Biological invasions are a population-level rather than a species-level phenomenon.

Biological invasions pose a rapidly expanding threat to the persistence, functioning and service provisioning of ecosystems globally, and to socio-economic interests. The stages of successful invasions are driven by the same mechanism that underlies adaptive changes across species in general-via natural selection on intraspecific variation in traits that influence survival and reproductive performance (i.e., fitness). Surprisingly, however, the rapid progress in the field of invasion science has resulted in a predominance of species-level approaches (such as deny lists), often irrespective of natural selection theory, local adaptation and other population-level processes that govern successful invasions. To address these issues, we analyse non-native species dynamics at the population level by employing a database of European freshwater macroinvertebrate time series, to investigate spreading speed, abundance dynamics and impact assessments among populations. Our findings reveal substantial variability in spreading speed and abundance trends within and between macroinvertebrate species across biogeographic regions, indicating that levels of invasiveness and impact differ markedly. Discrepancies and inconsistencies among species-level risk screenings and real population-level data were also identified, highlighting the inherent challenges in accurately assessing population-level effects through species-level assessments. In recognition of the importance of population-level assessments, we urge a shift in invasive species management frameworks, which should account for the dynamics of different populations and their environmental context. Adopting an adaptive, region-specific and population-focused approach is imperative, considering the diverse ecological contexts and varying degrees of susceptibility. Such an approach could improve and refine risk assessments while promoting mechanistic understandings of risks and impacts, thereby enabling the development of more effective conservation and management strategies.

Randomized Clinical Trials and Observational Tribulations: Providing Clinical Evidence for Personalized Surgical Pain Management Care Models.

Proving clinical superiority of personalized care models in interventional and surgical pain management is challenging. The apparent difficulties may arise from the inability to standardize complex surgical procedures that often involve multiple steps. Ensuring the surgery is performed the same way every time is nearly impossible. Confounding factors, such as the variability of the patient population and selection bias regarding comorbidities and anatomical variations are also difficult to control for. Small sample sizes in study groups comparing iterations of a surgical protocol may amplify bias. It is essentially impossible to conceal the surgical treatment from the surgeon and the operating team. Restrictive inclusion and exclusion criteria may distort the study population to no longer reflect patients seen in daily practice. Hindsight bias is introduced by the inability to effectively blind patient group allocation, which affects clinical result interpretation, particularly if the outcome is already known to the investigators when the outcome analysis is performed (often a long time after the intervention). Randomization is equally problematic, as many patients want to avoid being randomly assigned to a study group, particularly if they perceive their surgeon to be unsure of which treatment will likely render the best clinical outcome for them. Ethical concerns may also exist if the study involves additional and unnecessary risks. Lastly, surgical trials are costly, especially if the tested interventions are complex and require long-term follow-up to assess their benefit. Traditional clinical testing of personalized surgical pain management treatments may be more challenging because individualized solutions tailored to each patient's pain generator can vary extensively. However, high-grade evidence is needed to prompt a protocol change and break with traditional image-based criteria for treatment. In this article, the authors review issues in surgical trials and offer practical solutions.

Personalized Interventional Surgery of the Lumbar Spine: A Perspective on Minimally Invasive and Neuroendoscopic Decompression for Spinal Stenosis.

Pain generator-based lumbar spinal decompression surgery is the backbone of modern spine care. In contrast to traditional image-based medical necessity criteria for spinal surgery, assessing the severity of neural element encroachment, instability, and deformity, staged management of common painful degenerative lumbar spine conditions is likely to be more durable and cost-effective. Targeting validated pain generators can be accomplished with simplified decompression procedures associated with lower perioperative complications and long-term revision rates. In this perspective article, the authors summarize the current concepts of successful management of spinal stenosis patients with modern transforaminal endoscopic and translaminar minimally invasive spinal surgery techniques. They represent the consensus statements of 14 international surgeon societies, who have worked in collaborative teams in an open peer-review model based on a systematic review of the existing literature and grading the strength of its clinical evidence. The authors found that personalized clinical care protocols for lumbar spinal stenosis rooted in validated pain generators can successfully treat most patients with sciatica-type back and leg pain including those who fail to meet traditional image-based medical necessity criteria for surgery since nearly half of the surgically treated pain generators are not shown on the preoperative MRI scan. Common pain generators in the lumbar spine include (a) an inflamed disc, (b) an inflamed nerve, (c) a hypervascular scar, (d) a hypertrophied superior articular process (SAP) and ligamentum flavum, (e) a tender capsule, (f) an impacting facet margin, (g) a superior foraminal facet osteophyte and cyst, (h) a superior foraminal ligament impingement, (i) a hidden shoulder osteophyte. The position of the key opinion authors of the perspective article is that further clinical research will continue to validate pain generator-based treatment protocols for lumbar spinal stenosis. The endoscopic technology platform enables spine surgeons to directly visualize pain generators, forming the basis for more simplified targeted surgical pain management therapies. Limitations of this care model are dictated by appropriate patient selection and mastering the learning curve of modern MIS procedures. Decompensated deformity and instability will likely continue to be treated with open corrective surgery. Vertically integrated outpatient spine care programs are the most suitable setting for executing such pain generator-focused programs.

