precise timing
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2022 ◽  
Author(s):  
Thomas J O'Brien

The pharynx is a is a neuromuscular pump found at the anterior end of the alimentary tract, consisting of 20 muscles and 20 neurons. A proper feeding rate in worms is coordinated by the precise timing of pharyngeal movements, with one complete cycle of synchronous contraction and relaxation of the corpus and terminal bulb termed a “pump”. A simple way to measure C. elegans feeding is to count how many times worms pump in a minute (pumps per minute). Movement of the grinder (in the terminal bulb) can easily be observed using a stereomicroscope, and because cycles of contraction/relaxation are synchronised along the pharynx, pumps per minute can be measured simply by counting grinder movements.


2022 ◽  
Vol 15 ◽  
Author(s):  
Nathan R. Wilson ◽  
Forea L. Wang ◽  
Naiyan Chen ◽  
Sherry X. Yan ◽  
Amy L. Daitch ◽  
...  

Here we demonstrate a facile method by which to deliver complex spatiotemporal stimulation to neural networks in fast patterns, to trigger interesting forms of circuit-level plasticity in cortical areas. We present a complete platform by which patterns of electricity can be arbitrarily defined and distributed across a brain circuit, either simultaneously, asynchronously, or in complex patterns that can be easily designed and orchestrated with precise timing. Interfacing with acute slices of mouse cortex, we show that our system can be used to activate neurons at many locations and drive synaptic transmission in distributed patterns, and that this elicits new forms of plasticity that may not be observable via traditional methods, including interesting measurements of associational and sequence plasticity. Finally, we introduce an automated “network assay” for imaging activation and plasticity across a circuit. Spatiotemporal stimulation opens the door for high-throughput explorations of plasticity at the circuit level, and may provide a basis for new types of adaptive neural prosthetics.


2021 ◽  
Author(s):  
Markus Hobisch ◽  
Selin Kara

Fungal peroxygenases are promising biocatalysts for hydroxylation steps in various industry-relevant synthesis pathways. In this application note we describe a bioprocess for the production of unspecific peroxygenase (UPO) in Pichia pastoris. The process was divided in four phases, with different carbon requirements. Precise timing of culture feeding was crucial for optimal cell growth and protein expression. We demonstrate how the automation of culture feeding reduced manual work as well as the risk of process failure due to operator error.


2021 ◽  
Vol 17 (4) ◽  
pp. 1443-1454
Author(s):  
Kathleen A. Wendt ◽  
Xianglei Li ◽  
R. Lawrence Edwards ◽  
Hai Cheng ◽  
Christoph Spötl

Abstract. Investigating the precise timing of regional-scale climate changes during glacial terminations and the interglacial periods that follow is key to unraveling the mechanisms behind these global climate shifts. Here, we present a high-precision time series of climate changes in the Austrian Alps that coincide with the later portion of Termination III (TIII), the entire penultimate interglacial (Marine Isotope Stage (MIS) 7), Termination IIIa (TIIIa), and the penultimate glacial inception (MIS 7–6 transition). Using state-of-the-art mass spectrometry techniques, we have constructed a uranium-series chronology with relative age uncertainties averaging 1.7 ‰ (2σ) for our study period (247 to 191 thousand years before present, ka). Results reveal the onset of warming in the Austrian Alps associated with TIII at 242.5 ± 0.2 ka and the duration of MIS 7e warming between 241.8 and 236.7 (±0.6) ka. An abrupt shift towards higher δ18O values at 216.8 ka marks the onset of regional warming associated with TIIIa. Two periods of high δ18O values (greater than −10 ‰ Vienna Pee Dee Belemnite (VPDB)) between 215.9–213.3 and 204.3–197.5 (±0.4) ka coincide with interglacial substages MIS 7c and 7a, respectively. Multiple fluorescent inclusions suggest a partial retreat of the local Alpine glacier during peak obliquity forcings at 214.3 ± 0.4 ka. Two newly collected stalagmites from Spannagel Cave (SPA146 and 183) provide high-resolution replications of the latter portion of the MIS 7a-to-6e transition. The resulting multi-stalagmite record reveals important chronological constraints on climate shifts in the Austrian Alps associated with MIS 7 while offering new insight into the timing of millennial-scale changes in the North Atlantic realm leading up to TIII and TIIIa.


2021 ◽  
pp. 001083672110276
Author(s):  
Philippe Beauregard

Why did transatlantic policymakers target Russia with economic sanctions in response to its actions during the Ukraine conflict? Commentators perceived these sanctions as highly unlikely because they would have high costs for several European countries, and were surprised when they were finally adopted. Constructivist scholars employed explanations based on common norms and trust to explain the European Union’s agreement on economic sanctions in this case. I argue that the mechanism of international emotional resonance played a decisive role in altering the course of the United States and core European Union powers’ cooperation. A framework that combines resonance with emotional influence mechanisms of persuasion and contagion explains the precise timing of the policy shift, why European policymakers accepted sanctions at a substantial cost to their economy and how norms affected policy when they were empowered by intense emotions.


Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 821
Author(s):  
Pushpendra Singh ◽  
Pathik Sahoo ◽  
Komal Saxena ◽  
Jhimli Manna ◽  
Kanad Ray ◽  
...  

Hodgkin and Huxley showed that even if the filaments are dissolved, a neuron’s membrane alone can generate and transmit the nerve spike. Regulating the time gap between spikes is key to the brain’s cognitive function; however, the time modulation mechanism is still a mystery. By inserting a coaxial probe deep inside a neuron, we repeatedly show that the filaments transmit electromagnetic signals of ~200 μs before an ionic nerve spike sets in. To understand its origin, here, we mapped the electromagnetic vortex produced by a filamentary bundle deep inside a neuron, regulating the nerve spike’s electrical-ionic vortex. We used monochromatic polarized light to measure the transmitted signals beating from the internal components of a cultured neuron. A nerve spike is a 3D ring of the electric field encompassing the perimeter of a neural branch. Several such vortices flow sequentially to keep precise timing for the brain’s cognition. The filaments hold millisecond order time gaps between membrane spikes with microsecond order signaling of electromagnetic vortices. Dielectric resonance images revealed that ordered filaments inside neural branches instruct the ordered grid-like network of actin–beta-spectrin just below the membrane. That layer builds a pair of electric field vortices, which coherently activates all ion-channels in a circular area of the membrane lipid bilayer when a nerve spike propagates. When biomaterials vibrate resonantly with microwave and radio-wave, simultaneous quantum optics capture ultra-fast events in a non-demolition mode, revealing multiple correlated time-domain operations beyond the Hodgkin–Huxley paradigm. Neuron holograms pave the way to understanding the filamentary circuits of a neural network in addition to membrane circuits.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A712-A712
Author(s):  
Leanne M Ward ◽  
Josep Maria de Bergua ◽  
Marie-Eve Robinson ◽  
Ying Zhang ◽  
Carl Decker ◽  
...  

Abstract Background: Achondroplasia (ACH) is the most common form of dwarfism occurring in 1 in 22,000 births (95% CI 18,500 to 26,000). This skeletal dysplasia is caused by a gain-of-function mutation in the fibroblast growth factor receptor 3 (FGFR3) gene located on chromosome 4p16.3 and results in sustained activation of the FGFR3 pathway leading to impaired chondrogenesis and endochondral bone formation. Both typical childhood growth patterns and the impaired linear growth of ACH are modulated by the delicate balance between growth-inhibiting FGFR3/mitogen-activated phosphokinase and growth-promoting c-type natriuretic peptide/natriuretic peptide receptor B. Individuals with ACH frequently develop clinically significant comorbidities, many with onset during childhood. Currently, there are no therapies addressing the underlying pathology. Most available treatments are surgical with goals to alleviate the symptoms from specific comorbidities (i.e. foramen magnum and spinal stenosis or recurrent otitis media). Since the available therapies do not address the underlying etiology, individuals with ACH often undergo multiple surgeries and myriad other forms of supportive care throughout their lives. The precise timing of comorbidity onset and the natural history of many of the skeletal dysplasia features are incompletely defined. This information is needed to inform the design and conduct of pathology-targeted intervention studies. Aim: The purpose of this study is to gather information about the precise timing of comorbidity onset, the longitudinal growth trajectory, and the evolution of body proportionality in children with ACH. Methods and Future Results: The ACHieve study (NCT03875534) is a multi-center, longitudinal, observational cohort study in children with ACH from birth up to 8 years at enrollment. In this non-therapeutic study, children are evaluated every six months for up to 5 years in 25 centers from North America, Europe and Oceania. The first patient was enrolled in 2019 and a total of 84 children have been enrolled to date. At each assessment, children undergo comprehensive anthropometric studies, (including body proportionality measurements and recumbent or standing height) and information on the timing and nature of ACH-related comorbidities and their treatments are collected. Additional information about the baseline demographics, including sex, age distribution, race/ethnicity, and height standard deviation scores will be presented at the time of conference. Conclusions: The ACHieve study will provide additional insight into the natural history of growth, body proportionality, and comorbidities in children with ACH. These observations will serve as a benchmark for future intervention trials targeting the pathology of the underlying skeletal dysplasia.


Author(s):  
You Nakai

Tudor switched from the organ to the piano in his late teens. His approach to the new instrument, whose nature he regarded as percussion, centered on harnessing its mechanism of escapement, which resulted in the control of all parameters as a function of precise timing of attack and release. This proved especially well-suited to the pointillistic works being written by composers on both sides of the Atlantic. But close examination reveals that the relationship between Tudor and the composers around him, which gave birth to new methods of chance operations, indeterminacy, or graphic scores, was actually led by the pianist’s exploration of his instrument, many times at the bewilderment of others as to what captivated his attention. At the core of Tudor’s singular realizations was a focus on the physical bias of the score given to him, which he referred to as “material.” As the degree of indeterminacy in the composer’s materials increased throughout the 1950s, Tudor would more and more shift his attention to another kind of material involved in the realization of music: the physical nature of instruments, including his own self, which composers had already begun regarding as such.


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