a variety of other youth experiences in childhood (aged <18 years).

Main Outcomes and Measures

Participants were asked about their sexual and gender identities, 11 types of TFA occurring before the age of 18 years, and several potential risk factors. Prevalence rates of any TFA were compared across sexual and gender identity groups, and analyses were conducted to identify risk factors that help explain group differences. Weights were developed to compensate for gender, education, race and ethnicity, household income, census region, and metropolitan status disproportions.

Results

Among the 2510 respondents (mean [SD] age, 24.8 [2.8] years) who provided gender and sexual identity information, 46.5% (95% CI, 41.9%-51.1%) were cisgender heterosexual females, 25.2% (95% CI, 21.6%-29.1%) were cisgender sexual minority females, 18.3% (95% CI, 14.4%-22.9%) were cisgender heterosexual males, 6.8% (95% CI, 4.6%-9.9%) were cisgender sexual minority males, and 3.3% (95% CI, 2.0%-5.4%) were gender minority individuals. The prevalence of TFA occurring before the age of 18 years was highest among sexual minority females (55.3%; 95% CI, 48.0%-62.4%) and gender minority individuals (53.4%; 95% CI, 33.5%-72.2%). Rates of sexting were highest among cisgender sexual minority females (38.8%; 95% CI, 19.1%-58.8%) and gender minority individuals (36.7%; 95% CI, 19.1%-58.8%) and represented the strongest risk factor for TFA exposure (odds ratio, 5.7; 95% CI, 4.0-8.0). However, it explained little variation in TFA across groups once early in-person adversity, sexual abuse, bullying, and maltreatment were taken into account.

Conclusions and Relevance

This study demonstrates the risk of TFA among sexual and gender minority youths and the need to target prevention efforts toward these vulnerable groups. In addition to strategies to reduce risky behavior, efforts to lower the risk of early sexual abuse, bullying, and maltreatment are likely to also be effective in decreasing TFA among these marginalized groups.
The prefoldin‐like protein AtURI exhibits characteristics of intrinsically disordered proteins
Authors: Gómez‐Mínguez Yaiza , Palacios‐Abella Alberto , Costigliolo‐Rojas Cecilia , Barber Mariana , Hernández‐Villa Laura , Úrbez Cristina , Alabadí David
Published: February 2024

The prefoldin‐like protein UNCONVENTIONAL PREFOLDIN RPB5 INTERACTOR (URI) participates in diverse cellular functions, including protein homeostasis, transcription, translation, and signal transduction. Thus, URI is a highly versatile protein, although the molecular basis of this versatility remains unknown. In this work, we show that Arabidopsis thaliana (Arabidopsis) URI (AtURI) possesses a large intrinsically disordered region (IDR) spanning most of the C‐terminal part of the protein, a feature conserved in yeast and human orthologs. Our findings reveal two key characteristics of disordered proteins in AtURI: promiscuity in interacting with partners and protein instability. We propose that these two features contribute to providing AtURI with functional versatility.
A systematic map of studies testing the relationship between temperature and animal reproduction
Authors: Dougherty Liam R. , Frost Fay , Maenpaa Maarit I. , Rowe Melissah , Cole Benjamin J. , Vasudeva Ramakrishnan , Pottier Patrice , Schultner Eva , Macartney Erin L. , Lindenbaum Ina , Smith Jamie L. , Carazo Pau , Graziano Marco , Weaving Hester , Canal Domenech Berta , Berger David , Meena Abhishek , Bishop Tom Rhys , Noble Daniel W. A. , Simões Pedro , Baur Julian , Breedveld Merel C. , Svensson Erik I. , Lancaster Lesley T. , Ellers Jacintha , De Nardo Alessio N. , Santos Marta A. , Ramm Steven A. , Drobniak Szymon M. , Redana Matteo , Tuni Cristina , Pilakouta Natalie , Zizzari Z. Valentina , Iossa Graziella , Lüpold Stefan , Koppik Mareike , Early Regan , Gasparini Clelia , Nakagawa Shinichi , Lagisz Malgorzata , Bretman Amanda , Fricke Claudia , Snook Rhonda R. , Price Tom A. R.
Published: February 2024

Exposure to extreme temperatures can negatively affect animal reproduction, by disrupting the ability of individuals to produce any offspring (fertility), or the number of offspring produced by fertile individuals (fecundity). This has important ecological consequences, because reproduction is the ultimate measure of population fitness: a reduction in reproductive output lowers the population growth rate and increases the extinction risk. Despite this importance, there have been no large‐scale summaries of the evidence for effect of temperature on reproduction.

