Evaluation of Anesthetic Specific EEG Dynamics during State Transitions between Loss and Return of Responsiveness

Purpose: electroencephalographic (EEG) information is used to monitor the level of cortical depression of a patient undergoing surgical intervention under general anesthesia. The dynamic state transitions into and out of anesthetic-induced loss and return of responsiveness (LOR, ROR) present a possibility to evaluate the dynamics of the EEG induced by different substances. We evaluated changes in the EEG power spectrum during anesthesia emergence for three different anesthetic regimens. We also assessed the possible impact of these changes on processed EEG parameters such as the permutation entropy (PeEn) and the cerebral state index (CSI). Methods: we analyzed the EEG from 45 patients, equally assigned to three groups. All patients were induced with propofol and the groups differed by the maintenance anesthetic regimen, i.e., sevoflurane, isoflurane, or propofol. We evaluated the EEG and parameter dynamics during LOR and ROR. For the emergence period, we focused on possible differences in the EEG dynamics in the different groups. Results: depending on the substance, the EEG emergence patterns showed significant differences that led to a substance-specific early activation of higher frequencies as indicated by the “wake” CSI values that occurred minutes before ROR in the inhalational anesthetic groups. Conclusion: our results highlight substance-specific differences in the emergence from anesthesia that can influence the EEG-based monitoring that probably have to be considered in order to improve neuromonitoring during general anesthesia.

Language emergence can take multiple paths: Using motion capture to track axis use in Nicaraguan Sign Language

Research on emergent sign languages suggests that younger sign languages may make greater use of the z-axis, moving outwards from the body, than more established sign languages when describing the relationships between participants and events (Padden, Meir, Aronoff, and Sandler, 2010). This has been suggested to reflect a transition from iconicity rooted in the body (Meir, Padden, Aronoff, and Sandler, 2007) towards a more abstract schematic iconicity. We present the results of an experimental investigation into the use of axis by signers of Nicaraguan Sign Language (NSL). We analysed 1074 verb tokens elicited from NSL signers who entered the signing community at different points in time between 1974 and 2003. We used depth and motion tracking technology to quantify the position of signers’ wrists over time, allowing us to build an automated and continuous measure of axis use. We also consider axis use from two perspectives: a camera-centric perspective and a signer-centric perspective. In contrast to earlier work, we do not observe a trend towards increasing use of the x-axis. Instead we find that signers appear to have an overall preference for the z-axis. However, this preference is only observed from the camera-centric perspective. When measured relative to the body, signers appear to be making approximately equal use of both axes, suggesting the preference for the z-axis is largely driven by signers moving their bodies (and not just their hands) along the z-axis. We argue from this finding that language emergence patterns are not necessarily universal and that use of the x-axis may not be a prerequisite for the establishment of a spatial grammar.

Weed emergence and seedbank after three years of repetitive shallow cultivation in a muck soil field

Frequent cultivation is often used to control weeds in crops such as lettuce. The efficacy of this technique on weed populations has been evaluated, but the effect on weed emergence and seedbanks is less documented. Studies in mineral soil indicate that soil disturbance can increase both weed emergence and seed persistence depending on where seeds are redistributed in the soil profile. Evaluations done in muck soil are scarce. This study evaluated the effect of two and four repetitive shallow (3.4 to 7.1 cm deep) cultivations on weed emergence and the weed seedbank in muck soil. Cultivation treatments (0, 2 and 4 cultivations using a inter-row rototiller) were done in lettuce plots from 2017 to 2019. Weed density was evaluated by species before each cultivation date and after crop harvest. Viable seedbanks were evaluated by collecting soil samples before and after each growing season and placing them in greenhouse flats. Statistical analyses were based on mixed models. Results showed that shallow cultivation modified the emergence patterns of weeds but did not reduce total emergence during the subsequent years or viable seedbanks. After two seasons without seed inputs, total emergence was reduced by 46.6% and the seedbank was reduced by 31.7% regardless of the cultivation treatment. However, the seedbank of the very abundant common purslane (<i>Portulaca oleracea</i>) remained high.

Hatching Under Brownification: DOC-Mediated Changes in Physical, but Not Chemical Properties of Water Affect Hatching Patterns of Cladocera Resting Eggs

Dissolved organic carbon (DOC) is often related to the brownification of water in continental aquatic systems and to changes in the physiology of zooplankton organisms. Zooplankton resting eggs are particularly sensitive to changes in light and chemical characteristics of water, but the physical and chemical effects associated to DOC on dormant stages have never been tested before. Herein we tested how DOC affects hatching rates and time to hatching of Cladocera (Diaphanosoma birgei) resting eggs. In order to analyze the chemical (i.e. toxic) and physical (i.e. light attenuation) effects of DOC on hatching patterns, resting eggs were exposed to different concentrations of DOC in an experimental design which isolated chemical from physical effects. We observed higher hatching rates and lower time to hatching at intermediate DOC concentrations. DOC effects on hatching mainly relied on light attenuation, while chemical effects were likely of minor importance. We conclude that DOC may change Cladocera emergence patterns mainly through light attenuation in the water column.

