Does phenology influence predation rate on Salmo trutta parr during lake migration?

Acoustic tags fitted with predation sensors, which trigger following ingestion by piscivorous predators, were used to compare direct predation rates during downstream migration (out-migration) of potamodromous (freshwater) brown trout (Salmo trutta L.) parr from their natal river into a large freshwater lake system during spring and autumn. Thirty-eight spring migrants were tagged across two study years (2021 and 2022) of which 13 individuals (34%) were predated. By contrast 40 autumn migrants were tagged (2020 and 2021) of which three individuals (7.5%) experienced predation. The overall predation loss rate for spring migrants was 0.342% day-1 and was 0.075% day-1 for autumn migrants. Most predation events during spring (77%) occurred within the lower river before tagged fish entered the lake, whilst no predation events were recorded within the river in the autumn. Predation events were significantly linked to tagging season (spring or autumn), with the probability of tags remaining untriggered (as a proxy for survival) being higher 93% (95% confidence interval [CI] [87%, 100%]) in autumn than in spring 66% (95% CI [53%, 83%]). The spring migration periods showed significantly lower river discharge (0.321 m3 /s mean daily discharge, April 1 to May 31) to those measured during autumn (1.056 m3 /s mean daily discharge, October 1 to November 30) (Mann-Whitney U-test, U = 1149, p < 0.001). Lower flows, clearer water, and longer sojourn in the river may have contributed to greater predation losses in the spring relative to the autumn.

Investigating the phenology of juvenile potamodromous brown trout (Salmo trutta L.) in two large lake catchments.

There is growing interest in the phenology of juvenile Salmo trutta and evidence of significant downstream migration during the autumn in some anadromous populations. The present study used acoustic telemetry to examine the phenology of potamodromous trout parr across a region encompassing two large lake catchments. One hundred sixty-seven trout parr were tagged in late summer across four lake tributaries between 2018 and 2020. In total, 75 tagged parr migrated into the lakes with 67 (89%) migrating between September and December and 8 (11%) migrating between March and June. Autumn migration was highly prevalent across all the tributaries, with 16%-66% of each tagged sample exhibiting autumn migration, and 0%-15% of each tagged sample exhibiting spring migration. Autumn migrants were significantly longer and heavier than spring migrants, but condition factor was similar. Autumn migrants were associated with higher river discharge levels and lower water temperatures than spring migrants. The management challenges posed by extensive autumn migration behaviour in migratory trout stocks are examined and discussed.

Long-term retention of dummy acoustic transmitters in adult brown trout.

A group of 36 1+ age class Salmo trutta were surgically implanted with dummy acoustic tags and monitored for 370 days. In total 13 tags were expelled throughout the experiment with an overall tag loss rate of c. 0.035 tags per day. Fish length was the only explanatory variable which had a significant association with subsequent tag expulsion. The estimated probability of retaining a tag for a year for a fish of length 32 cm was 0.76, 34 cm was 0.60 and 36 cm was 0.38. The long-term tag loss patterns were examined and discussed.

River lamprey present an unusual predation threat to Atlantic salmon smolts in Lough Neagh, Northern Ireland.

A new monitoring programme on the Lough Neagh catchment has documented a high incidence of river lamprey, Lampetra fluviatilis L., predation on Atlantic salmon smolts, Salmo salar L. In total 470 smolts were examined during the 2020 emigration period with 168 fish (36%) exhibiting lamprey scars of which 57 were lightly scarred and 111 were classed as heavily scarred. Lamprey predation was not size selective on Lough Neagh S. salar smolts.

Glycosylation in Indolent, Significant and Aggressive Prostate Cancer by Automated High-Throughput N-Glycan Profiling.

