Vocalization Behavior of the Endangered Bahama Oriole (Icterus northropi): Ontogenetic, Sexual, Temporal, Duetting Pair, and Geographic Variation

Many birds communicate via a diverse set of vocalizations, but the contexts, roles, and structure of their varied songs and calls may change with age, differ between sexes, and vary temporally and geographically. In New World orioles, most tropical species exhibit the ancestral states of sexual monochromatism (both sexes have similar plumage) and monovocalism (both sexes sing and often duet together), whereas migratory temperate species tend toward dichromatism (males brightly colored and females drab) and divocalism (males sing almost exclusively). In this study, I examined the vocalizations of the Bahama Oriole, a non-migratory, monochromatic species, to learn where it fits within this generalized dichotomy; to document sources of variation in vocalization rates and spectrographic structure; and to improve survey design for this critically endangered species. Accordingly, this study describes the primary vocalizations of the Bahama Oriole, and examines how vocalizations vary with age, between sexes, at different times of day, during the breeding season, and among the three remaining island metapopulations on Andros, The Bahamas. Hatchlings and fledglings produced vocalizations that were higher pitched than those of adults. Adults possessed a large repertoire, including five main vocalization types that were delivered independently or in combination. Second-year and aftersecond-year-plumaged adults produced spectrographically similar vocalizations at similar rates. Although adult males and females could not be reliably distinguished in the field, both individuals of pairs were often heard giving the full range of vocalizations and frequently duetted together, particularly during the pre-incubation period. Antiphonal duets involved mated pairs, were limited to songs and whistle calls, and exhibited similar within-individual and between-individual variation in the spectrographic and temporal features of duets. Thus, the Bahama Oriole more closely resembles tropical oriole species (monovocal) than temperate species (divocal) in its vocalization behaviors. Adults vocalized at similar rates throughout the day prior to incubation, suggesting that surveys can be conducted at virtually any time of day during this period. Singing and most call types waned after chicks hatched, but whines increased dramatically as adults engaged in caring for their offspring. Minor but significant clinal variation in singing existed among the three metapopulations, suggesting possible cultural drift

Vocalization Behavior of the Endangered Bahama Oriole (Icterus northropi): Ontogenetic, Sexual, Temporal, Duetting Pair, and Geographic Variation

Many birds communicate via a diverse set of vocalizations, but the contexts, roles, and structure of their varied songs and calls may change with age, differ between sexes, and vary temporally and geographically. In New World orioles, most tropical species exhibit the ancestral states of sexual monochromatism (both sexes have similar plumage) and monovocalism (both sexes sing and often duet together), whereas migratory temperate species tend toward dichromatism (males brightly colored and females drab) and divocalism (males sing almost exclusively). In this study, I examined the vocalizations of the Bahama Oriole, a non-migratory, monochromatic species, to learn where it fits within this generalized dichotomy; to document sources of variation in vocalization rates and spectrographic structure; and to improve survey design for this critically endangered species. Accordingly, this study describes the primary vocalizations of the Bahama Oriole, and examines how vocalizations vary with age, between sexes, at different times of day, during the breeding season, and among the three remaining island metapopulations on Andros, The Bahamas. Hatchlings and fledglings produced vocalizations that were higher pitched than those of adults. Adults possessed a large repertoire, including five main vocalization types that were delivered independently or in combination. Second-year and after second-year-plumaged adults produced spectrographically similar vocalizations at similar rates. Although adult males and females could not be reliably distinguished in the field, both individuals of pairs were often heard giving the full range of vocalizations and frequently duetted together, particularly during the pre-incubation period. Antiphonal duets involved mated pairs, were limited to songs and whistle calls, and exhibited similar within-individual and between-individual variation in the spectrographic and temporal features of duets. Thus, the Bahama Oriole more closely resembles tropical oriole species (monovocal) than temperate species (divocal) in its vocalization behaviors. Adults vocalized at similar rates throughout the day prior to incubation, suggesting that surveys can be conducted at virtually any time of day during this period. Singing and most call types waned after chicks hatched, but whines increased dramatically as adults engaged in caring for their offspring. Minor but significant clinal variation in singing existed among the three metapopulations, suggesting possible cultural drift

Population status, habitat dependence, and reproductive ecology of Bahama Orioles: a critically endangered synanthropic species.

