Small mammals reduce activity during high moon illumination under risk of predation by introduced predators

Predation influences prey survival and drives evolution of anti-predator behaviour. Anti-predator strategies by prey are stimulated by direct encounters with predators, but also by exposure to indicators of risk such as moonlight illumination and vegetation cover. Many prey species will suffer increased risk on moonlit nights, but risk may be reduced by the presence of dense vegetation. Determining the role of vegetation in reducing perceived risk is important, especially given predictions of increased global wildfire, which consumes vegetation and increases predation. We used remote cameras in southeastern Australia to compare support for the predation risk and habitat-mediated predation risk hypotheses. We examined the influence of moonlight and understorey cover on seven 20-2500 g mammalian prey species and two introduced predators, red foxes and feral cats. Activity of all prey species reduced by 40-70% with increasing moonlight, while one species (bush rat) reduced activity in response to increasing moonlight more sharply in low compared to high understorey cover. Neither predator responded to moonlight. Our findings supported the predation risk hypothesis and provided limited support for the habitat-mediated predation risk hypothesis. For prey, perceived costs of increased predation risk on moonlit nights outweighed any benefits of a brighter foraging environment.

Silica-Coated Micrometer-Sized Latex Particles

A series of silica-coated micrometer-sized poly(methyl methacrylate) latex particles are prepared using a Stöber silica deposition protocol that employs tetraethyl orthosilicate (TEOS) as a soluble silica precursor. Given the relatively low specific surface area of the latex particles, silica deposition is best conducted at relatively high solids to ensure a sufficiently high surface area. Such conditions aid process intensification. Importantly, physical adsorption of chitosan onto the latex particles prior to silica deposition minimizes secondary nucleation and promotes the formation of silica shells: in the absence of chitosan, well-defined silica overlayers cannot be obtained. Thermogravimetry studies indicate that silica formation is complete within a few hours at 20 °C regardless of the presence or absence of chitosan. Kinetic data obtained using this technique suggest that the adsorbed chitosan chains promote surface deposition of silica onto the latex particles but do not catalyze its formation. Systematic variation of the TEOS/latex mass ratio enables the mean silica shell thickness to be tuned from 45 to 144 nm. Scanning electron microscopy (SEM) studies of silica-coated latex particles after calcination at 400 °C confirm the presence of hollow silica particles, which indicates the formation of relatively smooth (albeit brittle) silica shells under optimized conditions. Aqueous electrophoresis and X-ray photoelectron spectroscopy studies are also consistent with latex particles coated in a uniform silica overlayer. The silica deposition formulation reported herein is expected to be a useful generic strategy for the efficient coating of micrometer-sized particles at relatively high solids.

178 The Effect of Ophthalmic Surgery for Graves’ Orbitopathy on Quality of Life – A Systematic Review and Meta-Analysis

Background

Graves’ orbitopathy has a profound negative impact on quality of life. Surgery is undertaken to preserve vision, correct diplopia and improve aesthetics. We aimed to quantify the effect of different surgical approaches on quality of life.

Method

Electronic databases were used from inception until 22nd March 2021 to identify studies assessing quality of life pre- and post-surgical intervention for Graves’ orbitopathy. Two reviewers independently extracted data and performed quality assessments. Random-effects and Bayesian models for meta-analyses were utilised.

Results

10 articles comprising 632 patients were included. All used the Graves’ Ophthalmopathy Quality of Life questionnaire (GO-QOL). For GO-QOL appearance, the pooled standardised mean improvement for patients after surgery was +0.72 (95% CI 0.50–0.94) I2=69% (95% CI 52–80%). For GO-QOL visual functioning, the pooled SMD for patients after surgery was +0.41 (95% CI 0.25–0.58) I2=60% (95% CI 36–74%). For visual appearance, orbital decompression yielded the greatest improvement (SMD+0.84, 95%CI 0.54–1.13) followed by eyelid surgery (SMD+0.38, 95% CI 0.05–0.70), while strabismus correction had no significant effect (SMD +0.94, 95% CI -0.10–1.99). Conversely strabismus correction was associated with the greatest improvement (SMD+1.25, 95%CI 0.29–2.21) in visual functioning, outperforming orbital decompression (SMD+0.29, 95%CI 0.15–0.43) and eyelid surgery (SMD+0.12, 95%CI -0.18–0.41).

