Contraction Type Research Articles

Families of pointed toric varieties and degenerations

The Losev–Manin moduli space parametrizes pointed chains of projective lines. In this paper we study a possible generalization to families of pointed degenerate toric varieties. Geometric properties of these families, such as flatness and reducedness of the fibers, are explored via a combinatorial characterization. We show that such families are described by a specific type of polytope fibration which generalizes the twisted Cayley sums, originally introduced to characterize elementary extremal contractions of fiber type associated to projective {mathbb {Q}}-factorial toric varieties with positive dual defect. The case of a one-dimensional simplex can be viewed as an alternative construction of the permutohedra.

EndoFLIP Topography: Motor Patterns in an Obstructed Esophagus

EndoFLIP Topography: Motor Patterns in an Obstructed Esophagus

Fixed Points of Proinov Type Multivalued Mappings on Quasimetric Spaces

In this paper, we obtain new results which have not been encountered before in the literature, in multivalued quasimetric spaces, inspired by Proinov type contractions. We use admissible function as proving theorems. We also give an example that supports our theorems.

Commonα-Fuzzy Fixed Point Results for Kannan Type Contractions with Application

The purpose of this paper is to utilize complex valued extendedb-metric space and obtain commonα-fuzzy fixed point theorems under Kannan type contractions. As application, we derive commonα-fixed point results for multivalued mappings in the context of complex valued extendedb-metric space.

Unification of common fixed point in C *-algebra valued metric spaces

In the present article, we prove some common fixed point results for two pairs of weakly compatible mappings satisfying certain type of contraction using E.A. and CLR property in C*-algebra valued metric spaces. To support the results some illustrations are provided. The proved results extend and generalize some of the results in the literature.

On Certain Quadruple Fixed Points of Integral Type Contraction Mappings in G-Metric Spaces and its Applications

In this paper, the existence of common quadruple fixed point results for integral type contraction of two mappings in G-metric spaces is established. Some interesting consequences of our results are achieved. Moreover, we give an illustration that presents the applicability of the achieved results.

Surface electromyography for evaluating patients with oromandibular dystonia

ABSTRACT Objective To investigate myoelectric signals of dystonic activities in oromandibular dystonia (OMD) subjects using surface electromyography (EMG). Methods Twelve OMD subjects were included in this study. Resting myoelectric activities of the superficial masseter, anterior temporalis, and anterior belly of the digastric muscle on both sides were monitored, and dystonic muscle contractions were recorded using surface EMG. Myoelectric signal amplitude, the type of muscle contraction, and contraction rate for phasic activities were evaluated. Results Surface EMG revealed that eight subjects had dystonic muscle activities in the phasic contraction pattern, three subjects had a tonic contraction pattern, and one subject had a mixed pattern. Synchronous contraction of dystonic muscles was frequently observed. Many of the monitored muscles showed high resting amplitudes. Conclusion Surface EMG detects abnormal muscle activities related to oromandibular dystonia. Surface EMG can serve as an objective method for diagnosing oromandibular dystonia.

Fuzzy Fixed Point Results in Convex C ∗ -Algebra-Valued Metric Spaces

The purpose of this note is to come up with some new directions in fuzzy fixed point theory. To this effect, notions of a C ∗ -algebra-valued fuzzy λ -contraction and related concepts in a convex C ∗ -algebra-valued metric space ( C ∗ -AVMS) are set-up. In line with the view of a Hausdorff distance function, an idea of a distance between two approximate quantities is proposed. Consequently, two fixed point results of a C ∗ -algebra-valued fuzzy mapping ( C ∗ -AVFM) for the new type of contractions are established using Mann and Ishikawa iterative schemes. For some future investigations of our results, two open problems are noted concerning sufficient criteria guaranteeing the existence of fixed points of a C ∗ -algebra-valued fuzzy λ -contraction and whether or not the Picard iteration for a C ∗ -algebra-valued fuzzy λ -contraction converges.

Fixed Point Results for a New Rational Contraction in Double Controlled Metric-like Spaces

In this paper, we present a new type of rational contraction in double controlled metric-like spaces and improve recent results of such spaces. Moreover, there is an example to verify the correctness of our results. Finally, we also obtain some new fixed point results, which can be derive directly from our main theorem.

