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Expert judgment underpins assessment of threatened ecosystems. However, experts are often narrowly defined, and variability in their judgments may be substantial. Models built from structured elicitation with large diverse expert panels can contribute to more consistent and transparent decision-making. We conducted a structured elicitation under a broad definition of expertise to examine variation in judgments of ecosystem viability and collapse in a critically endangered ecosystem. We explored whether variation in judgments among 83 experts was related to affiliation and management expertise and assessed performance of an average model based on common ecosystem indicators. There were systematic differences among individuals, much of which were not explained by affiliation or expertise. However, of the individuals affiliated with government, those in conservation and environmental departments were more likely to determine a patch was viable than those in agriculture and rural land management. Classification errors from an average model, in which all individuals were weighted equally, were highest among government agriculture experts (27%) and lowest among government conservation experts (12%). Differences were mostly cases in which the average model predicted a patch was viable but the individual thought it was not. These differences arose primarily for areas that were grazed or cleared of mature trees. These areas are often the target of restoration, but they are also valuable for agriculture. These results highlight the potential for conflicting advice and disagreement about policies and actions for conserving and restoring threatened ecosystems. Although adoption of an average model can improve consistency of ecosystem assessment, it can fail to capture and convey diverse opinions held by experts. Structured elicitation and models of ecosystem viability play an important role in providing data-driven evidence of where differences arise among experts to support engagement and discussion among stakeholders and decision makers and to improve the management of threatened ecosystems.
Análisis de los modelos de opiniones de expertos para informar la evaluación de la viabilidad y el colapso ambiental Resumen La evaluación de los ecosistemas amenazados se basa en la opinión de los expertos. Sin embargo, la definición de experto suele ser limitada y la variabilidad de sus juicios puede ser considerable. Los modelos elaborados a partir de consultas estructuradas con grupos de expertos amplios y diversos pueden contribuir a una toma de decisiones más coherente y transparente. Realizamos una consulta estructurada con una definición amplia de experto para analizar la variación en los juicios sobre la viabilidad y el colapso de un ecosistema en peligro crítico. Exploramos si la variación en los juicios entre 83 expertos estaba relacionada con la afiliación y la experiencia en gestión y evaluamos el rendimiento de un modelo medio basado en indicadores comunes del ecosistema. Observamos diferencias sistemáticas entre los expertos, gran parte de las cuales no se explicaban por la afiliación o la experiencia. Sin embargo, entre los expertos vinculados a la administración pública, los de los departamentos de conservación y medio ambiente tenían más probabilidades de determinar que una parcela era viable que los de agricultura y gestión de tierras rurales. Los errores de clasificación de un modelo medio con todos los individuos ponderados por igual, fueron mayores entre los expertos gubernamentales en agricultura (27%) y menores entre los expertos gubernamentales en conservación (12%). En la mayoría de los casos, las diferencias se debían a que el modelo medio predecía que una parcela era viable, pero el individuo pensaba que no lo era. Estas diferencias surgieron sobre todo en zonas que habían sido pastoreadas o con una tala total de árboles maduros. Estas zonas suelen ser objeto de restauración, pero también son valiosas para la agricultura. Estos resultados ponen de manifiesto la posibilidad de que se produzcan consejos contradictorios y desacuerdos sobre las políticas y acciones de conservación y restauración de los ecosistemas pastoreados y forestales. Si bien la adopción de un modelo medio puede mejorar la coherencia de la evaluación de los ecosistemas, también puede fallar a la hora de captar y transmitir las diversas opiniones de los expertos. Las consultas estructuradas y los modelos de viabilidad de los ecosistemas desempeñan un papel importante a la hora de aportar pruebas basadas en datos de dónde surgen las diferencias entre los expertos para apoyar el compromiso y el debate entre las partes interesadas y los responsables de la toma de decisiones, así como para mejorar la gestión de los ecosistemas amenazados.
