Improving the biological realism of predator-prey size relationships in food web models alters ecosystem dynamics.

Body-size relationships between predators and prey exhibit remarkable diversity. However, the assumption that predators typically consume proportionally smaller prey often underlies size-dependent predation in ecosystem models. In reality, some animals can consume larger prey or exhibit limited changes in prey size as they grow larger themselves. These distinct predator-prey size relationships challenge the conventional assumptions of traditional size-based models. Cephalopods, with their diverse feeding behaviours and life histories, offer an excellent case study to investigate the impact of greater biological realism in predator-prey size relationships on energy flow within a size-structured ecosystem model. By categorizing cephalopods into high and low-activity groups, in line with empirically derived, distinct predator-prey size relationships, we found that incorporating greater biological realism in size-based feeding reduced ecosystem biomass and production, while simultaneously increasing biomass stability and turnover. Our results have broad implications for ecosystem modelling, since distinct predator-prey size relationships extend beyond cephalopods, encompassing a wide array of major taxonomic groups from filter-feeding fishes to baleen whales. Incorporating a diversity of size-based feeding in food web models can enhance their ecological and predictive accuracy when studying ecosystem dynamics.

(Epi)genomic adaptation driven by fine geographical scale environmental heterogeneity after recent biological invasions.

Elucidating processes and mechanisms involved in rapid local adaptation to varied environments is a poorly understood but crucial component in management of invasive species. Recent studies have proposed that genetic and epigenetic variation could both contribute to ecological adaptation, yet it remains unclear on the interplay between these two components underpinning rapid adaptation in wild animal populations. To assess their respective contributions to local adaptation, we explored epigenomic and genomic responses to environmental heterogeneity in eight recently colonized ascidian (Ciona intestinalis) populations at a relatively fine geographical scale. Based on MethylRADseq data, we detected strong patterns of local environment-driven DNA methylation divergence among populations, significant epigenetic isolation by environment (IBE), and a large number of local environment-associated epigenetic loci. Meanwhile, multiple genetic analyses based on single nucleotide polymorphisms (SNPs) showed genomic footprints of divergent selection. In addition, for five genetically similar populations, we detected significant methylation divergence and local environment-driven methylation patterns, indicating the strong effects of local environments on epigenetic variation. From a functional perspective, a majority of functional genes, Gene Ontology (GO) terms, and biological pathways were largely specific to one of these two types of variation, suggesting partial independence between epigenetic and genetic adaptation. The methylation quantitative trait loci (mQTL) analysis showed that the genetic variation explained only 18.67% of methylation variation, further confirming the autonomous relationship between these two types of variation. Altogether, we highlight the complementary interplay of genetic and epigenetic variation involved in local adaptation, which may jointly promote populations' rapid adaptive capacity and successful invasions in different environments. The findings here provide valuable insights into interactions between invaders and local environments to allow invasive species to rapidly spread, thus contributing to better prediction of invasion success and development of management strategies.

Functional traits explain trophic allometries of cephalopods.

Individual body size strongly influences the trophic role of marine organisms and the structure and function of marine ecosystems. Quantifying trophic position-individual body size relationships (trophic allometries) underpins the development of size-structured ecosystem models to predict abundance and the transfer of energy through ecosystems. Trophic allometries are well studied for fishes but remain relatively unexplored for cephalopods. Cephalopods are important components of coastal, oceanic and deep-sea ecosystems, and they play a key role in the transfer of biomass from low trophic positions to higher predators. It is therefore important to resolve cephalopod trophic allometries to accurately represent them within size-structured ecosystem models. We assessed the trophic positions of cephalopods in an oceanic pelagic (0-500 m) community (sampled by trawling in a cold-core eddy in the western Tasman Sea), comprising 22 species from 12 families, using bulk tissue stable isotope analysis and amino acid compound-specific stable isotope analysis. We assessed whether ontogenetic trophic position shifts were evident at the species-level and tested for the best predictor of community-level trophic allometry among body size, taxonomy and functional grouping (informed by fin and mantle morphology). Individuals in this cephalopod community spanned two trophic positions and fell into three functional groups on an activity level gradient: low, medium and high. The relationship between trophic position and ontogeny varied among species, with the most marked differences evident between species from different functional groups. Activity-level-based functional group and individual body size are best explained by cephalopod trophic positions (marginal R2  = 0.43). Our results suggest that the morphological traits used to infer activity level, such as fin-to-mantle length ratio, fin musculature and mantle musculature are strong predictors of cephalopod trophic allometries. Contrary to established theory, not all cephalopods are voracious predators. Low activity level cephalopods have a distinct feeding mode, with low trophic positions and little-to-no ontogenetic increases. Given the important role of cephalopods in marine ecosystems, distinct feeding modes could have important consequences for energy pathways and ecosystem structure and function. These findings will facilitate trait-based and other model estimates of cephalopod abundance in the changing global ocean.

