Consistent Response Research Articles

EEG responses to standardised noxious stimulation during clinical anaesthesia: a pilot study.

During clinical anaesthesia, the administration of analgesics mostly relies on empirical knowledge and observation of the patient's reactions to noxious stimuli. Previous studies in healthy volunteers under controlled conditions revealed EEG activity in response to standardised nociceptive stimuli even at high doses of remifentanil and propofol. This pilot study aims to investigate the feasibility of using these standardised nociceptive stimuli in routine clinical practice. We studied 17 patients undergoing orthopaedic trauma surgery under general anaesthesia. We evaluated if the EEG could track standardised noxious phase-locked electrical stimulation and tetanic stimulation, a time-locked surrogate for incisional pain, before, during, and after the induction of general anaesthesia. Subsequently, we analysed the effect of tetanic stimulation on the surgical pleth index as a peripheral, vegetative, nociceptive marker. We found that the phase-locked evoked potentials after noxious electrical stimulation vanished after the administration of propofol, but not at low concentrations of remifentanil. After noxious tetanic stimulation under general anaesthesia, there were no consistent spectral changes in the EEG, but the vegetative response in the surgical pleth index was statistically significant (Hedges' g effect size 0.32 [95% confidence interval 0.12-0.77], P=0.035). Our standardised nociceptive stimuli are not optimised for obtaining consistent EEG responses in patients during clinical anaesthesia. To validate and sufficiently reproduce EEG-based standardised stimulation as a marker for nociception in clinical anaesthesia, other pain models or stimulation settings might be required to transfer preclinical studies into clinical practice. DRKS00017829.

Immunogenicity and safety of BPZE1, an intranasal live attenuated pertussis vaccine, versus tetanus–diphtheria–acellular pertussis vaccine: a randomised, double-blind, phase 2b trial

Bordetella pertussis epidemics persist as transmission remains unabated despite high acellular pertussis vaccination rates. BPZE1, a live attenuated intranasal pertussis vaccine, was designed to prevent B pertussis infection and disease. We aimed to assess the immunogenicity and safety of BPZE1 compared with the tetanus-diphtheria-acellular pertussis vaccine (Tdap). In this double-blind, phase 2b trial at three research centres in the USA, healthy adults aged 18-50 years were randomly assigned (2:2:1:1) via a permuted block randomisation schedule to receive BPZE1 vaccination followed by BPZE1 attenuated challenge, BPZE1 vaccination followed by placebo challenge, Tdap followed by BPZE1 attenuated challenge, or Tdap followed by placebo challenge. On day 1, lyophilised BPZE1 was reconstituted with sterile water and given intranasally (0·4 mL delivered to each nostril), whereas Tdap was given intramuscularly. To maintain masking, participants in the BPZE1 groups received an intramuscular saline injection, and those in the Tdap groups received intranasal lyophilised placebo buffer. The attenuated challenge took place on day 85. The primary immunogenicity endpoint was the proportion of participants achieving nasal secretory IgA seroconversion against at least one B pertussis antigen on day 29 or day 113. Reactogenicity was assessed up to 7 days after vaccination and challenge, and adverse events were recorded for 28 days after vaccination and challenge. Serious adverse events were monitored throughout the study. This trial is registered with ClinicalTrials.gov, NCT03942406. Between June 17 and Oct 3, 2019, 458 participants were screened and 280 were randomly assigned to the main cohort: 92 to the BPZE1-BPZE1 group, 92 to the BPZE1-placebo group, 46 to the Tdap-BPZE1 group, and 50 to the Tdap-placebo group. Seroconversion of at least one B pertussis-specific nasal secretory IgA was recorded in 79 (94% [95% CI 87-98]) of 84 participants in the BPZE1-BPZE1 group, 89 (95% [88-98]) of 94 in the BPZE1-placebo group, 38 (90% [77-97]) of 42 in the Tdap-BPZE1 group, and 42 (93% [82-99]) of 45 in the Tdap-placebo group. BPZE1 induced broad and consistent B pertussis-specific mucosal secretory IgA responses, whereas Tdap did not induce consistent mucosal secretory IgA responses. Both vaccines were well tolerated, with mild reactogenicity and no serious adverse events related to study vaccination. BPZE1 induced nasal mucosal immunity and produced functional serum responses. BPZE1 has the potential to avert B pertussis infections, which ultimately could lead to reduced transmission and diminished epidemic cycles. These results should be confirmed in large phase 3 trials. ILiAD Biotechnologies.

