8 research outputs found

    On Wings of the Minimum Induced Drag: Spanload Implications for Aircraft and Birds

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    For nearly a century Ludwig Prandtl's lifting-line theory remains a standard tool for understanding and analyzing aircraft wings. The tool, said Prandtl, initially points to the elliptical spanload as the most efficient wing choice, and it, too, has become the standard in aviation. Having no other model, avian researchers have used the elliptical spanload virtually since its introduction. Yet over the last half-century, research in bird flight has generated increasing data incongruous with the elliptical spanload. In 1933 Prandtl published a little-known paper presenting a superior spanload: any other solution produces greater drag. We argue that this second spanload is the correct model for bird flight data. Based on research we present a unifying theory for superior efficiency and coordinated control in a single solution. Specifically, Prandtl's second spanload offers the only solution to three aspects of bird flight: how birds are able to turn and maneuver without a vertical tail; why birds fly in formation with their wingtips overlapped; and why narrow wingtips do not result in wingtip stall. We performed research using two experimental aircraft designed in accordance with the fundamentals of Prandtl's second paper, but applying recent developments, to validate the various potentials of the new spanload, to wit: as an alternative for avian researchers, to demonstrate the concept of proverse yaw, and to offer a new method of aircraft control and efficiency

    Understanding the plasmapheresis donor in a voluntary, nonremunerated environment

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    Background: Increasing demand for plasma-derived products presents a major recruitment and retention challenge for blood collection agencies; however, little is known about what motivates individuals to become committed plasmapheresis donors. This study explored triggers for individuals first plasma donation and factors associated with continuing donations. Study Desing and Methods: A total of 103 plasma donors were recruited into 11 focus groups. Reasons for donating were discussed using a semistructured questioning approach. Transcripts were analyzed using a grounded theory approach. Categories of perceptions, beliefs, and attitudes were developed from the data, cross-validated, and when relevant, assigned to higher-order themes. Results: Awareness of plasmapheresis was most often gained when donors were unable to donate whole blood. Accordingly, the main trigger for conversion to plasma donation was a personal request by collection staff. A key benefit of plasma donation was its increased frequency, which facilitated the establishment of a routine and relationship development with staff and donors, whereas the key reported sacrifice was the greater donation time. Disappointment was the main response to an inability to donate. Functional tokens and refreshments were valued by donors, although it was felt that money spent on tokens would be better invested in making operations more efficient. Conclusion: Suitable whole blood donors should be made aware of plasmapheresis and its associated benefits through collection staff. Sustained donation can be encouraged by the establishment of a regular schedule and positive interactions with collection staff and other donors to enhance the donors subjective well-being

    Pharmacokinetics and Pharmacodynamics of Antibacterials, Antifungals, and Antivirals Used Most Frequently in Neonates and Infants

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    Antimicrobials and antivirals are widely used in young infants and neonates. These patients have historically been largely excluded from clinical trials and, as a consequence, the pharmacokinetics and pharmacodynamics of commonly used antibacterials, antifungals, and antivirals are incompletely understood in this population. This review summarizes the current literature specific to neonates and infants regarding pharmacokinetic parameters and changes in neonatal development that affect antimicrobial and antiviral pharmacodynamics. Specific drug classes addressed include aminoglycosides, aminopenicillins, cephalosporins, glycopeptides, azole antifungals, echinocandins, polyenes, and guanosine analogs. Within each drug class, the pharmacodynamics, pharmacokinetics, and clinical implications and future directions for prototypical agents are discussed. β-Lactam antibacterial activity is maximized when the plasma concentration exceeds the minimum inhibitory concentration for a prolonged period, suggesting that more frequent dosing may optimize β-lactam therapy. Aminoglycosides are typically administered at longer intervals with larger doses in order to maximize exposure (i.e., area under the plasma concentration–time curve) with gestational age and weight strongly influencing the pharmacokinetic profile. Nonetheless, safety concerns necessitate therapeutic drug monitoring across the entire neonatal and young infant spectrum. Vancomycin, representing the glycopeptide class of antibacterials, has a long history of clinical utility, yet there is still uncertainty about the optimal pharmacodynamic index in neonates and young infants. The high degree of pharmacokinetic variability in this population makes therapeutic drug monitoring essential to ensure adequate therapeutic exposure. Among neonates treated with the triazole agent fluconazole, it has been speculated that loading doses may improve pharmacodynamic target attainment rates. The use of voriconazole necessitates therapeutic drug monitoring and dose adjustments for patients with hepatic dysfunction. Neonates treated with lipid-based formulations of the polyene amphotericin B may be at an increased risk of death, such that alternative antifungal agents should be considered for neonates with invasive fungal infections. Alternative antifungal agents such as micafungin and caspofungin also exhibit unique pharmacokinetic considerations in this population. Neonates rapidly eliminate micafungin and require nearly three times the normal adult dose to achieve comparable levels of systemic exposure. Conversely, peak caspofungin concentrations have been reported to be similar among neonates and adults. However, both of these drugs feature favorable safety profiles. Recent studies with acyclovir have suggested that current dosing regimens may not result in therapeutic central nervous system concentrations and more frequent dosing may be required for neonates at later postmenstrual ages. Though ganciclovir and valganciclovir demonstrate excellent activity against cytomegalovirus, they are associated with significant neutropenia. In summary, many pharmacokinetic and pharmacodynamic studies have been conducted in this vulnerable population; however, there are also substantial gaps in our knowledge that require further investigation. These studies will be invaluable in determining optimal neonatal dosing regimens that have the potential to improve clinical outcomes and decrease adverse effects associated with antimicrobial and antiviral treatments