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This paper presents a new edge detection process implemented in an embedded IoT device called Bee Smart Detection node to detect catastrophic apiary events. Such events include swarming, queen loss, and the detection of Colony Collapse Disorder (CCD) conditions. Two deep learning sub-processes are used for this purpose. The first uses a fuzzy multi-layered neural network of variable depths called fuzzy-stranded-NN to detect CCD conditions based on temperature and humidity measurements inside the beehive. The second utilizes a deep learning CNN model to detect swarming and queen loss cases based on sound recordings. The proposed processes have been implemented into autonomous Bee Smart Detection IoT devices that transmit their measurements and the detection results to the cloud over Wi-Fi. The BeeSD devices have been tested for easy-to-use functionality, autonomous operation, deep learning model inference accuracy, and inference execution speeds. The author presents the experimental results of the fuzzy-stranded-NN model for detecting critical conditions and deep learning CNN models for detecting swarming and queen loss. From the presented experimental results, the stranded-NN achieved accuracy results up to 95%, while the ResNet-50 model presented accuracy results up to 99% for detecting swarming or queen loss events. The ResNet-18 model is also the fastest inference speed replacement of the ResNet-50 model, achieving up to 93% accuracy results. Finally, cross-comparison of the deep learning models with machine learning ones shows that deep learning models can provide at least 3-5% better accuracy results.
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Homologous recombination (HR) is a high-fidelity DNA double-strand break (DSB) repair pathway. Both familial and somatic loss of function mutation(s) in various HR genes predispose to a variety of cancer types, underscoring the importance of error-free repair of DSBs in human physiology. While environmental sources of DSBs have been known, more recent studies have begun to uncover the role of endogenous base damage in leading to these breaks. Base damage repair intermediates often consist of single-strand breaks, which if left unrepaired, can lead to DSBs as the replication fork encounters these lesions. This review summarizes various sources of endogenous base damage and how these lesions are repaired. We highlight how conversion of base repair intermediates, particularly those with 5'or 3' blocked ends, to DSBs can be a predominant source of genomic instability in HR-deficient cancers. We also discuss how endogenous base damage and ensuing DSBs can be exploited to enhance the efficacy of Poly (ADP-ribose) polymerase inhibitors (PARPi), that are widely used in the clinics for the regimen of HR-deficient cancers.
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Roturas del ADN de Doble Cadena , Inestabilidad Genómica , Neoplasias , Humanos , Neoplasias/genética , Neoplasias/metabolismo , Recombinación Homóloga , Reparación del ADN por Recombinación , Animales , Reparación del ADN , Daño del ADN , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacologíaRESUMEN
Type 2 respiratory failure, or hypercapnic respiratory failure, is brought on by low oxygenation (hypoxemia) and inadequate breathing (hypercapnia). It is produced by factors that can create an imbalance between the requirement and capacity of the respiratory system. The factors can include an increased requirement for muscles of respiration, reduction in their strength or effectiveness, or impediment of the ventilatory drive. Rarely, it can be caused by the bare lymphocyte syndrome (BLS), which usually affects young children and has a poor prognosis with accompanying debilitating disabilities. This is a case report that shares the unique findings of a 13-year-old patient with type 1 BLS and atopy, who is suffering from type 2 respiratory failure. She is susceptible to respiratory tract infections and has been treated for bronchopneumonia and tuberculosis in the past. She has been on assisted ventilation for the past 3.5 months, along with supplementary nutrition. She has been evaluated meticulously and methodically, ruling out other causes of her respiratory failure. Recognizing the root cause aided in her therapy and preventing mortality. This has been determined using clinical findings, lab results, and radiological reports. The diagnosis of hypercapnic respiratory failure was confirmed via an arterial blood gas analysis, whereas that of BLS was confirmed through a whole genome sequence test. Management entailed addressing the underlying cause, optimizing ventilation, and using mechanical ventilation to maintain respiratory function. Early detection and timely intervention were critical in enhancing the outcome for the patient.
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Preoperative antibiotic administration has become a standard practice to mitigate the risk of surgical site infections; however, it is not devoid of potential complications. This report delves into the case of a 67-year-old male who underwent a routine preoperative vancomycin infusion prior to an elective total knee arthroplasty and subsequently experienced an unexpected adverse reaction including diaphoresis, cutaneous flushing, hypotension, and eventually unresponsiveness involving cardiovascular collapse and non-ST-segment elevation myocardial infarction (NSTEMI), despite minimal underlying coronary artery disease. The report focuses on the management of the emergent condition at our facility, highlighting the immediate response and following management of additional complications. The successful management led to a full recovery with the electrocardiogram (EKG) returning to the preoperative baseline of sinus rhythm with first-degree atrioventricular (AV) block within two hours of the event. This study contributes valuable insights into the complexities associated with preoperative antibiotic use, underscores the importance of understanding individual patient profiles, and raises awareness of potential risks and strategies to be used for antibiotic administration from a healthcare professional perspective.