Linking Predator Responses to Alkaloid Variability in Poison Frogs.

Many chemically-defended/aposematic species rely on diet for sequestering the toxins with which they defend themselves. This dietary acquisition can lead to variable chemical defenses across space, as the community composition of chemical sources is likely to vary across the range of (an aposematic) species. We characterized the alkaloid content of two populations of the Dyeing Poison Frog (Dendrobates tinctorius) in northeastern French Guiana. Additionally, we conducted unpalatability experiments with naive predators, Blue Tits (Cyanistes caeruleus), using whole-skin secretion cocktails to assess how a model predator would respond to the defense of individuals from each population. While there was some overlap between the two D. tinctorius populations in terms of alkaloid content, our analysis revealed that these two populations are markedly distinct in terms of overall alkaloid profiles. Predator responses to skin secretions differed between the populations. We identified 15 candidate alkaloids (including three previously undescribed) in seven classes that are correlated with predator response in one frog population. We describe alkaloid profile differences between populations for D. tinctorius and provide a novel method for assessing unpalatability of skin secretions and identifying which toxins may contribute to the predator response. In one population, our results suggest 15 alkaloids that are implicated in predator aversive response. This method is the first step in identifying the causal link between alkaloids and behavioral responses of predators, and thus makes sense of how varying alkaloid combinations are capable of eliciting consistent behavioral responses, and eventually driving evolutionary change in aposematic characters (or characteristics).

Influences of CNT Dispersion Methods, W/C Ratios, and Concrete Constituents on Piezoelectric Properties of CNT-Modified Smart Cementitious Materials

In order to achieve effective monitoring of concrete structures for sound structural health, the addition of carbon nanotubes (CNTs) into cementitious materials offers a promising solution for fabricating CNT-modified smart concrete with self-sensing ability. This study investigated the influences of CNT dispersion method, water/cement (W/C) ratio, and concrete constituents on the piezoelectric properties of CNT-modified cementitious materials. Three CNT dispersion methods (direct mixing, sodium dodecyl benzenesulfonate (NaDDBS) and carboxymethyl cellulose (CMC) surface treatment), three W/C ratios (0.4, 0.5, and 0.6), and three concrete constituent compositions (pure cement, cement/sand, and cement/sand/coarse aggregate) were considered. The experimental results showed that CNT-modified cementitious materials with CMC surface treatment had valid and consistent piezoelectric responses to external loading. The piezoelectric sensitivity improved significantly with increased W/C ratio and reduced progressively with the addition of sand and coarse aggregates.

Varying response of breeding waders to experimental manipulation of their habitat and predators

Many ground-nesting bird species including waders are of conservation concern across Europe. Population declines of Eurasian Curlew Numenius arquata (hereafter Curlew), a globally Near-threatened wader, exemplify this and are driven by low breeding success due to predation, and loss and degradation of breeding habitat. We tested whether the combined delivery of vegetation management and lethal control of Red Foxes Vulpes vulpes and Carrion Crows Corvus corone and Hooded Crows C. cornix improved Curlew nesting success and breeding abundance across UK study sites over five years. On trial sites, vegetation management improved habitat condition and Curlew distributions shifted towards managed areas. However, changes in predator abundances, Curlew nesting success and Curlew breeding abundance did not differ between trial and reference sites. Northern Lapwing Vanellus vanellus numbers increased on trial sites and decreased on reference sites, whilst Common Snipe Gallinago gallinago numbers showed no treatment response. Some of these outcomes were associated with additional environmental variables added to Treatment:Year terms in three-way interactions (changes in fox abundance associated with abundance of non-native gamebirds; changes in Crow abundance associated with gamebirds and woodland area; changes in Curlew nesting success associated with crow abundance), highlighting that outcomes depend on site-specific contexts, and consistent responses to interventions cannot be assumed. The difficulty in increasing Curlew nesting success likely relates to underlying mesopredator densities in the UK, which are known to be high in a European context. Our results suggest that a model of delivery like this study, including management of predators using lethal control, at comparable intensities, is highly unlikely to be effective for Curlew or Snipe within agri-environment schemes, but could be for Northern Lapwing. To make progress on wader recovery it is imperative to understand the underlying drivers of high mesopredator densities and address these through landscape-scale intervention and policy changes.