The Changing Environment in Postgraduate Education in Orthopedic Surgery and Neurosurgery and Its Impact on Technology-Driven Targeted Interventional and Surgical Pain Management: Perspectives from Europe, Latin America, Asia, and The United States.

Personalized care models are dominating modern medicine. These models are rooted in teaching future physicians the skill set to keep up with innovation. In orthopedic surgery and neurosurgery, education is increasingly influenced by augmented reality, simulation, navigation, robotics, and in some cases, artificial intelligence. The postpandemic learning environment has also changed, emphasizing online learning and skill- and competency-based teaching models incorporating clinical and bench-top research. Attempts to improve work-life balance and minimize physician burnout have led to work-hour restrictions in postgraduate training programs. These restrictions have made it particularly challenging for orthopedic and neurosurgery residents to acquire the knowledge and skill set to meet the requirements for certification. The fast-paced flow of information and the rapid implementation of innovation require higher efficiencies in the modern postgraduate training environment. However, what is taught typically lags several years behind. Examples include minimally invasive tissue-sparing techniques through tubular small-bladed retractor systems, robotic and navigation, endoscopic, patient-specific implants made possible by advances in imaging technology and 3D printing, and regenerative strategies. Currently, the traditional roles of mentee and mentor are being redefined. The future orthopedic surgeons and neurosurgeons involved in personalized surgical pain management will need to be versed in several disciplines ranging from bioengineering, basic research, computer, social and health sciences, clinical study, trial design, public health policy development, and economic accountability. Solutions to the fast-paced innovation cycle in orthopedic surgery and neurosurgery include adaptive learning skills to seize opportunities for innovation with execution and implementation by facilitating translational research and clinical program development across traditional boundaries between clinical and nonclinical specialties. Preparing the future generation of surgeons to have the aptitude to keep up with the rapid technological advances is challenging for postgraduate residency programs and accreditation agencies. However, implementing clinical protocol change when the entrepreneur-investigator surgeon substantiates it with high-grade clinical evidence is at the heart of personalized surgical pain management.

Predicting the impact of invasive trees from different measures of abundance.

Biological invasions produce negative impacts worldwide, causing massive economic costs and ecological impacts. Knowing the relationship between invasive species abundance and the magnitude of their impacts (abundance-impact curves) is critical to designing prevention and management strategies that effectively tackle these impacts. However, different measures of abundance may produce different abundance-impact curves. Woody plants are among the most transformative invaders, especially in grassland ecosystems because of the introduction of hitherto absent life forms. In this study, our first goal was to assess the impact of a woody invader, Pinus contorta (hereafter pine), on native grassland productivity and livestock grazing in Patagonia (Argentina), building abundance-impact curves. Our second goal, was to compare different measure of pine abundance (density, basal area and canopy cover) as predictors of pine's impact on grassland productivity. Our third goal, was to compare abundance-impact curves among the mentioned measures of pine abundance and among different measures of impact: total grassland productivity, palatable productivity and sheep stocking rate (the number of sheep that the grassland can sustainably support). Pine canopy cover, closely followed by basal area, was the measure of abundance that best explained the impact on grassland productivity, but the shape of abundance impact curves differed between measures of abundance. While increases in pine density and basal area always reduced grassland productivity, pine canopy cover below 30% slightly increased grassland productivity and higher values caused an exponential decline. This increase in grassland productivity with low levels of pine canopy cover could be explained by the amelioration of stressful abiotic conditions for grassland species. Different measures of impact, namely total productivity, palatable productivity and sheep stocking rate, drew very similar results. Our abundance-impact curves are key to guide the management of invasive pines because a proper assessment of how many invasive individuals (per surface unit) are unacceptable, according to environmental or economic impact thresholds, is fundamental to define when to start management actions.

