bluuebunny/crossref_metadata_2025 huggingface dataset:
Purinergic P2 and glutamate NMDA receptor coupling contributes to osmotically driven excitability in hypothalamic magnocellular neurosecretory neurons
Authors: Ferreira‐Neto H. C. , Antunes V. R. , Stern J. E.
Published: May 2021

Key points

Purinergic and glutamatergic signalling pathways play a key role in regulating the activity of hypothalamic magnocellular neurosecretory neurons (MNNs).

However, the precise cellular mechanisms by which ATP and glutamate act in concert to regulate osmotically driven MNN neuronal excitability remains unknown.

Here, we report that ATP acts on purinergic P2 receptors in MNNs to potentiate in a Ca2+‐dependent manner extrasynaptic NMDAR function.

The P2‐NMDAR coupling is engaged in response to an acute hyperosmotic stimulation, contributing to osmotically driven firing activity in MNNs.

These results help us to better understand the precise mechanisms contributing to the osmotic regulation of firing activity and hormone release from MNNs.

The firing activity of hypothalamic magnocellular neurosecretory neurons (MNNs) located in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) is coordinated by the combined, fine‐tuned action of intrinsic membrane properties, synaptic and extrasynaptic signalling. Among these, purinergic and glutamatergic signalling pathways have been shown to play a key role regulating the activity of MNNs. However, the precise cellular mechanisms by which ATP and glutamate act in concert to regulate osmotically driven MNN neuronal excitability remains unknown. Whole‐cell patch‐clamp recordings obtained from MNNs showed that ATP (100 μM) induced an increase in firing rate, an effect that was blocked by either 4‐[[4‐formyl‐5‐hydroxy‐6‐methyl‐3‐[(phosphonooxy)methyl]2‐pyridinyl]azo]1,3‐benzenedisulfonic acid tetrasodium salt (PPADS) (10 μM) or kynurenic acid (1 mm). While ATP did not affect the frequency or magnitude of glutamatergic excitatory postsynaptic currents (EPSCs), it induced an inward shift in the holding current that was prevented by PPADS or kynurenic acid treatment, suggesting that ATP enhances a tonic extrasynaptic glutamatergic excitatory current. We observed that ATP‐potentiated glutamatergic receptor‐mediated currents were evoked by focal application of L‐glu (1 mm) and NMDA (50 μM), but not AMPA (50 μM). ATP potentiation of NMDA‐evoked currents was blocked by PPADS (10 μM) and by chelation of intracellular Ca2+ with BAPTA (10 mm). Finally, we report that a hyperosmotic stimulus (mannitol 1%, +55 mOsm/kgH2O) potentiated NMDA‐evoked currents and increased MNN firing activity, effects that were blocked by PPADS. Taken together, our data support a functional excitatory coupling between P2 and extrasynaptic NMDA receptors in MNNs, which is engaged in response to an acute hyperosmotic stimulus.
Daily changes in neuronal activities of the dorsal motor nucleus of the vagus under standard and high‐fat diet
Authors: Chrobok Lukasz , Klich Jasmin D. , Jeczmien‐Lazur Jagoda S. , Pradel Kamil , Palus‐Chramiec Katarzyna , Sanetra Anna M. , Piggins Hugh D. , Lewandowski Marian H.
Published: May 2021

Key points

 Recently, we found that the dorsal vagal complex displays autonomous circadian timekeeping properties

 The dorsal motor nucleus of the vagus (DMV) is an executory part of this complex – a source of parasympathetic innervation of the gastrointestinal tract

 Here, we reveal daily changes in the neuronal activities of the rat DMV, including firing rate, intrinsic excitability and synaptic input – all of these peaking in the late day

 Additionally, we establish that short term high‐fat diet disrupts these daily rhythms, boosting the variability in the firing rate, but blunting the DMV responsiveness to ingestive cues

 These results help us better understand daily control over parasympathetic outflow and provide evidence on its dependence on the high‐fat diet

The suprachiasmatic nuclei (SCN) of the hypothalamus function as the brain's primary circadian clock, but circadian clock genes are also rhythmically expressed in several extra‐SCN brain sites where they can exert local temporal control over physiology and behaviour. Recently, we found that the hindbrain dorsal vagal complex possesses strong daily timekeeping capabilities, with the area postrema and nucleus of the solitary tract exhibiting the most robust clock properties. The possibility that the executory part of this complex – the dorsal motor nucleus of the vagus (DMV) – also exhibits daily changes has not been extensively studied. The DMV is the source of vagal efferent motoneurons that regulate gastric motility and emptying and consequently influence meal size and energy homeostasis. We used a combination of multi‐channel electrophysiology and patch clamp recordings to gain insight into effects of time of day and diet on these DMV cells. We found that DMV neurons increase their spontaneous activity, excitability and responsiveness to metabolic neuromodulators at late day and this was paralleled with an enhanced synaptic input to these neurons. A high‐fat diet typically damps circadian rhythms, but we found that consumption of a high‐fat diet paradoxically amplified daily variation of DMV neuronal activity, while blunting the neurons responsiveness to metabolic neuromodulators. In summary, we show for the first time that DMV neural activity changes with time of day, with this temporal variation modulated by diet. These findings have clear implications for our understanding of the daily control of vagal efferents and parasympathetic outflow.
Forced Response Variation of a Compressor Utilizing Blade Tip Timing, Strain Gages, and As-Manufactured Finite Element Models
Authors: Gillaugh Daniel , Janczewski Timothy , Kaszynski Alex , Brown Jeffrey , Beck Joseph , Nessler Chase
Published: June 2021

