Sex-Role Reversal in Song? Females Sing More Frequently Than Males in the Streak-Backed Oriole

Birds in which both sexes produce complex song are more common in the tropics than in the temperate north, where typically only males sing. Yet surprisingly little is known about female song characteristics in most tropical species. Here we present a comparison of female and male singing behaviors in the Streak-backed Oriole (Icterus pustulatus), a tropical songbird in which both sexes perform solo songs. Females sing much more frequently than males and produce songs with similar acoustic complexity. Rates of singing by both sexes were higher during breeding than postbreeding while the rates of most other vocalizations did not change, suggesting that song plays an important role in breeding. To our knowledge, this is the first reported species in which females regularly sing at higher rates than males; however, few studies have examined female song in other sexually monomorphic or weakly dimorphic species, so such patterns might not be unique. En aves tropicales es más común que ambos sexos produzcan cantos complejos que en aves de zonas templadas, en donde típicamente el macho es el que canta. Por lo que es sorprendente que se conozca tan poco de las características del canto de las especies tropicales. Con nuestro estudio reportamos una comparación entre sexos de la conducta del canto en Icterus pustulatus, ambos sexos de esta ave canora tropical cantan. Las hembras cantaron con mayor frecuencia que los machos y produjeron cantos con complejidad acústica similar. Las tasas de canto de ambos sexos fueron mayores durante el periodo reproductivo que el post-reproductivo, mientras que las tasas de otras vocalizaciones no cambiaron, lo que sugiere que el canto juega un papel importante en la reproducción. Hasta donde sabemos este es la primera especie en donde se reporta que las hembras educantan regularmente con mayor tasa que los machos; sin embargo, pocos estudios han examinado el canto de las hembras en especies sexualmente monomórficas o poco dimórficas, por lo que este patrón puede no ser único

Typical males and unconventional females: songs and singing behaviors of a tropical, duetting oriole in the breeding and non-breeding season

Sherpa Romeo green journal. Open access article. Creative Commons Attribution License (CC BY) applies.Recent research emphasizes that female song is evolutionarily important, yet there are still few species for which we have quantified the similarities and differences between male and female song. Comparing song rates and the structure of female and male song is an important first step to forming hypotheses about functional and evolutionary differences that may exist between females and males, especially in year-round territorial species that may use their songs for breeding and non-breeding activities. We compared female and male singing rates and song structure in a tropical New World oriole, the Venezuelan troupial (Icterus icterus) during both the breeding and non-breeding season and between the dawn and day. Males sang solos at particularly high rates during the breeding season before dawn. Females, however, sang at consistent rates year-round, primarily during the day. Females answered 75% of male day songs, producing duets, whereas males answered only 42% of female songs. Duets were common year-round, but occurred more often during the non-breeding season. Structurally, female songs were higher pitched and shorter than male songs. We detected no sex differences in the number or order of syllables, however, interestingly, answers were shorter than duet initiations and solos, and, during the breeding season, songs that initiated duets were characterized by higher syllable diversity than were answers or solos. The fact that males sing more during the breeding season supports the classical hypothesis that male song is a sexually selected trait. However, our findings that females sing solos and answer the majority of male songs to create duets year-round suggests that female song may have evolved to serve multiple functions not exclusively tied to breeding.Ye

Historic genetic structuring and paraphyly within the Great-tailed Grackle

The Great-tailed Grackle (Quiscalus mexicanus) and Boat-tailed Grackle (Q. major) are sister species that have expanded their ranges during historical times. This expansion has created an area of sympatry between these species in Texas and Louisiana, and between distinctive Great-tailed Grackle subspecies in the southwestern United States and northern Mexico. We investigated the evolutionary histories of both species using mitochondrial DNA sequence data and modern phylogenetic methods. Our results reveal genetic structure within Great-tailed, but not Boat-tailed Grackles. Great-tailed Grackles are separated into two clades, but range expansion in the north has led to secondary contact between them. Boat-tailed Grackles are monophyletic and are embedded within the Great-tailed Grackle assemblage, rendering the latter paraphyletic. These results reveal a complex phylogeographic pattern caused by recent range expansion and secondary contact of once allopatric units

Secretoneurin Is an Endogenous Calcium/Calmodulin-Dependent Protein Kinase II Inhibitor That Attenuates Ca2+-Dependent Arrhythmia