Fast and ballistic contractions involve greater neuromuscular power production in older adults during resistance exercise

PurposeNeuromuscular power is critical for healthy ageing. Conventional older adult resistance training (RT) guidelines typically recommend lifting slowly (2-s; CONV), whereas fast/explosive contractions performed either non-ballistically (FAST-NB) or ballistically (FAST-B, attempting to throw the load) may involve greater acute power production, and could ultimately provide a greater chronic power adaptation stimulus. To compare the neuromechanics (power, force, velocity, and muscle activation) of different types of concentric isoinertial RT contractions in older adults.MethodsTwelve active older adult males completed three sessions, each randomly assigned to one type of concentric contraction (CONV or FAST-NB or FAST-B). Each session involved lifting a range of loads (20–80%1RM) using an instrumented isoinertial leg press dynamometer that measured power, force, and velocity. Muscle activation was assessed with surface electromyography (sEMG).ResultsPeak and mean power were markedly different, according to the concentric contraction explosive intent FAST-B > FAST-NB > CONV, with FAST-B producing substantially more power (+ 49 to 1172%, P ≤ 0.023), force (+ 10 to 136%, P < 0.05) and velocity (+ 55 to 483%, P ≤ 0.025) than CONV and FAST-NB contractions. Knee and hip extensor sEMG were typically higher during FAST-B than CON (all P < 0.02) and FAST-NB (≤ 50%1RM, P ≤ 0.001).ConclusionsFAST-B contractions produced markedly greater power, force, velocity and muscle activation across a range of loads than both CONV or FAST-NB and could provide a more potent RT stimulus for the chronic development of older adult power.

Genetic deletion of IL-6 increases CK-MB, a classic cardiac damage marker, and decreases UPRmt genes after exhaustive exercise.

The intensity, duration, type of contraction, and muscle damage influence interleukin-6 (IL-6) response to acute exercise. However, in response to an exhaustive exercise session, the upregulation of IL-6 in the serum and heart is associated with an inflammatory condition and can inhibit autophagy. This study aimed to investigate the role of IL-6 in autophagy pathway responses and mitochondrial function in the heart of mice submitted to acute exhaustive physical exercise. The mice were allocated into three groups, five animals per group, for the wild type (WT) and the IL-6 knockout (IL-6 KO): Basal (sedentary; Basal), 1 h (after 1 h of the acute exercise; 1 h), and 3 h (after 3 h of the acute exercise; 3 h). After the specific time for each group, the blood was collected, each mouse heart was removed, and the left ventricle (LV) was isolated. In summary, under basal conditions, without the influence of the acute exercise, the IL-6 KO group showed lower number of nuclei in the cardiac tissue, but higher collagen deposition; lower messenger RNA(mRNA) levels of Prkaa1 and Mtco1, but higher mRNA levels of Ulk1; and higher protein levels of the ratio p-AMPK/AMPK in the heart when compared to WT at the same time point. After the acute exercise (1and 3 h), the IL-6 KO group had lower mRNA levels of Tfam, Mtnd1, Mtco1, and Nampt in the heart when compared to WT after exercise; higher serum levels of creatine kinase(CK), CK-MB, and lactate dehydrogenase for the IL-6 group when compared to the WT group after the exercise. Specifically, the heat-shock protein 60protein levels in the heart increased 3 h after exhaustive exercise in the WT group, but not in the IL-6 KO group. The study emphasizes that IL-6 may offer cardioprotective effects, including mitochondrial adaptations in response to acute exhaustive exercise.

