Categorization of Thermoacoustic Modes in an Ideal Resonator with Phasor Diagrams

A recent study (Yong, Silva, and Polifke, Combust. Flame 228 (2021)) proposed the use of phasor diagrams to categorize marginally stable modes in an ideal resonator with a compact, velocity-sensitive flame. Modes with velocity phasors that reverse direction across the flame were categorized as ITA modes. The present study extends this concept to growing and decaying modes. In other words, with the method proposed, it is possible to distinguish whether a given thermoacoustic mode -- regardless of its stability -- should be categorized as acoustic or ITA. The method proposed does not rely on any parametric sweep, but on the angle relating the velocity phasors across the flame. This method of categorization reveals distinct regions in the complex plane where acoustic and ITA eigenfrequencies are localized. Additionally, we analyze the medium oscillation at the flame location to construct a physically intuitive understanding of the proposed categorization method.Comment: to be published in Combustion and Flam

Prevalence and Risk Factors of Mastitis among Dairy Buffaloes from the Departments of Antioquia and Córdoba, Colombia

Background: Mastitis is the most common disease among dairy buffaloes worldwide, and it significantly affects the economic profitability of buffalo farms as well as animal welfare and public health. Methods: This study was conducted between 2018 and 2019 at the Colombian departments of Antioquia and Córdoba, where 41% of the country’s total buffalo population is concentrated. Overall, 1,018 dairy buffaloes, including 603 in Antioquia and 415 in Córdoba, distributed among 11 farms, were assessed in the study. These animals were evaluated using the California mastitis test (CMT) and somatic cell count (SCC) to determine the presence of subclinical mastitis (SM). They were considered positive for SM when the results of CMT were higher than traces and SCC was >200,000 cells/mL. Results: The total prevalence of the disease was 7.9%, and microbiological culture was performed on the samples obtained from the SM-positive animals. The main isolated bacterium was coagulase-negative Staphylococcus. Furthermore, risk factors affecting milking routine, hygiene, and farm facilities were determined. Manual milking, milking in the barn, non-disinfection of milkers' hands, etc., were identified as risk factors for the disease. Conclusion: To the best of our knowledge, this is the first large-scale study of mastitis among buffaloes in Colombia

Physiological and biochemical responses of Eucalyptus seedlings to hypoxia

International audienceAbstractKey messageHypoxia promoted distinct changes in the levels of hormones, amino acids and organic acids in the roots and shoots of a seedling from 2Eucalyptusclones. These results indicate that modulation of hormone production, as well as specific chemical constituents associated with primary metabolism, contributes to the regulation of growth ofEucalyptusseedlings under hypoxic conditions.ContextAlthough floods in areas under Eucalyptus cultivation in Brazil negatively affect plant growth, chemical markers and/or indicators of hypoxia contributes to the regulation.sAimsThis study aimed to evaluate the hormonal and metabolic alterations induced by hypoxia on seedling growth.MethodsSeedlings of Eucalyptus urograndis clones VCC 975 and 1004 were grown in liquid solution and submitted to bubbling with air or with nitrogen. Levels of indol-3-acetic acid (IAA), abscisic acid (ABA), ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC), primary metabolite profile and photosynthetic parameters were evaluated after fourteen days.ResultsHypoxia did not affect shoot dry mass of the seedlings. However, it decreased stomatal conductance and photosynthetic CO2 assimilation rate, and increased levels of ABA in the shoot. Hypoxia greatly reduced the dry mass and volume of roots, concomitantly with higher ACC and ethylene production. Moreover, hypoxia promoted distinct changes in IAA levels, and in amino acid and organic acid metabolism in roots and shoots.ConclusionThe biosynthesis of ABA, ethylene and IAA and its quantity in root tissues indicates the regulation of metabolism in response to hypoxia in Eucalyptus clones

Association of increased Visfatin/PBEF/NAMPT circulating concentrations and gene expression levels in peripheral blood cells with lipid metabolism and fatty liver in human morbid obesity

BACKGROUND AND AIMS: Nicotinamide phosphoribosyltransferase (NAMPT) is an adipokine with physiological effects on the control of glucose homeostasis as well as potentially involved in inflammation. The association of circulating NAMPT concentrations with obesity has not been clearly established. The aim of the present work was to evaluate the effect of obesity on circulating concentrations and gene expression levels of NAMPT in human peripheral blood cells (PBCs) as well as its involvement in inflammation, glucose and lipid metabolism. METHODS AND RESULTS: Forty-four serum samples obtained from 14 lean and 30 obese volunteers were used to analyse the circulating concentrations of NAMPT. In addition, PBC, omental adipose tissue (OM) and liver biopsy samples obtained from a subgroup of subjects were used to determine transcript levels of NAMPT by Real-time PCR. Glucose and lipid profile as well as several inflammatory factors and hepatic enzymes were analysed. NAMPT circulating concentrations (P<0.01) and gene expression levels in PBC (P<0.05) were significantly increased in obese patients as compared to lean subjects. Total-cholesterol (P=0.016), HDL-cholesterol (P=0.036) and triglycerides (P=0.050) were significant and independent determinants of circulating concentrations of NAMPT (P<0.01). Moreover, a positive correlation (P<0.01) was found with the hepatic enzymes alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyltransferase after BMI adjustment. CONCLUSION: Our work shows that NAMPT circulating concentrations and mRNA expression levels in PBC are increased in obese patients and that plasma NAMPT levels are related to inflammation, lipid metabolism and hepatic enzymes suggesting a potential involvement in fatty liver disease and in the obesity-associated inflammatory stat