BACKGROUND: Circulating SN (secretoneurin) concentrations are increased in patients with myocardial dysfunction and predict poor outcome. Because SN inhibits CaMKII delta (Ca2+/calmodulin-dependent protein kinase II delta) activity, we hypothesized that upregulation of SN in patients protects against cardiomyocyte mechanisms of arrhythmia. METHODS: Circulating levels of SN and other biomarkers were assessed in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT; n=8) and in resuscitated patients after ventricular arrhythmia-induced cardiac arrest (n=155). In vivo effects of SN were investigated in CPVT mice (RyR2 [ryanodine receptor 2]-R2474S) using adeno-associated virus-9-induced overexpression. Interactions between SN and CaMKII delta were mapped using pull-down experiments, mutagenesis, ELISA, and structural homology modeling. Ex vivo actions were tested in Langendorff hearts and effects on Ca2+ homeostasis examined by fluorescence (fluo-4) and patchclamp recordings in isolated cardiomyocytes. RESULTS: SN levels were elevated in patients with CPVT and following ventricular arrhythmia-induced cardiac arrest. In contrast to NT-proBNP (N-terminal proB- type natriuretic peptide) and hs-TnT (high-sensitivity troponin T), circulating SN levels declined after resuscitation, as the risk of a new arrhythmia waned. Myocardial pro-SN expression was also increased in CPVT mice, and further adeno-associated virus-9-induced overexpression of SN attenuated arrhythmic induction during stress testing with isoproterenol. Mechanistic studies mapped SN binding to the substrate binding site in the catalytic region of CaMKII delta. Accordingly, SN attenuated isoproterenol induced autophosphorylation of Thr287-CaMKII delta in Langendorff hearts and inhibited CaMKII delta-dependent RyR phosphorylation. In line with CaMKII delta and RyR inhibition, SN treatment decreased Ca2+ spark frequency and dimensions in cardiomyocytes during isoproterenol challenge, and reduced the incidence of Ca2+ waves, delayed afterdepolarizations, and spontaneous action potentials. SN treatment also lowered the incidence of early afterdepolarizations during isoproterenol; an effect paralleled by reduced magnitude of L-type Ca2+ current. CONCLUSIONS: SN production is upregulated in conditions with cardiomyocyte Ca2+ dysregulation and offers compensatory protection against cardiomyocyte mechanisms of arrhythmia, which may underlie its putative use as a biomarker in at-risk patients.Peer reviewe

Secretogranin II; a Protein Increased in the Myocardium and Circulation in Heart Failure with Cardioprotective Properties

Background: Several beneficial effects have been demonstrated for secretogranin II (SgII) in non-cardiac tissue. As cardiac production of chromogranin A and B, two related proteins, is increased in heart failure (HF), we hypothesized that SgII could play a role in cardiovascular pathophysiology. Methodology/Principal Findings: SgII production was characterized in a post-myocardial infarction heart failure (HF) mouse model, functional properties explored in experimental models, and circulating levels measured in mice and patients with stable HF of moderate severity. SgII mRNA levels were 10.5 fold upregulated in the left ventricle (LV) of animals with myocardial infarction and HF (p<0.001 vs. sham-operated animals). SgII protein levels were also increased in the LV, but not in other organs investigated. SgII was produced in several cell types in the myocardium and cardiomyocyte synthesis of SgII was potently induced by transforming growth factor-beta and norepinephrine stimulation in vitro. Processing of SgII to shorter peptides was enhanced in the failing myocardium due to increased levels of the proteases PC1/3 and PC2 and circulating SgII levels were increased in mice with HF. Examining a pathophysiological role of SgII in the initial phase of post-infarction HF, the SgII fragment secretoneurin reduced myocardial ischemia-reperfusion injury and cardiomyocyte apoptosis by 30% and rapidly increased cardiomyocyte Erk1/2 and Stat3 phosphorylation. SgII levels were also higher in patients with stable, chronic HF compared to age-and gender-matched control subjects: median 0.16 (Q1-3 0.14-0.18) vs. 0.12 (0.10-0.14) nmol/L, p<0.001. Conclusions: We demonstrate increased myocardial SgII production and processing in the LV in animals with myocardial infarction and HF, which could be beneficial as the SgII fragment secretoneurin protects from ischemia-reperfusion injury and cardiomyocyte apoptosis. Circulating SgII levels are also increased in patients with chronic, stable HF and may represent a new cardiac biomarker

Association of 25-hydroxyvitamin D deficiency with NT-pro BNP levels in patients with acute myocardial infarction: a cross-sectional analysis

<p>Abstract</p> <p>Background</p> <p>Nutritional vitamin D deficiency is an emerging risk factor for acute myocardial infarction (AMI) and heart failure. The association of 25-hydroxyvitamin D levels with N-terminal pro B-type natriuretic peptide (NT-proBNP), a robust prognostic marker for post-AMI mortality and heart failure, is unknown and could illuminate a potential pathway for adverse outcomes among post-AMI patients with 25-hydroxyvitamin D deficiency.</p> <p>Methods</p> <p>In a cross-sectional analysis, we studied 238 AMI patients from 21 U.S. centers to test the association of nutritional vitamin D (25-hydroxyvitamin D [25(OH)D]) deficiency with NT-proBNP levels. Levels of 25(OH)D levels were categorized as normal (≥30 ng/mL), insufficient (>20 - <30 ng/mL), deficient (>10 - ≤20 ng/mL), or severely deficient (≤10 ng/mL).</p> <p>Results</p> <p>Low 25(OH)D levels were found in 95.7% of AMI patients. No significant trends for higher mean baseline log NT-proBNP levels in severely deficient (6.9 ± 1.3 pg/mL), deficient (6.9 ± 1.2 pg/mL), and insufficient (6.9 ± 0.9 pg/ml) groups were observed as compared with patients having normal (6.1 ± 1.7 pg/mL) levels, <it>P </it>= 0.17. Findings were similar in the subset of patients who had follow-up NT-proBNP levels drawn at one month. In multivariate regression modeling, after adjusting for multiple covariates, 25(OH)D was not associated with NT-proBNP.</p> <p>Conclusions</p> <p>Potential associations between nutritional vitamin D deficiency and prognosis in the setting of AMI are unlikely to be mediated through NT-proBNP pathways. Future studies should examine other mechanisms, such as inflammation and vascular calcification, by which 25(OH)D deficiency could mediate adverse outcomes post-AMI.</p