Joint International SILACO, SICCMII, ISASS Symposium as a Model for a Collaborative Framework to Create Literature on Advances in Spine Surgery, Patient Care, and Policy.

International collaborations can be the key to overcoming innovation implementation hurdles. The authors report on a joint symposium between the International Society For The Advancement of Spine Surgery (ISASS) and La Sociedad Iberolatinoamerica de Columna (SILACO), and La Sociedad Interamericana de Cirurgia de columna de Minima invasión (SICCMII) aimed at improving joint surgeon education programs. The symposium highlighted that patient-related spine care issues are similar across geographical, cultural, and language barriers. The sustainability of such programs depends on funding and mutually respectful relationships orchestrated by multi-lingual leaders who will bridge gaps created by geographical, cultural, and language barriers to effectively develop clinical research content focused on advancing surgeon education and improving patient outcomes across the Americas.

Identifying Priorities, Targets, and Actions for the Long-term Social and Ecological Management of Invasive Non-Native Species.

Formulating effective management plans for addressing the impacts of invasive non-native species (INNS) requires the definition of clear priorities and tangible targets, and the recognition of the plurality of societal values assigned to these species. These tasks require a multi-disciplinary approach and the involvement of stakeholders. Here, we describe procedures to integrate multiple sources of information to formulate management priorities, targets, and high-level actions for the management of INNS. We follow five good-practice criteria: justified, evidence-informed, actionable, quantifiable, and flexible. We used expert knowledge methods to compile 17 lists of ecological, social, and economic impacts of lodgepole pines (Pinus contorta) and American mink (Neovison vison) in Chile and Argentina, the privet (Ligustrum lucidum) in Argentina, the yellow-jacket wasp (Vespula germanica) in Chile, and grasses (Urochloa brizantha and Urochloa decumbens) in Brazil. INNS plants caused a greater number of impacts than INNS animals, although more socio-economic impacts were listed for INNS animals than for plants. These impacts were ranked according to their magnitude and level of confidence on the information used for the ranking to prioritise impacts and assign them one of four high-level actions-do nothing, monitor, research, and immediate active management. We showed that it is possible to formulate management priorities, targets, and high-level actions for a variety of INNS and with variable levels of available information. This is vital in a world where the problems caused by INNS continue to increase, and there is a parallel growth in the implementation of management plans to deal with them.

Soil biotic and abiotic effects on seedling growth exhibit context-dependent interactions: evidence from a multi-country experiment on Pinus contorta invasion.

The success of invasive plants is influenced by many interacting factors, but evaluating multiple possible mechanisms of invasion success and elucidating the relative importance of abiotic and biotic drivers is challenging, and therefore rarely achieved. We used live, sterile or inoculated soil from different soil origins (native range and introduced range plantation; and invaded plots spanning three different countries) in a fully factorial design to simultaneously examine the influence of soil origin and soil abiotic and biotic factors on the growth of invasive Pinus contorta. Our results displayed significant context dependency in that certain soil abiotic conditions in the introduced ranges (soil nitrogen, phosphorus or carbon content) influenced responses to inoculation treatments. Our findings do not support the enemy release hypothesis or the enhanced mutualism hypothesis, as biota from native and plantation ranges promoted growth similarly. Instead, our results support the missed mutualism hypothesis, as biota from invasive ranges were the least beneficial for seedling growth. Our study provides a novel perspective on how variation in soil abiotic factors can influence plant-soil feedbacks for an invasive tree across broad biogeographical contexts.

Invasive trees rely more on mycorrhizas, countering the ideal-weed hypothesis.