We provide a systematic map of studies testing the relationship between temperature and animal reproduction. We systematically searched for published studies that statistically test for a direct link between temperature and animal reproduction, in terms of fertility, fecundity or indirect measures of reproductive potential (gamete and gonad traits).

Overall, we collated a large and rich evidence base, with 1654 papers that met our inclusion criteria, encompassing 1191 species.

The map revealed several important research gaps. Insects made up almost half of the dataset, but reptiles and amphibians were uncommon, as were non‐arthropod invertebrates. Fecundity was the most common reproductive trait examined, and relatively few studies measured fertility. It was uncommon for experimental studies to test exposure of different life stages, exposure to short‐term heat or cold shock, exposure to temperature fluctuations, or to independently assess male and female effects. Studies were most often published in journals focusing on entomology and pest control, ecology and evolution, aquaculture and fisheries science, and marine biology. Finally, while individuals were sampled from every continent, there was a strong sampling bias towards mid‐latitudes in the Northern Hemisphere, such that the tropics and polar regions are less well sampled.

This map reveals a rich literature of studies testing the relationship between temperature and animal reproduction, but also uncovers substantial missing treatment of taxa, traits, and thermal regimes. This database will provide a valuable resource for future quantitative meta‐analyses, and direct future studies aiming to fill identified gaps.
Relations between perceptions of parental messages supporting fighting and nonviolence and adolescents' physical aggression: Beliefs as mediators
Authors: Coleman Jasmine N. , Smith Phillip N. , Mehari Krista R. , Farrell Albert D.
Published: February 2024

The purpose of this study was to examine adolescents' beliefs about fighting as mediators of longitudinal relations between perceptions of parental support for fighting and nonviolence and changes in adolescents' physical aggression. Participants were 2575 middle school students (Mage = 12.20, SD = 1.02; 52% female; 83% African American) from the southeastern US attending schools in communities with high rates of violence. Participants completed four waves of assessments every 3 months (i.e., fall, winter, spring, and summer). Each belief subscale mediated relations between perceptions of parental support for fighting and nonviolence and changes in aggression. Parental support for nonviolence was negatively associated with beliefs supporting reactive aggression and positively associated with beliefs against fighting. Parental support for retaliation was positively associated with beliefs supporting reactive and proactive aggression, and negatively associated with beliefs against fighting. Parental support for fighting as sometimes necessary was positively associated with beliefs supporting reactive aggression and beliefs that fighting is sometimes necessary. Beliefs supporting reactive and proactive aggression and beliefs that fighting is sometimes necessary were positively associated with aggression, whereas beliefs against fighting were negatively associated with aggression. Parents' support for fighting and for nonviolence may directly and indirectly reduce adolescents' physical aggression by influencing beliefs about the appropriateness of using aggression for self‐defense and to attain a goal. This highlights the importance of jointly investigating multiple types of parental messages and types of beliefs about fighting.
Screening Tools for Spondyloarthritis in Patients With Psoriasis, Uveitis, and Inflammatory Bowel Disease: A Scoping Review
Authors: Kesarwani Vartika , Sinnappan Stephanie , Husni M. Elaine , Weisman Michael H. , Ermann Joerg
Published: February 2024

Objective

Extramusculoskeletal manifestations of spondyloarthritis (SpA) may precede the development of articular features. Patients seen in ophthalmology, dermatology, and gastroenterology clinics with uveitis, psoriasis, or inflammatory bowel disease (IBD) may have undiagnosed SpA. We set out to identify and evaluate screening tools for SpA in patients with psoriasis, uveitis, and IBD and determine factors that influence the performance of these instruments.

Methods

This scoping review followed Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines. PubMed, Embase, and Web of Science were searched from inception to January 2022.

Results

We identified 13 screening tools for psoriatic arthritis, 2 SpA screening tools for uveitis, and 3 SpA screening tools for IBD. All screening tools were patient‐oriented questionnaires except for the Dublin Uveitis Evaluation Tool, a physician‐applied algorithm. The questionnaires varied in length, scoring method, cutoff score, and spectrum of included SpA features. Average completion time was less than five minutes. Across the three patient populations, the sensitivities and specificities of these screening tools were comparable in the primary validation cohorts. Sensitivities and specificities were generally lower in secondary validation studies, with marked variability among cohorts.