Is Cardiorespiratory Fitness Related to Cardiometabolic Health and All-Cause Mortality Risk in Patients with Coronary Heart Disease? A CARE CR Study

Background: Higher cardiorespiratory fitness (CRF) is associated with lower morbidity and mortality in patients with coronary heart disease (CHD). The mechanisms for this are not fully understood. A more favourable cardiometabolic risk factor profile may be responsible, however few studies have comprehensively evaluated cardiometabolic risk factors in relation to CRF, among patients with CHD. Objective: To explore differences in cardiometabolic risk and 5-year all-cause mortality risk in patients with CHD who have low, moderate, and high levels of CRF. Methods: Patients with CHD underwent maximal cardiopulmonary exercise testing (CPET), echocardiogram, carotid intima-media thickness measurement, spirometry, and dual X-ray absorptiometry assessment. Full blood count, biochemical lipid pro-files, high sensitivity (hs)- C-reactive protein and NT-proBNP were analysed. Pa-tients were defined as having low, moderate, or high CRF based on established prognostic thresholds. Results: 70 patients with CHD (age 63.1 ± 10.0 years, 86% male) were recruited. Patients with low CRF had a lower ventilatory anaerobic threshold, peak oxygen pulse, post-exercise heart rate recovery and poor ventilatory efficiency. The low CRF group also had higher NT pro-BNP, hs-CRP, non-fasting glucose concentrations and lower haemoglobin and haematocrit. Five-year mortality risk (CALIBER risk score) was also greatest in the lowest CRF group (14.9%). Conclusion: Practitioners should interpret low CRF as an important clinical risk factor associated with adverse cardiometabolic health and poor prognosis. Study registry; researchregistry.com (researchregistry3548). Key Words: Coronary Heart Disease, Cardiac Rehabilitation, Cardiometabolic Health, Exercise Training, Atherosclerosis, VO2peak, Maximal Cardiopulmonary Exercise Testing, Caliber 5-year ris

Određivanje alergena Asp f 1 (Aspergillus fumigatus) u peradarniku enzimimunokemijskom metodom

Poultry farms contain high levels of allergenic fungi, and Aspergillus spp. is the most common genus of moulds. Aspergillus fumigatus antigens are responsible for the development of several respiratory diseases including asthma. The aim of this study was to measure the mass fraction of Asp f 1, a major allergen of Asperillus fumigatus in 37 indoor dust samples collected from four poultry farms in a rural area of the Zagreb County (Croatia) using the enzyme-linked immunosorbent assay. More than 62 % of dust samples had detectable Asp f 1 levels (limit of detection 3.6 ng g-1). The overall mean Asp f 1 level was 17.9 ng g-1 [range (3.8 to 72.4) ng g-1]. Satisfactory results were obtained for analytical within-run imprecision (6.7 %), between-run imprecision (10.5 %), and accuracy (91 % to 115 %). Microclimate parameters (air temperature, relative humidity, and velocity) were within the recommended ranges in all poultry farms. This study has shown that Asp f 1 settles on dust at poultry farms and that occupational exposure to this allergen deserves monitoring in livestock buildings.Peradarnici sadržavaju veliku koncentraciju alergenih plijesni, a rod Aspergillus najčešće je zastupljen. Antigeni soja Aspergillus fumigatus odgovorni su za nastanak nekoliko respiratornih bolesti uključujući astmu. Cilj ovoga rada bio je odrediti masenu frakciju Asp f 1, glavnog alergena soja Asperillus fumigatus u 37 uzoraka prašine uzorkovanih u četiri peradarnika sa šireg područja Zagrebačke županije rabeći enzimimunokemijsku metodu. Više od 62 % uzoraka prašine u tri peradarnika imalo je mjerljivu koncentraciju Asp f 1 (granica detekcije = 3.6 ng g-1). Ukupni srednji maseni udio Asp f 1 iznosio je 17.9 ng g-1 (raspon od 3.8 ng g-1 do 72.4 ng g-1). Dobiveni su zadovoljavajući rezultati za analitičku nepreciznost u seriji (6.7 %), nepreciznost iz dana u dan (10.5 %) i točnost (91 % do 115 %). Mikroklimatski parametri (temperatura zraka, relativna vlaga i protok zraka) u svim peradarnicima bili su u okviru preporučenih vrijednosti. Rezultati ovoga rada pokazuju da Asp f 1 sedimentira na prašinu u peradarnicima te da profesionalnu izloženost tom alergenu treba pratiti u jedinicama za uzgoj stoke