The dynamic response of turbine engine components varies widely due to manufacturing deviations in the blades known as mistuning. This dynamic variation is investigated using a single stage compressor experimentally using both blade tip timing (BTT) and strain gage (SG) measurements and using as-manufactured finite element models (AMMs) on a 1st bend mode. Operational BTT and SG safety limits were generated using both averaged and AMM models via Goodman material properties. The predicted individual blade stress/deflection (S/D) ratios and strain gage ratios for this mode will be compared to the average finite element counterparts. Additionally, the correlation between BTT and SG's will be presented. This correlation will be performed using two approaches: blade maximum stress comparisons and measured response compared to the sensors safety limits. It will be shown that accounting for geometry with AMMs produce more accurate strain gage to BTT correlation compared to average models. An experimental model updating procedure is developed to increase the strain gage to BTT correlation by optimizing the location the BTT optical spot probes measure on the blade chord. Implementing this procedure using as-manufactured models are able to improve strain gage to BTT correlation.
Reduction of exogenous cytochrome c by Neurospora crassa conidia: effects of superoxide dismutase and blue light
Authors: Takahama U , Shimizu-Takahama M , Egashira T
Published: June 2021

The reduction of externally added cytochrome c by Neurospora crassa conidia was observed. The reduction was stimulated by antimycin A and suppressed partially by superoxide dismutase. When conidia were treated with diethyldithiocarbamate, which inactivated endogenous superoxide dismutase, the cytochrome c reduction was stimulated. Blue light also stimulated the cytochrome c reduction. Azide, which inhibits photochemical reactions mediated by flavins, suppressed the blue light effect. Superoxide dismutase partially suppressed the cytochrome c reduction in the light. The results suggest that O2(-) participates in the cytochrome c reduction by conidia and the flavins or flavoproteins are candidates for the receptor pigment of blue light to stimulate the cytochrome c reduction. It was also suggested that the redox component(s), which could directly transfer its reducing equivalents to exogenous cytochrome c, was present at the surface of conidia.
Pathway of lysine degradation in Fusobacterium nucleatum
Authors: Barker H A , Kahn J M , Hedrick L
Published: June 2021

Lysine was fermented by Fusobacterium nucleatum ATCC 25586 with the formation of about 1 mol each of acetate and butyrate. By the use of [1-14C]lysine or [6-14C]lysine, acetate and butyrate were shown to be derived from both ends of lysine, with acetate being formed preferentially from carbon atoms 1 and 2 and butyrate being formed preferentially from carbon atoms 3 to 6. This indicates that the lysine carbon chain is cleaved between both carbon atoms 2 and 3 and carbon atoms 4 and 5, with the former predominating [1-14C]acetate was also extensively incorporated into butyrate, preferentially into carbon atoms 3 and 4. Cell-free extracts of F. nucleatum were shown to catalyze the reactions of the 3-keto,5-aminohexanoate pathway of lysine degradation, previously described in lysine-fermenting clostridia. The 3-keto,5-aminohexanoate cleavage enzyme was partially purified and shown to have properties much like those of the clostridial enzyme. We conclude that both the pathway and the enzymes of lysine degradation are similar in F. nucleatum and lysine-fermenting clostridia.
New Antibiotic Substance Produced by
Salmonella typhimurium
LT2
Authors: Ben-Gurion Renana , Flashner Yehuda
Published: June 2021

Salmonella typhimurium
LT2 excreted under certain conditions an antibiotic substance designated typhimuricin. It is suggested that the LT2 “cryptic” plasmid is involved in its production and in the immunity to it. Preliminary characterization of typhimuricin is presented.
Different control circuits for growth rate-dependent regulation of 6-phosphogluconate dehydrogenase and protein components of the translational machinery in Escherichia coli
Authors: Farrish E E , Baker H V , Wolf R E
Published: June 2021

Previous studies showed that the level of 6-phosphogluconate (6PG) dehydrogenase increases about fourfold with increasing growth rate when the growth rate is varied by varying the carbon source. When the growth rate was reduced by anaerobic growth or by using mutations to divert metabolism to less efficient pathways, the level of 6PG dehydrogenase was the same as in a wild-type strain growing aerobically on other carbon sources that yielded the same growth rate. Thus, expression of gnd, which encodes 6PG dehydrogenase, is regulated by the cellular growth rate and not by specific nutrients in the medium. Growth rate-dependent regulation was independent of temperature. After a nutritional shift-up, 6PG dehydrogenase and total protein did not attain the postshift rate of accumulation for 30 min, whereas RNA accumulation increased immediately. The kinetics of accumulation of 6PG dehydrogenase and RNA were coincident after a nutritional shift-down. Partial amino acid starvation of a strain that controls RNA synthesis stringently (rel+) had no effect on the differential rate of accumulation of the enzyme. The level of 6PG dehydrogenase in cells harboring a gnd+ multicopy plasmid was in approximate proportion to gene dosage and somewhat higher at faster growth rates. Growth rate control of chromosomal gnd was normal in strains carrying multiple copies of the promoter-proximal and promoter-distal portions of gnd. These results show that gnd is not part of the same regulatory network as components of the translational apparatus since gnd shows a delayed response to a nutritional shift-up, is not autoregulated, and is not subject to stringent control. Models to account for growth rate-dependent regulation of gnd are discussed.
Effect of 4,5',8-trimethylpsoralen interstrand cross-links present in recipient Bacillus subtilis on the integration of transforming DNA
Authors: Mooibroek H , van Randen J , Venema G
Published: June 2021