Feasibility and Validity of Postural Reaction Tests in the Neurological Examination in Healthy Rabbits

Neurological examination remains a fundamental step in the care of patients with neurological disorders. However, studies evaluating the feasibility and validity of neurological examination in rabbits are limited. In this study, postural reaction tests or methods commonly performed in dogs and cats were evaluated in clinically healthy rabbits, and we aimed to postulate a simplified examination list according to the results. The feasibility and validity of each test were determined and screened using a cut-off value of 90%. For the remaining tests/methods, the response rates of tests with similar neuroanatomical pathways were compared. Among the 34 healthy rabbits tested, one method of the hopping reaction (holding then lowering the rabbit quickly towards the floor with only the tested limb touching the ground), the hemi-walking test, the wheelbarrowing test, and the righting response yielded a feasibility and validity of over 90%. When comparing tests/methods with similar neuroanatomical pathways, the normal response rate of the hopping reaction was comparable to that of the hemi-walking test. We conclude that in healthy rabbits, hopping reaction tests using the method mentioned above, hemi-walking, wheelbarrowing, and righting responses are likely to be feasible postural reaction tests that yield consistent and normal responses.

Acute Treatment of Migraine in Adolescents: Real-World Analysis of Remote Electrical Neuromodulation (REN)

Nearly 10% of children and adolescents in the United States experience migraine. Pharmacologic treatment of migraine in adolescents is limited due to only few US Food and Drug Administration (FDA)-approved medications, limited efficacy, or lack of tolerability. Remote Electrical Neuromodulation (REN) is a nonpharmacologic abortive treatment for migraine, cleared by the FDA for patients aged 12 years and above. This study evaluated real-world efficacy of REN in adolescents aged 12 to 17 years. Real-world data were collected from patients aged 12 to 17 years treated with the REN device (Nerivio) from January 1, 2021, to May 31, 2022. Study's end points included consistent efficacy two hours after treatment, use of REN as a standalone versus as an adjunct therapy, treatment intensity, and safety. Of 1629 adolescents included in the study, consistent response in at least 50% of treatments at two hours posttreatment was achieved by 60.3% of patients for pain relief, 26.3% for pain freedom, 66.3% for functional disability relief, and 41.2% for functional disability freedom. Of 2365 treatments in which medication usage was reported, REN was used as standalone therapy in 64.4% of the treatments, REN was combined with over-the-counter medications in 18.6%, and it was combined with prescription medications in 17%. Mean treatment intensity from 13,716 treatments was 28.5% (±13.6%) of the max stimulator output. Only three device-related adverse events were reported, all minor. This real-world analysis demonstrates the persistent efficacy of REN for abortive treatment of migraine in adolescents, extending findings of prior clinical trials in adolescents and real-world studies in adults.

Sensory test A-Not A rating signal detection: Panel’s sensory learning and stability of decision criteria

Signal detection theory (SDT) sensory discrimination analysis using A-Not A with a two-step rating is an efficient approach to in-house sensory quality management in the food industry. For such sensory analysis using an internal panel, the panels’ ability to use stable decision criteria and provide a consistent response distribution responding to “A” vs “Not A” is critical for guaranteeing the data quality. This study examined the effects of the familiarization procedure (FP) and reference presentation probability (RPP) in the SDT A-Not A rating protocol on the panels’ sensory learning of samples and stability of decision criteria using SDT parameters, recognition d' (d'Rec),criteria location (c), and discrimination d' indices. Three different protocols were compared using ice-tea samples with small differences: Control, 0.25 RPP with repeated reference tasting (FPR); Modified-1, 0.25 RPP with reference categorization (FPC); Modified-2, 0.5 RPP with reference categorization (FPC). An independent sample design with three groups having equal sensitivity was used to identify the differences among the protocols. For each protocol, two sub-groups with similar decision criteria (response bias) were formed according to the results obtained from the pre-test and used for the main-test analysis. SDT analysis results indicated that the Modified-2 protocol with a higher RPP (0.5) induced the most efficient sensory learning of the reference. The protocol improved the subjects’ recognition of the reference and test samples, better differentiating from the reference and stabilizing the decision criterion, resulting in higher discrimination performance (larger d'). The results showed that d'Rec analysis, together with d' analysis using a sensory panel, is a useful tool for monitoring the panel performance and checking for the sensory data quality of the sensory difference tests. In the present paper, a detailed illustration of the A-Not A sensory test procedure and examples of how to apply the SDT indices for different business decision-making is also introduced using the design and results of the present experiment.

