We develop a biophysically realistic model of the nematode C. elegans that includes: (i) its muscle structure and activation, (ii) key connectomic activation circuitry, and (iii) a weighted and ...time-dynamic proprioception. In combination, we show that these model components can reproduce the complex waveforms exhibited in C. elegans locomotive behaviors, chiefly omega turns. This is achieved via weighted, time-dependent suppression of the proprioceptive signal. Though speculative, such dynamics are biologically plausible due to the presence of neuromodulators which have recently been experimentally implicated in the escape response, which includes an omega turn. This is the first integrated neuromechanical model to reveal a mechanism capable of generating the complex waveforms observed in the behavior of C. elegans, thus contributing to a mathematical framework for understanding how control decisions can be executed at the connectome level in order to produce the full repertoire of observed behaviors.
Abstract Time-restricted feeding ameliorates the deleterious effects of a high-fat diet on body weight and metabolism in young adult mice. Because obesity is highly prevalent in the middle-aged ...population, this study tested the hypothesis that time-restricted feeding alleviates the adverse effects of a high-fat diet in male middle-aged (12 months) mice. C57BL6/J mice were fed one of three diets for 21–25 weeks: 1) high-fat diet (60% total calories from fat) ad-libitum (HFD-AL), 2) HFD, time-restricted feeding (HFD-TRF), and 3) low-fat diet (10% total calories from fat) ad-libitum (LFD-AL) (n = 15 each). HFD-TRF mice only had food access for 8 h/day during their active period. HFD-TRF mice gained significantly less weight than HFD-AL mice (~ 20% vs 55% of initial weight, respectively). Caloric intake differed between these groups only during the first 8 weeks and accounted for most but not all of their body weight difference during this time. TRF of a HFD lowered glucose tolerance in terms of incremental area under the curve (iAUC) (p < 0.02) to that of LFD-AL mice. TRF of a HFD lowered liver weight (p < 0.0001), but not retroperitoneal or epididymal fat pad weight, to that of LFD-AL mice. Neither HFD-AL nor HFD-TRF had any effect on performance in the novel object recognition or object location memory tests. Circulating corticosterone levels either before or after restraint stress were not affected by diet. In conclusion, TRF without caloric restriction is an effective strategy in middle-aged mice for alleviating the negative effects of a HFD on body weight, liver weight, and glucose tolerance.
Moisture loss in rock is known to generate acoustic emissions (AE). Phenomena that result in AE during drying are related to the movement of fluids through the pores and induced‐cracks that arise ...from differential mineral shrinkage, especially in clay‐bearing rock. AE from the movement of fluids occurs from the reconfiguration of fluid interfaces during drying, while AE from mineral shrinkage involves the debonding within or between minerals. Here, analogue rock samples were used to examine the differences in the AE signatures when one or both AE source‐types are present. An unsupervised sparse regression model, Dynamic Mode Decomposition with control, that extends Dynamic Mode Decomposition is used to characterize the AE signals recorded during the drying of porous analogue rock samples fabricated with ordinary Portland cement, with and without clay. This method can effectively and accurately reconstruct acoustic signals emitted from samples that only experience moisture loss without cracking. However, the method struggles to reconstruct signals from samples with intricate crack networks that formed during drying because AE generating mechanisms can emit contemporaneously, and the resulting waves propagate through drying‐induced cracks that can lead to multiple internal reflections. Thus, the differential reconstruction accuracy of time series generated by different underlying physical processes provides a robust filter for reducing large data catalogs. In general, both dynamics and sparse initiating events are learned directly from data and this method exposes a data hierarchy based on the complexity of the intrinsic dynamics.
Plain Language Summary
Moisture loss from porous media, in particular clay‐rich rocks, can generate sound known as acoustic emissions (AE), as water moves through the pore structure and cracking caused by mineral shrinkage from dehydration occurs. Unique information about processes giving rise to these sounds and the changes in the material can be extracted from the AE data. To examine the differences in these signals, distinct sample types were fabricated with ordinary Portland cement, and in some instances with clay. A machine learning method requiring no prior information that is informed by the data was used to sort through and identify the AE signals. This method works best for AE signals emitted from samples that only experience movement of fluids with no cracking. When both processes occur, the AE signals contain overlapping information that simultaneously are related to drying and cracking. While this method does not perform well on AE data that contain information from many sources, it does provide a strong filter for large volumes of data which are quite challenging to examine and extract relevant information from. In general, this method is most robust to simultaneously learn the initiating action generated by the single sources and characteristics of the AE.
Key Points
Application of an extension of a dimensionality reduction technique, Dynamic Mode Decomposition
Sparse Regression can be used to simultaneously discover intrinsic dynamics and external initiating events
Acoustic emissions events related to the infiltration of the drying front are well captured by a linear dynamical system and a single initiating event
From 2009 to 2011, marine spatial planning (MSP) rapidly gained visibility in the United States as a promising ocean management tool. A few small-scale planning efforts were completed in state ...waters, and the Obama Administration proposed a framework for large-scale regional MSP throughout the U.S. Exclusive Economic Zone. During that same time period, the authors engaged a variety of U.S ocean stakeholders in a series of dialogs with several goals: to share information about what MSP is or could be, to hear stakeholder views and concerns about MSP, and to foster better understanding between those who depend on ocean resources for their livelihood and ocean conservation advocates. The stakeholder meetings were supplemented with several rounds of in-depth interviews and a survey. Despite some predictable areas of conflict, project participants agreed on a number of issues related to stakeholder engagement in MSP: all felt strongly that government planners need to engage outsiders earlier, more often, more meaningfully, and through an open and transparent process. Equally important, the project affirmed the value of bringing unlike parties together at the earliest opportunity to learn, talk, and listen to others with whom they rarely engage.