The ideal-weed hypothesis predicts that invasive plants should be less dependent on mutualisms. However, evidence in favor of or against this hypothesis comes mainly from observational studies. Here, we experimentally tested this hypothesis using a two-factor greenhouse experiment, comparing the seedling growth response of different Pinus species (varying in invasiveness) to ectomycorrhizal fungal inoculation. Most species showed no response until they were 6 mo old, at which point inoculation increased growth between 10 and 260% among the different species. This growth response was higher for species with lower seed mass, higher dispersal ability, higher Z score (a proxy for invasiveness) and higher number of naturalized regions, all of which correspond to higher invasiveness. Our results show that timing is a crucial factor when comparing mycorrhizal dependency of different species. Dependence on mutualistic microorganisms could be part of a strategy in which invasive species produce smaller seeds, in greater number, which can disperse further, but where seedlings are more reliant on mycorrhizas to improve access to water, nutrients, and protection from pathogens. Our results suggest that reliance on mutualisms may enhance, rather than limit, nonnative species in their ability to spread, establish, and colonize.

Cordomas cervicales. Reporte de casos / Cervical chordomas. Case report

Introducción La detección temprana del cordoma constituye un desafío médico dada su baja frecuencia, calculada entre 2-4% de todos los tumores primarios del hueso, requiriendo un alto índice de sospecha clínica. El diagnóstico tardío incrementa la morbimortalidad y compromete la sobrevida del paciente, por lo que el conocimiento actualizado sobre su etiopatogenia, clínica y tratamiento es de suma importancia para el cirujano espinal, quien forma parte esencial del grupo interdisciplinario terapéutico. Reporte de casos Reportamos dos casos de cordomas cervicales, localmente agresivos sin extensión sistémica, el primero de ellos ubicado en la columna cervical y el segundo en la unión craneocervical. Ambos con diferentes formas de presentación, síntomas, tiempo de evolución (5 años y 7 meses respectivamente), infiltración tumoral y abordaje quirúrgico, pero similar tratamiento oncológico. El objetivo del manuscrito es demostrar la variedad de presentación cervical de la entidad y las diferentes formas de abordarla. Se incluye una revisión actualizada de la literatura donde se evidencia la importancia de la inmunoterapia como nuevo horizonte terapéutico, y se reafirma la resección quirúrgica como base del mismo. Discusión Se presentan los resultados imagenológicos de descompresión medular, resección ósea y de partes blandas, los tipos de fijación espinal y la evolución clínica, sin recidiva local a los 2 años y a los 12 meses respectivamente en cada caso, luego del manejo quirúrgico y la radioterapia adyuvante.

Background Early detection of chordoma is a medical challenge given its low frequency, a high index of clinical suspicion is required for the diagnosis. The late diagnosis increases morbidity and mortality and compromises the survival of the patient. Knowledge about its etiology, clinical manifestations and treatment is of utmost importance for the spinal surgeon as well as for the therapeutic group. The aim of the report is to demonstrate the variety of cervical presentation of the entity and the different ways of approaching it. Case Report We report two cases of locally aggressive cervical chordomas without systemic extension, the first one located in the cervical spine and the second in the craniocervical junction. Both with different forms of presentation, symptoms, evolution time (5 years and 7 months respectively), tumor infiltration and surgical approach, but similar oncological treatment. Discussion The imaging results of medullar decompression, bone and soft tissue resection, types of spinal fixation and clinical evolution were presented. No local recurrence at 2 years and 12 months respectively after surgical management and adjuvant radiation therapy were found.

Highly invasive tree species are more dependent on mutualisms.

Why some species become invasive while others do not remains an elusive question. It has been proposed that invasive species should depend less on mutualisms, because their spread would then be less constrained by the availability of mutualistic partners. We tested this idea with the genus Pinus, whose degree of invasiveness is known at the species level (being highly and negatively correlated with seed size), and which forms obligate mutualistic associations with ectomycorrhizal fungi (EMF). Mycorrhizal dependence is defined as the degree to which a plant needs the mycorrhizal fungi to show the maximum growth. In this regard, we use plant growth response to mycorrhizal fungi as a proxy for mycorrhizal dependence. We assessed the responsiveness of Pinus species to EMF using 1,206 contrasts published on 34 species, and matched these data with data on Pinus species invasiveness. Surprisingly, we found that species that are more invasive depend more on mutualisms (EMF). Seedling growth of species with smaller seeds benefited more from mutualisms, indicating a higher dependence. A higher reliance on EMF could be part of a strategy in which small-seeded species produce more seeds that can disperse further, and these species are likely to establish only if facilitated by mycorrhizal fungi. On the contrary, big-seeded species showed a lower dependence on EMF, which may be explained by their tolerance to stressful conditions during establishment. However, the limited dispersal of larger seeds may limit the spread of these species. We present strong evidence against a venerable belief in ecology that species that rely more on mutualisms are less prone to invade, and suggest that in certain circumstances greater reliance on mutualists can increase spread capacity.