Neural response generation for task completion using conversational knowledge graph.

Effective dialogue generation for task completion is challenging to build. The task requires the response generation system to generate the responses consistent with intent and slot values, have diversity in response and be able to handle multiple domains. The response also needs to be context relevant with respect to the previous utterances in the conversation. In this paper, we build six different models containing Bi-directional Long Short Term Memory (Bi-LSTM) and Bidirectional Encoder Representations from Transformers (BERT) based encoders. To effectively generate the correct slot values, we implement a copy mechanism at the decoder side. To capture the conversation context and the current state of the conversation we introduce a simple heuristic to build a conversational knowledge graph. Using this novel algorithm we are able to capture important aspects in a conversation. This conversational knowledge-graph is then used by our response generation model to generate more relevant and consistent responses. Using this knowledge-graph we do not need the entire utterance history, rather only the last utterance to capture the conversational context. We conduct experiments showing the effectiveness of the knowledge-graph in capturing the context and generating good response. We compare these results against hierarchical-encoder-decoder models and show that the use of triples from the conversational knowledge-graph is an effective method to capture context and the user requirement. Using this knowledge-graph we show an average performance gain of 0.75 BLEU score across different models. Similar results also hold true across different manual evaluation metrics.

Response of Soil Erosion to Climate and Subsequent Vegetation Changes in a High-Mountain Basin

Soil erosion is one of the global threats to the environment. Further, climate and vegetation changes have pronounced effects on soil erosion in high-mountain areas. In this study, the revised universal soil loss equation (RUSLE) was improved by developing a method for calculating snowmelt runoff erosivity based on a simulated snowmelt runoff and the observed sediment load, using which the soil erosion rate in the upper Heihe River Basin (UHRB) was calculated. The proposed approach provides an effective method for estimating the soil erosion rate and identifying the causes for its change in high-mountain areas. The normalized difference vegetation index (NDVI) was significantly and positively correlated with both precipitation and temperature in the region and exhibited a significant increasing trend. The increase in NDVI led to a decrease in the soil erosion rate (for the annual, rainfall, and snowmelt periods), although erosive rainfall and snowmelt runoff showed increasing trends, indicating the dominating impact of vegetation cover on soil erosion. The average soil erosion rate of UHRB was 806.2 t km−2 a−1 from 1982 to 2015. On average, soil erosion during rainfall and snowmelt periods contributed to 90.67% and 9.33% of annual soil erosion, respectively. However, the resultant soil erosion rate caused by 1 mm of snowmelt runoff was about 1.9 times that caused by 1 mm erosive rainfall. Soil erosion during the snowmelt period was particularly sensitive to temperature and showed consistent responses to climate and vegetation changes in UHRB and its two tributaries. An increasing NDVI promoted by climate change and anthropogenic factors played a major role in alleviating soil erosion, and the warming exerted intense impacts on soil erosion during the snowmelt period. These findings would be helpful for proposing effective measures for soil conservation in high-mountain areas under climate and vegetation changes.