When recipient Bacillus subtilis carrying chromosomal trimethylpsoralen cross-links were transformed, the donor marker activity decreased with the extent of cross-linking. Additional donor marker activity was lost upon incubation of the reextracted DNA with nuclease S1, particularly at higher levels of cross-linking. Physical analysis of the reextracted DNA showed that the donor DNA was progressively excluded from heteroduplex formation as the frequency of cross-links in the recipient DNA increased. In the donor-recipient complexes still being formed, increasing amounts of donor DNA became susceptible to nuclease S1 digestion under these conditions. These results suggest that resident interstrand cross-links interfere both with initiation of recombination and with the completion of heteroduplex formation.
Detection of primase specified by IncB plasmid R864a
Authors: Dalrymple B P , Williams P H
Published: June 2021

Plasmid R864a (IncB) contains nucleotide sequences homologous with the sog primase determinant of IncI alpha plasmid ColIb-P9. Extracts of Escherichia coli carrying a mutant R864a derepressed for transfer functions showed enhanced primase activity, and contained a large polypeptide identical in size (apparent Mr = 220,000) to the IncI alpha sog gene product.
Physical map of a plasmid from Caedibacter taeniospiralis 51
Authors: Quackenbush R L , Dilts J A , Maser R L
Published: June 2021

Caedibacter taeniospiralis 51 carries at least two plasmids, pKAP51 and pKAP52. The smaller plasmid, pKAP51, contains 43 kilobase pairs. The larger plasmid, pKAP52, contains more than 110 kilobase pairs. Relative positions of recognition sequences for seven different restriction endonucleases were determined, and a physical map of pKAP51, consisting of a total of 28 restriction sites, was constructed.
Interconversion of valine and leucine by Clostridium sporogenes
Authors: Monticello D J , Costilow R N
Published: June 2021

Clostridium sporogenes has been found to require L-leucine and L-valine for growth in a minimal medium, although valine can be replaced by isobutyrate and leucine by isovalerate. Cells grown in minimal media incorporated significant 14C from [14C]valine into leucine and from [14C]leucine into valine. Growth with [4,5-3H]leucine also resulted in the incorporation of 3H into valine. These results indicate that these bacteria can interconvert leucine and valine.
Analysis of hemolytic determinants of plasmid pHly185 by Tn5 mutagenesis
Authors: Stark J M , Shuster C W
Published: June 2021

A nonconjugative hemolysin plasmid, pHly185, was isolated from Escherichia coli 185. Tn5 mutagenesis produced nonhemolytic derivatives that either expressed no hemolytic activity or did not secrete activity. These Tn5 insertions were located in three contiguous EcoRI fragments. Insertions inactivating hemolysin structural gene(s) were identified on all three EcoRI fragments. Mutations affecting the secretory function were clustered in one portion of a single EcoRI fragment.
Mixed disulfides of acyl carrier protein and coenzyme A with specific soluble proteins in Escherichia coli
Authors: Rock C O
Published: June 2021

Three soluble proteins in Escherichia coli specifically from mixed disulfides with either acyl carrier protein or coenzyme A. Coenzyme A was attached to one of these proteins, and the amount bound depended on the cellular coenzyme A concentration. The other two proteins were mixed disulfides between acyl carrier protein and each of the two 3-ketoacyl-acyl carrier protein synthases.
Rescue of mitomycin C- or psoralen-inactivated Micrococcus radiodurans by additional exposure to radiation or alkylating agents
Authors: Hansen M T
Published: June 2021

The processing of damaged DNA was altered in a mitomycin C-sensitive mutant (mtcA) of Micrococcus radiodurans. Even though the mutant retained resistance to 254-nm UV radiation, it did not, in contrast to the wild-type strain, show any excessive DNA degradation or cell death when incubated with chloramphenicol after sublethal doses of either UV light or mitomycin C. The results suggest the constitutive synthesis of an enzyme system responsible for wild-type proficiency in the repair of mitomycin C-induced damage. An alternative system able to repair damage caused by mitomycin C was demonstrated in the mtcA background. In this strain, additional damage inflicted upon the cellular DNA effected a massive rescue of cells previously inactivated by mitomycin C. Rescue was provoked by ionizing radiation, by UV light, or by simple alkylating agents. Cells treated with psoralen plus near-UV radiation could be rescued only when inactivation was due primarily to psoralen-DNA interstrand cross-links rather than to monoadducts. The rescue of inactivated cells was prevented in the presence of chloramphenicol. These results can be interpreted most readily in terms of an alternative repair system able to overcome DNA interstrand cross-links produced by mitomycin C or psoralen plus near-UV light, but induced only by the more abundant number of damages produced by radiation or simple alkylating agents.
Identification of Neisseria gonorrhoeae from primary cultures by a slide agglutination test
Authors: Malysheff C , Wallace R , Ashton F E , Diena B B , Perry M B
Published: June 2021