Conclusion

Our results highlight the heterogeneity and limitations of existing SpA screening tools. Although these tools show promise for use within a specific target population, none are generalizable to all patients with extramusculoskeletal manifestations at risk of SpA. Future studies should explore the utility of a generic patient‐oriented SpA screening tool that can be applied to patients with psoriasis, uveitis, or IBD; is easy to use and comprehend; and captures all clinical domains of SpA.
Rapid Generation of hPSC‐Derived High Endothelial Venule Organoids with In Vivo Ectopic Lymphoid Tissue Capabilities
Authors: Wang Xichi , Li Xiaofei , Zhao Jing , Li Yi , Shin Su Ryon , Ligresti Giovanni , Ng Alex H. M. , Bromberg Jonathan S. , Church George , Lemos Dario R. , Abdi Reza
Published: February 2024

Bioengineering strategies for the fabrication of implantable lymphoid structures mimicking lymph nodes (LNs) and tertiary lymphoid structures (TLS) could amplify the adaptive immune response for therapeutic applications such as cancer immunotherapy. No method to date has resulted in the consistent formation of high endothelial venules (HEVs), which is the specialized vasculature responsible for naïve T cell recruitment and education in both LNs and TLS. Here orthogonal induced differentiation of human pluripotent stem cells carrying a regulatable ETV2 allele is used to rapidly and efficiently induce endothelial differentiation. Assembly of embryoid bodies combining primitive inducible endothelial cells and primary human LN fibroblastic reticular cells results in the formation of HEV‐like structures that can aggregate into 3D organoids (HEVOs). Upon transplantation into immunodeficient mice, HEVOs successfully engraft and form lymphatic structures that recruit both antigen‐presenting cells and adoptively‐transferred lymphocytes, therefore displaying basic TLS capabilities. The results further show that functionally, HEVOs can organize an immune response and promote anti‐tumor activity by adoptively‐transferred T lymphocytes. Collectively, the experimental approaches represent an innovative and scalable proof‐of‐concept strategy for the fabrication of bioengineered TLS that can be deployed in vivo to enhance adaptive immune responses.
Topological Spin Textures in an Insulating van der Waals Ferromagnet
Authors: Grebenchuk Sergey , McKeever Conor , Grzeszczyk Magdalena , Chen Zhaolong , Šiškins Makars , McCray Arthur R. C. , Li Yue , Petford‐Long Amanda K. , Phatak Charudatta M. , Ruihuan Duan , Zheng Liu , Novoselov Kostya S. , Santos Elton J. G. , Koperski Maciej
Published: February 2024

Generation and control of topological spin textures constitutes one of the most exciting challenges of modern spintronics given their potential applications in information storage technologies. Of particular interest are magnetic insulators, which due to low damping, absence of Joule heating and reduced dissipation can provide energy‐efficient spin‐textures platform. Here, it is demonstrated that the interplay between sample thickness, external magnetic fields, and optical excitations can generate a prolific paramount of spin textures, and their coexistence in insulating CrBr3 van der Waals (vdW) ferromagnets. Using high‐resolution magnetic force microscopy and large‐scale micromagnetic simulation methods, the existence of a large region in T‐B phase diagram is demonstrated where different stripe domains, skyrmion crystals, and magnetic domains exist and can be intrinsically selected or transformed to each‐other via a phase‐switch mechanism. Lorentz transmission electron microscopy unveils the mixed chirality of the magnetic textures that are of Bloch‐type at given conditions but can be further manipulated into Néel‐type or hybrid‐type via thickness‐engineering. The topological phase transformation between the different magnetic objects can be further inspected by standard photoluminescence optical probes resolved by circular polarization indicative of an existence of exciton‐skyrmion coupling mechanism. The findings identify vdW magnetic insulators as a promising framework of materials for the manipulation and generation of highly ordered skyrmion lattices relevant for device integration at the atomic level.
Optimization of the Bulk Refractive Index Sensitivity of Silver NanoPrisms
Authors: Szántó Géza , Pritzke Pia , Kluitmann Jonas Jakobus , Köhler Johann Michael , Csáki Andrea , Fritzsche Wolfgang , Csarnovics István , Bonyár Attila
Published: February 2024

The sensitivity and optical properties of silver nanoprisms (triangular plates with round‐truncated corners) are investigated in this paper. Results of boundary element method simulations are compared with experimental results and literature data. Based on electron microscopy images of the synthesized nanoprisms, a single‐particle model is set up for simulations with three running parameters: edge length, thickness, and roundness (defined as the radius of the circumscribed circle divided by the edge length). These geometric parameters can be optimized during chemical synthesis to create sensors with improved sensitivity. The effect of biomolecular layers is also investigated. As a novel approach to improve the agreement between the simulated and experimentally measured extinction spectra, the single‐particle model is extended to consider the variation of the prisms' parameters in the form of distributions. The resulting extinction cross‐section spectra correspond well with the experimental data. The calculated bulk refractive index sensitivity is 670 nm/RIU (RIU stands for refractive index unit) for the single particle model (length = 150 nm, thickness = 10 nm, and roundness = 0.1), while (690 ± 5) nm/RIU for the extended model. The presented model and obtained relations between sensitivity and geometry can be effectively used to design and optimize the fabrication technologies for silver nanoprism‐based sensing applications.
Copper‐Catalyzed Radical Silylarylation of Activated Alkenes: Preparation of β‐Silyl Amide‐Pharmaceutical Hybrids
Authors: Chen Fei , Liu Shi‐Yu , Li Xiao , Jia Jia‐Lu , Li Yi , Lu Xiao‐Lan , Jia Lin , Zheng Yang , Yan Zhongfei , Li Gang , Lv Yunhe , Rong Haojie
Published: February 2024

