RESUMO
Birds morph their wing shape to accomplish extraordinary manoeuvres1-4, which are governed by avian-specific equations of motion. Solving these equations requires information about a bird's aerodynamic and inertial characteristics5. Avian flight research to date has focused on resolving aerodynamic features, whereas inertial properties including centre of gravity and moment of inertia are seldom addressed. Here we use an analytical method to determine the inertial characteristics of 22 species across the full range of elbow and wrist flexion and extension. We find that wing morphing allows birds to substantially change their roll and yaw inertia but has a minimal effect on the position of the centre of gravity. With the addition of inertial characteristics, we derived a novel metric of pitch agility and estimated the static pitch stability, revealing that the agility and static margin ranges are reduced as body mass increases. These results provide quantitative evidence that evolution selects for both stable and unstable flight, in contrast to the prevailing narrative that birds are evolving away from stability6. This comprehensive analysis of avian inertial characteristics provides the key features required to establish a theoretical model of avian manoeuvrability.
Assuntos
Voo Animal , Asas de Animais , Animais , Fenômenos Biomecânicos , Aves , Modelos Biológicos , Movimento (Física)RESUMO
Sertaconazole is a new antifungal agent. To compare the efficacy and tolerability of sertaconazole and miconazole cream in cutaneous dermatophytosis, this prospective, randomized, multicentric comparative, phase 4 study was undertaken in 260 patients with cutaneous dermatophytosis after approvals from Institutional Ethics Committees. Patients were assigned to sertaconazole cream (2%) or miconazole cream (2%) topically twice daily for 2 weeks after obtaining informed consent. Efficacy variables included changes in mean scores of erythema, pruritus, desquamation, erythema/itching, burning/weeping, scaling/pustule and overall global assessment. Safety and tolerability were also assessed. A total of 122 patients in the sertaconazole group and 128 in the miconazole group completed the study with 10 drop-outs. There was a significant decrease (P < 0.05) in mean symptom scores and total scores from the first week onwards, sustained till 2 weeks and statistically significant (P < 0.05) in favour of sertaconazole. Moreover, 62.3% patients had complete clinical cure in the sertaconazole group (P < 0.05) compared with 44.6% in miconazole users. Both drugs were well tolerated and five patients in the sertaconazole group and nine in the miconazole group reported mild to moderate adverse events. Therapy with sertaconazole cream (2%) provided a better efficacy and tolerability compared with the miconazole cream (2%) and could thus be a therapeutic option in cutaneous dermatophytosis.
Assuntos
Antifúngicos/administração & dosagem , Dermatomicoses/tratamento farmacológico , Imidazóis/administração & dosagem , Miconazol/administração & dosagem , Tiofenos/administração & dosagem , Administração Tópica , Adolescente , Adulto , Idoso , Antifúngicos/efeitos adversos , Dermatomicoses/patologia , Feminino , Humanos , Imidazóis/efeitos adversos , Masculino , Miconazol/efeitos adversos , Pessoa de Meia-Idade , Estudos Prospectivos , Tiofenos/efeitos adversos , Resultado do Tratamento , Adulto JovemRESUMO
Birds dynamically adapt to disparate flight behaviours and unpredictable environments by actively manipulating their skeletal joints to change their wing shape. This in-flight adaptability has inspired many unmanned aerial vehicle (UAV) wings, which predominately morph within a single geometric plane. By contrast, avian joint-driven wing morphing produces a diverse set of non-planar wing shapes. Here, we investigated if joint-driven wing morphing is desirable for UAVs by quantifying the longitudinal aerodynamic characteristics of gull-inspired wing-body configurations. We used a numerical lifting-line algorithm (MachUpX) to determine the aerodynamic loads across the range of motion of the elbow and wrist, which was validated with wind tunnel tests using three-dimensional printed wing-body models. We found that joint-driven wing morphing effectively controls lift, pitching moment and static margin, but other mechanisms are required to trim. Within the range of wing extension capability, specific paths of joint motion (trajectories) permit distinct longitudinal flight control strategies. We identified two unique trajectories that decoupled stability from lift and pitching moment generation. Further, extension along the trajectory inherent to the musculoskeletal linkage system produced the largest changes to the investigated aerodynamic properties. Collectively, our results show that gull-inspired joint-driven wing morphing allows adaptive longitudinal flight control and could promote multifunctional UAV designs.
Assuntos
Charadriiformes , Voo Animal , Animais , Fenômenos Biomecânicos , Aves , Modelos Biológicos , Asas de AnimaisRESUMO
Avian wing shape is highly variable across species but only coarsely associated with flight behavior, performance, and body mass. An underexplored but potentially explanatory feature is the ability of birds to actively change wing shape to meet aerodynamic and behavioral demands. Across 61 species, we found strong associations with flight behavior and mass for range of motion traits but not wing shape and strikingly different associations for different aspects of motion capability. Further, static morphology exhibits high phylogenetic signal, whereas range of motion shows greater evolutionary lability. These results suggest a new framework for understanding the evolution of avian flight: Rather than wing morphology, it is range of motion, an emergent property of morphology, that is predominantly reshaped as flight strategy and body size evolve.
