Veni, vidi, vici? Future spread and ecological impacts of a rapidly expanding invasive predator population.

Economic and ecological consequences of invasive species make biological invasions an influential driver of global change. Monitoring the spread and impacts of non-native species is essential, but often difficult, especially during the initial stages of invasion. The Joro spider, Trichonephila clavata (L. Koch, 1878, Araneae: Nephilidae), is a large-bodied orb weaver native to Asia, likely introduced to northern Georgia, U.S. around 2010. We investigated the nascent invasion of T. clavata by constructing species distribution models (SDMs) from crowd-sourced data to compare the climate T. clavata experiences in its native range to its introduced range. We found evidence that the climate of T. clavata's native range differs significantly from its introduced range. Species distribution models trained with observations from its native range predict that the most suitable habitats in North America occur north of its current introduced range. Consistent with SDM predictions, T. clavata appears to be spreading faster to the north than to the south. Lastly, we conducted surveys to investigate potential ecological impacts of T. clavata on the diversity of native orb weaving spiders. Importantly, Trichonephila clavata was the most common and abundant species observed in the survey, and was numerically dominant at half of the sites it was present in. Our models also suggest that there is lower native orb weaver species richness and diversity closer to where T. clavata was initially found and where it has been established the longest, though human population density complicates this finding. This early study is the first to forecast how widely this spider may spread in its introduced range and explore its potential ecological impacts. Our results add evidence that T. clavata is an invasive species and deserves much more ecological scrutiny.

Risk Assessment and the Effects of Refuge Availability on the Defensive Behaviors of the Southern Unstriped Scorpion (Vaejovis carolinianus).

Selection should favor individuals that acquire, process, and act on relevant environmental signals to avoid predation. Studies have found that scorpions control their use of venom: both when it is released and the total volume expelled. However, this research has not included how a scorpion's awareness of environmental features influences these decisions. The current study tested 18 Vaejovis carolinianus scorpions (nine females and nine males) by placing them in circular arenas supplied with varying numbers (zero, two, or four) of square refuges and by tracking their movements overnight. The following morning, defensive behaviors were elicited by prodding scorpions on the chelae, prosoma, and metasoma once per second over 90 s. We recorded stings, venom use, chelae pinches, and flee duration. We found strong evidence that, across all behaviors measured, V. carolinianus perceived prods to the prosoma as more threatening than prods to the other locations. We found that stinging was a common behavior and became more dominant as the threat persisted. Though tenuous, we found evidence that scorpions' defensive behaviors changed based on the number of refuges and that these differences may be sex specific. Our findings suggest that V. carolinianus can assess risk and features of the local environment and, therefore, alter their defensive strategies accordingly.

Venom Collection from Spiders and Snakes: Voluntary and Involuntary Extractions ("Milking") and Venom Gland Extractions.

Venom collection (often called "milking") provides the toxic secretions essential for studying animal venoms and/or generating venom products. Methods of venom collection vary widely, falling into three broad categories: voluntary venom extraction (inducing the animal to willingly release its venom), involuntary venom extraction (glandular massage, electrical stimulation, or administration of induction chemicals to promote venom expulsion), and venom gland extraction (surgical aspiration or trituration of homogenized gland tissue). Choice of method requires consideration of animal species, animal welfare, human safety (avoiding envenomation), venom yield and composition desired, and level of toxin purity required. Here, we summarize the materials and methods used to obtain venom by each of these approaches from spiders and snakes.

Active recombinant Tol2 transposase for gene transfer and gene discovery applications.

BACKGROUND: The revolutionary concept of "jumping genes" was conceived by McClintock in the late 1940s while studying the Activator/Dissociation (Ac/Ds) system in maize. Transposable elements (TEs) represent the most abundant component of many eukaryotic genomes. Mobile elements are a driving force of eukaryotic genome evolution. McClintock's Ac, the autonomous element of the Ac/Ds system, together with hobo from Drosophila and Tam3 from snapdragon define an ancient and diverse DNA transposon superfamily named hAT. Other members of the hAT superfamily include the insect element Hermes and Tol2 from medaka. In recent years, genetic tools derived from the 'cut' and 'paste' Tol2 DNA transposon have been widely used for genomic manipulation in zebrafish, mammals and in cells in vitro. RESULTS: We report the purification of a functional recombinant Tol2 protein from E.coli. We demonstrate here that following microinjection using a zebrafish embryo test system, purified Tol2 transposase protein readily catalyzes gene transfer in both somatic and germline tissues in vivo. We show that purified Tol2 transposase can promote both in vitro cutting and pasting in a defined system lacking other cellular factors. Notably, our analysis of Tol2 transposition in vitro reveals that the target site preference observed for Tol2 in complex host genomes is maintained using a simpler target plasmid test system, indicating that the primary sequence might encode intrinsic cues for transposon integration. CONCLUSIONS: This active Tol2 protein is an important new tool for diverse applications including gene discovery and molecular medicine, as well as for the biochemical analysis of transposition and regulation of hAT transposon/genome interactions. The measurable but comparatively modest insertion site selection bias noted for Tol2 is largely determined by the primary sequence encoded in the target sequence as assessed through studying Tol2 protein-mediated transposition in a cell-free system.