Modeling seasonal emergence of Poa annua in urban greenspace

Turfgrasses are perennial components of urban greenspaces found in parks, recreational areas, golf courses, sports fields, and lawns that confer many ecosystem services. A copious seed producer, Poa annua is the most troublesome weed of turfgrass and continually threatens the ecosystem services provided by urban greenspaces. Field research was conducted in Knoxville, TN to better understand environmental conditions triggering P. annua seedling emergence patterns to assist managers with optimally timing interventions—both chemical and non-chemical—for control. Fluctuations in cooling degree day (CDD21C) accumulation accounted for 82% of the variance in yearly cumulative P. annua emergence data collected in a single irrigated sward of hybrid bermudagrass [C. dactylon (L.) Pers. x. C. transvaalensis Burtt-Davy]. However, non-linear models using CDD21C data developed ex post were not able to accurately predict P. annua emergence patterns ex ante. In both years, P. annua emergence changed most rapidly between the 40th and 43rd week of the year when seven-day mean soil temperature and rainfall were 18.9 °C and 12.7 mm, respectively. Future research should explore the efficacy of herbicide mixtures applied when P. annua emergence is most rapidly changing in lieu of developing models to predict when specific emergence thresholds occur.

Enhanced Detection of Recently Emerged SARS-CoV-2 Variants of Concern in Wastewater

SARS-CoV-2 RNA shedding in stool enabled wastewater surveillance for the genetic material of the virus. With the emergence of novel variants of concern and interest it becomes increasingly important to track arrival and spread of these variants. However, most current approaches rely on the manually curated lists of mutations phenotypically associated with the variants of concern. The resulting data has many overlaps between distinct variants leading to less specific characterization of complex sample mixtures that result from wastewater monitoring. In our work we propose a simple and specific method for characterization of wastewater samples by introducing the concept of quasi-unique mutations. Our approach is data driven and results in earlier detection and higher resolution of variants of concern emergence patterns in wastewater data.ImportanceWastewater-based epidemiology has emerged as a powerful tool for public health response to the SARS-CoV-2 pandemic. As wastewater is a pooled, community sample of all persons contributing to the waste stream, there are several challenges in using sequencing information from wastewater samples to detect variants. Wastewater typically will consist of fragmented genomes from multiple, circulating variants. While it is straightforward to call the mutations present in a wastewater sample, it is more challenging to call the presence of variants that are defined by a set of characteristic mutations, particularly when mutations are shared among many circulating variants. Hence, we present a novel approach for screening for variants of concern in wastewater. Our computational approach introduces the concept of a “quasi-unique mutation” corresponding to a given PANGO lineage. We show that our method enables detection of the emergence of variants of concern in communities, providing a new approach for wastewater-based epidemiology of SARS-CoV-2.

CAUSAL MAPPING TO EXPLORE EMERGENCE OF CONSTRUCTION DISPUTES

Disputes, frequently encountered in construction projects, can substantially affect project success, necessitating a clear understanding of how and why disputes occur. Previous studies on disputes mostly yielded exhaustive lists or hierarchies of possible causes of disputes, which can hardly be used to understand how these causes come together to form a dispute. To address this gap, this study provides an alternative approach to understand the underlying causes of disputes, and their relationship within a specific context, using causal map analysis. This study is conducted using causal mapping approach to understand dispute emergence patterns in practice. Initially, a causal map of construction disputes is developed based on literature. The map is altered and verified through an expert workshop, considering projects contracted through FIDIC Yellow Book. The causal representation of the dispute emergence patterns highlights the importance of pre-construction studies, people factor, and contract terms. It is revealed that significant causes are either result of a chain of preceding factors or are triggers for further ones. This finding reinforces that the occurrence of disputes does not only depend on individual causes; rather, these causes combine with a series of other factors for a dispute to occur.

Seed Biology of Witchgrass (Panicum capillare L.) Ensures Its Success Under Different Environmental Conditions

Witchgrass (Panicum capillare L.) is a summer growing grass weed species and is increasing its prevalence in southern Australia. A better understanding of the seed biology is needed to effectively manage this weed. A series of field and laboratory studies were conducted to determine seed germination factors, field emergence patterns, and soil seedbank longevity. Witchgrass germination was stimulated by light and it germinated better at temperature over 20°C, with 93–100% germination at the two constant temperatures of 20 and 30°C, and the two alternating day/night temperatures of 30/25 and 35/25°C. It is highly tolerant to moisture stress at germination, with 2–7% germination even at −0.48 Mpa. Witchgrass seed lost 47–68% viability after 12 months of burial in the soil, however the seed persisted for more than 4 years if buried at 10 cm in the soil. Witchgrass emergence in southern New South Wales (NSW) commenced in mid spring (early October), with peak emergence of 63–83% in November and then significantly reduced to 16–37% emergence in December. Little emergence (&lt;1%) occurred in the summer months from January to February. These results provide useful information for designing effective management strategies and the optimum timing of control. Climate change could favor the phenological development and the further spread of this weed, which present new challenges for its effective management. Further study is needed to investigate the impact of climate change on the biology, spread, and management of witchgrass.

Emergence Patterns of Winter and Summer Annual Weeds in Ethiopian mustard (Brassica carinata) Cropping System

Ethiopian mustard (Brassica carinata A. Braun) is a biofuel crop that was recently introduced in the southeastern United States. In order for this crop to be successful, there is a need to develop integrated weed management strategies that complement its rotation with summer cash crops. The objectives of this research were to evaluate the effect of previous season summer crops on winter weed emergence patterns during Ethiopian mustard growing season and to assess the impact of planting Ethiopian mustard on the emergence patterns of summer weed species. Gompertz models were fit to winter and summer weed emergence patterns. All models represented more than 80% of the variation with RMSE values less than 0.20. The emergence pattern for winter weed species was best described using Growing Degree Days (GDD) accumulation, and this model can be utilized for implementing weed control strategies at the critical Ethiopian mustard growth stages. The results also showed that summer weeds can emerge during the winter in northern Florida but do not survive frost damage, which might create off-season seed bank reductions before the summer crop growing season.