Publications by authors named "David B Green"

Article Synopsis
  • - The text discusses a system for autonomic nervous regulation using electrical current, which involves both increasing and decreasing neural activity through techniques like vagus nerve stimulation (VNS) and kilohertz frequency alternating current (KHFAC).
  • - VNS can be fine-tuned by adjusting frequency for better control, while KHFAC can block neural signals and can also be easily adjusted through amplitude modulation.
  • - The research uses fuzzy logic control (FLC) to manage the vagus nerve, allowing it to stabilize or alter heart rate effectively in response to physiological changes.
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Intestinal microbiota, diet, and physical activity are inextricably linked to inflammation occurring in the presence of tumor progression and declining neurocognition. This study aimed to explore how fecal microbiota, inflammatory biomarkers, and neurocognitive behavior are influenced by voluntary exercise and surplus dietary protein and folic acid which are common health choices. Dietary treatments provided over 8 weeks to C57BL/CJ male mice ( = 76) were: Folic Acid (FA) Protein (P) Control (FPC, 17.

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Although electrical vagus nerve stimulation has been shown to augment parasympathetic control of the heart, the effects of electrical conduction block have been less rigorously characterized. Previous experiments have demonstrated that direct current (DC) nerve block can be applied safely and effectively in the autonomic system, but additional information about the system dynamics need to be characterized to successfully deploy DC nerve block to clinical practice.The dynamics of the heart rate (HR) from DC nerve block of the vagus nerve were measured by stimulating the vagus nerve to lower the HR, and then applying DC block to restore normal rate.

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Anthropogenic climate change is resulting in spatial redistributions of many species. We assessed the potential effects of climate change on an abundant and widely distributed group of diving birds, Eudyptes penguins, which are the main avian consumers in the Southern Ocean in terms of biomass consumption. Despite their abundance, several of these species have undergone population declines over the past century, potentially due to changing oceanography and prey availability over the important winter months.

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Objectives: KiloHertz frequency alternating current waveforms produce conduction block in peripheral nerves. It is not clearly known how the waveform shape affects block outcomes, and if waveform effects are frequency dependent. We determined the effects of waveform shape using two types of electrodes.

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Although vagus nerve stimulation (VNS) can be used to reduce heartrate by enhancing parasympathetic activity, a fully controllable intervention would also require a method for downregulating parasympathetic activity. A direct current (DC) block can be applied to a nerve to block its action potential conduction. This nerve block can be used to downregulate parasympathetic activity by blocking afferent reflexes.

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Homocysteine, cysteine, cysteinyl-glycine, and glutathione are significant biological aminothiols (ATs) that are marker-molecules in Down syndrome, Alzheimer's disease, or have been implicated as risk factors in atherosclerosis and other vascular diseases, and therefore rapid determination of these molecules is desirable. After reduction of the disulfides, a widely used method utilizes derivatization with ammonium 7-fluorobenzo-2-oxa-1,3-diazole-4-sulfonate (SBD-F) as a fluorogenic probe prior to reversed-phase HPLC separation followed by fluorescence detection. The traditional HPLC determination of ATs is time consuming and economically expensive.

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Article Synopsis
  • Seabirds rely heavily on vocal communication for reproduction on land but have adapted to life at sea with unique foraging techniques.
  • This study investigates underwater vocalizations of three penguin species, finding 203 instances of calls that are short and primarily linked to hunting behaviors.
  • The results suggest that vocalizations might play a role in hunting, but further research is needed to fully understand their function in the underwater environment.
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One of the main central processes affecting the cortical representation of conspecific vocalizations is the collateral output from the extended motor system for call generation. Before starting to study this interaction we sought to compare the characteristics of calls produced by stimulating four different parts of the brain in guinea pigs (Cavia porcellus). By using anaesthetised animals we were able to reposition electrodes without distressing the animals.

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Article Synopsis
  • Amphibian chemical defenses, such as tetrodotoxin (TTX) in newts, can be induced by environmental stressors, which challenges the idea that these traits are fixed.
  • In experiments, adult California newts increased TTX levels quickly in response to simulated predator threats, and lab-reared larvae showed significantly higher TTX concentrations compared to those in the wild.
  • This suggests that amphibians can adapt their chemical defenses based on perceived risks, highlighting the importance of considering these dynamic responses in ecological studies and predator-prey interactions.
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In childhood, partial hearing loss can produce prolonged deficits in speech perception and temporal processing. However, early therapeutic interventions targeting temporal processing may improve later speech-related outcomes. Gap detection is a measure of auditory temporal resolution that relies on the auditory cortex (ACx), and early auditory deprivation alters intrinsic and synaptic properties in the ACx.

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Quasicrystals possess long-range order but lack the translational symmetry of crystalline solids. In solid state physics, periodicity is one of the fundamental properties that prescribes the electronic band structure in crystals. In the absence of periodicity and the presence of quasicrystalline order, the ways that electronic states change remain a mystery.