The obestatin receptor (GPR39) is expressed in human adipose tissue and is down-regulated in obesity-associated type 2 diabetes mellitus

The G protein-coupled receptor 39 (GPR39) has recently been identified as the receptor for obestatin, a peptidic hormone involved in energy homeostasis. However, the expression levels of this receptor in human adipose tissue in obesity and obesity-associated type 2 diabetes mellitus (T2DM) remain unknown. Therefore, we evaluated the actual presence of GPR39 mRNA in human adipose tissue and whether GPR39 expression levels are altered in obesity and obesity-associated T2DM. DESIGN: Omental adipose tissue biopsies obtained from 15 women were used in the study. Patients were classified as lean (body mass index 20.8 +/- 1.0 kg/m(2)), obese normoglycaemic (body mass index 48.4 +/- 2.1 kg/m(2)) and obese T2DM patients (body mass index 52.6 +/- 4.9 kg/m(2)). Anthropometric measurements and biochemical profiles were assessed for each subject. Real-time RT-PCR analyses were performed to quantify transcript levels of GPR39 and adiponectin. RESULTS: Obese T2DM patients exhibited significantly lower GPR39 expression levels compared to lean (P = 0.016) and obese normoglycaemic subjects (P = 0.008), while no differences between lean and obese normoglycaemic patients were observed. The mRNA expression levels of GPR39 were negatively correlated to fasting glucose concentrations (r = -0.581, P = 0.023), while exhibiting a positive correlation to adiponectin mRNA expression levels (r = 0.674, P = 0.006). CONCLUSION: GPR39 is expressed in human adipose tissue. The reduced expression levels of GPR39 in omental adipose tissue observed in obese patients with T2DM suggest an involvement of obestatin signalling in glucose homeostasis and T2DM development

Expression of caveolin-1 in human adipose tissue is upregulated in obesity and obesity-associated type 2 diabetes mellitus and related to inflammation

Caveolin-1 (CAV-1) plays important roles in many aspects of cellular biology, including vesicular transport, cholesterol homeostasis and signal transduction. The aim of the present study was to explore gene expression levels of CAV-1 in human adipose tissue in obesity and obesity-associated type 2 diabetes mellitus (T2DM) and to analyse its potential implication in the inflammatory state associated with obesity. DESIGN AND METHODS: Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) obtained from 15 females were used in the study. Patients were classified as lean (BMI 20.8 +/- 1.0 kg/m(2)) or obese (BMI 50.5 +/- 2.6 kg/m(2)). The obese group was further subclassified as normoglycaemic (NG) or patients with T2DM. Anthropometric measurements as well as circulating metabolites, hormones and adipokines were determined. Real-time polymerase chain reaction (PCR) analyses were performed to quantify transcript levels of CAV-1 and monocyte chemoattractant protein (MCP-1). RESULTS: The presence of CAV-1 protein was detected in VAT and SAT by immunohistochemistry. Both obese NG and with T2DM patients exhibited significantly higher CAV-1 expression levels in VAT and SAT compared with lean subjects (P < 0.05). No differences between obese NG and T2DM patients were observed in VAT. However, obese T2DM patients were found to have higher CAV-1 expression levels in SAT (P < 0.05) compared with obese NG patients. A significant correlation was found between CAV-1 mRNA expression levels in VAT and different circulating inflammatory markers such as sialic acid (SA) (P < 0.001) and fibrinogen (P < 0.001) as well as with MCP1 mRNA expression (P < 0.05). CONCLUSION: Our findings show for the first time the upregulation of mRNA CAV-1 expression levels in VAT and SAT of obese NG and obese T2DM patients compared with lean controls, suggesting a role for CAV-1 in obesity and T2DM development. The association with different inflammatory markers further suggests an implication of CAV-1 in the low-grade inflammation accompanying obesity

Increased circulating and visceral adipose tissue expression levels of YKL-40 in obesity-associated type 2 diabetes are related to inflammation: impact of conventional weight loss and gastric bypass

