A network investigation of eating disorder symptoms and risk factors before and after a prevention program in adolescent girls.

Eating disorders (EDs) are psychological disorders characterized by disturbances in eating that commonly develop during adolescence and may be influenced by risk factors, both ED-specific (i.e., factors linked to future ED symptoms) and transdiagnostic (i.e., factors underlying multiple psychological disorders). Network analysis allows for the study of the connections between ED symptoms and risk factors by identifying central symptoms (i.e., the most interconnected symptoms) and bridge symptoms (i.e., symptoms which strongly connect across the symptom and risk factor clusters). Examining networks of ED symptoms and risk factors in adolescence can inform how risk factors influence ED development, as well as how this can be disrupted by prevention programs. The current study (N=301 adolescents) used network analysis to estimate the unique connections across ED symptoms, ED-specific risk factors (feared concerns about eating, food avoidance behaviors, eating anxiety, thinness and restricting expectancies, and exercise dependence), and transdiagnostic risk factors (emotion dysregulation, maladaptive perfectionism, social appearance anxiety, and negative urgency) in adolescent girls before and after an ED prevention program. The most central symptom in both networks was feared concerns about eating. The most central bridge symptoms in the pre-network were thinness/restricting expectancies and feared concerns about eating. The most central bridge symptom in the post-network was thinness/restricting expectancies. A network comparison test revealed twenty significantly different edges. These findings suggest that prevention programs targeting central risk factors (e.g., feared concerns about eating) and bridge risk factors (e.g., thinness/restricting expectancies) may limit the escalation of risk factors to full-threshold EDs in adolescents. Understanding ED risk factors specific to adolescents can result in better prevention programs optimized to reduce incidence and address the heterogeneity of EDs

Social Appearance Anxiety is Strongly Related to Eating Disorder Symptoms regardless of Age in both Clinical Eating Disorder and Nonclinical Cases

Eating disorders (EDs) are serious mental illnesses that often develop in adolescence and persist in adulthood. Social appearance anxiety (SAA; fear of appearance-based judgment) is a risk factor for EDs and related to ED symptoms. SAA is more prevalent in non-clinical adolescents than non-clinical adults, yet no research has investigated the relationship between SAA and ED symptoms across age. The present study tested if age moderated the relationship between SAA and drive for thinness (DT), bulimic symptoms, and body dissatisfaction in a clinical ED sample (N=952, 28.5%), a nonclinical sample (N=1,693; 51.7%), and the full sample (N = 3,273). In the clinical ED sample, there was a significant interaction between age and SAA on DT, such that SAA and DT were more strongly related in older participants (b=.43, p\u3c.001), compared to younger participants (b=.25, p\u3c.001). Age did not moderate the relationship between SAA and ED symptoms in the overall sample or nonclinical sample (p\u3e.05), and results indicate SAA is strongly related to all three domains of ED symptoms regardless of age (bs=.25-.62, ps\u3c.001). These results support SAA as a core factor in EDs across all age groups. Interventions focused on SAA may be used with people of all ages and levels of ED symptoms to improve outcomes. Future studies should examine the associations between SAA and ED symptoms across all developmental stages and duration of illness. Future research should test the influence of social media and technology on the relationship between SAA and ED symptoms across different age groups.https://ir.library.louisville.edu/uars/1014/thumbnail.jp

Stably accessing octave-spanning microresonator frequency combs in the soliton regime

Microresonator frequency combs can be an enabling technology for optical frequency synthesis and timekeeping in low size, weight, and power architectures. Such systems require comb operation in low-noise, phase-coherent states such as solitons, with broad spectral bandwidths (e.g., octave-spanning) for self-referencing to detect the carrier-envelope offset frequency. However, stably accessing such states is complicated by thermo-optic dispersion. For example, in the Si3N4 platform, precisely dispersion-engineered structures can support broadband operation, but microsecond thermal time constants have necessitated fast pump power or frequency control to stabilize the solitons. In contrast, here we consider how broadband soliton states can be accessed with simple pump laser frequency tuning, at a rate much slower than the thermal dynamics. We demonstrate octave-spanning soliton frequency combs in Si3N4 microresonators, including the generation of a multi-soliton state with a pump power near 40 mW and a single-soliton state with a pump power near 120 mW. We also develop a simplified two-step analysis to explain how these states are accessed in a thermally stable way without fast control of the pump laser, and outline the required thermal properties for such operation. Our model agrees with experimental results as well as numerical simulations based on a Lugiato-Lefever equation that incorporates thermo-optic dispersion. Moreover, it also explains an experimental observation that a member of an adjacent mode family on the red-detuned side of the pump mode can mitigate the thermal requirements for accessing soliton states