Conclusions

Ophthalmic surgery results in substantial improvements in quality of life in patients with Graves’ orbitopathy, with greater perceived effects on appearance than visual function. Orbital decompression has particular impact on visual appearance, strabismus surgery may benefit both visual appearance and function equally whereas eyelid surgery benefits appearance alone.

414 Are Lumbar Drains Necessary in Endoscopic Transellar Surgery with an Intraoperative High Flow Leak? a Systematic Review

Aim

Perioperative lumbar drains have been used to facilitate healing of the dura and prevent postoperative cerebrospinal fluid (CSF) leaks. However, the use of perioperative lumbar drains is controversial and has primarily been left to the surgeon's preferences. Through the use of meta-analysis, we aim to find out whether lumbar drains effectively reduce the risk of postoperative CSF leak in the context of a high flow intraoperative leak.

Method

A systematic review was conducted using PRISMA guidelines. Databases used in literature searching include PubMed, Ovid (including Embase and Medline), Scopus and Cochrane Library. Articles published in 2006 or later were searched. The random-effects model was used in statistical analysis.

Results

A total of 2623 articles were identified. After screening and full-text reviews, 21 studies were included. From the quantitative data analysis, lumbar drains did not significantly lower the rates of postoperative CSF leaks. In addition, lumbar drains were associated with complications as well as a lengthier hospital stay.

Conclusions

Modern and rigorous repair techniques after endoscopic transsellar surgery are sufficient, and the use of lumbar drains is not necessary.

245 Changing Demographics of Head Injury During the COVID-19 Pandemic

Introduction

Studies have shown that men are more likely to sustain head injuries (HI) due to a higher likelihood of participation in high-risk behaviours. However, the COVID-19 lockdown caused substantial alterations to the daily routines of the Welsh population. We aimed to describe the demographical changes of HI patients caused by this large-scale restriction of public social activity.

Method

A retrospective review of our neurosurgical referral database was performed between 1/1/19 to 31/12/20 to extract patient demographics and referral outcomes (admission/advice only) of adult head injury patients. Referrals during lockdown in Wales (26/3/20 – 1/6/20 and 31/10/20 and 2/12/20) were compared with non-lockdown periods in 2019 and 2020.

Results

There was no significant difference in HI referral volume in 2019 (n = 1228) vs 2020 (n = 1179) (OR: 0.71; 95% CI: 0.53 – 0.96, p = 0.02). Women were less likely to be admitted in 2019 (OR: 0.60, 95%CI: 0.39 – 0.91, p = 0.02) and 2020 (OR: 0.52, 95%CI: 0.31–0.88, p = 0.01). We observed evidence of interaction by age and sex in lockdown vs non-lockdown (p = 0.02). Most strikingly, there was higher odds of admission in women aged 40–70 years during lockdown (OR: 10.4, 95%CI: 1.13 – 95.8, p = 0.04).

Conclusions

We observed significant demographical shifts in HI during lockdown periods, with striking increases in admission rates of men under 40 years and women aged 40–70. The cause of these substantial changes need clarification and have important public health implications. Given likely reduced road traffic accidents during lockdown, other factors such as alcohol or assault need considering.

The transCampus Metabolic Training Programme Explores the Link of SARS-CoV-2 Virus to Metabolic Disease

Currently, we are experiencing a true pandemic of a communicable disease by the virus SARS-CoV-2 holding the whole world firmly in its grasp. Amazingly and unfortunately, this virus uses a metabolic and endocrine pathway via ACE2 to enter our cells causing damage and disease. Our international research training programme funded by the German Research Foundation has a clear mission to train the best students wherever they may come from to learn to tackle the enormous challenges of diabetes and its complications for our society. A modern training programme in diabetes and metabolism does not only involve a thorough understanding of classical physiology, biology and clinical diabetology but has to bring together an interdisciplinary team. With the arrival of the coronavirus pandemic, this prestigious and unique metabolic training programme is facing new challenges but also new opportunities. The consortium of the training programme has recognized early on the need for a guidance and for practical recommendations to cope with the COVID-19 pandemic for the community of patients with metabolic disease, obesity and diabetes. This involves the optimal management from surgical obesity programmes to medications and insulin replacement. We also established a global registry analyzing the dimension and role of metabolic disease including new onset diabetes potentially triggered by the virus. We have involved experts of infectious disease and virology to our faculty with this metabolic training programme to offer the full breadth and scope of expertise needed to meet these scientific challenges. We have all learned that this pandemic does not respect or heed any national borders and that we have to work together as a global community. We believe that this transCampus metabolic training programme provides a prime example how an international team of established experts in the field of metabolism can work together with students from all over the world to address a new pandemic.

