Invasive Asian Carps in North America

<em>Abstract</em>.—Bighead carp <em>Hypophthalmichthys nobilis </em>have become established within the Mississippi River system (MRS) and pose a serious threat to native fishes and aquatic ecosystems throughout North America. Determining their dispersal dynamics will be a key management tool for controlling their expansion. To better understand how bighead carp have spread through the MRS, we developed a simple diffusion model to be used as a heuristic tool to generate insights regarding dispersion patterns. First, we collected occurrence data from fish museums and government agencies spanning more than 30 years of sampling in the MRS and nearby rivers. These were then combined into a geographic information system database and used to create yearly occurrence maps for this species. We then developed a diffusion model for bighead carp using information on their movement and reproduction. The resulting model can be used to track the dispersal of hypothetical carp populations from different points of introduction within the MRS. With this model, we generated and compared four possible dispersal scenarios for bighead carp based on likely points of introduction. For each of these, we calculated Cohen’s kappa and sensitivity (measures of predictive success) to determine which dispersal scenarios were the most accurate in predicting bighead carp occurrence pattern after 30 years. We found significant agreement between the actual and predicted distributions of carp after 30 years of expansion for all four dispersal scenarios (Cohen’s kappa: range = 0.136–0.426, <em>p </em>< 0.05). The single introduction scenario (in the Arkansas River) had the lowest agreement with the occurrence data (Cohen’s kappa = 0.136, sensitivity = 32%) compared with the scenarios representing multiple points of carp introduction: introductions in the Arkansas and Missouri rivers (Cohen’s kappa = 0.370, sensitivity = 71%), introductions in the Arkansas and lower Ohio rivers (Cohen’s kappa = 0.391, sensitivity = 68%), and introductions in all three river locations (Cohen’s kappa = 0.426, sensitivity = 85%). The triple introduction scenario also had the highest sensitivity (sensitivity = 66%) when it was compared to the other three scenarios for accuracy on a year-to-year basis: Arkansas River only (sensitivity = 25%), Arkansas and Missouri rivers (sensitivity = 39%), and Arkansas and lower Ohio rivers (sensitivity = 46%). These results suggest expanding bighead carp populations in the MRS began from multiple origins rather than a single introduction. Other insights derived from the dispersal scenarios include evidence that bighead carp are possibly more widely dispersed than current occurrence data indicate and that the species is likely extending its range “under the radar” of standardized sampling. Finally, we used these dispersal scenarios to predict potential high carp density hot spots that could develop over the next 20 years in the MRS and should be targeted for control management.

<em>Abstract</em>.—Numerous natural resource agency and media reports have alleged that Asian carps were introduced into the wild through escapes from commercial fish farms. This chapter traces the chronology associated with importations of Asian carps to North America and discusses the likeliest pathways of their introduction to the wild. The U.S. Fish and Wildlife Service first imported an Asian carp species, grass carp <em>Ctenopharyngodon idella</em>, in 1963. Since then, state and federal agencies, universities, and private fish farmers have interacted to import Asian carps, to develop production technologies, and to promote their use in both public and private sectors in a number of different states. These importations and stocking, whether in confinement or, in the case of the grass carp, sometimes in open waters, were purposeful and legal. Asian carps were introduced to take advantage of their unique food preferences (planktivory by silver carp <em>Hypophthalmichthys molitrix </em>and bighead carp <em>H. nobilis</em>, herbivory by grass carp, and molluscivory by black carp <em>Mylopharyngodon piceus</em>). The first known accidental release of diploid grass carp was in 1966 by the U.S. Fish and Wildlife Service in Stuttgart, Arkansas. Other early reports of grass carp in the wild were from waters in Alabama, Georgia, and Florida. Grass carp were reported from the wild in 1970, 2 years before the first private hatchery received grass carp. By 1972, grass carp had been stocked in open water systems in 16 different states. Silver carp and bighead carp were first imported purposely by a commercial fish producer in Arkansas in 1973. All silver and bighead carps were transferred to the Arkansas Game and Fish Commission by March 1974 where they first successfully spawned silver carp and bighead carp later that year. The first report of silver carp in the wild was in Arizona in 1972, although strong evidence suggests that this may have been a misidentification, followed by reports in Arkansas in the wild in 1975. The Arkansas report occurred 2 years before bighead carp and silver carp were returned to private hatcheries for commercial production. By 1977, silver carp and bighead carp had been introduced to Alabama, Arizona, Arkansas, Illinois, and Tennessee. Research and stockings of silver carp and bighead carp were conducted by at least six state and federal agencies and three universities in seven states in the 1970s and 1980s. Public-sector agencies, which were successful in encouraging development and use of Asian carps that today are in commercial trade, are the likeliest pathways for the earliest escapes of grass carp, silver carp, and bighead carp.