A Kerr-microresonator optical clockwork

Kerr microresonators generate interesting and useful fundamental states of electromagnetic radiation through nonlinear interactions of continuous-wave (CW) laser light. Using photonic-integration techniques, functional devices with low noise, small size, low-power consumption, scalable fabrication, and heterogeneous combinations of photonics and electronics can be realized. Kerr solitons, which stably circulate in a Kerr microresonator, have emerged as a source of coherent, ultrafast pulse trains and ultra-broadband optical-frequency combs. Using the f-2f technique, Kerr combs support carrier-envelope-offset phase stabilization for optical synthesis and metrology. In this paper, we introduce a Kerr-microresonator optical clockwork based on optical-frequency division (OFD), which is a powerful technique to transfer the fractional-frequency stability of an optical clock to a lower frequency electronic clock signal. The clockwork presented here is based on a silicon-nitride (Si$_3$N$_4$) microresonator that supports an optical-frequency comb composed of soliton pulses at 1 THz repetition rate. By electro-optic phase modulation of the entire Si$_3$N$_4$ comb, we arbitrarily generate additional CW modes between the Si$_3$N$_4$ comb modes; operationally, this reduces the pulse train repetition frequency and can be used to implement OFD to the microwave domain. Our experiments characterize the residual frequency noise of this Kerr-microresonator clockwork to one part in $10^{17}$, which opens the possibility of using Kerr combs with high performance optical clocks. In addition, the photonic integration and 1 THz resolution of the Si$_3$N$_4$ frequency comb makes it appealing for broadband, low-resolution liquid-phase absorption spectroscopy, which we demonstrate with near infrared measurements of water, lipids, and organic solvents

Direct N-glycosylation profiling of urine and prostatic fluid glycoproteins and extracellular vesicles

Expressed prostatic secretions (EPS), also called post digital rectal exam urines, are proximal fluids of the prostate that are widely used for diagnostic and prognostic assays for prostate cancer. These fluids contain an abundant number of glycoproteins and extracellular vesicles secreted by the prostate gland, and the ability to detect changes in their N-glycans composition as a reflection of disease state represents potential new biomarker candidates. Methods to characterize these N-glycan constituents directly from clinical samples in a timely manner and with minimal sample processing requirements are not currently available. In this report, an approach is described to directly profile the N-glycan constituents of EPS urine samples, prostatic fluids and urine using imaging mass spectrometry for detection. An amine reactive slide is used to immobilize glycoproteins from a few microliters of spotted samples, followed by peptide N-glycosidase digestion. Over 100 N-glycan compositions can be detected with this method, and it works with urine, urine EPS, prostatic fluids, and urine EPS-derived extracellular vesicles. A comparison of the N-glycans detected from the fluids with tissue N-glycans from prostate cancer tissues was done, indicating a subset of N-glycans present in fluids derived from the gland lumens. The developed N-glycan profiling is amenable to analysis of larger clinical cohorts and adaptable to other biofluids

Money spider dietary choice in pre- and post-harvest cereal crops using metabarcoding

Money spiders (Linyphiidae) are an important component of conservation biological control in cereal crops, but they rely on alternative prey when pests are not abundant, such as between cropping cycles. To optimally benefit from these generalist predators, prey choice dynamics must first be understood. Money spiders and their locally available prey were collected from cereal crops 2 weeks pre‐ and post‐harvest. Spider gut DNA was amplified with two novel metabarcoding primer pairs designed for spider dietary analysis, and sequenced. The combined general and spider‐exclusion primers successfully identified prey from 15 families in the guts of the 46 linyphiid spiders screened, whilst avoiding amplification of Erigone spp. The primers show promise for application to the diets of other spider families such as Agelenidae and Pholcidae. Distinct invertebrate communities were identified pre‐ and post‐harvest, and changes in spider diet and, to a lesser extent, prey choice reflected this. Spiders were found to consume one another more than expected, indicating their propensity towards intraguild predation, but also consumed common pest families. Changes in spider prey choice may redress prey community changes to maintain a consistent dietary intake. Consistent provision of alternative prey via permanent refugia should be considered to sustain effective conservation biocontrol

Density-independent prey choice, taxonomy, life history and web characteristics determine the diet and biocontrol potential of spiders (Linyphiidae and Lycosidae) in cereal crops

Spiders are among the dominant invertebrate predators in agricultural systems and are significant regulators of insect pests. The precise dynamics of biocontrol of pests in the field are, however, poorly understood. This study investigates how density-independent prey choice, taxonomy, life stage, sex, and web characteristics affect spider diet and biocontrol. We collected spiders in four genera of Linyphiidae (i.e., Bathyphantes, Erigone, Tenuiphantes, and Microlinyphia), and individuals from the Lycosidae genus Pardosa, and their proximate prey communities from barley fields in Wales, UK between April and September 2018. We analyzed the gut contents of 300 individual spiders using DNA metabarcoding. From the 300 spiders screened, 89 prey taxa were identified from 45 families, including a wide range of pests and predators. Thrips were the dominant prey, present in over a third of the spiders sampled, but a type IV functional response appears to reduce their predation at peak abundances. Spider diets significantly differed based on web characteristics, but this depended on the genus and sex of the spider and it was not the principal separating factor in the trophic niches of linyphiids and lycosids. Diets significantly differed between spider genera and life stages, reflected in different propensities for intraguild predation and pest predation. Adult spiders predated a greater diversity of other predators, and juveniles predated a greater diversity of pests. Overall, Tenuiphantes spp. and Bathyphantes spp. exhibited the greatest individual potential for biocontrol of the greatest diversity of pest genera. The greater trophic niche complementarity of Pardosa spp. and Erigone spp., however, suggests that their complementary predation of different pests might be of greater overall benefit to biocontrol. Sustainable agriculture should aim to optimize conditions throughout the cropping cycle for effective biocontrol, prioritizing provision for a diversity of spiders which predate a complementary diversity of pest species