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AIMS: To compare all-cause claims associated with the LATERA Absorbable Nasal Implant and surgical repair of nasal vestibular stenosis in patients with nasal valve collapse. METHODS: This retrospective cohort study utilized data from STATinMED RWD Insights. A defined set of HCPCS, ICD-10-CM and CPT codes were used to identify patients with ≥1 claim for a LATERA procedure, and patients with ≥1 claim for surgical repair between June 1, 2015- March 31, 2023. Patients with continuous capture for at least 12 months before and at least 6 months after the index date were selected. The index date was defined as earliest date of encounter for a LATERA or surgical repair procedure. Inverse probability of treatment weighting (IPTW) was used to ensure balance between cohorts. Descriptive analyses were provided for all claims data using standard summary statistics. All-cause claims were assessed during the baseline, index date, and follow-up period. Chi-squared tests and independent sample t-tests were used to assess differences in cohorts for categorical and continuous variables, respectively. RESULTS: The study population included 5,032 LATERA patients and 26,553 surgical repair patients. During the baseline and follow-up periods, the matched cohorts exhibited similar all-cause claims. On the index date, LATERA patients incurred lower claims vs. surgical repair, likely due to LATERA's ability to be implanted in the physician office setting. LATERA patients and surgical repair patients mean (SD) total costs were $9,612 [$14,930] vs $11,846 [$17,037] (p ≤ 0.0001), respectively. CONCLUSIONS: Treatment with the LATERA Absorbable Nasal Implant is a potentially cost saving option for payers on the index date compared to traditional surgical repair in patients with nasal valve collapse due to the ability to be performed in the office. All-cause claims were similar in the baseline and follow-up periods. When performed with concomitant procedures, all-cause claims during follow-up were similar between groups.
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Implantes Absorbibles , Revisión de Utilización de Seguros , Humanos , Estudios Retrospectivos , Femenino , Masculino , Persona de Mediana Edad , Adulto , Obstrucción Nasal/cirugía , Anciano , Gastos en Salud/estadística & datos numéricosRESUMEN
OBJECTIVE: The efficacy of hypoglossal nerve stimulation (HGNS) therapy is limited by obstruction of the oropharyngeal lateral walls (OLWs). Our objective was to investigate the effect of palatine tonsillectomy on HGNS efficacy in obstructive sleep apnea (OSA) patients with OLW collapse. STUDY DESIGN: Case-control study of patients with moderate-to-severe OSA, complete-or-partial OLW collapse, and small tonsils (1 - 2+). Concomitant palatine tonsillectomy and HGNS (HGNS+T) were compared against a control group of patients who underwent HGNS alone. SETTING: Single academic institution. METHODS: Study outcomes were measures of HGNS efficacy defined as a %reduction in apnea-hypopnea index (AHI) (primary) and successful treatment response (50% AHI reduction to <15/h, logistic regression), respectively. Regression analyses quantified the additional effect of tonsillectomy (HGNS+T vs HGNS alone, independent variable) on HGNS efficacy. Analyses were adjusted for OLW collapse severity (complete vs partial), tonsil size, age, sex, body mass index, and baseline AHI. RESULTS: Nineteen patients underwent HGNS+T and had follow-up sleep testing for the current analysis. The control group (HGNS alone) consisted of 78 patients. Baseline demographics and OSA severity were similar between the groups, except HGNS+T group had increased prevalence of complete OLW collapse. Linear regression demonstrated that adding tonsillectomy resulted in an additional 22.9% [7.5, 35.2] reduction in AHI [95% confidence interval, CI] (P = .006), and 8.6 [1.7,43.4] (P = .010) greater odds [95% CI] of a successful treatment response with HGNS. CONCLUSION: Compared to historically poorer outcomes of HGNS in patients with OLW collapse, these early results suggest combining tonsillectomy with HGNS may represent a promising strategy to improve success rates.