<em>Abstract</em>.—The Asian black carp <em>Mylopharyngodon piceus </em>is of interest to the aquaculture industry in the United States as a biological control for snails and mollusks. However, past experience in North America with other Asian carps has raised concern that black carp will establish wild populations and negatively affect native populations of fish and invertebrates, especially mollusks. The demand for black carp has led biologists to seek ways to allow their use while at the same time maintaining control over their distribution and reproduction. Physical containment and restrictions on importation, release, and stocking have mostly failed. Control of reproduction holds more promise. The induction of triploidy (having three sets of chromosomes), which can render an individual biologically sterile, is of particular interest. The main purpose of this study was to evaluate the efficiency of proposed testing procedures used to assure genetic triploidy in black carp prior to distribution by the state of Missouri, using black carp and grass carp <em>Ctenopharyngodon idella</em>. Our objectives were to (1) verify if the ploidy determination methodology (nuclear size) employed was 100% accurate, (2) determine growth and survival of juvenile black carp over extended periods of time under laboratory and pond conditions, and (3) histologically examine development and gametogenesis in gonads collected from triploid and diploid black and grass carps of different ages and stages of maturation. Comparison of erythrocyte nuclear size using the Coulter counter method versus the more accurate method of flow cytometry that measures DNA content indicated an error rate of 0.25% by the former method. Black carp grew and survived well in mid-Missouri ponds. Triploid grass carp males appeared to produce functional gametes, and some triploid black carp male testes had apparently normal spermatocytes within cysts. A few normally developing oocytes at previtellogenic and vitellogenic stages were observed in triploid grass carp females, and a few normal perinuclear oocytes could be identified in triploid black carp females. Currently, the standards of the U.S. Fish and Wildlife Service’s triploid grass carp voluntary inspection program are being followed by some states to manage triploid black carp. Our results indicate that although the percentage of diploid black carp that could pass through the currently proposed screening program is small, overall numbers of diploid black carp distributed in a state could be substantial depending on the number of triploids distributed. Furthermore, despite indications that triploid male black carp can be expected to be functionally sterile, reproductive studies may be warranted given the large wild populations of diploid grass carp, bighead carp <em>Hypophthalmichthys nobilis</em>, and silver carp <em>H. molitrix </em>in the Mississippi River basin system.


<em>Abstract</em>.—The response of bighead carp <em>Hypophthalmichthys nobilis </em>and silver carp <em>H. molitrix </em>to conspecific skin extracts was determined during free-field observations and avoidance tests. The extracts induced freezing/motionlessness, cessation of food-searching activities, and reduced swimming activity in the fish. Silver carp tended to avoid the area where the extract was released and a strong schooling response was induced in bighead carp. In avoidance tests using countercurrent chambers, young bighead carp (5–8 cm total length) were unresponsive to the skin extract (<EM>P </EM>> 0.05). However, in both species, older juveniles (12–25 cm total length) spent significantly less time (<EM>P </EM>< 0.01) in the side of the chamber receiving skin extract solutions. The extract was effective whether freshly prepared or aged at room temperature for 24 h. Freezing did not alter the effectiveness of fresh or frozen extracts. These studies suggest that bighead and silver carp are responsive to conspecific skin extracts and that the use of extracts might be useful to repel carp from habitats of concern.