0024 PTSD with Concurrent Excessive Daytime Sleepiness Alters Gene Expression in Military Personnel and Veterans; An RNA-Sequencing Study

Introduction

Up to 91% of military personnel and veterans with posttraumatic stress disorder (PTSD) report co-occurring sleep disturbances, including. insomnia and excessive daytime sleepiness (EDS). Sleep disturbances have been shown not only to increase the risk of developing PTSD, but to exacerbate and maintain PTSD symptomology. The aim of this study was to examine gene expression in active duty military personnel and veterans with PTSD, with and without EDS. Participants were categorized into three groups; 1) PTSD with EDS (PTSDwEDS; n=21), 2) PTSD without EDS (PTSDnoEDS; n=25), or 3) Controls (no PTSD and no EDS; n=57).

Methods

Participants were 79% male, mean age of 37.6years (SD=11.2years). PTSD symptoms were measured using the PTSD checklist for civilians (PCL-C); participants were classified as PTSD-present using DSM-IV-TR criteria of “moderate-to-severe”. Daytime sleepiness was assessed using the Epworth Sleepiness Scale (ESS), high sleepiness was indicated by an ESS score >13. We performed RNA-seq with Illumina’s HiSeq 2500 in paired-end. We conducted quality control using FastQC and aligned to GRCh38 reference genome using STAR (v2.5.3a). Differentially expressed genes identified using DESeq2 (v1.20.0) with False Discovery Rate of 0.10. Finally, Ingenuity Pathway Analysis (IPA) was conducted to identify dysregulated gene networks.

Results

Between the Controls and PTSDnoEDS groups, two genes were significantly dysregulated. In controls and PTSDwEDS groups, 251 genes were dysregulated. The IPA networks showed that genes associated with inflammation were significantly dysregulated. Finally, between PTSDwEDS and PTSDnoEDS there were 1,873 significantly dysregulated genes. The IPA networks identified dysregulation of genes related to sleep, fatigue, circadian, and mitochondrial function.

Conclusion

Taken together this data indicates that EDS that is co-morbidly experienced with PTSD is associated with significant gene dysregulation, above and beyond that observed in participants with PTSD without significant EDS and controls. Treating EDS in military personnel and veterans with PTSD is important.

Support

This work was supported by the Center for Neuroscience and Regenerative Medicine (CNRM)