Interviewing Animals Through Animal Communicators

Abstract Animal communicators worldwide employ intuitive interspecies communication (IIC) to engage in detailed, two-way communication with nonhuman animals. IIC’s potential for doing research with rather than on animals has been insufficiently explored, due to contingent onto-epistemological biases. Cooperating with animal communicators as interpreters, pilot interviews with felines were conducted. Challenges included clearly filtering the animals’ voices and bridging ontological divides and communication modes. Nevertheless, the interviews produced clear, distinct, and consistent responses, challenging and confronting both animal communicators and the researcher to reflect on their perspectives, expectations and assumptions. Engaging animals as research participants through IIC simultaneously unsettles hierarchical divides between humans and other animals, as well as between different ways of knowing. IIC can support researchers and (non)human participants in the co-creation of novel methodological multispecies strategies that form a practical counterpart to the largely theoretical explorations of the ontological and species turns, and further multivocality in academia.

Effect of cover cropping on soil organic matter characteristics: Insights from a five-year field experiment in Nebraska

Cover crops are increasingly incorporated into crop rotations to improve soil health including the postulated positive impact on soil organic carbon (SOC) storage. However, a consistent positive response of SOC to cover cropping was not observed in several studies, necessitating further clarification of mechanisms by which cover crops impact soil organic matter (SOM) dynamics. In this study, we evaluated the effect of five years of winter cover cropping within a corn-soybean rotation in Nebraska under no-till on SOC and nitrogen (N) storage in the bulk topsoil (0–10 cm depth) as well as in particulate (free and occluded), water-extractable, and mineral-associated organic matter fractions. Furthermore, cover crop effects on potential C and N losses from the topsoil in form of CO2 and N2O emissions and leached organic C and N were evaluated. The different SOM fractions were analyzed for their functional group composition using diffused reflectance infrared Fourier transform spectroscopy to account for potential changes in the SOM composition due to cover crops. Our results indicated no effect of cover cropping on C and N losses (gaseous and leaching) and on bulk SOC and total N storage five years after implementation. Differences were detected for the SOM fractions, with a positive effect of cover crops on the amount of water-extractable organic matter. The spectroscopic results suggested a significant cover crop effect on the composition of free particulate organic matter fraction. Both fractions seem to be suitable for detecting early changes in SOM characteristics due to cover cropping under the studied conditions. A significantly measurable impact on bulk SOC and N storage in 0–10 cm depth for the studied corn-soybean systems might require more than five years of cover cropping, or management changes that target an increase in cover crop biomass production and input into the soil.

What predicts individual response to language treatment in bilingual children with developmental language disorder?

For bilingual children with developmental language disorder (DLD), language treatment response is the degree to which an individual child progresses in both of their languages. Understanding what predicts language treatment response for an individual child can help clinicians plan treatment more effectively. This study is a retrospective analysis of data from Ebert et al. (2014). Participants included 32 school-age Spanish-English bilingual children with DLD who completed an intensive language treatment program. Gains in Spanish and English were measured using raw test scores in each language. Predictors of language gains include language, cognitive, and demographic variables. To examine which predictors were significant, we calculated partial correlations between the potential predictors and the posttreatment language test scores, controlling for the effects of pretreatment test scores. In Spanish, several predictors correlated with the outcome measures. After controlling for pretreatment scores, English grammaticality, female sex, processing speed, age, and fluid reasoning were related to Spanish posttreatment scores. In English, correlations with individual predictors were minimal. After controlling for pretreatment scores, only one variable was associated with one English posttreatment score: English grammaticality. The original study reported limited gains in Spanish compared to robust gains in English (Ebert et al., 2014). Treatment response in Spanish is more variable given the lack of environmental support for Spanish in the US. As a result, individual factors (including nonverbal cognition, pretreatment language levels, and demographic variables) influence treatment gains in Spanish. In contrast, strong environmental support for English supports a more consistent treatment response, with a smaller role for individual factors.

Mesh‐size independent rigid‐body spring network for simulation of the dynamic fracture behavior of concrete

AbstractIn this study, a numerical approach is developed for simulating the rate‐dependent behaviors of concrete without mesh sensitivity. The rheological units (e.g., dashpot) are integrated with the six directional springs in the rigid‐body spring network (RBSN) elements to reflect the rate‐dependent behavior of concrete. Previously, the viscoplastic damage model was associated with the elemental degrees of freedom. However, in the present approach, a viscoelastic constitutive law is newly defined for the normal direction as a function of the strain rate, from which the internal forces can be updated from the regularized elemental stresses. Such improvements are validated through the numerical simulations of the direct tensile test and spalling test using the modified split‐Hopkinson pressure bar (SHPB). The simulated results show consistent structural responses without mesh dependence on the strain rate. In addition, the influences of the softening curve shapes on the crack localizations are examined. It is shown that the rheological parameters can be optimized and determined for consistent applications through virtual experiments. The proposed numerical approach enables the mesh construction procedure without concerning the mesh‐size sensitivity due to the strain rate, and various applications are expected for the simulations of detailed numerical models of concrete materials and structures under high loading rates.