    Male breast cancer in BRCA1 and BRCA2 mutation carriers: pathology data from the Consortium of Investigators of Modifiers of BRCA1/2

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    Abstract Background BRCA1 and, more commonly, BRCA2 mutations are associated with increased risk of male breast cancer (MBC). However, only a paucity of data exists on the pathology of breast cancers (BCs) in men with BRCA1/2 mutations. Using the largest available dataset, we determined whether MBCs arising in BRCA1/2 mutation carriers display specific pathologic features and whether these features differ from those of BRCA1/2 female BCs (FBCs). Methods We characterised the pathologic features of 419 BRCA1/2 MBCs and, using logistic regression analysis, contrasted those with data from 9675 BRCA1/2 FBCs and with population-based data from 6351 MBCs in the Surveillance, Epidemiology, and End Results (SEER) database. Results Among BRCA2 MBCs, grade significantly decreased with increasing age at diagnosis (P = 0.005). Compared with BRCA2 FBCs, BRCA2 MBCs were of significantly higher stage (P for trend = 2 × 10−5) and higher grade (P for trend = 0.005) and were more likely to be oestrogen receptor–positive [odds ratio (OR) 10.59; 95 % confidence interval (CI) 5.15–21.80] and progesterone receptor–positive (OR 5.04; 95 % CI 3.17–8.04). With the exception of grade, similar patterns of associations emerged when we compared BRCA1 MBCs and FBCs. BRCA2 MBCs also presented with higher grade than MBCs from the SEER database (P for trend = 4 × 10−12). Conclusions On the basis of the largest series analysed to date, our results show that BRCA1/2 MBCs display distinct pathologic characteristics compared with BRCA1/2 FBCs, and we identified a specific BRCA2-associated MBC phenotype characterised by a variable suggesting greater biological aggressiveness (i.e., high histologic grade). These findings could lead to the development of gender-specific risk prediction models and guide clinical strategies appropriate for MBC management

    Next-generation ARIA care pathways for rhinitis and asthma: a model for multimorbid chronic diseases

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    Abstract Background In all societies, the burden and cost of allergic and chronic respiratory diseases are increasing rapidly. Most economies are struggling to deliver modern health care effectively. There is a need to support the transformation of the health care system into integrated care with organizational health literacy. Main body As an example for chronic disease care, MASK (Mobile Airways Sentinel NetworK), a new project of the ARIA (Allergic Rhinitis and its Impact on Asthma) initiative, and POLLAR (Impact of Air POLLution on Asthma and Rhinitis, EIT Health), in collaboration with professional and patient organizations in the field of allergy and airway diseases, are proposing real-life ICPs centred around the patient with rhinitis, and using mHealth to monitor environmental exposure. Three aspects of care pathways are being developed: (i) Patient participation, health literacy and self-care through technology-assisted “patient activation”, (ii) Implementation of care pathways by pharmacists and (iii) Next-generation guidelines assessing the recommendations of GRADE guidelines in rhinitis and asthma using real-world evidence (RWE) obtained through mobile technology. The EU and global political agendas are of great importance in supporting the digital transformation of health and care, and MASK has been recognized by DG Santé as a Good Practice in the field of digitally-enabled, integrated, person-centred care. Conclusion In 20 years, ARIA has considerably evolved from the first multimorbidity guideline in respiratory diseases to the digital transformation of health and care with a strong political involvement

    Next-generation ARIA care pathways for rhinitis and asthma: a model for multimorbid chronic diseases

    No full text
    Abstract Background In all societies, the burden and cost of allergic and chronic respiratory diseases are increasing rapidly. Most economies are struggling to deliver modern health care effectively. There is a need to support the transformation of the health care system into integrated care with organizational health literacy. Main body As an example for chronic disease care, MASK (Mobile Airways Sentinel NetworK), a new project of the ARIA (Allergic Rhinitis and its Impact on Asthma) initiative, and POLLAR (Impact of Air POLLution on Asthma and Rhinitis, EIT Health), in collaboration with professional and patient organizations in the field of allergy and airway diseases, are proposing real-life ICPs centred around the patient with rhinitis, and using mHealth to monitor environmental exposure. Three aspects of care pathways are being developed: (i) Patient participation, health literacy and self-care through technology-assisted “patient activation”, (ii) Implementation of care pathways by pharmacists and (iii) Next-generation guidelines assessing the recommendations of GRADE guidelines in rhinitis and asthma using real-world evidence (RWE) obtained through mobile technology. The EU and global political agendas are of great importance in supporting the digital transformation of health and care, and MASK has been recognized by DG Santé as a Good Practice in the field of digitally-enabled, integrated, person-centred care. Conclusion In 20 years, ARIA has considerably evolved from the first multimorbidity guideline in respiratory diseases to the digital transformation of health and care with a strong political involvement
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