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OBJECTIVES: Chronic abdominal pain is occasionally caused by an abdominal wall entity such as anterior cutaneous nerve entrapment syndrome (ACNES). This syndrome is thought to occur due to intercostal nerve branches (T7-12) that are entrapped in the rectus abdominis muscles. The diagnosis is largely based on subjective clues in patient history and physical examination. A test referred to as the scratch collapse test (SCT) is used as an additional diagnostic tool in peripheral nerve entrapment syndromes such as the carpal tunnel syndrome. The aim of the present study is to investigate whether an SCT was positive in patients with suspected ACNES. If so, this finding may support its hypothesized neuropathic character. METHODS: A prospective, case-control study was performed among patients with ACNES (n = 20) and two control groups without ACNES (acute intra-abdominal pathology n = 20; healthy n = 20), all were consecutively included. ACNES was diagnosed based on previously published criteria. The SCT test was executed at the painful abdominal area in both patient groups and at a corresponding area in healthy controls. Predictive values, sensitivity, and specificity were calculated. Videos of tests were evaluated by blinded observers. RESULTS: SCT was judged positive in 19 of 20 ACNES patients but not in any of the 40 controls. A 95% sensitivity (confidence interval [CI]: 75-99) and optimal specificity (100%; CI: 83-100) were calculated. CONCLUSIONS: The positive SCT supports the hypothesis that ACNES is an entrapment neuropathy. A positive SCT should be considered a major diagnostic criterion for ACNES.
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Síndromes de Compresión Nerviosa , Humanos , Síndromes de Compresión Nerviosa/diagnóstico , Estudios de Casos y Controles , Masculino , Femenino , Estudios Prospectivos , Persona de Mediana Edad , Adulto , Dolor Abdominal , Sensibilidad y Especificidad , Nervios Intercostales , AncianoRESUMEN
BACKGROUND: Despite hip function typically deteriorating in the post-collapse stage of osteonecrosis of the femoral head (ONFH), some patients can still demonstrate long-term favorable hip function, a state termed "survival with collapse". This study aims to identify the characteristics of patients suitable for "survival with collapse" in cases of ONFH. METHODS: This cross-sectional study included 65 patients (87 hips) diagnosed with post-collapse ONFH for ≥ 3 years (average 9.1 years, range 3-23 years). Hip function was assessed using the Harris Hip Score (HHS). Demographic, clinical, and radiographic data were compared between the favorable group (HHS > 80) and the poor group (HHS ≤ 80). Independent protective factors for hip function were identified by multivariate analysis and receiver operating characteristic (ROC) curve analysis was further applied to evaluate these factors' diagnostic efficacy. RESULTS: The favorable and poor groups included 46 and 41 hips, respectively. Significant differences were found in body mass index (BMI), Association Research Circulation Osseous (ARCO) stage, collapse degree, Japanese Investigation Committee (JIC) classification, necrotic size, and hip subluxation between the two groups (p < 0.05). Multivariate logistic regression identified collapse < 3 mm(OR:14.49, 95%CI: 3.52-59.68, p < 0.001), JIC types B (OR: 11.08, 95% CI: 1.07-115.12, p < 0.05) and C1(OR: 5.18, 95% CI: 1.47-18.20, p < 0.05) as independent protective factors for hip function, while BMI (OR: 0.76, 95% CI: 0.59-0.97, p = 0.029) was an independent risk factor. ROC curve analysis demonstrated that both collapse degree (AUC = 0.798, sensitivity = 91.3%, specificity = 68.3%, p < 0.0001) and JIC classification (AUC = 0.787, sensitivity = 80.4%, specificity = 73.2%, p < 0.0001) had satisfactory diagnostic value for hip function. Combining JIC classification and collapse degree (AUC = 0.868, sensitivity = 76.1%, specificity = 85.4%, p < 0.0001) significantly enhanced diagnostic efficacy compared to using either alone (p < 0.05). CONCLUSION: In ONFH, femoral head collapse does not necessarily determine a poor prognosis. Patients with mild collapse (< 3 mm) and preserved anterolateral wall are more likely to retain satisfactory hip function, making them candidates for "survival with collapse."