Diffusion tensor imaging (DTI) of human lower leg muscles: correlation between DTI parameters and muscle power with different ankle positions

PurposeTo compare diffusion tensor imaging (DTI) parameters in healthy adult human lower leg muscles and to determine the correlation between DTI parameters and muscle power measurements among different types of muscle contraction.Materials and methodsDTI measurements of the unilateral lower leg muscles having three different types of contraction (non-contraction state, isometric contraction, and soleus shortening) were obtained from 10 healthy adults using a 3-T MRI scanner. DTI parameters (λ1, λ2, λ3, mean diffusivity, and fractional anisotropy) were calculated. The values of the DTI parameters and correlation between the DTI parameters and muscle power measurements (maximum power and maximum amount of work) obtained from a dynamometer were statistically compared among the different types of contraction. Intra- and inter-class correlation coefficients were calculated for analysis of reproducibility.ResultsThe λ1, λ2, λ3, and mean diffusivity of the soleus muscle are significantly lower in the non-contraction state as compared with isometric contraction and soleus shortening (p < 0.05). A positive correlation of the soleus muscle in the non-contraction state was seen between the maximum power and the λ1, λ2, and mean diffusivity. There was a positive correlation between the maximum amount of work and fractional anisotropy in the non-contraction state for the soleus muscle. A negative correlation for the tibialis anterior muscle in the non-contraction state was seen between the maximum amount of work and fractional anisotropy. Overall reproducibility of the DTI parameters was excellent.ConclusionsDTI parameters were significantly changed depending on the ankle joint position and type of muscle contraction.

Introducing Web in a Telephone Employee Survey: Effects on Nonresponse and Costs

Abstract Policy decisions in business and economic fields are often informed by surveys of employees. Many employee surveys use costly interviewer-administered modes to reach this special population. However, certain employee subgroups may be especially hard to reach using these modes. Thus, besides high administration costs, nonresponse bias is a concern. To reduce costs and potential nonresponse bias, some employee surveys have introduced web as part of a sequential mixed-mode design. However, the impact of introducing web on response rates, nonresponse bias, and costs in employee surveys is understudied. The present study addresses this research gap by analyzing a mode design experiment in which employees selected for a national survey in Germany were randomly assigned to a single-mode telephone design or a sequential web-telephone mixed-mode design. The study revealed four main findings. First, introducing the web mode significantly increased the response rate compared to the single-mode design. Second, despite the higher response rate, aggregate nonresponse bias was higher in the mixed-mode design than in the single-mode design. Third, the likelihood of web participation varied across certain employee subgroups, including occupation type and employment contract. Lastly, potential cost savings were evident under the mixed-mode design.

Temporal evolution of scour at bridge abutments in compound channels

Bridge abutment-induced sediment scour in compound river channels is time-sensitive during floods, and, thus, estimating the scour rate has significance in design. In the current study, large-scale laboratory experiments were done to examine the influence of multiple factors on scour evolution, including channel geometry, bed mobility (clear-water or live-bed), and lateral (embankment intrusion) and vertical (deck submergence) flow contractions. A new method is applied for scour measurement and determination of characteristic scour trends. Results show that the non-dimensional time scale is related to flow intensity and may peak before reaching the clear-water scour threshold; the corresponding equations also are derived. It is found that the use of scour countermeasures has a significant impact on the scour rate, and the existing equations for unprotected abutments have limitations. Under clear-water conditions, the scour rate is closely related to the overall flow contraction, which can be better reflected by the ratio of the approaching unit discharge to that at the bridge section. Specifically, the effect of vertical flow contraction on scour rate is more dominant than other factors. Two scour rate curves are derived to suit different structural and flow contraction types for clear-water scour. In contrast, the live-bed scour rate data are generally consistent and fall in a narrow band, showing less dependence on other factors. Finally, a new design approach is established to estimate the time scale and scour rate using the new equations proposed in this paper.

New Fixed Point Theorems for Admissible Hybrid Maps

The aim of this work is to investigate the concept of a new hybrid Suzuki contractive by using the Rus-Reich-Ćirić-type interpolative mappings in b -metric spaces. We seek the presence and uniqueness of a fixed point of such new contraction type mappings and prove some related results. We further give an application of Ulam-Hyers-type stability to show the well-posedness of our results.

The relationship between driving distance and different types of contraction in core muscles in Korea elite female golfers.