The diagnosis and treatment of prostate cancer (PCa) is a major health-care concern worldwide. This cancer can manifest itself in many distinct forms and the transition from clinically indolent PCa to the more invasive aggressive form remains poorly understood. It is now universally accepted that glycan expression patterns change with the cellular modifications that accompany the onset of tumorigenesis. The aim of this study was to investigate if differential glycosylation patterns could distinguish between indolent, significant, and aggressive PCa. Whole serum N-glycan profiling was carried out on 117 prostate cancer patients' serum using our automated, high-throughput analysis platform for glycan-profiling which utilizes ultra-performance liquid chromatography (UPLC) to obtain high resolution separation of N-linked glycans released from the serum glycoproteins. We observed increases in hybrid, oligomannose, and biantennary digalactosylated monosialylated glycans (M5A1G1S1, M8, and A2G2S1), bisecting glycans (A2B, A2(6)BG1) and monoantennary glycans (A1), and decreases in triantennary trigalactosylated trisialylated glycans with and without core fucose (A3G3S3 and FA3G3S3) with PCa progression from indolent through significant and aggressive disease. These changes give us an insight into the disease pathogenesis and identify potential biomarkers for monitoring the PCa progression, however these need further confirmation studies.

Migration and survival of Atlantic salmon Salmo salar smolts in a large natural lake.

An investigation with acoustic telemetry of the passage of Salmo salar smolts through a large natural lake found heavy mortality occurred at the river-to-lake confluences (mean 31.2% km-1 ), but was lower in the main body of the lake (mean 2.4% km-1 ). Predation was a significant pressure on emigrating smolts as tagged pike Esox lucius aggregated at river-to-lake confluences during the peak of the smolt run. Tagged smolts mainly emmigrated into the lake in the late evening after dusk, possibly as a predator-avoidance behaviour.

Reconciling the structural attributes of avian antibodies.

Antibodies are high value therapeutic, diagnostic, biotechnological, and research tools. Combinatorial approaches to antibody discovery have facilitated access to unique antibodies by surpassing the diversity limitations of the natural repertoire, exploitation of immune repertoires from multiple species, and tailoring selections to isolate antibodies with desirable biophysical attributes. The V-gene repertoire of the chicken does not utilize highly diverse sequence and structures, which is in stark contrast to the mechanism employed by humans, mice, and primates. Recent exploitation of the avian immune system has generated high quality, high affinity antibodies to a wide range of antigens for a number of therapeutic, diagnostic and biotechnological applications. Furthermore, extensive examination of the amino acid characteristics of the chicken repertoire has provided significant insight into mechanisms employed by the avian immune system. A paucity of avian antibody crystal structures has limited our understanding of the structural consequences of these uniquely chicken features. This paper presents the crystal structure of two chicken single chain fragment variable (scFv) antibodies generated from large libraries by phage display against important human antigen targets, which capture two unique CDRL1 canonical classes in the presence and absence of a non-canonical disulfide constrained CDRH3. These structures cast light on the unique structural features of chicken antibodies and contribute further to our collective understanding of the unique mechanisms of diversity and biochemical attributes that render the chicken repertoire of particular value for antibody generation.

Basin-scale phenology and effects of climate variability on global timing of initial seaward migration of Atlantic salmon (Salmo salar).

Migrations between different habitats are key events in the lives of many organisms. Such movements involve annually recurring travel over long distances usually triggered by seasonal changes in the environment. Often, the migration is associated with travel to or from reproduction areas to regions of growth. Young anadromous Atlantic salmon (Salmo salar) emigrate from freshwater nursery areas during spring and early summer to feed and grow in the North Atlantic Ocean. The transition from the freshwater ('parr') stage to the migratory stage where they descend streams and enter salt water ('smolt') is characterized by morphological, physiological and behavioural changes where the timing of this parr-smolt transition is cued by photoperiod and water temperature. Environmental conditions in the freshwater habitat control the downstream migration and contribute to within- and among-river variation in migratory timing. Moreover, the timing of the freshwater emigration has likely evolved to meet environmental conditions in the ocean as these affect growth and survival of the post-smolts. Using generalized additive mixed-effects modelling, we analysed spatio-temporal variations in the dates of downstream smolt migration in 67 rivers throughout the North Atlantic during the last five decades and found that migrations were earlier in populations in the east than the west. After accounting for this spatial effect, the initiation of the downstream migration among rivers was positively associated with freshwater temperatures, up to about 10 °C and levelling off at higher values, and with sea-surface temperatures. Earlier migration occurred when river discharge levels were low but increasing. On average, the initiation of the smolt seaward migration has occurred 2.5 days earlier per decade throughout the basin of the North Atlantic. This shift in phenology matches changes in air, river, and ocean temperatures, suggesting that Atlantic salmon emigration is responding to the current global climate changes.