<em>Abstract</em>.—In the United States, a variety of outreach has been done on bighead carp <em>Hypophthalmichthys nobilis </em>and silver carp <em>H. molitrix </em>by a number of organizations and institutions. Because many of these outreach efforts were localized, nonlocalized entities often are unaware of them. Many of the entities conducting outreach, too, do not have a systematic bighead and silver carp (BSC) outreach plan and thus their efforts may not be as efficient or effective as possible. To address these issues, we surveyed organizations in areas where BSC have been found and compiled the reported BSC outreach activities. We then created a comprehensive outreach plan as a template for those conducting BSC outreach and compared it to existing efforts. In this comparison, we found that (1) targeted audiences could be more narrowly focused, (2) easily accessible tools could be more fully utilized, and (3) systematic evaluations need to be conducted to ensure that outreach efforts are being effective. We hope that this compilation and the comprehensive outreach plan will help improve the collective future BSC outreach, making it more efficient and effective.


Author(s):  
Miriam Athmann ◽  
Roya Bornhütter ◽  
Nicolaas Busscher ◽  
Paul Doesburg ◽  
Uwe Geier ◽  
...  

AbstractIn the image forming methods, copper chloride crystallization (CCCryst), capillary dynamolysis (CapDyn), and circular chromatography (CChrom), characteristic patterns emerge in response to different food extracts. These patterns reflect the resistance to decomposition as an aspect of resilience and are therefore used in product quality assessment complementary to chemical analyses. In the presented study, rocket lettuce from a field trial with different radiation intensities, nitrogen supply, biodynamic, organic and mineral fertilization, and with or without horn silica application was investigated with all three image forming methods. The main objective was to compare two different evaluation approaches, differing in the type of image forming method leading the evaluation, the amount of factors analyzed, and the deployed perceptual strategy: Firstly, image evaluation of samples from all four experimental factors simultaneously by two individual evaluators was based mainly on analyzing structural features in CapDyn (analytical perception). Secondly, a panel of eight evaluators applied a Gestalt evaluation imbued with a kinesthetic engagement of CCCryst patterns from either fertilization treatments or horn silica treatments, followed by a confirmatory analysis of individual structural features. With the analytical approach, samples from different radiation intensities and N supply levels were identified correctly in two out of two sample sets with groups of five samples per treatment each (Cohen’s kappa, p = 0.0079), and the two organic fertilizer treatments were differentiated from the mineral fertilizer treatment in eight out of eight sample sets with groups of three manure and two minerally fertilized samples each (Cohen’s kappa, p = 0.0048). With the panel approach based on Gestalt evaluation, biodynamic fertilization was differentiated from organic and mineral fertilization in two out of two exams with 16 comparisons each (Friedman test, p < 0.001), and samples with horn silica application were successfully identified in two out of two exams with 32 comparisons each (Friedman test, p < 0.001). Further research will show which properties of the food decisive for resistance to decomposition are reflected by analytical and Gestalt criteria, respectively, in CCCryst and CapDyn images.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexandre Maciel-Guerra ◽  
Necati Esener ◽  
Katharina Giebel ◽  
Daniel Lea ◽  
Martin J. Green ◽  
...  