Recent elevation of critically endangered Bahama Orioles (Icterus northropi) to species status promptedustoevaluate theirpopulation status,habitatuse,andbreedingecology.Fromsurveys,weestimatedthat at least 141 to 254 individuals remain globally, with 90 to 162, 24 to 44, and 27 to 48 individuals remaining on North Andros Island, Mangrove Cay, and South Andros Island, The Bahamas, respectively. Orioles were observed nesting exclusively in anthropogenic habitat (residential and agricultural land), but home ranges also included nearby pine forest and coppice (dry broadleaf forest). Most nests (40 of 46, or 87%) were in nonnative coconut palm (Cocos nucifera), with native Sabal palmetto and Thrinax morrisii, and an introduced Brassaia actinophylla also used. Trees selected by orioles for nesting were significantly taller, less likely to have shrubs underneath, further from cover, and had more palm trees nearby than randomly selected palm trees. Three of eight nests with known contents were parasitized by Shiny Cowbirds (Molothrus bonariensis). Lethal yellowing disease recently devastated coconutpalmsandreducedthenumberoforiolesonNorthAndros,butpalmsonMangroveCayandSouthAndros remain healthy. The juxtaposition of anthropogenic habitat to suitable native habitats may be more important than any single factor for Bahama Orioles, especially for breeding adults and fledged young. Conservation of coppice habitat, at high risk for agricultural and residential development, is crucial for survival of this critically endangered synanthropic species

Loss of the SIN3 transcriptional corepressor results in aberrant mitochondrial function

<p>Abstract</p> <p>Background</p> <p>SIN3 is a transcriptional repressor protein known to regulate many genes, including a number of those that encode mitochondrial components.</p> <p>Results</p> <p>By monitoring RNA levels, we find that loss of SIN3 in <it>Drosophila </it>cultured cells results in up-regulation of not only nuclear encoded mitochondrial genes, but also those encoded by the mitochondrial genome. The up-regulation of gene expression is accompanied by a perturbation in ATP levels in SIN3-deficient cells, suggesting that the changes in mitochondrial gene expression result in altered mitochondrial activity. In support of the hypothesis that SIN3 is necessary for normal mitochondrial function, yeast <it>sin3 </it>null mutants exhibit very poor growth on non-fermentable carbon sources and show lower levels of ATP and reduced respiration rates.</p> <p>Conclusions</p> <p>The findings that both yeast and <it>Drosophila </it>SIN3 affect mitochondrial activity suggest an evolutionarily conserved role for SIN3 in the control of cellular energy production.</p

Population status of chuck-will’s-widow (Caprimulgus carolinensis) in the bahamas

The Chuck-will’s-widow (Caprimulgus carolinensis) in the Bahama Islands has been regarded as a rare to uncommon winter visitor. We conducted breeding season surveys on the three largest northern islands (North Andros, Grand Bahama, and Great Abaco) to examine the status of this species. We encountered singing birds on most survey routes on all three islands, suggesting that sizeable breeding populations are widespread in the northern Bahamas with an aggregate estimate of 500–1,000 pairs. Our density estimates were somewhat less than those from the primary range in the United States, suggesting either a lower carrying capacity in the Bahama Islands or recently established populations that have yet to reach carrying capacity. Received 24 August 2009. Accepted 3 January 2010

Exposure to combustion generated environmentally persistent free radicals enhances severity of influenza virus infection

© 2014 Lee et al. Background: Exposures to elevated levels of particulate matter (PM) enhance severity of influenza virus infection in infants. The biological mechanism responsible for this phenomenon is unknown. The recent identification of environmentally persistent free radicals (EPFRs) associated with PM from a variety of combustion sources suggests its role in the enhancement of influenza disease severity. Methods: Neonatal mice (\u3c seven days of age) were exposed to DCB230 (combustion derived PM with a chemisorbed EPFR), DCB50 (non-EPFR PM sample), or air for 30 minutes/day for seven consecutive days. Four days post-exposure, neonates were infected with influenza intranasally at 1.25 TCID50/neonate. Neonates were assessed for morbidity (% weight gain, peak pulmonary viral load, and viral clearance) and percent survival. Lungs were isolated and assessed for oxidative stress (8-isoprostanes and glutathione levels), adaptive immune response to influenza, and regulatory T cells (Tregs). The role of the EPFR was also assessed by use of transgenic mice expressing human superoxide dismutase 2. Results: Neonates exposed to EPFRs had significantly enhanced morbidity and decreased survival following influenza infection. Increased oxidative stress was also observed in EPFR exposed neonates. This correlated with increased pulmonary Tregs and dampened protective T cell responses to influenza infection. Reduction of EPFR-induced oxidative stress attenuated these effects. Conclusions: Neonatal exposure to EPFR containing PM resulted in pulmonary oxidative stress and enhanced influenza disease severity. EPFR-induced oxidative stress resulted in increased presence of Tregs in the lungs and subsequent suppression of adaptive immune response to influenza