Hen antigonococcal lipopolysaccharide hen serum was used in a simple slide agglutination test for the identification of Neisseria gonorrhoeae from primary isolates.
Search for Acinetobacter calcoaceticus subsp. anitratus: enrichment of fecal samples
Authors: Grehn M , von Graevenitz A
Published: June 2021

None of 50 healthy individuals and only 2 of 50 hospitalized patients (with Acinetobacter anitratus elsewhere) yielded A. anitratus on enrichment from fecal samples.
Double-label fluorescence immunoassay of bacteria
Authors: Gillis T P , Thompson J J
Published: June 2021

Fluorescence of sensitized bacterial suspensions, reactive with either fluorescein-labeled or rhodamine-labeled antiglobulins, could be quantitatively distinguished in dual-labeled preparations by fluorescence immunoassay.
Electron Capture Gas-Liquid Chromatographic Study of Metabolites Produced by Some Arthritic Transudate-Associated Organisms In Vitro and In Vivo in Rabbit Models
Authors: Brooks John B. , Melton A. Richard
Published: June 2021

Computerized, frequency-pulsed, modulated electron capture gas-liquid chromatography was used to study the acid metabolites produced in vitro in fetal calf serum and in vivo in an animal chamber model. Several strains of
Diplostreptococcus agalactiae, Propionibacterium acnes, Staphylococcus aureus
, and
Streptococcus
serogroups A, B, and G were studied. All of these organisms have been reported to be associated with arthritic transudates in humans. Metabolites were detected by this method from derivatized extracts of both spent fetal calf serum and chamber fluids. Since there was little host response to the organisms cultured in the chambers, it is highly probable that the products detected represent metabolites produced in an in vivo type of environment. The metabolic patterns were reproducible and exhibited many similarities in vitro and in vivo. Production of the acids detected was reproducible, and these acids were useful identification markers. The data support published reports (J. B. Brooks, C. C. Alley, and J. A. Liddle, Anal. Chem.
46:
1930-1934, 1974; J. B. Brooks, G. Choudhary, R. B. Craven, D. Edman, C. C. Alley, and J. A. Liddle, J. Clin. Microbiol.
5:
625-628, 1977; J. B. Brooks, R. B. Craven, A. R. Melton, and C. C. Alley,
in
H. H. Johnson and W. B. Newson, ed.,
Second International Symposium on Rapid Methods and Automation on Microbiology
, 1976; J. B. Brooks, R. B. Craven, D. Schlossberg, C. C. Alley, and F. M. Pitts, J. Clin. Microbiol.
8:
203-208, 1978; J. B. Brooks, D. S. Kellogg, C. C. Alley, H. B. Short, and H. H. Handsfield, J. Infect. Dis.
129:
660-668, 1974) that bacterial metabolites might be detectable in diseased body fluids. The growth characteristics of the organisms in the animal model and fetal calf serum are discussed, and a moderately priced computer for performing data manipulations is evaluated.
Metabolically deficient dwarf-colony mutants of Escherichia coli: deficiency and resistance to antibiotics of strains isolated from urine culture
Authors: Borderon E , Horodniceanu T
Published: June 2021

Sixteen metabolically deficient dwarf-colony mutants of Escherichia coli were isolated from urine culture and represented about 2% of all E. coli isolated during the same period. In 14 cases, mutants were isolated from debilitated patients: elderly persons or patients in the terminal stages of a chronic disease. In 15 of these subjects, deficient dwarf-colony mutants appeared to be the true cause of urinary tract infection, since there was leukocyturia and important bacteriuria, and organisms were obtained in pure culture. Study of metabolic deficiencies on Davis synthetic medium and nutritive agar resulted in the identification of eleven deficiencies in cysteine, two in thiamine, two in thymidine, and one in glutamine. Study of resistance to antibiotics revealed that nine were susceptible to all antibiotics, three were resistant to tetracycline alone, two were resistant to two antibiotics (chloramphenicol-tetracycline, streptomycin-tetracycline), and two were resistant to three antibiotics (ampicillin-chloramphenicol-tetracycline, ampicillin-streptomycin-tetracycline). Resistance was coded for by conjugative plasmids in five strains.
Rapid entry port for an anaerobic glove box
Authors: Gill V J , Tipton H W , Gersch S M
Published: June 2021

A rapid entry mechanism for an anaerobic glove box is described. The entry port is practical for entry or removal of one or two items and requires only seconds to operate. No deleterious effect on isolation or growth of anaerobes has been encountered since installation of the rapid entry port 3.5 years ago. Details for its construction are given.
One-Cell Metabolic Phenotyping and Sequencing of Soil Microbiome by Raman-Activated Gravity-Driven Encapsulation (RAGE)
Authors: Jing Xiaoyan , Gong Yanhai , Xu Teng , Meng Yu , Han Xiao , Su Xiaolu , Wang Jianmei , Ji Yuetong , Li Yuandong , Jia Zhongjun , Ma Bo , Xu Jian
Published: May 2021