Radiation Cataractogenesis: The Progression of Our Understanding and Its Clinical Consequences.

In the high-volume and increasingly complex world of image-guided therapy and medical imaging, awareness of the potential risks secondary to occupational radiation exposure in medical professionals needs greater focus. One of these risks is radiation-induced cataracts, a recently recognized entity, which may impact the physician's professional proficiency, quality of life, and career span. This review article aims to explain the pathogenesis of radiation-induced cataracts, exploring emerging evidence regarding their development. It also explores the existing monitoring and protection measures available to protect against such radiation-induced pathologic conditions.

Adverse Reactions to Contrast Material: A Canadian Update.

Imaging techniques frequently employ contrast agents to improve image resolution and enhance pathology detection. These gadolinium- and iodine-based media, although generally considered safe, are associated with a number of adverse effects ranging from mild to severe. Reactions are classified as either anaphylactoid ("anaphylaxis-like") or nonanaphylactoid, depending on a number of elements that will be reviewed. Herein, we have summarized predisposing risk factors for adverse events resulting from the use of contrast, their associated pathophysiological mechanisms as well as known prophylaxis for the antitreatment of high-risk patients. In the unlikely event that a serious adverse reaction does occur, we have provided a comprehensive summary of treatment protocols. Our goal was to thoroughly evaluate the current literature regarding adverse reactions to radiocontrast agents and provide an up to date review for the health care provider.

Intradiscal O2O3: Rationale, Injection Technique, Short- and Long-term Outcomes for the Treatment of Low Back Pain Due to Disc Herniation.

The management of low back pain should always start with a conservative approach; however, when it fails, intervention is required and at that moment the most appropriate choice remains unclear. Before invasive surgery, minimally invasive techniques can be adopted. In European trials and in a trans-Canadian clinical trial 03 ozone has been used successfully. In total over 50,000 patients have been treated safely. Ozone is a gas normally present in the atmosphere with potent oxidizing power; it has been used for percutaneous intradiscal injection combined with oxygen (O2O3) at very low concentrations for 15 years in Europe. The main indication is back pain with or without radicular pain but without motor deficits, which is refractory to 4-6 weeks of conservative therapies. Its mechanism of action on the disc is mechanical (volume reduction by subtle dehydration of the nucleus pulposis) and antinflammatory. The intradiscal ozone injection is performed with a thin needle (18-22 gauge) image guided by computed tomography or angiofluoroscopy and is usually complimented by periganglionic injection of corticosteroids and anesthetics. This combination gives immediate pain relief and allows time for the ozone to act. It is a cost-effective procedure that presents a very low complication rate (0.1%). The radicular pain is resolved before the back pain does, as is seen with microdiscectomy. Peer-reviewed publications of large randomized trials, case series, and meta analysis from large samples of patients have demonstrated the procedure to be safe and effective in the short and the long terms, with benefits recognized up to 10 years after treatment. We aim to review the principles of action of O2O3 and report the injection techniques, complications, and short- and long-term outcomes.

Imaging Findings in Elder Abuse: A Role for Radiologists in Detection.

PURPOSE: Emergency department assessment represents a critical but often missed opportunity to identify elder abuse, which is common and has serious consequences. Among emergency care providers, diagnostic radiologists are optimally positioned to raise suspicion for mistreatment when reviewing imaging of geriatric injury victims. However, little literature exists describing relevant injury patterns, and most radiologists currently receive neither formal nor informal training in elder abuse identification. METHODS: We present 2 cases to begin characterisation of the radiographic findings in elder abuse. RESULTS: Findings from these cases demonstrate similarities to suspicious findings in child abuse including high-energy fractures that are inconsistent with reported mechanisms and the coexistence of acute and chronic injuries. Specific injuries uncommon to accidental injury are also noted, including a distal ulnar diaphyseal fracture. CONCLUSIONS: We hope to raise awareness of elder abuse among diagnostic radiologists to encourage future large-scale research, increased focus on chronic osseous findings, and the addition of elder abuse to differential diagnoses.