Seed predation does not explain pine invasion success.

Why some non-native plant species invade, and others fail remains an elusive question. Plant invasion success has been associated with specific species traits. Yet, we have limited knowledge of the mechanisms relating these traits to invasion potential. General patterns of biotic resistance by seed predation may provide a mechanism that helps separate invasive from non-invasive plants. Seed predation is an important barrier against plant establishment for many plant species. It may, therefore, create a selective filter against non-native plant establishment based on plant traits related to seed predation rate. In two cafeteria-style seed predation experiments in a steppe ecosystem in Patagonia (Argentina) we provided seeds of 16 non-native Pinaceae covering a 300-fold variation in seed mass, a 200-fold variation in seed volume and 75-fold variation in seed toughness. Seed removal decreased with seed mass and seed volume. Seed toughness was not a significant predictor while seed volume was the best predictor of predators' preference. However, for species of this family small seed size is the most important predictor of species invasiveness. Our results show that seed predation does not explain Pinaceae invasive success. In our system, species that have smaller seeds (i.e., more invasive) are preferentially consumed by seed predators. Seed mass was not the best predictor of granivory rates, despite being the seed trait on which most studies have been focused. Our ability to predict future invasion and understand invasion success could benefit from other studies that focus on the mechanisms behind invasive traits.

Insights on the persistence of pines (Pinus species) in the Late Cretaceous and their increasing dominance in the Anthropocene.

Although gymnosperms were nearly swept away by the rise of the angiosperms in the Late Cretaceous, conifers, and pines (Pinus species) in particular, survived and regained their dominance in some habitats. Diversification of pines into fire-avoiding (subgenus Haploxylon) and fire-adapted (subgenus Diploxylon) species occurred in response to abiotic and biotic factors in the Late Cretaceous such as competition with emerging angiosperms and changing fire regimes. Adaptations/traits that evolved in response to angiosperm-fuelled fire regimes and stressful environments in the Late Cretaceous were key to pine success and are also contributing to a new "pine rise" in some areas in the Anthropocene. Human-mediated activities exert both positive and negative impacts of range size and expansion and invasions of pines. Large-scale afforestation with pines, human-mediated changes to fire regimes, and other ecosystem processes are other contributing factors. We discuss traits that evolved in response to angiosperm-mediated fires and stressful environments in the Cretaceous and that continue to contribute to pine persistence and dominance and the numerous ways in which human activities favor pines.

Errata: Análisis comparativo de pacientes con estenosis degenerativa lumbar pura (EDLP) y estenosis secundaria a espondilolistesis degenerativa lumbar (ELDL) tratados quirúrgicamente en el período de 2008 a 2011... / Errata de: Análise comparativa de pacientes com estenose degenerativa pura lombar (EDPL) e estenose secundária a espondilolistese lombar degenerativa lombar (ELDL) tratados cirurgicamente no período de 2008 a 2011 no Hospital Metropolitano de Quito, Equador / Erratum to: Comparative analysis in patients with pure degenerative lumbar stenosis (EDLP) and stenosis secundary to degenerative lumbar spondilolisthesis (ELDL) surgically treated between 2008-2011 at the Hospital Metropolitano, Quito, Ecuador

Solicitação de alteração da ordem dos autores do artigo "Análisis comparativo de pacientes con estenosis degenerativa lumbar pura (EDLP) y estenosis secundaria a espondilolistesis degenerativa lumbar (ELDL) tratados quirúrgicamente en el período de 2008 a 2011 en el Hospital Metropolitano de Quito-Ecuador"