Copper‐catalyzed silylarylation of N‐(arylsulfonyl)acrylamides via a tandem silyl radical addition/1,4‐aryl migration/desulfonylation sequence has been developed. This method employs silanes as the precursor of silyl radical and di‐tert‐butyl peroxide (DTBP) as the initiator. By using this cascade procedure, a series of β‐silyl amide‐pharmaceutical hybrids which contain an α‐all‐carbon quaternary stereocenter were facilely synthesized.
Identifying and Understanding the Positive Impact of Defects for Optoelectronic Devices
Authors: Deng Yu‐Hao
Published: February 2024

Defects are generally regarded to have negative impacts on carrier recombination, charge transport, and ion migration in materials, which thus lower the efficiency, speed, and stability of optoelectronic devices. Meanwhile, lots of efforts which focused on minimizing defects have greatly improved the performances of devices. Then, can defects be positive in optoelectronic devices? Herein, relying on in‐depth understanding of defect‐associated effects in semiconductors, trapping of photo‐generated carriers by defects is applied to enlarge photoconductive gain in photodetection. Therefore, the record photoconductive gain, gain‐bandwidth product, and detection limit are achieved in this photodetector. Exceeding the general concept that defects are harmful, a new view that the defects can be positive in photodetection is identified, which may guide to design high‐performance photodetectors.
Modulating Internal Coordination Configurations for High‐Density Atomic Antimony toward Advanced Fast‐Charging Sodium‐Ion Batteries
Authors: Zhao Wenqing , Lei Shuya , Li Jiexiang , Jiang Feng , Wu Tianjing , Yang Yue , Sun Wei , Ji Xiaobo , Ge Peng
Published: February 2024

Fast‐charging ability of sodium‐ion batteries (SIBs) is mainly determined by a highly effective redox reaction rate. However, traditional metal@carbon composites rarely achieve atom‐level dispersion at high density, resulting in poor reaction rates. Herein, supported by the introduction of carbon vacancies, abundant C─S/C─O chemical bonds are successfully established in a carbon carrier. Then, plenty of Sb single atoms (Sb SA/PC) are first anchored with a high loading of 31.4 wt%, achieving a high yield of 210.56 g per batch. Benefiting from dense Sb─O─C/Sb─S─C interfacial chemical bonds, Sb─S2O coordination configurations are firmly confined in the interior of carbon. Surprisingly, the conductivity of Sb SA/PC‐2 is approximately 2.2 × 107 times greater than that of pristine Sb2S3. Consequently, Sb SA/PC‐2 exhibits ultrahigh fast‐charging capability (201.7 mAh g−1 at 20.0 A g−1) and ultralong cycling life (364.4 mAh g−1 at 5.0 A g−1 after 5000 cycles). Theoretical calculations reveal that the fast‐charging capability can be attributed to the low migration barrier and increased number of active sites. Moreover, owing to the structural integrity of Sb single atoms, phase separation is effectively inhibited. This work is anticipated to open an avenue toward designing advanced electrode materials for ultrafast‐charging SIBs.
From sweet tooth to healthy choices: How Chilean food policies are changing household diets
Authors: Melo Grace , Chomali Laura , Ishdorj Ariun
Published: February 2024

Using data from a nationally representative household survey, this study investigates whether changes in food‐at‐home (FAH) purchases occurred following the introduction, modification, and implementation of the Chilean food labeling and marketing regulations. This study further examines whether changes in sugar, sodium, saturated fat, or calorie intake occurred. The results provide evidence of some improvements in dietary intake. In particular, sugar intake decreased primarily due to food modifications—that emerged as a supply response to regulations. This improvement in dietary intake was only found among those households who mainly buy FAH or shop mostly at grocery stores. Considering that across all households, nearly 10% of total FAH calories come from products with added sugars, the results suggest that there are missing opportunities that policy could leverage to improve food choices, especially among those less likely to be influenced by existing regulations—those who mainly spend on food away from home or those who primarily shop at alternative FAH outlets. [EconLit Citations: D22, L51, Q13].