Understanding microcystin-LR antibody binding interactions using in silico docking and in vitro mutagenesis.

Microcystins (MCs) are a group of highly potent cyanotoxins that are becoming more widely distributed due to increased global temperatures and climate change. Microcystin-leucine-arginine (MC-LR) is the most potent and most common variant, with a guideline limit of 1 µg/l in drinking water. We previously developed a novel avian single-chain fragment variable (scFv), designated 2G1, for use in an optical-planar waveguide detection system for microcystin determination. This current work investigates interactions between 2G1 and MC-LR at the molecular level through modelling with an avian antibody template and molecular docking by AutoDock Vina to identify key amino acid (AA) residues involved. These potential AA interactions were investigated in vitro by targeted mutagenesis, specifically, by alanine scanning mutations. Glutamic acid (E) was found to play a critical role in the 2G1-MC-LR binding interaction, with the heavy chain glutamic acid (E) 102 (H-E102) forming direct bonds with the arginine (R) residue of MC-LR. In addition, alanine mutation of light chain residue aspartic acid 57 (L-D57) led to an improvement in antigen-binding observed using enzyme-linked immunosorbent assay (ELISA), and was confirmed by surface plasmon resonance (SPR). This work will contribute to improving the binding of recombinant anti-MC-LR to its antigen and aid in the development of a higher sensitivity harmful algal toxin diagnostic.

Integrating biomarkers across omic platforms: an approach to improve stratification of patients with indolent and aggressive prostate cancer.

Classifying indolent prostate cancer represents a significant clinical challenge. We investigated whether integrating data from different omic platforms could identify a biomarker panel with improved performance compared to individual platforms alone. DNA methylation, transcripts, protein and glycosylation biomarkers were assessed in a single cohort of patients treated by radical prostatectomy. Novel multiblock statistical data integration approaches were used to deal with missing data and modelled via stepwise multinomial logistic regression, or LASSO. After applying leave-one-out cross-validation to each model, the probabilistic predictions of disease type for each individual panel were aggregated to improve prediction accuracy using all available information for a given patient. Through assessment of three performance parameters of area under the curve (AUC) values, calibration and decision curve analysis, the study identified an integrated biomarker panel which predicts disease type with a high level of accuracy, with Multi AUC value of 0.91 (0.89, 0.94) and Ordinal C-Index (ORC) value of 0.94 (0.91, 0.96), which was significantly improved compared to the values for the clinical panel alone of 0.67 (0.62, 0.72) Multi AUC and 0.72 (0.67, 0.78) ORC. Biomarker integration across different omic platforms significantly improves prediction accuracy. We provide a novel multiplatform approach for the analysis, determination and performance assessment of novel panels which can be applied to other diseases. With further refinement and validation, this panel could form a tool to help inform appropriate treatment strategies impacting on patient outcome in early stage prostate cancer.

Biosensors for the monitoring of harmful algal blooms.

Harmful algal blooms (HABs) are a major global concern due to their propensity to cause environmental damage, healthcare issues and economic losses. In particular, the presence of toxic phytoplankton is a cause for concern. Current HAB monitoring programs often involve laborious laboratory-based analysis at a high cost and with long turnaround times. The latter also hampers the potential to develop accurate and reliable models that can predict HAB occurrence. However, a promising solution for this issue may be in the form of remotely deployed biosensors, which can rapidly and continuously measure algal and toxin levels at the point-of-need (PON), at a low cost. This review summarises the issues HABs present, how they are difficult to monitor and recently developed biosensors that may improve HAB-monitoring challenges.