Assuntos
Comportamento Animal/fisiologia , Aves/fisiologia , Peso Corporal , Voo Animal/fisiologia , Amplitude de Movimento Articular/fisiologia , Asas de Animais/fisiologia , Animais , Evolução Biológica , Fenômenos Biomecânicos , Movimento (Física) , Asas de Animais/anatomia & histologiaRESUMO
A gliding bird's ability to stabilize its flight path is as critical as its ability to produce sufficient lift. In flight, birds often morph the shape of their wings, but the consequences of avian wing morphing on flight stability are not well understood. Here, we investigate how morphing the gull elbow joint in gliding flight affects their static pitch stability. First, we combined observations of freely gliding gulls and measurements from gull wing cadavers to identify the wing configurations used during gliding flight. These measurements revealed that, as wind speed and gusts increased, gulls flexed their elbows to adopt wing shapes characterized by increased spanwise camber. To determine the static pitch stability characteristics of these wing shapes, we prepared gull wings over the anatomical elbow range and measured the developed pitching moments in a wind tunnel. Wings prepared with extended elbow angles had low spanwise camber and high passive stability, meaning that mild perturbations could be negated without active control. Wings with flexed elbow angles had increased spanwise camber and reduced static pitch stability. Collectively, these results demonstrate that gliding gulls can transition across a broad range of static pitch stability characteristics using the motion of a single joint angle.
Assuntos
Charadriiformes , Voo Animal/fisiologia , Modelos Biológicos , Asas de Animais , Animais , Charadriiformes/anatomia & histologia , Charadriiformes/fisiologia , Asas de Animais/anatomia & histologia , Asas de Animais/fisiologiaRESUMO
Heart failure and diabetes mellitus are chronic complex medical conditions that are closely related and commonly coexist.Treatment options have varied over the years, but newer treatment modalities have developed which have improved prognosis and longevity of patients with these conditions. Unfortunately, despite these advances, the evidence base remains insufficient, and larger randomised control trials need to be conducted. Here we discuss the available evidence and treatment and management of these inter-related conditions.
Assuntos
Diabetes Mellitus/epidemiologia , Diabetes Mellitus/terapia , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/terapia , Disfunção Ventricular Esquerda/epidemiologia , Disfunção Ventricular Esquerda/terapia , Doença Crônica , Comorbidade , Diabetes Mellitus/mortalidade , Medicina Baseada em Evidências , Insuficiência Cardíaca/mortalidade , Humanos , Hipoglicemiantes/efeitos adversos , Incidência , Prevalência , Medição de Risco , Fatores de Risco , Resultado do Tratamento , Disfunção Ventricular Esquerda/mortalidadeRESUMO
A chlorophyll deficient mutant of clover has been examined by SDS-PAGE, spectrophotometric and electron microscopic methods. By a comparison of the absorption and first derivative spectra of acetone extracts from the mutant and normal biotypes, we observed a deficiency in chlorophyll b for the mutant biotype. The calculated chlorophyll a/b ratios, using the method of Arnon (Plant Physiol. 24, 1-15, 1949), approached infinity for the mutant whereas it ranged from 3.0-3.3 in the wild-type. The low temperature (77 degrees K) fluorescence emission bands in the 685-695 nm region could not be differentiated for the biotypes; however, the long wavelength emission band (near 740 nm in the wild-type) was shifted to shorter wavelengths (ca 720-725 nm) in the mutant indicating loss of photosystem I antenna. The SDS-PAGE profile of the mutant biotype showed a dramatic decline in the Coomassie stained polypeptides of apparent molecular weights similar to those of LHC II. Transmission electron micrographs of the mutant and normal tissue exhibited similar extents of grana-stacking, indicating that a component(s) other than the LHC II may be responsible for membrane adhesion in this mutant.