Soil is home to an enormous and complex microbiome that features arguably the highest genomic diversity and metabolic heterogeneity of cells on Earth. Their
in situ
metabolic activities drive many natural processes of pivotal ecological significance or underlie industrial production of numerous valuable bioactivities.
Component Parts of Bacteriophage Virions Accurately Defined by a Machine-Learning Approach Built on Evolutionary Features
Authors: Thung Tze Y. , White Murray E. , Dai Wei , Wilksch Jonathan J. , Bamert Rebecca S. , Rocker Andrea , Stubenrauch Christopher J. , Williams Daniel , Huang Cheng , Schittelhelm Ralf , Barr Jeremy J. , Jameson Eleanor , McGowan Sheena , Zhang Yanju , Wang Jiawei , Dunstan Rhys A. , Lithgow Trevor
Published: May 2021

In response to the global problem of antimicrobial resistance, there are moves to use bacteriophages (phages) as therapeutic agents. Selecting which phages will be effective therapeutics relies on interpreting features contributing to shelf-life and applicability to diagnosed infections.
Use of the Lyapunov Functions for Calculating the Locally Optimal Control of a Thrust Vector during Low-Thrust Interorbital Transfer
Authors: Yelnikov R. V.
Published: May 2021

Abstract—

This paper presents a method for locally optimal control of the thrust vector of the electric propulsion system (EPS) for a spacecraft that performs a multiturn interorbital transfer from the initial elliptical orbit into a geostationary orbit (GSO). The control represents the time dependences of the angles that characterize the EPS thrust vector orientation in space. Here, it is assumed that the EPS is always on. The proposed control algorithm belongs to the class of feedback control algorithms and is based on using the Lyapunov functions. Numerical examples are presented, which characterize the operability of the proposed control technique. Considerable attention is paid to the comparison of given solutions with the optimal solutions obtained within the framework of the maximum principle formalism.
On an alternative quantization of R-NS strings
Authors: Yuki Tsubasa , Nakayama Yu
Published: June 2021

We investigate an alternative quantization of R-NS string theory. In the alternative quantization, we define the distinct vacuum for the left-moving mode and the right-moving mode by exchanging the role of creation operators and annihilation operators in the left-moving sector. The resulting string theory has only a finite number of propagating degrees of freedom. We show that an appropriate choice of the GSO projection makes the theory tachyon free. The spectrum coincides with the massless sector of type IIA or type IIB superstring theory without any massive excitations.
About this title - Characterization of Modern and Historical Seismic–Tsunamic Events, and Their Global–Societal Impacts
Authors: Dilek Y. , Ogawa Y. , Okubo Y.
Published: May 2021

Earthquakes and tsunamis are devastating geohazards with significant societal impacts. Most recent occurrences have shown that their impact on the stability of nations–societies and the world geopolitics is immense, potentially triggering a tipping point for a major downturn in the global economy. This Special Publication presents the most current information on the causes and effects of some of the modern and historical earthquake–tsunami events, and effective practices of risk assessment–disaster management, implemented by various governments, international organizations and intergovernmental agencies. Findings reported here show that the magnitude of human casualties and property loss resulting from earthquakes–tsunamis are highly variable around the globe, and that increased community, national and global resilience is significant to empower societal preparedness for such geohazards. It is clear that all stakeholders, including scientists, policymakers, governments, media and world organizations must work together to disseminate accurate, objective and timely information on geohazards, and to develop effective legislation for risk reduction and realistic hazard mitigation–management measures in our globally connected world of today.
Moving in the Cube
Authors: Raheb Katerina El , Stergiou Marina , Katifori Akrivi , Ioannidis Yannis
Published: May 2021

Labanotation is one of the most used systems for notating, analysing, and preserving movement and dance, an important part of Intangible Cultural Heritage. Labanotation consists of a powerful expressive symbolic language for documenting movement with a long history in dance research, history, and anthropology since its introduction by Rudolf von Laban in the beginning of the 20th century. A number of valuable scores in this language are curated in both physical and digital archives throughout the world, describing both traditional dances and works of historical choreographers. Nevertheless, while Labanotation is considered the official language of dance scholars, it is not at all popular among dance educators, students, practitioners, and choreographers. In fact, few people of the dance community are familiar with it. One of the reasons is that it is considered a quite difficult symbolic system with a long learning curve, and practitioners are not easily motivated to learn it. Together with dance experts, we co-designed a movement-based experience in Kinect, based on the principles of playful design, to introduce dance and non-dance experts to Labanotation introductory concepts and symbols. We evaluate the experience with both people that have experience in dance or other movement practices, as well as participants with no expertise in movement or dance. The results show promising findings toward changing the attitude of the participants toward Labanotation, and all participants seemed to memorize or start learning the logic of this symbolic language for movement. We discuss the results of the evaluation on the whole experience and the potential of this symbolic language in the digital environment, as well as the potential and challenges that arise from this experiment based on the background of the participants, the limitation of the applied technology and interaction, as well as feedback on the introduced symbolic language.
Design Space Exploration for Secure IoT Devices and Cyber-Physical Systems
Authors: Gressl Lukas , Steger Christian , Neffe Ulrich
Published: May 2021