Antibodies and antibody-derived analytical biosensors.

The rapid diagnosis of many diseases and timely initiation of appropriate treatment are critical determinants that promote optimal clinical outcomes and general public health. Biosensors are now being applied for rapid diagnostics due to their capacity for point-of-care use with minimum need for operator input. Antibody-based biosensors or immunosensors have revolutionized diagnostics for the detection of a plethora of analytes such as disease markers, food and environmental contaminants, biological warfare agents and illicit drugs. Antibodies are ideal biorecognition elements that provide sensors with high specificity and sensitivity. This review describes monoclonal and recombinant antibodies and different immobilization approaches crucial for antibody utilization in biosensors. Examples of applications of a variety of antibody-based sensor formats are also described.

Use of biosensors for the detection of marine toxins.

Increasing occurrences of harmful algal blooms (HABs) in the ocean are a major concern for countries around the globe, and with strong links between HABs and climate change and eutrophication, the occurrences are only set to increase. Of particular concern with regard to HABs is the presence of toxin-producing algae. Six major marine biotoxin groups are associated with HABs. Ingestion of such toxins via contaminated shellfish, fish, or other potential vectors, can lead to intoxication syndromes with moderate to severe symptoms, including death in extreme cases. There are also major economic implications associated with the diverse effects of marine biotoxins and HABs. Thus, effective monitoring programmes are required to manage and mitigate their detrimental global effect. However, currently legislated detection methods are labour-intensive, expensive and relatively slow. The growing field of biosensor diagnostic devices is an exciting area that has the potential to produce robust, easy-to-use, cost-effective, rapid and accurate detection methods for marine biotoxins and HABs. This review discusses recently developed biosensor assays that target marine biotoxins and their microbial producers, both in harvested fish/shellfish samples and in the open ocean. The effective deployment of such biosensor platforms could address the pressing need for improved monitoring of HABs and marine biotoxins, and could help to reduce their global economic impact.

Comprehensive N-Glycan Profiling of Avian Immunoglobulin Y.

Recent exploitation of the avian immune system has highlighted its suitability for the generation of high-quality, high-affinity antibodies to a wide range of antigens for a number of therapeutic and biotechnological applications. The glycosylation profile of potential immunoglobulin therapeutics is species specific and is heavily influenced by the cell-line/culture conditions used for production. Hence, knowledge of the carbohydrate moieties present on immunoglobulins is essential as certain glycan structures can adversely impact their physicochemical and biological properties. This study describes the detailed N-glycan profile of IgY polyclonal antibodies from the serum of leghorn chickens using a fully quantitative high-throughput N-glycan analysis approach, based on ultra-performance liquid chromatography (UPLC) separation of released glycans. Structural assignments revealed serum IgY to contain complex bi-, tri- and tetra-antennary glycans with or without core fucose and bisects, hybrid and high mannose glycans. High sialic acid content was also observed, with the presence of rare sialic acid structures, likely polysialic acids. It is concluded that IgY is heavily decorated with complex glycans; however, no known non-human or immunogenic glycans were identified. Thus, IgY is a potentially promising candidate for immunoglobulin-based therapies for the treatment of various infectious diseases.

Stapedectomy outcomes: titanium versus teflon wire prosthesis.