7 Pregnancy from a vitrified-warmed alpaca pre-implantation embryo

The alpaca (Vicugna pacos) is a ruminant livestock species in the South American camelid family. There are more than 9 million South American camelids globally that make important contributions to the livelihoods of rural farmers through conversion of low quality roughages to high quality food and fibre. Reproductive biotechnologies for alpacas are not well developed compared with those for other ruminant livestock species. In particular, embryo cryopreservation technologies are lacking. The objective of this study was to evaluate under field conditions a vitrification protocol originally developed for old world camels that we adapted for use in alpacas. Potential donors were evaluated for follicular development using a 7.5-MHz ultrasound probe. Hembras (sexually mature female alpacas) with ovarian follicles 7-10mm in diameter were behaviour tested to determine sexual receptivity, and receptive females were naturally mated to a proven herd sire. At the time of breeding, non-superovulated donors (n=4) received 30μg gonadorelin. Embryos were nonsurgically collected 7 days after breeding and handled at 20°C. Diameter of harvested embryos (n=4 quality grade 1 hatched expanded blastocysts) was measured using an eyepiece reticle. All recovered embryos were placed individually into 0.5-mL drops of vitrification solution (VS1: 1.4M glycerol) for 5min, 0.5-mL drops of VS2 (1.4 M glycerol + 3.6M ethylene glycol) for 5min, 0.05-mL drops of VS3 (3.4 M glycerol + 4.6M ethylene glycol) for 20s, and 0.05-mL drops of VS3 for 20s while loading into open-pulled straws (OPS). Each OPS was plunged directly into liquid nitrogen for storage for 29 days. At warming, each OPS was submerged into a 1-mL drop of warming solution 1 (WS1: 0.5M galactose) for 1min followed by 1min in WS2 (0.25 M galactose) for 5min before being incubated at 37°C in 5% CO2 in humidified air for 21h in 1mL of Syngro holding medium supplemented with 10% (vol/vol) alpaca serum. Embryos that grew during culture (n=2) were transferred individually into synchronous recipients, and embryos that did not appear to grow (n=2) were transferred together as a pair. Prior to embryo transfer, potential recipients were evaluated ultrasonographically as described previously. Hembras with ovarian follicles 7-10mm in diameter were behaviour tested, and sexually receptive females received 30μg gonadorelin 6 days before embryo transfer. Final selection of recipients (n=3) was based on presence of a corpus luteum and nonreceptive behaviour to a herd sire 24h before transfer. Pregnancy was detected ultrasonographically, and fetal heartbeat was detected 29 days post-transfer in one of the three recipients. Ultrasound at 177 days post-transfer revealed that the pregnancy, generated from a 400μm×375μm vitrified-warmed embryo that had grown in culture, was still ongoing. If this pregnancy results in the birth of a live cria (newborn alpaca), it would represent-to the best of our knowledge-the world's first cria born from a cryopreserved alpaca pre-implantation embryo. It would also demonstrate the potential utility of this protocol under field conditions.

Association between HbA1c and the development of cystic fibrosis-related diabetes

AIMS

To examine HbA_1c as a predictor of risk for future development of cystic fibrosis-related diabetes and to assess the association with the development of retinopathy in people with cystic fibrosis-related diabetes.

METHODS

A 7-year retrospective longitudinal study was conducted in 50 adults with cystic fibrosis, comparing oral glucose tolerance test results with HbA_1c values in predicting the development of cystic fibrosis-related diabetes. Retinal screening data were also compared with HbA_1c measurements to assess microvascular outcome.

RESULTS

An HbA_1c value ≥37 mmol/mol (5.5%; hazard ratio 3.49, CI 1.5-8.1) was significantly associated with the development of dysglycaemia, as defined by the oral glucose tolerance test over a 7-year period. Severity of diabetic retinopathy was associated with a higher HbA_1c and longer duration of cystic fibrosis-related diabetes.

CONCLUSION

There is a link between HbA_1c level and the future development of dysglycaemia in cystic fibrosis based on oral glucose tolerance test, as well as microvascular outcomes. Although current guidance does not advocate the use of HbA_1c as a diagnostic tool in cystic fibrosis-related diabetes, it may be of clinical use in determining individuals at risk of future development of cystic fibrosis-related diabetes.

Magnetoterahertz Response and Faraday Rotation from Massive Dirac Fermions in the Topological Crystalline Insulator Pb_{0.5}Sn_{0.5}Te

Pb_{1-x}Sn_{x}Te has been shown to be an interesting tunable topological crystalline insulator system. We present a magnetoterahertz spectroscopic study of thin films of Pb_{0.5}Sn_{0.5}Te. The complex Faraday rotation angle and optical conductivity in the circular basis are extracted without any additional assumptions. Our quantitative measures of the THz response allow us to show that the sample studied contains two types of bulk carriers. One is p type and originates in 3D Dirac bands. The other is n type and appears to be from more conventional 3D bands. These two types of carriers display different cyclotron resonance dispersions. Through simulating the cyclotron resonance of hole carriers, we can determine the Fermi energy and Fermi velocity. Furthermore, the scattering rates of p-type and n-type carriers were found to show opposite field dependences, which can be attributed to their different Landau level broadening behaviors under magnetic field. Our work provides a new way to isolate real topological signatures of bulk states in Dirac and Weyl semimetals.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Studies of black silicon and black diamond as materials for antibacterial surfaces

'Black silicon' (bSi) samples with surfaces covered in nanoneedles of varying length, areal density and sharpness, have been fabricated using a plasma etching process. These nanostructures were then coated with a conformal uniform layer of diamond using hot filament chemical vapour deposition to produce 'black diamond' (bD) surfaces. The effectiveness of these bSi and bD surfaces in killing Gram-negative (E. coli) and Gram-positive (S. gordonii) bacteria was investigated by culturing the bacteria on the surfaces for a set time and then measuring the live-to-dead ratio. All the nanostructured surfaces killed E. coli at a significantly higher rate than the respective flat Si or diamond control samples. The length of the needles was found to be less important than their separation, i.e. areal density. This is consistent with a model for mechanical bacteria death based on the stretching and disruption of the cell membrane, enhanced by the cells motility on the surfaces. In contrast, S. gordonii were unaffected by the nanostructured surfaces, possibly due to their smaller size, thicker cell membrane and/or their lack of motility.