With the advent of the Internet of Things (IoT) and Cyber-Physical Systems (CPS), embedded devices have been gaining importance in our daily lives, as well as industrial processes. Independent of their usage, be it within an IoT system or a CPS, embedded devices are always an attractive target for security attacks, mainly due to their continuous network availability and the importance of the data they handle. Thus, the design of such systems requires a thorough consideration of the various security constraints they are liable to. Introducing these security constraints, next to other requirements, such as power consumption, and performance increases the number of design choices a system designer must consider. As the various constraints are often conflicting with each other, designers face the complex task of balancing them. System designers facilitate Design Space Exploration (DSE) tools to support a system designer in this job. However, available DSE tools only offer a limited way of considering security constraints during the design process. In this article, we introduce a novel DSE framework, which allows the consideration of security constraints, in the form of attack scenarios, and attack mitigations in the form of security tasks. Based on the descriptions of the system’s functionality and architecture, possible attacks, and known mitigation techniques, the framework finds the optimal design for a secure IoT device or CPS. Our framework’s functionality and its benefits are shown based on the design of a secure sensor system.
On the Performance Comparisons of Native and Clientless Real-Time Screen-Sharing Technologies
Authors: Huang Chun-ying , Cheng Yun-chen , Huang Guan-zhang , Fan Ching-ling , Hsu Cheng-hsin
Published: May 2021

Real-time screen-sharing provides users with ubiquitous access to remote applications, such as computer games, movie players, and desktop applications (apps), anywhere and anytime. In this article, we study the performance of different screen-sharing technologies, which can be classified into native and clientless ones. The native ones dictate that users install special-purpose software, while the clientless ones directly run in web browsers. In particular, we conduct extensive experiments in three steps. First, we identify a suite of the most representative native and clientless screen-sharing technologies. Second, we propose a systematic measurement methodology for comparing screen-sharing technologies under diverse and dynamic network conditions using different performance metrics. Last, we conduct extensive experiments and perform in-depth analysis to quantify the performance gap between clientless and native screen-sharing technologies. We found that our WebRTC-based implementation achieves the best overall performance. More precisely, it consumes a maximum of 3 Mbps bandwidth while reaching a high decoding ratio and delivering good video quality. Moreover, it leads to a steadily high decoding ratio and video quality under dynamic network conditions. By presenting the very first rigorous comparisons of the native and clientless screen-sharing technologies, this article will stimulate more exciting studies on the emerging clientless screen-sharing technologies.
Rural Islandness as a Lens for (Rural) HCI
Authors: Robinson Sarah , Bidwell Nicola J. , Cibin Roberto , Linehan Conor , Maye Laura , Mccarthy John , Pantidi Nadia , Teli Maurizio
Published: May 2021

This article contributes to research that aims to better understand and describe the rural context for rural computing. We argue that the particularities of rurality are heightened by the experience of ‘islandness’. We report on our experiences of engaging on one small island as islanders established community radio using a novel platform. Data comes from 12 semi-structured interviews with community members and ethnographic field notes assembled through eight researcher visits to the island. Transcripts and notes were analysed using thematic analysis. We discuss how rural islandness as a socio-cultural lens influenced technology appropriation and factors to support participation. We explore the elements of rural islandness that can be used as an analytic tool for rural HCI and HCI more broadly, through three main contributions of rural islandness that we believe have not yet been sufficiently explored in HCI. These are (1) separateness, (2) pushing things ahead, and (3) publics and rural pluralities.
Playing Games with Tito
Authors: Løvlie Anders Sundnes , Ryding Karin , Spence Jocelyn , Rajkowska Paulina , Waern Annika , Wray Tim , Benford Steve , Preston William , Clare-Thorn Emily
Published: May 2021

This article brings together two distinct, but related perspectives on playful museum experiences: Critical play and hybrid design. The article explores the challenges involved in combining these two perspectives, through the design of two hybrid museum experiences that aimed to facilitate critical play with/in the collections of the Museum of Yugoslavia and the highly contested heritage they represent. Based on reflections from the design process as well as feedback from test users, we describe a series of challenges: Challenging the norms of visitor behaviour, challenging the role of the artefact, and challenging the curatorial authority. In conclusion, we outline some possible design strategies to address these challenges.
Critique on Natural Noise in Recommender Systems
Authors: Jurdi Wissam Al , Abdo Jacques Bou , Demerjian Jacques , Makhoul Abdallah
Published: May 2021

Recommender systems have been upgraded, tested, and applied in many, often incomparable ways. In attempts to diligently understand user behavior in certain environments, those systems have been frequently utilized in domains like e-commerce, e-learning, and tourism. Their increasing need and popularity have allowed the existence of numerous research paths on major issues like data sparsity, cold start, malicious noise, and natural noise, which immensely limit their performance. It is typical that the quality of the data that fuel those systems should be extremely reliable. Inconsistent user information in datasets can alter the performance of recommenders, albeit running advanced personalizing algorithms. The consequences of this can be costly as such systems are employed in abundant online businesses. Successfully managing these inconsistencies results in more personalized user experiences. In this article, the previous works conducted on natural noise management in recommender datasets are thoroughly analyzed. We adequately explore the ways in which the proposed methods measure improved performances and touch on the different natural noise management techniques and the attributes of the solutions. Additionally, we test the evaluation methods employed to assess the approaches and discuss several key gaps and other improvements the field should realize in the future. Our work considers the likelihood of a modern research branch on natural noise management and recommender assessment.
Living in a City, Living a Rural Life
Authors: Wang Yi
Published: May 2021