Context: Plasma YKL-40 is elevated in patients with type 2 diabetes. The potential role of visceral adipose tissue (VAT) as a significant source of YKL-40 is unknown. Objective: In the study circulating and expression levels of YKL-40 were examined in VAT analyzing the contribution of adipocytes and stromovascular fraction cells (SVFCs).Wealso explored YKL-40’s implication in insulin resistance and inflammation and the effect of weight loss on plasma YKL-40 concentrations. PatientsandMethods: Samples obtained from 53 subjects were used in the study.Geneandprotein expression levels of YKL-40 were analyzed in VAT as well as in both adipocytes and SVFCs. In addition, circulating YKL-40 concentrations were measured before and after weight loss achieved either by Roux-en-Y gastric bypass (n 26) or after a conventional dietetic program (n 20). Results: Circulating concentrations and VAT expression of YKL-40 were increased in obese patients with type 2 diabetes (P 0.01) as well as associated with variables of insulin resistance and inflammation. No differences in YKL-40 expression levels between adipocytes and SVFCs were detected. Monocyte chemoattractant protein-1 and homeostasis model assessment emerged (P 0.01) as independent factors predicting circulating YKL-40. Elevated levels of YKL-40 in obese patients decreased after weight loss following a conventional hypocaloric diet (P 0.05) but not via a surgery-induced negative energy balance mediated by the Roux-en-Y gastric bypass. Conclusions: The association of increased YKL-40 mRNA and protein levels in VAT with its circulating concentrations indicates an important contribution of VAT in YKL-40 regulation. Furthermore, our data suggest a relevant role of glucose metabolism and inflammation on YKL-40 regulation

Giardia lamblia and respiratory allergies: a study of children from an urban area with a high incidence of protozoan infections

OBJECTIVES: There is a high incidence of intestinal parasite infection in urban areas in the Northeast of Brazil. Giardia lamblia infections have been associated with increased prevalence of cutaneous allergies and gastrointestinal disorders. However, little is known about the relationship between giardiasis and allergic diseases of the airways. The present study aimed to investigate the possible association between respiratory allergic diseases and infections by G. lamblia in children from urban areas. METHODS: This study recruited 110 patients of both sexes aged 5-15 years. Patients were administered a questionnaire evaluating clinical symptoms and were given skin tests, parasite tests and serum tests. RESULTS: A high incidence of G. lamblia was observed (45%, 50/110). Infections by this protozoan were not associated with increased risk of respiratory allergy (p = 0.075), high total IgE levels (p = 0.701), positive specific IgE tests (p = 0.250), or positive skin tests for a range of environmental allergens (p = 0.239). CONCLUSION: This study demonstrated that symptoms of asthma, skin allergy and serum markers were not associated with G. lamblia infections in this sample of children from urban areas.OBJETIVO: Uma elevada incidência de enteroparasitoses é encontrada em regiões urbanas do nordeste brasileiro. As infecções por Giardia lamblia têm sido relacionadas com aumento da prevalência de alergias cutâneas e gastrointestinais. Contudo, ainda existe pouca informação sobre a associação entre a giardíase e doenças alérgicas das vias aéreas. Diante disso, o presente estudo se propôs a verificar a relação entre a infecção por G. lamblia em crianças de área urbana e reatividade alérgica respiratória. MÉTODOS: O estudo incluiu 110 pacientes, de ambos os sexos e idades, entre 5 e 15 anos. Os pacientes foram submetidos a questionários de avaliação dos sintomas clínicos, testes cutâneos de leitura imediata e exames coproparasitológicos e sorológicos. RESULTADOS: Foi verificada uma frequência elevada de crianças infectadas por G. lamblia (45%, 50/110). A infecção pelo protozoário não foi associada com maior risco de alergias respiratórias (p = 0,075), elevação de IgE total (p = 0,701), IgE específica (p = 0,250) ou teste cutâneo positivo para diferentes alérgenos ambientais (p = 0,239). CONCLUSÃO: O estudo demonstrou que a presença dos sintomas de asma, atopia cutânea e marcadores sorológicos não foram associados com a presença de infecção pela G. lamblia nessa amostra de crianças.Ministério da Saúde (Governo Federal do Brasil)Ministério da Ciência e e Tecnologia (Governo Federal do Brasil)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de Pernambuco Laboratório de Imunopatologia Keizo AsamiUFPE Laboratório de Imunopatologia Keizo AsamiUFPE Hospital das Cínicas ImunologiaUFPE Hospital das Clínicas ImunologiaUFPE Hospital das ClínicasUniversidade Federal de São Paulo (UNIFESP) Pediatria e Ciências AplicadasUNIFESP Imunologia Clínica e Reumatologia Pediatria e Ciências Aplicadas PediatriaUFPEUFPE Programa de Pós-graduação em Ciências da SaúdeUNIFESP, Pediatria e Ciências AplicadasUNIFESP, Imunologia Clínica e Reumatologia Pediatria e Ciências Aplicadas PediatriaCNPq: 402666/2005-4SciEL