Generation of neutrophil extracellular traps in patients with acute liver failure is associated with poor outcome

Background and Aims: Acute liver failure (ALF) is characterized by significant changes in the hemostatic system and by systemic inflammation. The formation of neutrophil extracellular traps (NETs), in which an activated neutrophil expels its DNA, histones, and granular enzymes, such as myeloperoxidase (MPO), has been associated with immune-mediated and thrombotic diseases. We hypothesized that formation of NETs in patients with ALF contributes to progression of disease. Approach and Results: A total of 676 patients with ALF (international normalized ratio [INR], >= 1.5) or severe acute liver injury (ALI; INR, >= 2.0) were recruited from the U.S. ALF Study Group Registry between 2011 and 2018, of whom 308 patients (45.6%) had acetaminophen-induced ALF. Up to 21 days after admission, 483 patients (71.5%) survived without liver transplantation (LT). Levels of cell-free DNA (cfDNA) and the specific NET marker MPO-DNA complexes were measured in plasma samples obtained on admission and compared to levels in healthy controls. In addition, liver tissue obtained at transplantation of 20 ALF patients was stained for NETs. Levels of cfDNA were 7.1-fold, and MPO-DNA complexes 2.5-fold, higher in patients with ALF compared to healthy controls. cfDNA levels were not associated with 21-day transplant-free survival, but were higher in those patients with more-severe disease on admission, as reflected by various laboratory and clinical parameters. MPO-DNA levels were 30% higher in patients with ALF who died or required urgent LT. Liver tissue of ALF patients stained positive for NETs in 12 of 18 evaluable patients. Conclusions: Here, we provide evidence for NET formation in patients with ALF. Elevated plasma levels of MPO-DNA complexes in patients with ALF were associated with poor outcome, which suggests that NET formation contributes to disease progression

Nutrient sensor O-GlcNAc transferase controls cancer lipid metabolism via SREBP-1 regulation

Elevated O-GlcNAcylation is associated with disease states such as diabetes and cancer. O-GlcNAc transferase (OGT) is elevated in multiple cancers and inhibition of this enzyme genetically or pharmacologically inhibits oncogenesis. Here we show that O-GlcNAcylation modulates lipid metabolism in cancer cells. OGT regulates expression of the master lipid regulator the transcription factor sterol regulatory element binding protein 1 (SREBP-1) and its transcriptional targets both in cancer and lipogenic tissue. OGT regulates SREBP-1 protein expression via AMP-activated protein kinase (AMPK). SREBP-1 is critical for OGT-mediated regulation of cell survival and of lipid synthesis, as overexpression of SREBP-1 rescues lipogenic defects associated with OGT suppression, and tumor growth in vitro and in vivo. These results unravel a previously unidentified link between O-GlcNAcylation, lipid metabolism and the regulation of SREBP-1 in cancer and suggests a crucial role for O-GlcNAc signaling in transducing nutritional state to regulate lipid metabolism

The Search for Stable, Massive, Elementary Particles

In this paper we review the experimental and observational searches for stable, massive, elementary particles other than the electron and proton. The particles may be neutral, may have unit charge or may have fractional charge. They may interact through the strong, electromagnetic, weak or gravitational forces or through some unknown force. The purpose of this review is to provide a guide for future searches - what is known, what is not known, and what appear to be the most fruitful areas for new searches. A variety of experimental and observational methods such as accelerator experiments, cosmic ray studies, searches for exotic particles in bulk matter and searches using astrophysical observations is included in this review.Comment: 34 pages, 8 eps figure