Rural-urban migrants (mingongs) provide crucial labor for China’s economic growth and global supply chains. Today, second generation mingongs who have spent most of their lives in cities have grown up. However, we know little about if their experiences with technologies are similar to their “urban-native” peers. This study reports on a qualitative study in a community in Beijing. We found a new type of “rurality”: second generation mingongs’ experiences with technologies differed from their urban-native peers in nearly every aspect, but exhibited similarities with their peers in rural areas. Taking nostalgia and memory as theoretical lenses, we demonstrate that such a “rurality” could be a coping mechanism for mingongs’ identity struggles. Our work contributed to HCI and CSCW literature by identifying the existence of a new type of “rurality.” That is, although residing in the city for nearly almost all of their lives, these second generation mingongs experiences greatly differed from their urban-native peers while exhibiting certain similarities with people living in rural areas.
On the Enumeration Complexity of Unions of Conjunctive Queries
Authors: Carmeli Nofar , Kröll Markus
Published: May 2021

We study the enumeration complexity of
Unions of Conjunctive Queries (UCQs)
. We aim to identify the UCQs that are tractable in the sense that the answer tuples can be enumerated with a linear preprocessing phase and a constant delay between every successive tuples. It has been established that, in the absence of self-joins and under conventional complexity assumptions, the CQs that admit such an evaluation are precisely the free-connex ones. A union of tractable CQs is always tractable. We generalize the notion of free-connexity from CQs to UCQs, thus showing that some unions containing intractable CQs are, in fact, tractable. Interestingly, some unions consisting of only intractable CQs are tractable too. We show how to use the techniques presented in this article also in settings where the database contains cardinality dependencies (including functional dependencies and key constraints) or when the UCQs contain disequalities. The question of finding a full characterization of the tractability of UCQs remains open. Nevertheless, we prove that, for several classes of queries, free-connexity fully captures the tractable UCQs.
Embedded Functional Dependencies and Data-completeness Tailored Database Design
Authors: Wei Ziheng , Link Sebastian
Published: May 2021

We establish a principled schema design framework for data with missing values. The framework is based on the new notion of an embedded functional dependency, which is independent of the interpretation of missing values, able to express completeness and integrity requirements on application data, and capable of capturing redundant data value occurrences that may cause problems with processing data that meets the requirements. We establish axiomatic, algorithmic, and logical foundations for reasoning about embedded functional dependencies. These foundations enable us to introduce generalizations of Boyce-Codd and Third normal forms that avoid processing difficulties of any application data, or minimize these difficulties across dependency-preserving decompositions, respectively. We show how to transform any given schema into application schemata that meet given completeness and integrity requirements, and the conditions of the generalized normal forms. Data over those application schemata are therefore fit for purpose by design. Extensive experiments with benchmark schemata and data illustrate the effectiveness of our framework for the acquisition of the constraints, the schema design process, and the performance of the schema designs in terms of updates and join queries.
Graph Indexing for Efficient Evaluation of Label-constrained Reachability Queries
Authors: Chen Yangjun , Singh Gagandeep
Published: May 2021

Given a directed edge labeled graphG, to check whether vertexvis reachable from vertexuunder a label setSis to know if there is a path fromutovwhose edge labels across the path are a subset ofS. Such a query is referred to as alabel-constrained reachability(LCR) query. In this article, we present a new approach to store a compressed transitive closure ofGin the form of intervals over spanning trees (forests). The basic idea is to associate each vertexvwith two sequences of some other vertices: one is used to check reachability fromvto any other vertex, by using intervals, while the other is used to check reachability tovfrom any other vertex. We will show that such sequences are in general much shorter than the number of vertices inG.Extensive experiments have been conducted, which demonstrates that our method is much better than all the previous methods for this problem in all the important aspects, including index construction times, index sizes, and query times.
∃ℝ-complete Decision Problems about (Symmetric) Nash Equilibria in (Symmetric) Multi-player Games
Authors: Bilò V. , Mavronicolas M.
Published: May 2021

A
decision problem
about
Nash equilibria
is concerned with whether a given game has a Nash equilibrium with certain natural properties. We settle the complexity of such decision problems over multi-player games, establishing that (nearly) all decision problems that were before shown
NP
-complete over 2-player games in References [5, 12, 18] become ∃ℝ-complete over multi-player games. ∃ℝ [27] is the class capturing the complexity of deciding the
Existential Theory of the Reals
. Specifically, we present a simple, unifying, parametric polynomial time reduction from the problem of deciding, given a 3-player (symmetric) game, whether there is a (symmetric) Nash equilibrium where all strategies played with non-zero probability come from a given set, which was shown ∃ℝ-complete in Reference [17]. By suitably working on the tuning parameters, our reduction delivers two extensive catalogs of ∃ℝ-complete decision problems in multi-player games. The first addresses Nash equilibria in general games, while the second encompasses symmetric Nash equilibria in symmetric games. These results resolve completely the main open problem from Reference [17] to enlarge the class of ∃ℝ-complete decision problems about (symmetric) Nash equilibria in multi-player (symmetric) games.
Exploring Button Designs for Mid-air Interaction in Virtual Reality: A Hexa-metric Evaluation of Key Representations and Multi-modal Cues
Authors: Bermejo Carlos , Lee Lik Hang , Chojecki Paul , Przewozny David , Hui Pan
Published: May 2021