► Ocean users and ENGOs identified areas of agreement through facilitated dialog. ► Stakeholders want to be engaged in MSP earlier and more meaningfully. ► Emerging ocean industries need a clear path to access ocean space. ► Established sectors are familiar with the status quo and leery of any new hurdles. ► Conflicts remain about the correct balance between environmental and economic goals.
Ventral midbrain dopaminergic neurons project to the striatum as well as the cortex and are involved in movement control and reward-related cognition. In Parkinson's disease, nigrostriatal midbrain ...dopaminergic neurons degenerate and cause typical Parkinson's disease motor-related impairments, while the dysfunction of mesocorticolimbic midbrain dopaminergic neurons is implicated in addiction and neuropsychiatric disorders. Study of the development and selective neurodegeneration of the human dopaminergic system, however, has been limited due to the lack of an appropriate model and access to human material. Here, we have developed a human in vitro model that recapitulates key aspects of dopaminergic innervation of the striatum and cortex. These spatially arranged ventral midbrain-striatum-cortical organoids (MISCOs) can be used to study dopaminergic neuron maturation, innervation and function with implications for cell therapy and addiction research. We detail protocols for growing ventral midbrain, striatal and cortical organoids and describe how they fuse in a linear manner when placed in custom embedding molds. We report the formation of functional long-range dopaminergic connections to striatal and cortical tissues in MISCOs, and show that injected, ventral midbrain-patterned progenitors can mature and innervate the tissue. Using these assembloids, we examine dopaminergic circuit perturbations and show that chronic cocaine treatment causes long-lasting morphological, functional and transcriptional changes that persist upon drug withdrawal. Thus, our method opens new avenues to investigate human dopaminergic cell transplantation and circuitry reconstruction as well as the effect of drugs on the human dopaminergic system.
The modern domestic cat has changed little morphologically or behaviorally since its semi- domestication 5000-8000 years ago. Today, domestic cats are some of the most popular companion animals. ...However, many cats are allowed to roam outside and are responsible for deaths of billions of wildlife prey annually. While cats that are owned and let outside (indoor/outdoor cats) have been relatively well studied, other types of cats living outdoors have been only poorly studied. Colony cats, which are outdoor cats that live in a limited outdoor area and are fed by humans, are rarely friendly, making them difficult to study. This study aims to find whether colony cats predate wildlife similarly to indoor/outdoor cats, and whether their predation on wildlife changes along an urban-suburban gradient. This study was conducted on Long Island, New York, with six cat colonies located in different urban-suburban settings. Cat colony population sizes were determined by point counts and camera traps. Scat was located, macroscopically analyzed, and then sent for DNA analyses. Both building numbers and roof area at each colony were calculated to quantify urbanness of cat colony locations. My results showed that there was no relationship between the number of buildings or total roof area and % of scats with vertebrate prey. Predation could not be directly compared with studies done on indoor/outdoor cats because scats were used and number of prey individuals could not be determined. However, much like studies done on indoor/outdoor cats, colony cats in this study ate mostly mammals, specializing on rodents. Surprisingly, the only non-native prey species I found was Norway rats.
Fish assemblage data from 69 brooks and small streams were analysed to derive a fish-based typology of small lowland streams in the “Central Plains” ecoregion of northeastern Germany. Altogether 32 ...native, 1 non-native fish species and 2 lamprey species were detected in the lowland rivers studied. Species number and diversity varied significantly according to mean summer water temperatures and size of the watercourses. Summer-cold brooks contained on average 3–5 species, brooks with higher summer temperatures 5–8 species and small lowland rivers around 10–14 species. Small lowland brooks contained a significantly higher number of fish species when they flowed into or out of lakes: typically around 8–12.
In the northeastern German lowlands the following three different river types were distinguished according to their fish assemblages: (1) The “lowland trout brook”, where brown trout (
Salmo trutta L.) are reference species and accompanied by stone loach (
Barbatula barbatula (L.)), brook lamprey (
Lampetra planeri (Bloch)), three-spined stickleback (
Gasterosteus aculeatus L.), ten-spined stickleback (
Pungitius pungitius (L.)) and gudgeon (
Gobio gobio (L.)); (2) The “perch- and roach-dominated lowland brook”, where perch (
Perca fluviatilis L.) and roach (
Rutilus rutilus (L.)) are reference species, accompanied by pike (
Esox lucius L.), three-spined stickleback and gudgeon; and (3) The “lowland lake connected brook” inhabited by higher numbers of fish species, with higher proportions of cyprinid fishes, and higher proportions of limnophilic fish. Apart from perch and roach, bleak (
Alburnus alburnus (L.)), common bream (
Abramis brama (L.)), silver bream (
Blicca bjoerkna (L.)) and rudd (
Scardinius erythrophthalmus (L.)) also occurred frequently.
Further two observed fish-based types were not considered: The potential stone loach-dominated brook was not sufficiently represented in this study to be verified, and the stickleback brook was considered to represent degradation of lowland trout brooks.
The correspondence between the fish-based typology and the morphology-based German stream typology was rather weak and requires further investigation.
Social media are continuously gaining ground in PR workplaces as Facebook, Twitter and Co. are on their way of becoming standard tools in professional communication. But even though PR is one of the ...pioneering fields in terms of social media acceptance, not all professionals make equal use of social media nor do they feel equally at home in the new social communication paradigm. On the basis of an online survey among 1579 PR practitioners from 30 European countries, we propose four clusters of social media users in professional communication. The results of our quantitative analysis show, that there are considerable differences among PR professionals in terms of the extent, purpose and virtuosity of their social media usage as well as their attitude towards social media in general. We also show that the differences in social media usage do not necessarily follow traditional demographic patterns of gender, position or age.
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