Multisociety consensus quality improvement guidelines for intraarterial catheter-directed treatment of acute ischemic stroke, from the American Society of Neuroradiology, Canadian Interventional Radiology Association, Cardiovascular and Interventional Radiological Society of Europe, Society for Cardiovascular Angiography and Interventions, Society of Interventional Radiology, Society of NeuroInterventional Surgery, European Society of Minimally Invasive Neurological Therapy, and Society of Vascular and Interventional Neurology.

PURPOSE: In this international multispecialty document, quality benchmarks for processes of care and clinical outcomes are defined. It is intended that these benchmarks be used in a quality assurance program to assess and improve processes and outcomes in acute stroke revascularization. MATERIALS AND METHODS: Members of the writing group were appointed by the American Society of Neuroradiology, Canadian Interventional Radiology Association, Cardiovascular and Interventional Radiological Society of Europe, Society of Cardiac Angiography and Interventions, Society of Interventional Radiology, Society of NeuroInterventional Surgery, European Society of Minimally Invasive Neurological Therapy, and Society of Vascular and Interventional Neurology. The writing group reviewed the relevant literature from 1986 through February 2012 to create an evidence table summarizing processes and outcomes of care. Performance metrics and thresholds were then created by consensus. The guideline was approved by the sponsoring societies. It is intended that this guideline be fully updated in 3 years. RESULTS: In this international multispecialty document, quality benchmarks for processes of care and clinical outcomes are defined. These include process measures of time to imaging, arterial puncture, and revascularization and measures of clinical outcome up to 90 days. CONCLUSIONS: Quality improvement guidelines are provided for endovascular acute ischemic stroke revascularization procedures.

A study of inventiveness among Society of Interventional Radiology members and the impact of their social networks.

PURPOSE: To investigate the nature of inventiveness among members of the Society of Interventional Radiology (SIR) and learn what influenced the inventors and assisted their creativity. MATERIALS AND METHODS: The membership directory of the SIR was cross-referenced with filings at the United States Patent and Trademark Organization (USPTO) and the Patent Cooperation Treaty (PCT). The inventors were queried with an online survey to illuminate their institutions of training and practice as well as enabling or inhibiting factors to their inventiveness. Responses were analyzed through the construction of social network maps and thematic and graphical analysis. RESULTS: It was found that 457 members of the SIR held 2,492 patents or patent filings. After 1986, there was a marked and sustained increase in patent filings. The online survey was completed by 73 inventors holding 470 patents and patent filings. The social network maps show the key role of large academic interventional radiology departments and individual inventors in the formation of interconnectivity among inventors and the creation of the intellectual property (IP). Key inhibitors of the inventive process include lack of mentorship, of industry contacts, and of legal advice. Key enablers include mentorship, motivation, and industry contacts. CONCLUSIONS: Creativity and inventiveness in SIR members stem from institutions that are hubs of innovation and networks of key innovators; inventors are facilitated by personal motivation, mentorship, and strong industry contacts.

Multisociety consensus quality improvement guidelines for intraarterial catheter-directed treatment of acute ischemic stroke, from the American Society of Neuroradiology, Canadian Interventional Radiology Association, Cardiovascular and Interventional Radiological Society of Europe, Society for Cardiovascular Angiography and Interventions, Society of Interventional Radiology, Society of NeuroInterventional Surgery, European Society of Minimally Invasive Neurological Therapy, and Society of Vascular and Interventional Neurology.

PURPOSE: In this international multispecialty document, quality benchmarks for processes of care and clinical outcomes are defined. It is intended that these benchmarks be used in a quality assurance program to assess and improve processes and outcomes in acute stroke revascularization. MATERIALS AND METHODS: Members of the writing group were appointed by the American Society of Neuroradiology, Canadian Interventional Radiology Association, Cardiovascular and Interventional Radiological Society of Europe, Society of Cardiac Angiography and Interventions, Society of Interventional Radiology, Society of NeuroInterventional Surgery, European Society of Minimally Invasive Neurological Therapy, and Society of Vascular and Interventional Neurology. The writing group reviewed the relevant literature from 1986 through February 2012 to create an evidence table summarizing processes and outcomes of care. Performance metrics and thresholds were then created by consensus. The guideline was approved by the sponsoring societies. It is intended that this guideline be fully updated in 3 years. RESULTS: In this international multispecialty document, quality benchmarks for processes of care and clinical outcomes are defined. These include process measures of time to imaging, arterial puncture, and revascularization and measures of clinical outcome up to 90 days. CONCLUSIONS: Quality improvement guidelines are provided for endovascular acute ischemic stroke revascularization procedures.

Ecological Review of the Ciona Species Complex.