This study compared and examined the relationship between the concentric, eccentric, and isometric muscular contraction measurements that are commonly used to assess trunk strength and power, and the driving distance in elite female golfers. The purpose of this study was to utilize as a basis to evaluate the driving distance-related physical training program design and its efficacy. Eighteen female golfers from A club in Gyeonggi province are recruited. The driving distance, medicine ball throwing, isokinetic trunk flexor, and extensor strength and power, and isometric strength in the 3D electromagnetic motion analysis system were assessed. The statistical analysis adopted the Students' t-test to adjust the different units in each assessment method, and then interrelation and correlation analysis between the driving distance was conducted. The result of this study is as the following: the medicine ball throwing, isokinetic trunk extensor power, isometric trunk flexor, and extensor strength, and left and right flexor and rotator strength showed high correlation with the driving distance. In the comparison between strength factors, isokinetic trunk extensor strength had a high correlation (R2=0.452), while the medicine ball throw and isokinetic trunk extensor power were reported a higher correlation in order (R2=0.740). In the overall comparison analysis, the isometric trunk left rotation, and isometric trunk extensor had an R2 value of 0.893. Consequently, the isometric trunk rotational strength and extensor strength had the highest correlation with the driving distance. This result can be used to design the physical fitness program for golfers.

Virus inactivation on common indoor contract fabrics

Background: During the COVID-19 pandemic, office workers were displaced from their places of employment. This situation caused a heightened interest in understanding viral disease transmission in indoor spaces including offices. Although data has been published on the survival of various coronaviruses including SARS-CoV-2 on a variety of surfaces, most related to impermeable materials common to healthcare environments. Methods: We studied two typical contract fabrics (polyester and wool) and cotton for HCoV-OC43 (ATCC #VR-1558) persistence up to 24 h using a modified ISO 18184 test protocol. Results: We found that HCoV-OC43 was undetectable after 12 h on cotton fabric, 24 h on polyester fabric, and was reduced by 93 +/− 6% within 24 h on wool fabric compared to an inoculum-only control. Differences in droplet-fabric contact angles were observed for the three fabrics, and absorption correlated with virus inactivation. Conclusions: Polyester and wool exhibit virus-inactivating properties similar to cotton, although the degree of inactivation is different between the three materials. Liquid absorption is likely a key factor involved in the inactivation process. When the results are extrapolated to real-world environmental temperature and relative humidity conditions, commonly used fabrics in interior offices spaces are determined as unlikely sources of human coronavirus transmission.

AUTOMATIZATION OF INTERNATIONAL LAW IN THE FOURTH INDUSTRIAL REVOLUTION THROUGH SMART LEGAL CONTRACTS

Purpose – Smart contracts minimise transaction costs and boost efficiency. Smart contracts are costly, single-use, and inefficient. This study proposes a smart contract mechanism to address these issues. Design/methodology/approach – This study examines smart contract research history, models, and platforms to highlight their flaws. Based on typical contract content, a smart contracts model is built. Findings – This paper describes smart contract operation using several models. Decomposing smart contracts into sub-contracts facilitates global implementation. Then, smart contract benefits and deployment strategies are examined. Here's an illustration of how smart contracts will affect our lives. Originality/value – Smart contract is expanding. This article describes smart contract structure and functioning. Keywords: AI, 4th IR, Applicability, international law, Smart contracts.

Existence of α L -Fuzzy Fixed Points of L-Fuzzy Mappings

In this research article, fixed point theory is beautifully combined with fuzzy set theory. Two fuzzy fixed point theorems of L-fuzzy mappings are established and proved for two different contractive type conditions in the scenario of complete b-metric space. In order to give the strength of these results, nontrivial supportive examples for both results are also provided. The notion of L-fuzzy mappings is a generalized form of fuzzy mappings as well as multivalued mappings. In this approach, our results provide uniqueness, extension, and successive generalizations of many valuable recent and conventional results existing in the literature.

Some remarks on \u03b1-admissibility in S-metric spaces

The concept of α-admissible mapping introduced by Samet et al. (Nonlinear Anal. 75:2154–2165, 2012) has various generalizations. In this paper, we introduce the concept of alpha _{s}-admissible mapping and its various forms by generalizing the concept of α-admissible mapping in the setting of S-metric spaces. Further, we also introduce generalized rational alpha _{s}-Geraghty contraction type mappings and study the existence of fixed point theorems in S-metric spaces. Examples are also given to verify the main results.