Hepatitis C, disease and its management: a cost-effectiveness analysis of the new generation oral protease inhibitors.

BACKGROUND: Hepatitis C, caused by a single-stranded RNA virus, has become a global health problem. Infecting millions of individuals in the United States alone, chronic HCV infection can lead to devastating medical problems including cirrhosis and hepatocellular carcinoma. These problems create millions of dollars in health-care costs for treatment and management. This study determines the cost-effectiveness of hepatitis C treatment with the new generation of oral protease inhibitors. METHODS: A Markov model was constructed to simulate the progression of genotype-1 chronic hepatitis C disease in a cohort of 50-year-old patients. A decision tree, along with the Markov model, was then used to determine duration of disease, treatment success, progression of disease and mortality. At the end of each stage in the model, the cost and quality-adjusted life years (QALY) were summed for each individual. These were then used to calculate the overall cost-effectiveness ratio (CER) using QALY as the unit of effectiveness. Four treatment options were modelled: sofosbuvir with pegylated interferon-α and ribavirin (SOF/PEG-IFN+RBV), sofosbuvir with ribavirin (SOF/RBV), simeprevir with pegylated interferon-α and ribavirin (SMV/PEG-IFN+RBV) and simeprevir with sofosbuvir (SMV/SOF). RESULTS: SOF/PEG-IFN+RBV yielded a CER ratio of $6,796.22/QALY, SMV/PEG-IFN+RBV of $7,642.60/QALY and SMV/SOF of $8,959.11/QALY. SOF/RBV had a higher CER of $16,295.30/QALY. It is important to note however that SMV/SOF had the highest QALY at 19.08. CONCLUSIONS: After consideration of quality of life, treatment regimens and treatment side effects, the SMV/SOF regimen yields acceptable cost-effectiveness ratios with high QALY.

Net Clinical Benefits of Guidelines and Decision Tool Recommendations for Oral Anticoagulant Use among Patients with Atrial Fibrillation.

BACKGROUND: The 2012 American College of Chest Physicians' Evidence-Based Clinical Practice (CHEST), the 2012 European Society of Cardiology, and the 2014 American Heart Association guidelines and published decision tools by LaHaye and Casciano offer oral anticoagulant (OAC) recommendations for patients with atrial fibrillation (AF). The aim of our study was to compare the net clinical benefit (NCB) of OAC prescribing that was concordant with these decision aids. METHODS: A cohort study of the 2001-2013 LifeLink claims data was used. NCB in concordance with each decision aid was defined as adverse events (thromboembolic and major bleed events) prevented per 10,000 person-years. Cox proportional hazard models were used to assess the relative risk of AF adverse events associated in concordance with each decision aid adjusted for potential confounders. FINDINGS: The study included 15,129 patients with AF, contributing 33,512 person-years. The NCB of the CHEST guidelines was the highest (NCB = 30.07; 95% confidence interval [CI] = 28.66, 31.49) and the European Society of Cardiology guidelines the lowest (NCB = 7.38; 95% CI = 5.97, 8.80). Significant unadjusted decreases in the risk of AF adverse events associated with concordant OAC use/nonuse were found for the CHEST guidelines (hazard ratio [HR] = .825; 95% CI = .695, .979), Casciano tool (HR = .838; 95% CI = .706, .995), and LaHaye tool (HR = .841; 95% CI = .709, .999); however, none were significant after multivariate adjustment. CONCLUSION: Concordant OAC use with any of the decision aids except for the aggressive LaHaye tool led to a positive NCB. The decision aids based on the CHA2DS2-VASc algorithm did not consistently improve the NCB compared to CHADS2-based aids. Recommending OAC use when CHA2DS2-VASc score = 1 resulted in a lower NCB when all other factors guiding recommendations were held constant.

Perianal North American blastomycosis.

Cutaneous North American blastomycosis most often results from the hematogenous spread of Blastomyces dermatitidis following pulmonary infection. Cutaneous lesions, which may be either verrucous or ulcerative plaques, commonly occur on or around orifices contiguous to the respiratory tract. We report the case of a 57-year-old man with cutaneous North American blastomycosis who presented with a well-demarcated, firm, moist, verrucous perianal plaque 4 months following the onset of a prolonged upper respiratory tract infection. Dissemination of B dermatitidis to the perianal skin is rare, but North American blastomycosis should be considered in the broad differential diagnosis of perianal lesions in any patients who have lived in or traveled to endemic regions.