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Necrosis de la Cabeza Femoral , Articulación de la Cadera , Humanos , Necrosis de la Cabeza Femoral/diagnóstico por imagen , Masculino , Femenino , Estudios Transversales , Adulto , Persona de Mediana Edad , Articulación de la Cadera/diagnóstico por imagen , Articulación de la Cadera/patología , Adulto Joven , AdolescenteRESUMEN
OBJECTIVE: To evaluate the humeral head bone volume of patients with cuff tear arthropathy (CTA) and examine the therapeutic effect of zoledronate in a rat modified model of CTA (mCTA). DESIGN: The bone mass in patients with CTA was measured using Hounsfield units from CT images. The mCTA was induced by transecting the rotator cuff, biceps brachii tendon, and superior half of the joint capsule in adult rat shoulders. A single subcutaneous injection of zoledronate was followed by bone histomorphometry and immunohistochemistry of the humeral head, as well as the Murine Shoulder Arthritis Score (MSAS) assessment. RESULTS: The humeral head bone volume was decreased in patients with CTA. In the mCTA model, M1 macrophages were increased in the synovium and were decreased by zoledronate treatment. The increased expressions of TNF-α, IL-1ß and IL-6 in mCTA synovium and articular cartilage were suppressed in the zoledronate-treated mCTA group. The expression of catabolic enzymes in the articular cartilage and MSAS showed similar results. The zoledronate-treated mCTA group showed a decreased subchondral bone collapse with a decreased RANKL/OPG expression ratio and a suppressed number of osteoclasts compared with the control mCTA group. The enhanced expressions of HMGB1 and S100A9 in the mCTA shoulders were eliminated in the zoledronate-treated mCTA group. CONCLUSIONS: The humeral head subchondral bone was decreased in patients with CTA. In the mCTA model, the collapse and osteoarthritic changes were prevented by zoledronate administration. Zoledronate seemed to suppress the number of M1 macrophages in the synovium and osteoclasts in the subchondral bone.
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OBJECTIVES: The aim of this study was to describe the incidence of and modifiable risk factors for post intubation hemodynamic collapse in prehospital and interfacility critical care transport. METHODS: Single center retrospective chart review of adult patients (≥18 years) intubated by a critical care transport team between January 2017 and May 2023. The primary outcome was incidence of hemodynamic collapse (systolic blood pressure < 90 mmHg for greater than 30 minutes, new vasopressor requirement, vasopressor dose increase, fluid bolus of >15 mL/kg, systolic blood pressure < 65 mmHg at least once, or cardiac arrest). Secondary outcomes included post intubation hypoxia, as well as association of hemodynamic collapse with potentially modifiable risk factors including pre intubation shock index, pre intubation heart rate, pre intubation systolic blood pressure, and induction agent. RESULTS: Three hundred and thirty-three patients were included. Ninety-seven (29.1%) patients experienced hemodynamic collapse and 36 (10.8%) of patients experienced life threatening hemodynamic collapse. Pre intubation shock index >1 (OR 3.18, 95% CI 1.15-8.74) was associated with post intubation hemodynamic collapse. Choice of induction agent, fluid bolus prior to intubation, location of intubation, presence of traumatic injury, and age were not correlated with risk of hemodynamic collapse. The number of intubation attempts and methods of intubation were similar between groups. CONCLUSIONS: Hemodynamic collapse and life-threatening hemodynamic collapse after intubation occurred frequently in this critical care transport cohort. Shock index greater than one was associated with significantly higher risk of hemodynamic collapse and life-threatening hemodynamic collapse.
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Mediastinal teratomas are rare, often asymptomatic, but clinically significant neoplasms that can manifest with a spectrum of symptoms, frequently attributed to the compression of surrounding critical anatomical structures. Here, we present the case of a 19-year-old male with respiratory distress and chest pain attributed to a large anterior mediastinal mass, ultimately diagnosed as a benign mature teratoma of the thymus. Radiological imaging revealed a large, partially cystic mass compressing the pulmonary arteries, aortic arch, and left main bronchus. Surgical excision was deemed necessary due to symptomatic presentation. Anaesthesia management during mediastinal mass excision posed significant challenges, with prompt sternotomy due to ventilation difficulties after induction. Immediate decompression of the mass improved ventilation and saturation. Despite postoperative complications, including pulmonary leaks necessitating tracheostomy, the patient achieved significant recovery. Anaesthesia strategy was to prioritise avoiding muscle relaxants and maintaining spontaneous ventilation to mitigate airway collapse and hemodynamic instability during induction. Collaboration between anaesthesia, surgical, and intensive care teams is vital for comprehensive preoperative assessment, intraoperative readiness, and postoperative care. This case underscores the importance of interdisciplinary collaboration and meticulous planning to optimise outcomes in patients undergoing surgery for mediastinal teratomas.
