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Full-Text Articles in Life Sciences
Selective Feeding On Nutrient-Rich Particles By Gizzard Shad Dorosoma Cepedianum Does Not Involve Mechanical Sorting, M. K. Heidman, L. L. Holley, Randolph Chambers, S. Laurie Sanderson
Selective Feeding On Nutrient-Rich Particles By Gizzard Shad Dorosoma Cepedianum Does Not Involve Mechanical Sorting, M. K. Heidman, L. L. Holley, Randolph Chambers, S. Laurie Sanderson
Arts & Sciences Articles
Previous field and laboratory studies have concluded that suspension-feeding detritivorous fish such as gizzard shad Dorosoma cepedianum selectively ingest nutrient-rich particles using either mechanical sorting within the oropharyngeal cavity or behavioral selectivity within the environment, but none have distinguished between these hypothesized selection mechanisms. To determine whether mechanical selectivity occurs within the oropharyngeal cavity, gizzard shad were fed particles of standardized size but different carbon and nitrogen content in homogeneous particle suspensions vs. non-homogeneous particle distributions. By comparing foregut and epibranchial organ contents with the particles available in a homogeneous suspension, we demonstrated that the fish did not use mechanical …
Anthropogenic Noise Is Associated With Reductions In The Productivity Of Breeding Eastern Bluebirds (Sialia Sialis), Caitlin R. Kight, Margaret S. Saha, John P. Swaddle
Anthropogenic Noise Is Associated With Reductions In The Productivity Of Breeding Eastern Bluebirds (Sialia Sialis), Caitlin R. Kight, Margaret S. Saha, John P. Swaddle
Arts & Sciences Articles
Although previous studies have related variations in environmental noise levels with alterations in communication behaviors of birds, little work has investigated the potential long-term implications of living or breeding in noisy habitats. However, noise has the potential to reduce fitness, both directly (because it is a physiological stressor) and indirectly (by masking important vocalizations and/or leading to behavioral changes). Here, we quantified acoustic conditions in active breeding territories of male Eastern Bluebirds (Sialia sialis). Simultaneously, we measured four fitness indicators: cuckoldry rates, brood growth rate and condition, and number of fledglings produced (i.e., productivity). Increases in environmental noise …
Multiple Novel Signals Mediate Thyroid Hormone Receptor Nuclear Import And Export, Manohara S. Mavinakere, Jeremy M. Powers, Kelly S. Subramanian, Vincent R. Roggero, Lizabeth A. Allison
Multiple Novel Signals Mediate Thyroid Hormone Receptor Nuclear Import And Export, Manohara S. Mavinakere, Jeremy M. Powers, Kelly S. Subramanian, Vincent R. Roggero, Lizabeth A. Allison
Arts & Sciences Articles
Thyroid hormone receptor (TR) is a member of the nuclear receptor superfamily that shuttles between the cytosol and nucleus. The fine balance between nuclear import and export of TR has emerged as a critical control point for modulating thyroid hormone-responsive gene expression; however, sequence motifs of TR that mediate shuttling are not fully defined. Here, we characterized multiple signals that direct TR shuttling. Along with the known nuclear localization signal in the hinge domain, we identified a novel nuclear localization signal in the A/B domain of thyroid hormone receptor a1 that is absent in thyroid hormone receptor B1 and inactive …
Constraints On Acoustic Signaling Among Birds Breeding In Secondary Cavities: The Effects Of Weather, Cavity Material, And Noise On Sound Propagation, John P. Swaddle, Caitlin R. Kight, Saji Perera, Eduardo Davila-Reyes, Shena Sikora
Constraints On Acoustic Signaling Among Birds Breeding In Secondary Cavities: The Effects Of Weather, Cavity Material, And Noise On Sound Propagation, John P. Swaddle, Caitlin R. Kight, Saji Perera, Eduardo Davila-Reyes, Shena Sikora
Arts & Sciences Articles
Increasing evidence suggests that anthropogenic noise from urbanization affects animal acoustic communication. We investigated whether the begging calls of nestling Eastern Bluebirds (Sialia sialis) varied along a disturbance gradient of ambient noise. Contrary to our prediction and the results of a previous study of nestling Tree Swallows (Tachycineta bicolor), we found that nestling Eastern Bluebirds did not increase the amplitude or structural characteristics—including frequency, rate, and duration—of their vocalizations in response to ambient noise. However, we found that prevalent temperature and humidity conditions attenuated begging calls. Specifically, in warmer, more humid weather, vocalizations of nestling Eastern …
Acoustic Space Is Affected By Anthropogenic Habitat Features: Implications For Avian Vocal Communication, Caitlin R. Kight, Mark H. Hinders, John P. Swaddle
Acoustic Space Is Affected By Anthropogenic Habitat Features: Implications For Avian Vocal Communication, Caitlin R. Kight, Mark H. Hinders, John P. Swaddle
Arts & Sciences Articles
Human-altered landscapes often include structural features, such as higher levels of impervious surface cover (ISC) and less vegetation, that are likely to affect the transmission of avian vocalizations. We investigated the relationships between human habitat modifications and signal transmission by measuring four acoustic parameters—persistence, reverberation, and signal-to-noise ratio (SNR) of broadcast tones, as well as absolute ambient noise level—in each of 39 avian breeding territories across an anthropogenic disturbance gradient. Using a geographic information system, we quantified the amounts of different habitat features (e.g., ISC, grass, trees) at each site; a principal component analysis was used to identify which of …
Cumulative Lesioning Of Respiratory Interneurons Disrupts And Precludes Motor Rhythms In Vitro, Xueying Wang, John A. Hayes, Christopher A. Del Negro
Cumulative Lesioning Of Respiratory Interneurons Disrupts And Precludes Motor Rhythms In Vitro, Xueying Wang, John A. Hayes, Christopher A. Del Negro
Arts & Sciences Articles
How brain functions degenerate in the face of progressive cell loss is an important issue that pertains to neurodegenerative diseases and basic properties of neural networks. We developed an automated system that uses two-photon microscopy to detect rhythmic neurons from calcium activity, and then individually laser ablates the targets while monitoring network function in real time. We applied this system to the mammalian respiratory oscillator located in the pre-Bötzinger Complex (preBötC) of the ventral medulla, which spontaneously generates breathing-related motor activity in vitro. Here, we show that cumulatively deleting preBötC neurons progressively decreases respiratory frequency and the amplitude of motor …
The Sumo-Targeted Ubiquitin Ligase Rnf4 Regulates The Localization And Function Of The Htlv-1 Oncoprotein Tax, Kimberly A. Fryrear, Xin Guo, Oliver Kerscher, O John Semmes
The Sumo-Targeted Ubiquitin Ligase Rnf4 Regulates The Localization And Function Of The Htlv-1 Oncoprotein Tax, Kimberly A. Fryrear, Xin Guo, Oliver Kerscher, O John Semmes
Arts & Sciences Articles
The Really Interesting New Gene (RING) Finger Protein 4 (RNF4) represents a class of ubiquitin ligases that target Small Ubiquitin-like Modifier (SUMO)–modified proteins for ubiquitin modification. To date, the regulatory function of RNF4 appears to be ubiquitin-mediated degradation of sumoylated cellular proteins. In the present study, we show that the Human T-cell Leukemia Virus Type 1 (HTLV-1) oncoprotein Tax is a substrate for RNF4 both in vivo and in vitro. We mapped the RNF4-binding site to a region adjacent to the Tax ubiquitin/SUMO modification sites K280/K284. Interestingly, RNF4 modification of Tax protein results in relocalization of the oncoprotein from the …