Assuntos
Clorofila/genética , Plantas/genética , Clorofila A , Cloroplastos/ultraestrutura , Eletroforese em Gel de Poliacrilamida , Microscopia Eletrônica , Mutação , Fotossíntese , Plantas/ultraestrutura , Espectrometria de Fluorescência , EspectrofotometriaRESUMO
Management of acute postoperative pain remains sub-optimal despite the availability of multiple analgesics and improved pain management strategies (with nearly 80 % of patients reporting moderate to extreme pain following surgery). To evaluate the role of parecoxib as a pre-emptive analgesic in patients undergoing general surgery, the present study was undertaken. Eighty patients of either sex, aged 18 to 70 years, requiring elective ambulatory general surgery like hernioplasty, appendicectomy, cholecystectomy, etc, were enrolled in this prospective, randomised, assessor-blind, parallel-group, comparative trial. Eligible patients were randomised to receive a single dose of 40 mg of parecoxib IM/IV either 30-45 minutes prior to induction of anesthesia (pre-emptive analgesia) or in the postoperative period when one reported pain or when the effects of anesthesia were worn off (whichever was earlier). The primary measures of efficacy were pain intensity scores measured on a visual analog scale (VAS) and pain relief before and after therapy. Adverse event monitoring, physical examination and changes in laboratory tests, chest x-ray and ECG were used to evaluate safety. A comparison of the pain intensity scores between the two groups revealed that patients treated with parecoxib preoperatively did not complain of pain in the entire postoperative period up to 12 hours. Mild pain (1.05+/-1.36) was reported by patients in this group only at the 24 hours assessment. On the other hand, patients treated with parecoxib in the postoperative period, experienced severe pain at baseline, which declined gradually up to 12 hours. The difference in the pain intensity scores between the two groups was statistically significant at all the time intervals from 0 hour to 24 hours. All the 40 patients (100%) in the pre-operatively treated group reported total pain relief at 12 hours compared to only 22 patients (55%) in the postoperative period. At 24 hours total pain relief was reported by 70% of the patients in the pre-operatively treated group, compared to only 20% (8) patients in the postoperatively treated group. The difference between the two groups was statistically significant in favour of the pre-operatively treated group (p<0.05). Present results suggested that pre-operative administration of parecoxib was more effective than a postoperative use in providing pain relief in postoperative period in patients undergoing elective general surgical procedures. Both the regimens were well tolerated. Based on the above data, it appears that pre-operative dose of parecoxib 40 mg IV/IM is a useful optionfor pre-emptive analgesia in general surgical practice.
Assuntos
Inibidores de Ciclo-Oxigenase/uso terapêutico , Isoxazóis/uso terapêutico , Dor Pós-Operatória/prevenção & controle , Adolescente , Adulto , Idoso , Procedimentos Cirúrgicos Ambulatórios , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Cuidados Pós-Operatórios , Cuidados Pré-Operatórios , Estudos ProspectivosRESUMO
UNLABELLED: Two unrelated female infants with homozygous protein C (Pr C) deficiency are reported. Both are of U.K. Pakistani origin and in each case the parents are consanguinous. A previous sibling had died in each family. Both sets of parents were shown to be carriers. The concentration of Pr C in both infants was low at birth. Both developed necrotic skin lesions (purpura fulminans) and responded well to Pr C concentrate. Both are developing normally although one has visual impairment due to retinal artery thrombosis which occurred before treatment was commenced. Both infants are treated with intravenous Pr C concentrate administered daily by the parents at home. Studies of the half-life of exogenous Pr C in one of the patients has shown an increase from 2.7 to 10.8 h during the course of treatment thus enabling it to be administered once daily while still maintaining effective plasma concentrations. In the other patient half-life has fluctuated but Pr C is also given once daily. This is the first report of this condition being treated in this way in the United Kingdom. CONCLUSION: Infusion of Pr C is a safe and efficient way of treating infants with homozygous Pr C deficiency in the medium term.
Assuntos
Homozigoto , Deficiência de Proteína C , Púrpura/genética , Testes de Coagulação Sanguínea , Aberrações Cromossômicas/genética , Transtornos Cromossômicos , Consanguinidade , Esquema de Medicação , Feminino , Genes Recessivos , Humanos , Recém-Nascido , Proteína C/administração & dosagem , Púrpura/terapiaRESUMO
We report on an accurate, rapid and inexpensive test for the identification of animals infected with the Bovine C-type virus (BLV). The test involves the detection of serum antibodies to BLV using the immunofluorescent (IF) technique on acetone-fixed, infected cells. The specificity of the test was demonstrated by the fact that virus was found by electron microscopy in 90% of cattle showing positive reactions. In contrast, virus was not found despite extensive examination in antibody negative animals. Thus, the presence of IF antibody is an accurate indicator of current rather than past BLV infection. In order for the IF test to be specific it is of critical importance that the target cells used are infected only with BLV. BLV antibodies can also be detected by the immunoprecipitation (Ouchterlony) technique. However, a significant proportion of BLV infected animals showing positive reactions in the IF test failed to show precipitin antibodies to the virus. Likewise, BLV infection was demonstrated by both the IF test and electron microscopy in many animals with persistently normal levels of blood lymphocytes. Thus, neither the precipitin test nor the blood lymphocyte count (Bendixen's key) can be used to rule out BLV infection.