The continued advancement in user interfaces comes to the era of virtual reality that requires a better understanding of how users will interact with 3D buttons in mid-air. Although virtual reality owns high levels of expressiveness and demonstrates the ability to simulate the daily objects in the physical environment, the most fundamental issue of designing virtual buttons is surprisingly ignored. To this end, this paper presents four variants of virtual buttons, considering two design dimensions of key representations and multi-modal cues (audio, visual, haptic). We conduct two multi-metric assessments to evaluate the four virtual variants and the baselines of physical variants. Our results indicate that the 3D-lookalike buttons help users with more refined and subtle mid-air interactions (i.e. lesser press depth) when haptic cues are available; while the users with 2D-lookalike buttons unintuitively achieve better keystroke performance than the 3D counterparts. We summarize the findings, and accordingly, suggest the design choices of virtual reality buttons among the two proposed design dimensions.
Bringing Things Closer: Enhancing Low-Vision Interaction Experience with Office Productivity Applications
Authors: Lee Hae-Na , Ashok Vikas , Ramakrishnan IV
Published: May 2021

Many people with low vision rely on screen-magnifier assistive technology to interact with productivity applications such as word processors, spreadsheets, and presentation software. Despite the importance of these applications, little is known about their usability with respect to low-vision screen-magnifier users. To fill this knowledge gap, we conducted a usability study with 10 low-vision participants having different eye conditions. In this study, we observed that most usability issues were predominantly due to high spatial separation between main edit area and command ribbons on the screen, as well as the wide span grid-layout of command ribbons; these two GUI aspects did not gel with the screen-magnifier interface due to lack of instantaneous WYSIWYG (What You See Is What You Get) feedback after applying commands, given that the participants could only view a portion of the screen at any time. Informed by the study findings, we developed MagPro, an augmentation to productivity applications, which significantly improves usability by not only bringing application commands as close as possible to the user's current viewport focus, but also enabling easy and straightforward exploration of these commands using simple mouse actions. A user study with nine participants revealed that MagPro significantly reduced the time and workload to do routine command-access tasks, compared to using the state-of-the-art screen magnifier.
Press-n-Paste: Copy-and-Paste Operations with Pressure-sensitive Caret Navigation for Miniaturized Surface in Mobile Augmented Reality
Authors: Lee Lik Hang , Zhu Yiming , Yau Yui-Pan , Hui Pan , Pirttikangas Susanna
Published: May 2021

Copy-and-paste operations are the most popular features on computing devices such as desktop computers, smartphones and tablets. However, the copy-and-paste operations are not sufficiently addressed on the Augmented Reality (AR) smartglasses designated for real-time interaction with texts in physical environments. This paper proposes two system solutions, namely Granularity Scrolling (GS) and Two Ends (TE), for the copy-and-paste operations on AR smartglasses. By leveraging a thumb-size button on a touch-sensitive and pressure-sensitive surface, both the multi-step solutions can capture the target texts through indirect manipulation and subsequently enables the copy-and-paste operations. Based on the system solutions, we implemented an experimental prototype named Press-n-Paste (PnP). After the eight-session evaluation capturing 1,296 copy-and-paste operations, 18 participants with GS and TE achieve the peak performance of 17,574 ms and 13,951 ms per copy-and-paste operation, with 93.21% and 98.15% accuracy rates respectively, which are as good as the commercial solutions using direct manipulation on touchscreen devices. The user footprints also show that PnP has a distinctive feature of miniaturized interaction area within 12.65 mm * 14.48 mm. PnP not only proves the feasibility of copy-and-paste operations with the flexibility of various granularities on AR smartglasses, but also gives significant implications to the design space of pressure widgets as well as the input design on smart wearables.
Reliability-aware Scheduling and Routing for Messages in Time-sensitive Networking
Authors: Zhou Yuanbin , Samii Soheil , Eles Petru , Peng Zebo
Published: May 2021

Time-sensitive Networking (TSN) on Ethernet is a promising communication technology in the automotive and industrial automation industries due to its real-time and high-bandwidth communication capabilities. Time-triggered scheduling and static routing are often adopted in these areas due to high requirements on predictability for safety-critical applications. Deadline-constrained routing and scheduling in TSN have been studied extensively in past research. However, scheduling and routing with reliability requirements in the context of transient faults are not yet studied. In this work, we propose an Satisfiability Modulo Theory-based technique to perform scheduling and routing that takes both reliability constraints and end-to-end deadline constraints into consideration. Heuristics have been applied to improve the scalability of the solution. Extensive experiments have been conducted to demonstrate the efficiency of our proposed technique.