Variation in Anticoagulant Recommendations by the Guidelines and Decision Tools among Patients with Atrial Fibrillation.

Published atrial fibrillation (AF) guidelines and decision tools offer oral anticoagulant (OAC) recommendations; however, they consider stroke and bleeding risk differently. The aims of our study are: (i) to compare the variation in OAC recommendations by the 2012 American College of Chest Physicians guidelines, the 2012 European Society of Cardiology (ESC) guidelines, the 2014 American Heart Association (AHA) guidelines and two published decision tools by Casciano and LaHaye; (ii) to compare the concordance with actual OAC use in the overall study population and the population stratified by stroke/bleed risk. A cross-sectional study using the 2001-2013 Lifelink claims data was used to contrast the treatment recommendations by these decision aids. CHA2DS2-VASc and HAS-BLED algorithms were used to stratify 15,129 AF patients into nine stroke/bleed risk groups to study the variation in treatment recommendations and concordance with actual OAC use/non-use. The AHA guidelines which were set to recommend OAC when CHA2DS2-VASc = 1 recommended OAC most often (86.30%) and the LaHaye tool recommended OAC the least often (14.91%). OAC treatment recommendations varied considerably when stroke risk was moderate or high (CHA2DS2-VASc > 0). Actual OAC use/non-use was highly discordant (>40%) with all of the guidelines or decision tools reflecting substantial opportunities to improve AF OAC decisions.

Multimodal sensory reliance in the nocturnal homing of the amblypygid Phrynus pseudoparvulus (Class Arachnida, Order Amblypygi)?

Like many other nocturnal arthropods, the amblypygid Phrynus pseudoparvulus is capable of homing. The environment through which these predators navigate is a dense and heterogeneous tropical forest understory and the mechanism(s) underlying their putatively complex navigational abilities are presently unknown. This study explores the sensory inputs that might facilitate nocturnal navigation in the amblypygid P. pseudoparvulus. Specifically, we use sensory system manipulations in conjunction with field displacements to examine the potential involvement of multimodal - olfactory and visual - stimuli in P. pseudoparvulus' homing behavior. In a first experiment, we deprived individuals of their olfactory capacity and displaced them to the opposite side of their home trees (<5m). We found that olfaction-intact individuals were more likely to be re-sighted in their home refuges than olfaction-deprived individuals. In a second experiment, we independently manipulated both olfactory and visual sensory capacities in conjunction with longer-distance displacements (8m) from home trees. We found that sensory-intact individuals tended to be re-sighted on their home tree more often than sensory-deprived individuals, with a stronger effect of olfactory deprivation than visual deprivation. Comparing across sensory modality manipulations, olfaction-manipulated individuals took longer to return to their home trees than vision-manipulated individuals. Together, our results indicate that olfaction is important in the nocturnal navigation of P. pseudoparvulus and suggest that vision may also play a more minor role.

Variation in venom yield and protein concentration of the centipedes Scolopendra polymorpha and Scolopendra subspinipes.

Venom generally comprises a complex mixture of compounds representing a non-trivial metabolic expense. Accordingly, natural selection should fine-tune the amount of venom carried within an animal's venom gland(s). The venom supply of scolopendromorph centipedes likely influences their venom use and has implications for the severity of human envenomations, yet we understand very little about their venom yields and the factors influencing them. We investigated how size, specifically body length, influenced volume yield and protein concentration of electrically extracted venom in Scolopendra polymorpha and Scolopendra subspinipes. We also examined additional potential influences on yield in S. polymorpha, including relative forcipule size, relative mass, geographic origin (Arizona vs. California), sex, time in captivity, and milking history. Volume yield was linearly related to body length, and S. subspinipes yielded a larger length-specific volume than S. polymorpha. Body length and protein concentration were uncorrelated. When considering multiple influences on volume yield in S. polymorpha, the most important factor was body length, but yield was also positively associated with relative forcipule length and relative body mass. S. polymorpha from California yielded a greater volume of venom with a higher protein concentration than conspecifics from Arizona, all else being equal. Previously milked animals yielded less venom with a lower protein concentration. For both species, approximately two-thirds of extractable venom was expressed in the first two pulses, with remaining pulses yielding declining amounts, but venom protein concentration did not vary across pulses. Further study is necessary to ascertain the ecological significance of the factors influencing venom yield and how availability may influence venom use.

Poisons, toxungens, and venoms: redefining and classifying toxic biological secretions and the organisms that employ them.