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Background: The grade of tracheal collapse (TC) is assessed by the diameter of the narrowed lumen. However, studies on the relationship between TC grade and clinical symptom severity are lacking. Objectives: To investigate the clinical characteristics of small-breed dogs diagnosed with TC and determine if fluoroscopic grading correlates with cough severity. Methods: We retrospectively reviewed medical records from 2022 to 2024. TC diagnosis was confirmed using fluoroscopic examination. Multiple linear regression was employed to investigate factors influencing cough severity, with a significance level set at p < 0.05. Results: A total of 132 dogs with TC were identified, of which 22 were excluded. The final cohort consisted of 110 dogs, aged between 2-19 years, with no significant sex differences. The majority (97.2%) of dogs had a BCS of ≥4. Among the top four breeds (Maltese, Pomeranian, Poodle, and Chihuahua), the most severe collapse was observed in the carinal region. The grade of collapse on fluoroscopy was mostly related to high BCS (p < 0.007) and low body weight (p < 0.001). However, interestingly, fluoroscopic findings of collapse location and grade did not correlate with cough severity (p = 0.350). Notably, clinical symptoms improved in 86.6% of cases following interventions such as weight reduction, environmental changes, and pharmacotherapy. Conclusions and clinical relevance: In small-breed dogs, the severity of cough was not associated with the region or grade of TC diagnosed by fluoroscopy.
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In this paper, a computational approach based on numerical dissipation is proposed to simulate rocking blocks. A rocking block is idealized as a solid body interacting with its foundation through a contact-based formulation. An implicit time integration scheme with numerical dissipation, set to optimally treat dissipation in contact problems, is employed. The numerical dissipation is ruled by the time step and the rocking dissipative phenomenon at impacts is accurately predicted without any damping model. A broad numerical campaign is conducted to define a regression law in analytic form for the setting of the time step, depending on the block size and aspect ratio, the contact stiffness, as well as the coefficient of restitution selected. The so-obtained regression law appears accurate and an a posteriori validation with cases not in the training dataset confirms the effectiveness of the approach. Finally, the comparison with available experimental tests highlights the approach efficacy for free rocking and harmonic loading cases (in a deterministic sense), and for earthquake-like loading cases (in a statistical sense). It is found that rocking blocks with sizes of interest for structural engineering (e.g., cultural heritage structures) can be simulated with time steps within 10-3 ÷ 10-1 s, so allowing very fast computations.
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In this article, we claim that recent developments in climate science and renewable energy should prompt a reframing of debates surrounding climate change mitigation. Taken together, we argue that these developments suggest (1) global climate collapse in this century is a non-negligible risk, (2) mitigation offers substantial benefits to current generations, and (3) mitigation by some can generate social tipping dynamics that could ultimately make renewables cheaper than fossil fuels. We explain how these claims undermine familiar framings of climate change, wherein mitigation is understood as self-sacrifice that individuals and governments must be morally persuaded or incentivized to undertake.
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Polymer composite materials are increasingly used in civil aircraft structures. The failure mode and energy-absorption characteristics of polymer composite structures have garnered significant attention from academia and industry. For thin-walled polymer composite C-channels with layups of [0/90]3s, [45/-45]3s, and [45/90/-45/0]3, low-speed axial compression tests were performed to investigate the failure modes, failure mechanisms, and energy-absorbing characteristics. After parametric studies using [0] and [90] single-element models, stacked shell models of thin-walled composite C-channels were established using the Lavadèze single-layer damage constitutive model, Puck 2000, and Yamada Sun failure criteria. The results show that these thin-walled composite C-channels exhibit a stable progressive crushing process with a local buckling failure mode, encompassing local buckling, fiber break-age, matrix cracks, delamination, and corner cracking. The stacked shell model demonstrates reasonable agreement with the progressive crushing process of thin-walled composites, accurately capturing interlayer matrix failure and interface delamination cracking behavior. A comparison of the specific energy absorption (SEA) and mean crushing force (Fmean) between the simulation and test results yields a difference of less than 6%, indicating a strong correlation between the simulation results and the experimental energy-absorbing characteristics. It also shows that a deep understanding of the parameters is helpful for accurate numerical modeling.
