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Construction, characterization and crystal structure of a fluorescent single-chain Fv chimera
No full textIn vitro display technologies based on phage and yeast have a successful history of selecting single-chain variable fragment (scFv) antibodies against various targets. However, single-chain antibodies are often unstable and poorly expressed in Escherichia coli. Here, we explore the feasibility of converting scFv antibodies to an intrinsically fluorescent format by inserting the monomeric, stable fluorescent protein named thermal green, between the light- and heavy-chain variable regions. Our results show that the scTGP format maintains the affinity and specificity of the antibodies, improves expression levels, allows one-step fluorescent assay for detection of binding and is a suitable reagent for epitope binning. We also report the crystal structure of an scTGP construct that recognizes phosphorylated tyrosine on FcεR1 receptor of the allergy pathway
Vertebrate responses against arthropod salivary proteins and their therapeutic potential
No full textThe saliva of hematophagous arthropods contains a group of active proteins to counteract host responses against injury and to facilitate the success of a bloodmeal. These salivary proteins have significant impacts on modulating pathogen transmission, immunogenicity expression, the establishment of infection, and even disease severity. Recent studies have shown that several salivary proteins are immunogenic and antibodies against them may block infection, thereby suggesting potential vaccine candidates. Here, we discuss the most relevant salivary proteins currently studied for their therapeutic potential as vaccine candidates or to control the transmission of human vectorborne pathogens and immune responses against different arthropod salivary proteins
Ecological Correlates of Alligator Snapping Turtle Bite Performance
No full textThe Alligator Snapping Turtle (Macrochelys temminckii) is one of many turtle species facing conservation challenges. Nearly extirpated in the 1980s, it is currently the subject of a head-start initiative, of which, any lasting behavioral or physiological effects were—until now—unknown! To evaluate the ability of captive-reared individuals to excel in natural habitats, and to foresee any future research or conservation challenges regarding this animal, I explored a suite of variables that influence bite performance and behaviors including captive or free-ranging status, and environmental conditions including body temperature and season. My results indicated that free-ranging M. temminckii outperform those residing in captivity, and that captive individuals housed in outdoor ponds outperform their counterparts housed indoors. Further, I found free-ranging individuals more willing to engage in bite behaviors, a trend that significantly impacted maximum bite force among test groups. I also found that aspects of bite performance including bite velocity, acceleration, and duration all improve with increases in temperature, and that seasonality significantly influences jaw and lunge movements to an extent that was previously unanticipated, resulting in greater performance at identical temperatures, in the summer than in the Winter. Bite force was relatively robust to temperature and season; but it was maximized at higher temperatures and in the winter. These results indicate that time spent outdoors while in captivity should be maximized to support optimal performance upon release, that rigorous standardization of temperature is required in studies of ectotherm performance, and that care must be taken in selecting the time of year in which temperature studies are conducted
Scale associated coupling between channel morphology and riparian vegetation in a bedrock-controlled stream
No full textMost fluvial systems exhibit systematic, continuous upstream to downstream variations in channel morphology and related ecological and hydrological parameters (emphasized by conceptual frameworks such as downstream hydraulic geometry and the river continuum concept), and discontinuous, shorter range variations (emphasized by hierarchical patch dynamics). This study investigates the relative importance of broader-scale upstream to downstream variation and local variation at the hydraulic unit scale in a bedrock-controlled stream in central Kentucky, USA. A nested ANOVA analytical approach was used to determine the relative importance of three nested spatial scales in explaining variations in channel morphology and riparian trees. Results show that channel morphology is largely controlled by local-scale variation explaining about 92% of slope, 46% of bankfull width, 99% of average depth, 54% of width-depth ratio, 86% of channel cross-sectional area, and 100% of the hydraulic radius of the channel. Different categories of substrate characteristics, however, represent anomalies with respect to variance explained at different levels. Furthermore, local-scale controls explain 60% of variations in species richness, 59% of variations in the total number of individual trees, 68% of variation in the proportion of Platanus occidentalis basal area and 43% of variation in the total number of biogeomorphic impacts. These results are consistent with the idea of tight coupling between channel morphology and riparian vegetation, although they do not, by themselves, prove such interactions. The morphological variation of the channel at the local scale is primarily attributable to the geological controls (e.g., faults, bedding planes, joints and fractures) and incision status associated with the study area. The local scale variation in vegetation pattern can be explained by the highly local edaphic differences along the riparian corridor, which is likely to be related to the local scale fluvial process-form variations, and biogeomorphic impacts and feedbacks. These patterns may therefore be common in bedrock rivers strongly influenced by geological controls
Synthesizing the Multiple-Probe Experimental Design With the PEAK Relational Training System in Applied Settings
No full textThe scientist-practitioner model necessitates embedding experimental designs within applied practice. This technical report describes a procedure for embedding a multiple-probe experimental design within the PEAK Relational Training System across all four PEAK modules. Baseline probes provide a direct test of target skills negatively endorsed within the PEAK assessment battery and can provide an estimate of skill acquisition in the absence of direct training. Temporal staggering of the probes maintains the fidelity of the experimental design and allows for the design to evolve along with learner skill acquisition. Achievement of mastery criteria demonstrates the efficacy of programming, and failure to achieve mastery can be remedied through programming adjustments that can be captured within the design. We additionally conducted a field test of the design with a child with disabilities, supporting the viability of this procedure within applied settings
Freshwater turtle community composition in strip pit lakes on mined lands