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In the last several decades, obesity rates have reached epidemic proportions, and increases the risk for a host of comorbidities, including diabetes, cardiovascular disease, and certain kinds of cancers. Boba milk tea, first became popular in the 1990s throughout Asia, and has gained more popularity in the United States and in Europe since 2000. Currently, available nutrition data from online sites suggest this beverage contains high amounts of sugar and fat.

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The coding of sound level by ensembles of neurons improves the accuracy with which listeners identify how loud a sound is. In the auditory system, the rate at which neurons fire in response to changes in sound level is shaped by local networks. Voltage-gated conductances alter local output by regulating neuronal firing, but their role in modulating responses to sound level is unclear.

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Perceptual learning (training-induced performance improvement) can be elicited by task-irrelevant stimulus exposure in humans. In contrast, task-irrelevant stimulus exposure in animals typically disrupts perception in juveniles while causing little to no effect in adults. This may be due to the extent of exposure, which is brief in humans while chronic in animals.

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Article Synopsis
  • Behaviors that influence habitat selection are key to understanding species movement patterns, particularly site fidelity, which is crucial for California newts during their breeding seasons.
  • This study focused on the chemical defense compound tetrodotoxin (TTX) in male California newts to see how it relates to their site fidelity over five breeding seasons.
  • Findings showed that while TTX concentrations vary greatly among individuals, these levels play a significant role in determining whether newts stay in or leave a breeding pool, hinting at complex interactions between chemical defenses and predator-prey relationships.
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This article argues that love and justice are interlocking themes that undergird and motivate the poetry and activism of the Black lesbian feminist Pat Parker. Parker was a prolific working-class poet, a committed Black lesbian feminist, and an international trailblazer whose poems, like her famous "Womanslaughter" discussed in this article, document the many injustices that Black women endured in an anti-Black, rabidly homophobic, and patriarchal U.S.

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During breeding, animal behaviour is particularly sensitive to environmental and food resource availability. Additionally, factors such as sex, body condition, and offspring developmental stage can influence behaviour. Amongst seabirds, behaviour is generally predictably affected by local foraging conditions and has therefore been suggested as a potentially useful proxy to indicate prey state.

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Eight bis-ligated, homoleptic, zinc complexes were synthesized through the reaction of NNO Schiff base ketoimines bearing varying substituents with diethyl zinc in an inert atmosphere glovebox at room temperature and isolated in 62-95% yield. The complexes were characterized with (1)H, (13)C, and (19)F nuclear magnetic resonance spectroscopy, absorbance spectroscopy, high resolution mass spectrometry, elemental analysis, and single crystal X-ray crystallography. The complexes were shown to adopt distorted octahedral coordination geometry around zinc.

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Article Synopsis
  • * The study introduces a non-destructive method for sampling TTX levels in adult newts and their embryos, eliminating the need to capture and remove them from their habitats.
  • * By utilizing advanced extraction techniques and a custom high performance liquid chromatography (HPLC) system, researchers achieved improved recovery and quantification of TTX, revealing significant geographic variations in toxin levels even over short distances.
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The present study reports an improved method to quickly and reproducibly isolate the saccharides from a variety of dairy and soy products utilizing reversed-phase solid-phase extraction to quantitatively remove fats, fatty acids, and lipids followed by desalination and deproteinization by ion-exchange solid-phase extraction with no loss of saccharides during extraction. Analysis of the isolated saccharides was performed by ligand-exchange HPLC. The method presented requires no prolonged heating (thus protecting the saccharides from hydrolysis or isomerization), uses benign reagents, and realizes a significant time savings over existing methods.

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Volatile organic compounds emitted from a several decade series of bound periodicals (1859-1939) printed on ground wood paper, as well as historical books dating from the 1500s to early 1800s made from cotton/linen rag, were studied using an improved headspace SPME/GC-MS method. The headspace over the naturally aging books, stored upright in glass chambers, was monitored over a 24-h period, enabling the identification of a wide range of organic compounds emanating from the whole of the book. The detection of particular straight chain aldehydes, as well as characteristic alcohols, alkenes and ketones is correlated with oxidative degradation of the C(18) fatty acid constituency of paper.

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Cargo transport by microtubule-based motors is essential for cell organisation and function. The Bicaudal-D (BicD) protein participates in the transport of a subset of cargoes by the minus-end-directed motor dynein, although the full extent of its functions is unclear. In this study, we report that in Drosophila zygotic BicD function is only obligatory in the nervous system.

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Discovery of the fuel additive methyl tert-butyl ether (MTBE) in groundwater, surface water, and stormwater has prompted studies of its sources, transport and fate. More limited data, however, is available on the extent of contamination of coastal waters, as well as the persistence of MTBE in the marine environment. We apply here the combination of solid phase microextraction and gas chromatography-mass spectrometry to the detection of sub-to-low microgram/l concentrations of MTBE in seawater samples.

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