AbstractStreptococcus uberis is one of the leading pathogens causing mastitis worldwide. Identification of S. uberis strains that fail to respond to treatment with antibiotics is essential for better decision making and treatment selection. We demonstrate that the combination of supervised machine learning and matrix-assisted laser desorption ionization/time of flight (MALDI-TOF) mass spectrometry can discriminate strains of S. uberis causing clinical mastitis that are likely to be responsive or unresponsive to treatment. Diagnostics prediction systems trained on 90 individuals from 26 different farms achieved up to 86.2% and 71.5% in terms of accuracy and Cohen’s kappa. The performance was further increased by adding metadata (parity, somatic cell count of previous lactation and count of positive mastitis cases) to encoded MALDI-TOF spectra, which increased accuracy and Cohen’s kappa to 92.2% and 84.1% respectively. A computational framework integrating protein–protein networks and structural protein information to the machine learning results unveiled the molecular determinants underlying the responsive and unresponsive phenotypes.


Author(s):  
Maximilian Lutz ◽  
Martin Möckel ◽  
Tobias Lindner ◽  
Christoph J. Ploner ◽  
Mischa Braun ◽  
...  

Abstract Background Management of patients with coma of unknown etiology (CUE) is a major challenge in most emergency departments (EDs). CUE is associated with a high mortality and a wide variety of pathologies that require differential therapies. A suspected diagnosis issued by pre-hospital emergency care providers often drives the first approach to these patients. We aim to determine the accuracy and value of the initial diagnostic hypothesis in patients with CUE. Methods Consecutive ED patients presenting with CUE were prospectively enrolled. We obtained the suspected diagnoses or working hypotheses from standardized reports given by prehospital emergency care providers, both paramedics and emergency physicians. Suspected and final diagnoses were classified into I) acute primary brain lesions, II) primary brain pathologies without acute lesions and III) pathologies that affected the brain secondarily. We compared suspected and final diagnosis with percent agreement and Cohen’s Kappa including sub-group analyses for paramedics and physicians. Furthermore, we tested the value of suspected and final diagnoses as predictors for mortality with binary logistic regression models. Results Overall, suspected and final diagnoses matched in 62% of 835 enrolled patients. Cohen’s Kappa showed a value of κ = .415 (95% CI .361–.469, p < .005). There was no relevant difference in diagnostic accuracy between paramedics and physicians. Suspected diagnoses did not significantly interact with in-hospital mortality (e.g., suspected class I: OR .982, 95% CI .518–1.836) while final diagnoses interacted strongly (e.g., final class I: OR 5.425, 95% CI 3.409–8.633). Conclusion In cases of CUE, the suspected diagnosis is unreliable, regardless of different pre-hospital care providers’ qualifications. It is not an appropriate decision-making tool as it neither sufficiently predicts the final diagnosis nor detects the especially critical comatose patient. To avoid the risk of mistriage and unnecessarily delayed therapy, we advocate for a standardized diagnostic work-up for all CUE patients that should be triggered by the emergency symptom alone and not by any suspected diagnosis.


2021 ◽  
Vol 11 (6) ◽  
pp. 2723
Author(s):  
Fatih Uysal ◽  
Fırat Hardalaç ◽  
Ozan Peker ◽  
Tolga Tolunay ◽  
Nil Tokgöz

Fractures occur in the shoulder area, which has a wider range of motion than other joints in the body, for various reasons. To diagnose these fractures, data gathered from X-radiation (X-ray), magnetic resonance imaging (MRI), or computed tomography (CT) are used. This study aims to help physicians by classifying shoulder images taken from X-ray devices as fracture/non-fracture with artificial intelligence. For this purpose, the performances of 26 deep learning-based pre-trained models in the detection of shoulder fractures were evaluated on the musculoskeletal radiographs (MURA) dataset, and two ensemble learning models (EL1 and EL2) were developed. The pre-trained models used are ResNet, ResNeXt, DenseNet, VGG, Inception, MobileNet, and their spinal fully connected (Spinal FC) versions. In the EL1 and EL2 models developed using pre-trained models with the best performance, test accuracy was 0.8455, 0.8472, Cohen’s kappa was 0.6907, 0.6942 and the area that was related with fracture class under the receiver operating characteristic (ROC) curve (AUC) was 0.8862, 0.8695. As a result of 28 different classifications in total, the highest test accuracy and Cohen’s kappa values were obtained in the EL2 model, and the highest AUC value was obtained in the EL1 model.