European Influenza Surveillance Scheme on the Internet

In 1995, The European Influenza Surveillance Scheme was created with the participation of eight networks from seven countries. The main objectives were to continue the previous CARE Telematics Network and to adapt the project to the Internet environment as well as to improve substantially the quality of the surveillance according to new epidemiological requirements. Clinical and virological data from the general population and hospitals are collected in an interactive real-time database which can then be used for data entry, queries and consultations. Research programmes have been undertaken in various fields such as standardisation of clinical data and comparability between countries. Validation and security processes guarantee the quality assurance as well as regular assessment by the steering committee. Two additional countries will participate during the next influenza season (1997-98). This will represent an early warning system in a region of approximately 264 million inhabitants.

Elicitation and Representation of Expert Knowledge for Computer Aided Diagnosis in Mammography

Objectives: To study how professional radiologists describe, interpret and make decisions about micro-calcifications in mammograms. The purpose was to develop a model of the radiologists’ decision making for use in CADMIUM II, a computerized aid for mammogram interpretation that combines symbolic reasoning with image processing.

Methods: In Study 1, eleven radiologists were asked to ‘think out loud’ as they interpreted 20 sets of calcifications. Participants used 159 terms to describe calcifications. We used these data to design a scheme with 50 descriptors. In Study 2, ten radiologists used the scheme to describe 40 sets of calcifications. We assessed the capacity of the terms to discriminate between benign and malignant calcifications, testing them against radiologists’ assessments of malignancy and follow-up data.

Results: The descriptors that were found to be the most discriminating in Study 2 were included in CADIMUM II’s knowledge base. They were represented as arguments for either a benign or a malignant diagnosis. These arguments are the central component of the decision support provided by the system. Other components are: image processing algorithms for the detection and measurement of calcifications and a set of rules that use the measures to decide which of the arguments apply to a given set of calcifications.

Conclusions: Preliminary evaluations of the CADMIUM II prototype reinforce the value of representing explicitly decision making processes in computer aided mammography and of deriving these processes from image processing measurements. Decision support is presented here at a level of description that is both relevant and meaningful to the user.

Energetic Constraints Produce Self-sustained Oscillatory Dynamics in Neuronal Networks

Overview: We model energy constraints in a network of spiking neurons, while exploring general questions of resource limitation on network function abstractly.

Background: Metabolic states like dietary ketosis or hypoglycemia have a large impact on brain function and disease outcomes. Glia provide metabolic support for neurons, among other functions. Yet, in computational models of glia-neuron cooperation, there have been no previous attempts to explore the effects of direct realistic energy costs on network activity in spiking neurons. Currently, biologically realistic spiking neural networks assume that membrane potential is the main driving factor for neural spiking, and do not take into consideration energetic costs.

Methods: We define local energy pools to constrain a neuron model, termed Spiking Neuron Energy Pool (SNEP), which explicitly incorporates energy limitations. Each neuron requires energy to spike, and resources in the pool regenerate over time. Our simulation displays an easy-to-use GUI, which can be run locally in a web browser, and is freely available.

Results: Energy dependence drastically changes behavior of these neural networks, causing emergent oscillations similar to those in networks of biological neurons. We analyze the system via Lotka-Volterra equations, producing several observations: (1) energy can drive self-sustained oscillations, (2) the energetic cost of spiking modulates the degree and type of oscillations, (3) harmonics emerge with frequencies determined by energy parameters, and (4) varying energetic costs have non-linear effects on energy consumption and firing rates.

Conclusions: Models of neuron function which attempt biological realism may benefit from including energy constraints. Further, we assert that observed oscillatory effects of energy limitations exist in networks of many kinds, and that these findings generalize to abstract graphs and technological applications.