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In order to predict the maximum cavitation damage to hydraulic machinery in cryogenic engineering such as turbopumps in liquid rockets, it is essential to know the achievable intensity of bubble collapse. Rayleigh-Taylor instability imposes an extinction threshold for collapsing bubbles and determines the upper limit for the strongest collapse possible. In this study, we numerically investigate this information for collapsing bubbles in liquid oxygen. Our results reveal two distinct features of bubble instability in cryogenic liquids compared with that in water. First, high-order surface distortions are preferably developed on the bubble surface. Second, the bubble is most unstable when it collapses moderately, whereas it is stabilized as the collapse intensity is strengthened. A mechanistic study links these intriguing phenomena to the relatively slow bubble dynamics in cryogenic liquids. In that context, the growth time of the distortions emerges as a pivotal factor for the instability development. Together with the amplification rate, it controls the ultimate mode and amplitude of the instability.
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Burn injuries worldwide pose significant health risks due to frequent microbial infections, which worsen complications and increase mortality rates. The conventional antimicrobial formulations are available in the form of ointments and creams. These formulations are very greasy and stick to the clothes. The applications of these formulations by finger or applicator produce pain in the affected area and incur the possibility of microbial infection. To overcome these hurdles, authors developed a novel non-propellent foam (NPF) based formulation containing chlorhexidine for effective topical delivery. Initially, NPF containing Labrasol® (26.7%), sodium lauryl sulfate (1.2%), hydroxy propyl methyl cellulose (0.56%), butylated hydroxytoluene (0.1%), ethanol (1%), and distilled water was prepared and assessed for its consistency, and ability to form foam. The NPF was statistically optimized using the Box-Behnken design to determine the effect of polymer and surfactants on the critical foam properties. The optimized formulation showed a collapse time of 45 s with a unique nature of collapsing upon slight touch which is highly beneficial for burn patients with microbial infection. The diffusion study showed that more than 90% of the drug was released within 6 h. The skin permeation study showed that 23% of the total drug permeated through the skin after 6 h with 7.64 µg/cm2/h permeation flux. The developed formulation showed good antibacterial activity. The minimum inhibitory concentration of prepared NPF was found to be 2.5 µg/mL, 2.5 µg/mL, and 5.0 µg/mL against E. coli (MTCC-1687), P. aeruginosa (MTCC-1688), and S aureus (MTCC-737) respectively. The developed NPF formulation showed quick collapse time, excellent spreadability, good anti-bacterial activity, and a non-sticky nature representing a promising avenue for burn wound treatment without using any applicator.
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Quemaduras , Quemaduras/tratamiento farmacológico , Animales , Clorhexidina/administración & dosificación , Clorhexidina/química , Química Farmacéutica/métodos , Antiinfecciosos Locales/administración & dosificación , Antiinfecciosos Locales/farmacología , Antiinfecciosos Locales/química , Pruebas de Sensibilidad Microbiana , Composición de Medicamentos/métodos , Piel/metabolismo , Piel/efectos de los fármacos , Piel/microbiología , Staphylococcus aureus/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Tensoactivos/química , Antibacterianos/administración & dosificación , Antibacterianos/farmacología , Antibacterianos/química , Pseudomonas aeruginosa/efectos de los fármacos , Administración Cutánea , HumanosRESUMEN
OBJECTIVE: This paper investigates the critical role of material thickness in freeze-dried pellets for enhancing the storage stability of encapsulated bacteria. Freeze dried material of varying thicknesses obtained from different annealing durations is quantified using Scanning Electron Microscopy (SEM) and X-ray microtomography (µCT), the material thickness is then correlated to the storage stability of the encapsulated cells. METHODS: A formulation comprising of sucrose, maltodextrin, and probiotic cells is quenched in liquid nitrogen to form pellets. The pellets undergo different durations of annealing before undergoing freeze-drying. The material thickness is quantified using SEM and µCT. Storage stability in both oxygen-rich and oxygen-poor environments is evaluated by measuring CFU counts and correlated with the pellet structure. RESULTS: The varying annealing protocols produce a range of material thicknesses, with more extensive annealing resulting in thicker materials. Storage stability exhibits a positive correlation with material thickness, indicating improved stability with thicker materials. Non-annealed pellets exhibit structural irregularities and inconsistent storage stability, highlighting the impracticality of avoiding annealing in the freeze-drying process. CONCLUSIONS: Extensive annealing not only enhances the storage stability of probiotic products but also provides greater control over the freeze-drying process, ensuring homogeneous and reproducible products. This study underscores the importance of material thickness in freeze-dried pellets for optimizing storage stability for probiotic formulations, and emphasize the necessity of annealing as a critical step in freeze-drying quenched pellets to achieve desired structural and stability outcomes.