OBJECTIVE: To compare the effectiveness of two stapes prostheses in hearing improvement of patients undergoing stapes surgery for otosclerosis. STUDY DESIGN: Retrospective chart review. METHODS: Titanium and Teflon wire stapes prostheses were compared with regard to effectiveness in closing the air-bone gap. The charts of 461 stapedectomies performed by one surgeon from 1996 to 2001 were reviewed. Patients who underwent stapedectomy for reasons other than otosclerosis, revision cases, and those with inadequate preoperative or postoperative bone-conduction threshold data were excluded. Small fenestra technique using either laser or drill was used for all patients. Inclusion criteria were met by 218 patients. Patients were then grouped according to type of prosthesis used, and hearing outcomes were compared. Measured outcomes were four frequency air-bone gap closure, pure-tone threshold, and rate of sensorineural hearing loss (SNHL). RESULTS: The study group was comprised of 35 titanium and 183 Teflon wire prostheses. Closure of the air-bone gap to less than 10 dB was achieved in 86% of the patients with Teflon prosthesis compared with 71% of those with titanium prostheses. The groups were equivalent in regard to site of otosclerotic disease as well as technique, laser or drill, used to create the fenestra. Rate of SNHL was low for both groups and not significantly different. CONCLUSIONS: Both prostheses provided comparable results, although the Teflon platinum wire prosthesis was slightly superior. The smaller numbers in the titanium group may confound these results. The design of the titanium prosthesis provides a crimp that is circumferential around the incus, and that prosthesis was selected in cases with a narrow incus. The selection bias may also influence the results seen in this study.

Ventilation tubes and cochlear implants: what do we do?

OBJECTIVE: To determine current practice management with respect to ventilation tubes and cochlear implants. STUDY DESIGN: Questionnaire. SETTING: All members of the American Neurotology Society were sent questionnaires. MAIN OUTCOME MEASURES: Members were asked a series of questions including how they deal with ventilation tubes before cochlear implantation, how they manage serous otitis media in patients undergoing cochlear implantation, and how they manage otitis prone children with cochlear implants. RESULTS: Two hundred and twenty members returned questionnaires. Surgeons who replied perform an average of 25 implants per year: 15 in adults and 10 in children. Analysis of the data revealed a wide practice variation between surgeons. Fifty-six percent of surgeons will place a cochlear implant in a patient with a clean, dry ventilation tube in place. More than half the surgeons will place a ventilation tube in a child with serous otitis media, let the ear settle down, and perform the cochlear implant at a second operation. Wide variation in the management of otitis prone children with cochlear implants exists with respect to placement of ventilation tubes. Only 5% of surgeons reported any complications with cochlear implants that they attributed to ventilation tubes. There were a number who suggested their practice had changed since the recent identification of issues involving meningitis in implantees. CONCLUSION: Wide practice variation exists with the management of ventilation tubes in cochlear implant patients. On the basis of the results of this survey, it is acceptable to place cochlear implants in patients with clean, dry ventilation tubes. It also acceptable to place ventilation tubes in otitis prone children with cochlear implants. Despite theoretic concerns, the reported incidence of complications is low.

The need for effective pancreatic cancer detection and management: a biomarker-based strategy.

Pancreatic cancer (Pa) is generally a very aggressive disease, with few effective approaches available for early diagnosis or therapy. These factors, combined with the aggressiveness and chemoresistance of Pa, results in a bleak outcome post-diagnosis. Cancer-related biomarkers have established capabilities for diagnosis, prognosis and screening and can be exploited to aid in earlier less-invasive diagnosis and optimization of targeted therapies. Pa has only one US FDA-approved biomarker, CA19-9, which has significant limitations. Hence, it is vital that novel biomarkers are identified and validated to diagnose, treat, control and monitor Pa. This review focuses on existing and potential Pa-associated markers and discusses how they may be applied in cohort for improved management of Pa.

Detection of the cyanobacterial toxin, microcystin-LR, using a novel recombinant antibody-based optical-planar waveguide platform.

Microcystins are a major group of cyanobacterial heptapeptide toxins found in freshwater and brackish environments. There is currently an urgent requirement for highly-sensitive, rapid and in-expensive detection methodologies for these toxins. A novel single chain fragment variable (scFv) fragment was generated and is the first known report of a recombinant anti-microcystin avian antibody. In a surface plasmon resonance-based immunoassay, the antibody fragment displayed cross-reactivity with seven microcystin congeners (microcystin-leucine-arginine (MC-LR) 100%, microcystin-tyrosine-arginine (MC-YR) 79.7%, microcystin-leucine-alanine (MC-LA) 74.8%, microcystin-leucine-phenylalanine (MC-LF) 67.5%, microcystin-leucine-tryptophan (MC-LW) 63.7%, microcystin-arginine-arginine (MC-RR) 60.1% and nodularin (Nod) 69.3%, % cross reactivity). Following directed molecular evolution of the parental clone the resultant affinity-enhanced antibody fragment was applied in an optimized fluorescence immunoassay on a planar waveguide detection system. This novel immuno-sensing format can detect free microcystin-LR with a functional limit of detection of 0.19 ng mL(-1)and a detection range of 0.21-5.9 ng mL(-1). The assay is highly reproducible (displaying percentage coefficients of variance below 8% for intra-day assays and below 11% for inter-day assays), utilizes an inexpensive cartridge system with low reagent volumes and can be completed in less than twenty minutes.