How Would Americans Respond to Direct Cash Transfers? Results from Two Survey Experiments

Universal basic income has gained renewed interest among policy makers and researchers in the United States. Although research indicates that unconditional cash transfers produce diverse benefits for households, public support lags in part because of predicted unemployment and frivolous spending. To understand how Americans would reorganize their lives around unconditional cash transfers, this article examines the relationship between the structure of cash-transfer programs and their usage. We leverage experiments embedded in two nationally representative surveys to assess relationships between payment frequency, payment amount, and respondents’ anticipated usage. Though the survey experiments presented widely varying scenarios to survey participants, we saw largely consistent responses. Respondents most commonly reported they would use their payments for regular expenses, paying debts and building savings. Increased payment amounts were positively associated with spending on economic mobility-oriented goals and savings and debt decisions, but increased payment frequencies were negatively associated with these goals.

An omnivore vigour hypothesis? Nutrient availability strengthens herbivore suppression by omnivores across 48 field sites.

Nutrients regulate herbivore growth from the 'bottom-up' via improved plant vigour and food quality. Nitrogen also affects 'top-down' control of herbivores by moderating attraction of predators and the rates at which they consume herbivorous prey. Tri-trophic consequences of nitrogen availability are more challenging to predict among omnivorous natural enemies who feed on both plants and herbivores, limiting our ability to predict net outcomes of nutrient availability in food webs. In a two-year field survey of insects on zucchini host plants at 48 sites, I predicted that both herbivores and foliar-feeding omnivores would increase with nutrient availability, while predators would not. My results revealed positive relationships between omnivores and foliar nitrogen concentrations, while predators had neutral responses to foliar N. Surprisingly, herbivores declined with increasing foliar N across the field sites. Greenhouse experiments re-enforced these patterns, as herbivore growth inversely correlated with soil N concentrations in communities that included foliar-feeding omnivores. Conversely, herbivore growth was uncorrelated with soil N on plants with predators, nor on predator-free plants. These results suggest that omnivores mount strong and consistent responses to nitrogen in plant tissues in a variety of ecological contexts. In environments where omnivorous arthropods can thrive, their recruitment to nitrogen-rich plants may increase predation and thereby counterbalance and stabilize 'bottom-up' increases in herbivore performance supported by enhanced foliar nutrition.

Infant and maternal responses to emotional facial expressions: A longitudinal study

The current longitudinal study (N = 107) examined mothers’ facial emotion recognition using reaction time and their infants’ affect-based attention at 5, 7, and 14 months of age using eyetracking. Our results, examining maternal and infant responses to angry, fearful and happy facial expressions, show that only maternal responses to angry facial expressions were robustly and positively linked across time points, indexing a consistent trait-like response to social threat among mothers. However, neither maternal responses to happy or fearful facial expressions nor infant responses to all three facial emotions show such consistency, pointing to the changeable nature of facial emotion processing, especially among infants. In general, infants’ attention toward negative emotions (i.e., angry and fear) at earlier timepoints was linked to their affect-biased attention for these emotions at 14 months but showed greater dynamic change across time. Moreover, our results provide limited evidence for developmental continuity in processing negative emotions and for the bidirectional interplay of infant affect-biased attention and maternal facial emotion recognition. This pattern of findings suggests that infants’ affect-biased attention to facial expressions of emotion are characterized by dynamic changes.