No full textCreating and managing undeveloped lands is important for the perpetuation of species and communities they comprise, particularly for turtles, which are often impacted by human disturbance and are ill-equipped to adapt to sustained anthropogenic disturbance. Reclaimed land at the site of former surface mining operations often provides a large matrix of wetland, prairie, and woodland habitat that is protected from development. Such sites support robust communities of birds and amphibians, but few investigations have assessed their suitability for aquatic reptiles. To examine their suitability for turtle communities, we surveyed strip pit lakes and naturally occurring lakes at Mined Lands Wildlife Area in southeastern Kansas, USA. Community composition was different between the two classes of wetland due to differences in the abundance of Chelydra serpentina serpentina (Eastern Snapping Turtle), Chrysemys picta bellii (Western Painted Turtle), and Sternotherus odoratus (Eastern Musk Turtle). Catch per unit effort, however, only varied significantly for C. s. serpentina, which were captured at lower rates in strip pits. All other species were at least as abundant in strip pit lakes as in natural lakes, and C. p. bellii were slightly more abundant in strip pits. Sternotherus odoratus were very abundant in a single strip pit lake. Canonical correspondence analysis associated C. s. serpentina with shallow water and high percentage of canopy cover, while C. p. bellii were associated with deep water. Sternotherus odoratus were associated with abundant submerged vegetation; however, habitat features only explained 12% of the variation in species occurrence. Strip pit lakes appear to provide suitable habitat for most of the turtle species encountered, with the notable exception of C. s. serpentina, and may even be preferred over natural oxbows by some species
Analysis of Machine Learning Techniques for Lightweight DDoS Attack Detection on IoT Networks
No full textAs botnet style distributed denial of service (DDoS) attacks continue to proliferate the Internet of Things (IoT) landscape, researchers have struggled to provide a definitive way of addressing concerns related to the IoT’s security. In this paper, we work from the axiom that DDoS attacks are easiest to detect at the target of the attack but are best mitigated closer to the attacker by implementing four machine learning models that detect botnet-infected DDoS attackers on their access network. These models operate on network packet counts, which can easily be gathered by an access router, and run in real-time or near real-time, even on a low power device, namely a Raspberry Pi. We introduce a novel method for visualizing network activity as graphical heatmaps and use convolutional neural network (CNN) models designed for embedded devices and mobile platforms to classify network traffic as benign or malicious. We compare this approach using a support vector machine (SVM) and a long short-term memory recurrent neural network (LSTM). Based on our results, we conclude that the use of lightweight CNNs to analyze network traffic through graphical heatmaps provides highly accurate botnet-based DDoS attack detection for IoT access networks, with an average accuracy of 99.8%, despite our training dataset being between 73×–2170× smaller than those seen in related works, and runtimes ranging from 334 ms to 2 s on a Raspberry Pi
Diurnal variation in serum concentrations of cortisol in captive African (Loxodonta africana) and Asian (Elephas maximus) elephants
No full textCortisol is involved in a broad range of physiological processes and enables animals to adapt to new situations and challenges. Diurnal fluctuations in circulating cortisol concentrations in elephants have been demonstrated based on samples from urine and saliva. The aims of this study were to demonstrate diurnal cortisol fluctuations based on blood samples and compare concentrations between seasons, species, and changes in reproductive hormone concentrations. Nine African (Loxodonta africana) and three Asian (Elephas maximus) elephants at two facilities in the United States were included in this study. Blood samples were collected every 2–3 h at one location and every 1–6 h at another. Peak serum concentrations of cortisol averaged 28 ng/ml for both African and Asian elephants, and diurnal cycles included a fivefold decrease from morning peak to evening nadir concentrations. Diurnal cortisol profiles varied uniquely among individual elephants. During the winter, nadir concentrations of cortisol were slightly higher, and the timing of peak concentrations was less predictable. There was no correlation between diurnal serum concentrations of progesterone and cortisol; however, a significant correlation (p =.02) was identified between serum concentrations of testosterone and cortisol when a time lag of ~2–3 h was considered. The physiological significance of the positive correlations between diurnal serum concentrations of cortisol and testosterone in male elephants remains to be determined. If cortisol concentrations are being used to evaluate elephant health or welfare, samples should be obtained at the same time each day to minimize variation due to diurnal fluctuations, and ideally seasonal variations and individuality in diurnal profiles should also be considered
Ground Control Point Assessment for sUAS-based SfM Photogrammetry
No full textThe use of small Unmanned Aerial Systems (sUAS) in combination with Structure from Motion (SfM) photogrammetry is an evolving tool for geoscientists. SfM photogrammetry allows for rapid acquisition of the data that is required to create orthophotos and Digital Surface Models (DSMs) for a variety of field applications. Ground Control Points (GCPs) are used to reconstruct the DSM and evaluate the accuracy of aerial imagery collected from sUAS. When acquiring data for SfM photogrammetry, GCPs are required for spatial referencing. However, questions remain open regarding the effect of methodological techniques on the precision and accuracy of the resulting DSMs. This study focuses on assessing the relationship between DSM accuracy and the GCP methodology used to georeference the imagery. By determining the minimal number of GCPs necessary for a specific level of accuracy and precision in the final DSM products, both time and money are saved during data collection and processing
Incorporating an Activity Schedule during Schedule Thinning in Treatment of Problem Behavior
No full textWe incorporated an activity schedule (MacDuff et al., 1993) into schedule thinning (Hanley et al., 2014) following functional communication training in the treatment of problem behavior of a child with autism, systematically replicating and extending research on activity schedules and schedule thinning. When the activity schedule was introduced, independent engagement increased, rates of communication responses decreased, and problem behavior remained low. Results are discussed in terms of advantages of activity schedules during schedule thinning, conceptual implications for including activity schedules, and directions for future research