Author(s):  
Calli Ostrofsky ◽  
Jaishika Seedat

Background: Notwithstanding its value, there are challenges and limitations to implementing a dysphagia screening tool from a developed contexts in a developing context. The need for a reliable and valid screening tool for dysphagia that considers context, systemic rules and resources was identified to prevent further medical compromise, optimise dysphagia prognosis and ultimately hasten patients’ return to home or work.Methodology: To establish the validity and reliability of the South African dysphagia screening tool (SADS) for acute stroke patients accessing government hospital services. The study was a quantitative, non-experimental, correlational cross-sectional design with a retrospective component. Convenient sampling was used to recruit 18 speech-language therapists and 63 acute stroke patients from three South African government hospitals. The SADS consists of 20 test items and was administered by speech-language therapists. Screening was followed by a diagnostic dysphagia assessment. The administrator of the tool was not involved in completing the diagnostic assessment, to eliminate bias and prevent contamination of results from screener to diagnostic assessment. Sensitivity, validity and efficacy of the screening tool were evaluated against the results of the diagnostic dysphagia assessment. Cohen’s kappa measures determined inter-rater agreement between the results of the SADS and the diagnostic assessment.Results and conclusion: The SADS was proven to be valid and reliable. Cohen’s kappa indicated a high inter-rater reliability and showed high sensitivity and adequate specificity in detecting dysphagia amongst acute stroke patients who were at risk for dysphagia. The SADS was characterised by concurrent, content and face validity. As a first step in establishing contextual appropriateness, the SADS is a valid and reliable screening tool that is sensitive in identifying stroke patients at risk for dysphagia within government hospitals in South Africa.


Stroke ◽  
2021 ◽  
Author(s):  
Maximilian Nielsen ◽  
Moritz Waldmann ◽  
Andreas M. Frölich ◽  
Fabian Flottmann ◽  
Evelin Hristova ◽  
...  

Background and Purpose: Mechanical thrombectomy is an established procedure for treatment of acute ischemic stroke. Mechanical thrombectomy success is commonly assessed by the Thrombolysis in Cerebral Infarction (TICI) score, assigned by visual inspection of X-ray digital subtraction angiography data. However, expert-based TICI scoring is highly observer-dependent. This represents a major obstacle for mechanical thrombectomy outcome comparison in, for instance, multicentric clinical studies. Focusing on occlusions of the M1 segment of the middle cerebral artery, the present study aimed to develop a deep learning (DL) solution to automated and, therefore, objective TICI scoring, to evaluate the agreement of DL- and expert-based scoring, and to compare corresponding numbers to published scoring variability of clinical experts. Methods: The study comprises 2 independent datasets. For DL system training and initial evaluation, an in-house dataset of 491 digital subtraction angiography series and modified TICI scores of 236 patients with M1 occlusions was collected. To test the model generalization capability, an independent external dataset with 95 digital subtraction angiography series was analyzed. Characteristics of the DL system were modeling TICI scoring as ordinal regression, explicit consideration of the temporal image information, integration of physiological knowledge, and modeling of inherent TICI scoring uncertainties. Results: For the in-house dataset, the DL system yields Cohen’s kappa, overall accuracy, and specific agreement values of 0.61, 71%, and 63% to 84%, respectively, compared with the gold standard: the expert rating. Values slightly drop to 0.52/64%/43% to 87% when the model is, without changes, applied to the external dataset. After model updating, they increase to 0.65/74%/60% to 90%. Literature Cohen’s kappa values for expert-based TICI scoring agreement are in the order of 0.6. Conclusions: The agreement of DL- and expert-based modified TICI scores in the range of published interobserver variability of clinical experts highlights the potential of the proposed DL solution to automated TICI scoring.


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