AbstractThe set of four closely related solitary ascidians Ciona spp. were once considered a single cosmopolitan species, Ciona intestinalis, but are now recognized as genetically and morphologically distinct species. The possibility of ecological differences between the species was not widely considered in studies preceding the schism of Ciona spp. Consequently, there may be an over-generalization of the ecology of Ciona spp., with potential implications for the broad range of studies targeting these species, encompassing the evolution, development, genomics, and invasion biology of Ciona spp. We completed a comprehensive review of the ecology of Ciona spp. to establish the similarities and differences between the widely distributed Ciona robusta and C. intestinalis (and what little is known of the two other species, Ciona sp. C and Ciona sp. D). When necessary, we used study locations and the species' geographic ranges to infer the species in each study in the review. As expected, ecological similarities are the norm between the two species, spanning both abiotic and biotic interactions. However, there are also important differences that have potential implications for other aspects of the biology of Ciona spp. For example, differences in temperature and salinity tolerances likely correspond with the disparities in the geographic distribution of the species. Asymmetries in topics studied in each species diminish our ability to fully compare several aspects of the ecology of Ciona spp. and are priority areas for future research. We anticipate that our clarification of common and unique aspects of each species' ecology will help to provide context for future research in many aspects of the biology of Ciona spp.

Innovation in image-guided spine intervention.

Image-guided spine intervention continues to evolve and is still an intellectually active field. But it is important not to confuse market and commercial success with intellectual, medical, or long-term success. What drives this evolution and innovation, and where is the activity currently? The history of vertebroplasty is a good case in point.

Fire and ice: percutaneous ablative therapies and cement injection in management of metastatic disease of the spine.

Oncology intervention is actively moving beyond simple bone cement injection. Archimedes taught us that a volume displaces its volume. Where does the tumor we displace with our cement injection go? It is no longer acceptable that we displace tumor into the venous system with our cement injections. We must kill the tumor first. Different image-guided percutaneous techniques can be used for treatment in patients with primary or secondary bone tumors. Curative ablation can be applied for the treatment of specific benign or in selected cases of malignant localized spinal tumors. Pain palliation therapy of primary and secondary bone tumors can be achieved with safe, fast, effective, and tolerable percutaneous methods. Ablation (chemical, thermal, mechanical), cavitation (radiofrequency ionization), and consolidation (cementoplasty) techniques can be used separately or in combination. Each technique has its indications, with both advantages and drawbacks. To prevent pathological fractures, a consolidation is necessary. In spinal or acetabular tumors, a percutaneous cementoplasty should be associated with cryoablation to avoid a compression fracture. The cement is injected after complete thawing of the ice ball or the day after the cryotherapy. A syndrome of multiorgan failure, severe coagulopathy, and disseminated intravascular coagulation following hepatic cryoablation has been described and is referred to as the cryoshock phenomenon.

Tarlov cysts: an overlooked clinical problem.

Symptomatic Tarlov cysts typically cause chronic pelvic and lower extremity pain and sacral nerve root radiculopathy. Historically, open surgical treatment involved significant patient morbidity, particularly postoperative cerebrospinal fluid (CSF) leaks and infection. These CSF leaks often required multiple surgical procedures to seal. Over the past 20 years, there have been two or three isolated case reports of computed tomography (CT)-guided needle aspirations that offered limited evidence of treatment efficacy and safety. Some have reported high rates of postprocedure aseptic meningitis that were not well explained. These poor results dissuaded physicians from caring for these patients. As a group these patients are usually treated dismissively and told their cysts are asymptomatic and their pain must be coming from somewhere else. Many of them have had an unnecessary discectomy or a spinal fusion, and when these procedures did not relieve their pain they were told they are a "failed back patient." We have treated more than a hundred patients with symptomatic Tarlov cysts by CT fluoroscopic-guided needle aspiration and fibrin injection and have had excellent results with no meaningful complications and never a case of aseptic meningitis. We believe this is a safe, highly effective first-line treatment for symptomatic Tarlov cysts.

Percutaneous vertebral augmentation: the status of vertebroplasty and current controversies.

Vertebroplasty is a cost-effective procedure for the relief of pain and suffering in the appropriate patient when done by a skilled practitioner under good image guidance. No study has ever shown any cost benefit of any balloon-based osteoporotic spine intervention over simple vertebroplasty. No study has ever shown any benefit of any intravertebral implant over vertebroplasty for osteoporotic compression fracture. Recent controversy has highlighted weaknesses in our practice of technology evaluation, and we need to address these issues across the board in the future more scientifically then we have done in the past.