Análisis comparativo de pacientes con estenosis degenerativa lumbar pura (EDLP) y estenosis secundaria a espondilolistesis degenerativa lumbar (ELDL) tratados quirúrgicamente en el período de 2008 a 2011... / Análise comparativa de pacientes com estenose degenerativa pura lombar (EDPL) e estenose secundária a espondilolistese lombar degenerativa lombar (ELDL) tratados cirurgicamente no período de 2008 a 2011 no Hospital Metropolitano de Quito, Equador / Comparative analysis in patients with pure degenerative lumbar stenosis (EDLP) and stenosis secundary to degenerative lumbar spondilolisthesis (ELDL) surgically treated between 2008-2011 at the Hospital Metropolitano, Quito, Ecuador

OBJETIVO: Establecer si existen diferencias demográficas, de tratamiento y en resultados entre los grupos de EDLP y ELDL. MÉTODOS: Estudio retrospectivo observacional de 76 pacientes con EDL tratados quirúrgicamente. Se analizan por separado los datos demográficos y la evolución del grupo 1 (EDLP, 53 pacientes) y del grupo 2 (ELDL, 23 pacientes). RESULTADOS: Grupo 1: 51% mujeres y 49% varones. Edad promedio 56,8 años. Evolución preoperatoria 34 meses; Grupo 2: 78% de mujeres y 22% de varones. Edad promedio 63,4 años. Evolución preoperatoria 10 meses. Los dos grupos fueron intervenidos con la misma técnica, por el mismo equipo quirúrgico. El porcentaje de satisfacción postoperatoria fue mejor para el grupo 1 cuando el tiempo de evolución preoperatoria fue menor a 18 meses. En el grupo 2 los hallazgos no fueron significativos. CONCLUSIÓN: La estenosis por ELDL tiene características de edad y sexo muy diferentes dela EDLP. La cirugía precoz presentó un mayor porcentaje de satisfacción.

OBJETIVO: Determinar se existem diferenças demográficas, de tratamento e nos resultados entre os grupos EDLP e ELDL. MÉTODOS: Estudo observacional retrospectivo de 76 pacientes com EDLP tratados cirurgicamente. Analisamos separadamente os dados demográficos e os resultados do grupo 1 (EDLP, 53 pacientes) e do grupo 2 (ELDL, 23 pacientes). RESULTADOS: Grupo 1: 51% mulheres e 49% homens; média de idade, 56,8 anos. Evolução pré-operatória, 34 meses. Grupo 2: 78% mulheres e 22% homens; média de idade, 63,4 anos. Evolução pré-operatória, 10 meses. Os dois grupos foram operados com a mesma técnica e pela mesma equipe cirúrgica. A porcentagem de satisfação pós-operatória foi maior no Grupo 1 quando a evolução pré-operatória foi inferior a 18 meses. No Grupo 2, os resultados não foram significativos. CONCLUSÃO: Na estenose secundária a ELDL, a idade e distribução por gênero foram muito diferentes do encontrado na EDLP. A cirurgia precoce gerou uma maior porcentagem de satisfação.

OBJECTIVE: Establish whether there are differences regarding demographics, treatment and outcomes between the groups EDLP and ELDL. METHODS: Retrospective observational study of 76 patients with EDLP surgically treated. Demographic data and outcomes of Group 1 (EDLP, 53 patients) and Group 2 (ELDL, 23 patients) were analyzed separately. RESULTS: Group 1: 51% female; 49% male. Mean age, 56.8 years. Pre-surgical development, 34 months. Group 2: 78% female; 22% male. Mean age, 63.4 years. Pre-surgical development, 10 months. Both groups were operated with the same technique and by the same surgical team. In Group 1, postoperative satisfaction was higher when the pre-surgical development was less than 18 months. In Group 2 there where no significant findings. CONCLUSION: In stenosis secondary to ELDL, age and gender distribution were very different from that found in EDLP. Early surgery led to a higher percentage of satisfaction.

Gangrena gaseosa y tromboflebitis Séptica

Gangrena gaseosa y tromboflevitis séptica o supurativa, son dos entidades clínico quirúrgicas diferentes, poco frecuentes en la práctica médica y con una alta incidencia en lo que a morbimortalidad se refiere. El presente caso es el de un paciente jóven, quien desarrolla estas dos patologías al mismo tiempo, con na etiopatogenia atípica a la referida en la literatura médica. Se demuestra la eficacia de la resonancia magnética nuclear, como un estudio complementario fundamental en el diagnóstico de procesos infecciosos ocultos de las extremidades. Se hace un resumen del tratamiento médico agresivo que debe ser institutido en estos casos poco comunes.