Constructing simplified models for dynamic analysis of monopile-supported offshore wind turbines

Accurately modeling the complicated dynamic mechanisms of offshore wind turbines (OWTs) requires high numerical fidelity. However, since these models are computationally expensive for both forward and inverse problems, simplified OWT models are needed. The present study develops two approaches to constructing simplified numerical models based on full-order finite element models, which aim to accurately and efficiently simulate dynamic behaviours of monopile-supported OWTs. The first approach decomposes the structure into substructures and establishes a reduced-order model based on the similarity principle of modal parameters and time-domain responses, in accordance with full-order models. The second approach uses proper orthogonal decomposition and modal truncation techniques to construct a state-space model, which produces consistent time-domain responses with full-order models. For both approaches, model updating is used to improve the accuracy of the simplified models. The effectiveness of the approaches is demonstrated through the monopile-supported, 10 MW DTU reference wind turbine. The results show that the computational time required for both simplified models is less than 10% that of the full-order model, without the compromise of accuracy, i.e., less than 5% difference in modal frequency and an excellent agreement in time-domain responses. The proposed approach provides an efficient and accurate dynamic analysis solution for offshore structures.

Abstract WP139: Current Practice Trends In The Management Of Cervical Artery Dissection - Preliminary Results

Introduction: Cervical artery dissection (CAD) is a well-recognized cause of acute ischemic stroke, especially in young adults, accounting for up to 20-25% of all cases. Several studies reported an incidence between 2.5-5 per 100,000 in the general population. However, the actual incidence may be higher as many patients remain asymptomatic. Even though CAD is one of the leading causes of ischemic stroke, there is a lack of consensus in management. Our study surveyed practicing clinicians involved in the management of CAD to characterize current practice trends and provide a foundation for future research. Methods: An online case-based questionnaire with 11 questions regarding the management of cervical artery dissection was developed and piloted internally with 12 Mayo Clinic cerebrovascular neurologist/neurosurgeons. The survey was finalized, and initially sent to the STOP-CAD study group. We then sent the survey to practicing vascular neurologists across different academic institutions. Surveys were sent to 126 unique individuals. Results: A total of 42 clinicians completed the questionnaires. The response rate was 33% (42/126). Aspirin antiplatelet monotherapy was seen as the most appropriate therapy for asymptomatic CAD (81% [34/42]). Anticoagulation was the treatment of choice for cases with CAD and concomitant intraluminal thrombus (74% [31/42]). Most (74% [31/42]) of the participants recommended repeat imaging at three months. However, no consistent response regarding the type of antithrombotic agent for symptomatic CAD without intramural thrombus or cases with pseudoaneurysm. There was marked variability regarding the duration of antithrombotic therapy, ranging from three months to life-long treatment. Conclusion: Marked variability was seen in the management of CAD, especially regarding the choice of antithrombotic agent in symptomatic and complicated (stenosis or pseudoaneurysm) cases and the duration of such therapy, which reflects the lack of definitive clinical trial data. Ongoing research is needed to better guide the optimal management of these patients.

Genotype accounts for intraspecific variation in the timing and duration of multiple, sequential life-cycle events in a willow species.

Phenological variation among individuals within populations is common and has a variety of ecological and evolutionary consequences, including forming the basis for population-level responses to environmental change. Although the timing of life-cycle events has genetic underpinnings, whether intraspecific variation in the duration of life-cycle events reflects genetic differences among individuals is poorly understood. We used a common garden experiment of 10 genotypes of Salix hookeriana (coastal willow) from northern California, USA to investigate the extent to which genetic variation explains intraspecific variation in the timing and duration of multiple, sequential life-cycle events: flowering, leaf budbreak, leaf expansion, fruiting, and fall leaf coloration. We used seven clones of each genotype, for a total of 70 individual trees. Genotype affected each sequential life-cycle event independently and explained on average 62% of the variation in the timing and duration of vegetative and reproductive life-cycle events. All events were significantly heritable. A single genotype tended to be 'early' or 'late' across life-cycle events, but there was no consistent response within genotypes for event durations. This research demonstrates that genetic variation can be a major component underlying intraspecific variation in the timing and duration of life-cycle events. It is often assumed that the environment affects durations, but we show that genetic factors also play a role. Because the timing and duration of events are independent of one another, our results suggest that the effects of environmental change on one event will not necessarily cascade to subsequent events. This article is protected by copyright. All rights reserved.