Despite extensive study of poisonous and venomous organisms and the toxins they produce, a review of the literature reveals inconsistency and ambiguity in the definitions of 'poison' and 'venom'. These two terms are frequently conflated with one another, and with the more general term, 'toxin.' We therefore clarify distinctions among three major classes of toxins (biological, environmental, and anthropogenic or man-made), evaluate prior definitions of venom which differentiate it from poison, and propose more rigorous definitions for poison and venom based on differences in mechanism of delivery. We also introduce a new term, 'toxungen', thereby partitioning toxic biological secretions into three categories: poisons lacking a delivery mechanism, i.e. ingested, inhaled, or absorbed across the body surface; toxungens delivered to the body surface without an accompanying wound; and venoms, delivered to internal tissues via creation of a wound. We further propose a system to classify toxic organisms with respect to delivery mechanism (absent versus present), source (autogenous versus heterogenous), and storage of toxins (aglandular versus glandular). As examples, a frog that acquires toxins from its diet, stores the secretion within cutaneous glands, and transfers the secretion upon contact or ingestion would be heteroglandular-poisonous; an ant that produces its own toxins, stores the secretion in a gland, and sprays it for defence would be autoglandular-toxungenous; and an anemone that produces its own toxins within specialized cells that deliver the secretion via a penetrating wound would be autoaglandular-venomous. Adoption of our scheme should benefit our understanding of both proximate and ultimate causes in the evolution of these toxins.

Recurrence rates of aggressive histologic types of basal cell carcinoma after treatment with electrodesiccation and curettage alone.

BACKGROUND: Basal cell carcinoma (BCC) is the most common cancer in Caucasians. Treatment options include electrodesiccation and curettage (EDC), surgical excision, and Mohs micrographic surgery (MMS). EDC is standard for smaller BCCs in low-risk locations with nonaggressive histologic subtypes. Larger BCCs in higher-risk locations and aggressive histologic subtypes are treated using surgical excision or MMS. We found no studies reporting recurrence rates for aggressive BCC subtypes treated using EDC alone. OBJECTIVE: To determine recurrence rates of histologically aggressive BCC treated using EDC. METHODS AND MATERIALS: This population-based, retrospective case study reviewed 37 primary infiltrative, desmoplastic, morpheaform, or micronodular BCCs in 34 patients treated with EDC. Recurrence was defined as reappearance of BCC within the boundaries of or contiguous to the scar resulting from initial treatment. RESULTS: Of 37 primary aggressive BCCs, 10 recurred within 3.3 years. Average primary tumor diameter was 0.69 cm. Average primary tumor diameter was 0.73 cm for those that recurred and 0.67 cm for those that did not recur. Six recurrences were in high-risk areas, three in moderate-risk areas, and one in a low-risk area. CONCLUSION: We report a 27% recurrence rate for histologically aggressive BCCs treated using EDC alone with median 6.5 years follow-up.

Positivity ratio and reaction index: patch-test quality-control metrics applied to the north american contact dermatitis group database.

BACKGROUND: The positivity ratio (PR) and reaction index (RI) characterize the ability of patch-test preparations to produce strong (++ or +++) reactions as opposed to weak (+), questionable, or irritant reactions. OBJECTIVE: This study evaluates these measures for North American Contact Dermatitis Group (NACDG) patch-test preparations. METHODS: The PR and RI were calculated for 79 NACDG standard allergens tested from 1994 to 2006 (n = 26,479 patients). The median values were used as cutoff values for "acceptable" versus "problematic" preparations. RESULTS: The top 10 "acceptable" patch-test preparations (PR < or = 55 and RI > 0.46) were mixed dialkyl thioureas 1% in petrolatum (pet), tixocortol-21-pivalate 1% pet, ethylenediamine dihydrochloride 1% pet, sesquiterpene lactone mix 0.1% pet, nickel sulfate 2.5% pet, bacitracin 20% pet, thimerosal 0.1% pet, epoxy resin 1% pet, colophony 20% pet, and mercaptobenzothiazole 1% pet. The most "problematic" patch-test preparations (PR > 55 and RI < or = 0.46) were cocamidopropyl betaine 1% aqueous (aq), benzalkonium chloride 0.1% aq, jasmine absolute 2% pet, iodopropynyl butyl carbamate 0.1% pet, 2-bromo-2-nitropropane-1,3-diol 0.5% pet, methyldibromoglutaronitrile 0.4% pet, methyldibromoglutaronitrile/phenoxyethanol 2% pet and 2.5% pet, dimethylol dihydroxyethyleneurea 4.5% aq, and clobetasol-17-propionate 1% pet. CONCLUSION: Caution should be used when interpreting reactions to "problematic" patch-test preparations with a high proportion of weak, irritant, and questionable reactions.