Dominant optic atrophy, sensorineural hearing loss, ptosis, and ophthalmoplegia: a syndrome caused by a missense mutation in OPA1.

PURPOSE: To describe the clinical features of and identify the disease-causing mutation in a large Utah family segregating a dominantly inherited syndrome of optic atrophy, sensorineural hearing loss, ptosis, and ophthalmoplegia. DESIGN: Observational case series. METHODS: Thirty individuals at risk for a syndrome of optic atrophy, sensorineural hearing loss, ptosis, and ophthalmoplegia in a single family underwent clinical examinations and venipuncture. Linkage analysis and mutation screening of the optic atrophy 1 gene (OPA1) were performed. RESULTS: Eighteen individuals demonstrated characteristics of the syndrome. Genetic analysis identified a G-->A substitution at nucleotide position 1334 in exon 14 of OPA1 causing an arginine-to-histidine change (R445H) in all affected members of the family. This change segregated with the disease phenotype in the study family with a LOD score of 7.02 at theta; = 0 and was not found in 200 normal control subjects. Analysis of an unrelated Belgian family with a similar phenotype revealed the same R445H mutation segregating with the disease phenotype. CONCLUSIONS: This study describes a mutation in OPA1 causing a unique syndrome of optic atrophy, sensorineural hearing loss, ptosis, and ophthalmoplegia. These results expand the spectrum of human disease associated with mutations of OPA1 and indicate that ophthalmologists caring for patients with optic atrophy should inquire about possible associated hearing loss. Although OPA1 is a nuclear gene, the gene product localizes to mitochondria, suggesting that mitochondrial dysfunction may be the final common pathway for many forms of syndromic and nonsyndromic optic atrophy, hearing loss, and external ophthalmoplegia.

External auditory canal cholesteatoma: clinical and imaging spectrum.

BACKGROUND AND PURPOSE: Cholesteatoma is an inflammatory lesion of the temporal bone that uncommonly involves the external auditory canal (EAC). In this large case series, we aimed to define its imaging features and to determine the characteristics most important to its clinical management. METHODS: Thirteen cases of EAC cholesteatoma (EACC) were retrospectively reviewed. Clinical data were reviewed for the history, presentation, and physical examination findings. High-resolution temporal bone CT scans were examined for a soft-tissue mass in the EAC, erosion of adjacent bone, and bone fragments in the mass. The middle ear cavity, mastoid, facial nerve canal, and tegmen tympani were evaluated for involvement. RESULTS: Patients presented with otorrhea, otalgia, or hearing loss. Eight cases were spontaneous, and five were postsurgical or post-traumatic. CT imaging in all 13 cases showed a soft-tissue mass with adjacent bone erosion. Intramural bone fragments were identified in seven cases. This mass most often arose inferiorly (n = 8) or posteriorly (n = 8), but it was circumferential in two cases. We noted middle ear extension (n = 5), mastoid involvement (n = 4), facial canal erosion (n = 2), and tegmen tympani dehiscence (n = 1). CONCLUSION: Temporal bone CT shows EACC as a soft-tissue mass within the EAC, with adjacent bone erosion. Bone fragments may be present within the mass. The cholesteatoma may extend into the mastoid or middle ear, or it may involve the facial nerve canal or tegmen tympani. Recognition of this entity and its possible extension is important because it may influence clinical management.