A simple mass oscillator metasurface design with linear phase shift

In this paper, a simple mass oscillator metasurface is designed, which can regulate the phase shift of flexural wave covering 0-2π by adjusting the number of mass oscillators on the connecting bar. Based on the forced vibration theory, there is a simple approximately linear relationship between the number and phase shift of mass oscillators, which can more intuitively and accurately predict the phase of different number of mass oscillators, and then realize the metasurface design of mass oscillators with different requirements. Therefore, arbitrary regulation of flexural waves, such as abnormal refraction, beam focusing, and self-acceleration, can be realized by reasonably arranging the number of mass oscillators. The results show that the proposed metasurface can be greatly simplified both in the establishment of phase shift relation and in the fabrication of structure configuration, and will have broad application potential in the engineering field.

Heritability of distichiasis in Havanese dogs in Norway

Background Distichiasis is a presumed inherited eyelid disease, characterized by misplaced eyelashes. The effect on eye health and animal welfare varies between individuals; most mild cases show no clinical signs, but some affected animals develop painful corneal disease. In this study, we investigated the prevalence and heritability of distichiasis in the Norwegian population of Havanese dogs. Results A total of 1156 Havanese were included in the study. Out of these, 168 were affected with distichiasis, making the prevalence in our sample 14.5% (95% CI 12.5–16.6%). There was no sex predisposition. Most affected individuals were graded “mildly affected”. The estimates generally showed high heritabilities, which varied between 0.276 (linear model) and 0.720 (Bayesian threshold model). The linear estimates, after conversion to the underlying scale (h2l = 0.664–0.674), corresponds well to the results of the Bayesian models. Conclusions The estimated heritability of distichiasis in Havanese is high and the prevalence is moderate. The high heritability indicate that a significant selection response could be obtained by simple mass selection. To secure good animal welfare, it’s important to control the number of affected individuals and especially the severely affected.

Polar Quasinormal Modes of Neutron Stars in Massive Scalar-Tensor Theories

We study polar quasinormal modes of relativistic stars in scalar-tensor theories, where we include a massive gravitational scalar field and employ the standard Brans-Dicke coupling function. For the potential of the scalar field we consider a simple mass term as well as a potential associated with R2 gravity. The presence of the scalar field makes the spectrum of quasinormal modes much richer than the spectrum in General Relativity. We here investigate radial modes (l = 0) and quadrupole modes (l = 2). The general relativistic l = 0 normal modes turn into quasinormal modes in scalar-tensor theories, that are able to propagate outside of the stars. In addition to the pressure-led modes new scalar-led ϕ-modes arise. We analyze the dependence of the quasinormal mode frequencies and decay times on the scalar field mass.

Searching for the Optimal Arrangement of Mistuned Blades Based on Solving the Traveling Salesman Problem for Simple Mass-Spring Linear System

The article presents an approach to finding the optimal arrangement of blades in a bladed disk based on solving the traveling salesman problem using the ant colony algorithm. The solution to the problem is presented for an equivalent model of the bladed disk. The mistuning parameters are assumed as known — for example, from the data of geometric measurements for each blade from the set used for assembling the bladed disk — considering the influence of the rotation on the investigated resonance mode. Approaches have already been published for the construction of equivalent models and the use of combinatorial optimization methods, including solving the traveling salesman problem, to find the optimal arrangement of the blades. Therefore, this article focuses on demonstrating a simple program implementation of this method. This approach allows a quick assessment of the effect of the blade assembly in the bladed disk on the amplitudes of alternating stresses. It even considers several restarts of the algorithm to determine other possible configurations of the system.

Observed impact of meso-scale vertical motion on cloudiness

We use estimates of meso-scale vertical velocity and co-located cloud measurements from the second Next-Generation Aircraft Remote Sensing for Validation campaign (NARVAL2) in the tropical North Atlantic to show the observed impact of meso-scale vertical motion on tropical clouds. Our results not only confirm previously untested hypotheses about the role of dynamics being non-negligible in determining cloudiness, but go further to show that at the meso-scale, the dynamics has a more dominant control on cloudiness variability than thermodynamics. A simple mass-flux estimate reveals that meso-scale vertical velocity at the sub-cloud layer top explains much of the variations in peak shallow cumulus cloud fraction. In contrast, we find that thermodynamic cloud-controlling factors, such as humidity and stability, are unable to explain the variations in cloudiness at the meso-scale. Thus, capturing the observed variability of cloudiness may require not only a consideration of thermodynamic factors, but also dynamic ones such as the meso-scale vertical velocity.

Generation and Enforcement of Process-Driven Manufacturability Constraints: A Survey of Methods and Perspectives for Product Design

Design-for-manufacturing (DFM) concepts have traditionally focused on design simplification; this is highly effective for relatively simple, mass-produced products, but tends to be too restrictive for more complex designs. Effort in recent decades has focused on creating methods for generating and imposing specific, process-derived technical manufacturability constraints for some common problems. This paper presents an overview of the problem and its design implications, a discussion of the nature of the manufacturability constraints, and a survey of the existing approaches and methods for generating/enforcing the minimally-restrictive manufacturability constraints within several design domains. Five major design perspectives or viewpoints were included in the study, including the system design (top-down), product/component design (bottom-up), the manufacturing process-dominant case (product/component design under a specific process), the part-redesign perspective, and sustainability perspective. Manufacturability constraints within four design levels or scales were explored as well, ranging from macro-scale to sub-micro-scale design. Very little previous work was found in many areas, but it is clear from the existing literature that the problem and a general solution to it are very important to explore further in future DFM efforts.

A PROSPECTIVE COMPARATIVE STUDY BETWEEN EARLY AND INTERVAL APPENDICECTOMY FOR APPENDICULAR MASS

Acute appendicitis remains the most common cause of acute abdomen requiring surgical intervention. Patients presenting late in acute appendicitis are complicated by the development of an inammatory mass in the right iliac fossa. The treatment of appendicular mass is controversial. However, 1 there are several other management options for appendicular mass. Traditionally, these patients are managed conservatively, followed by interval appendicectomy 4-6 weeks later. Advocates of the initial conservative approach claim a lower rate of complications compared to the early 2 operative approach. Objective: To study the safety and feasibility of emergency appendicectomy for appendicular mass by comparing the complications, morbidity and mortality with conservatively treated patients. Materials & Methods: This is a prospective and comparative study conducted at Gitam Institute of Medical Sciences and Research, Visakhapatnam, from January 2018 to December 2019. A total of 60 patients with appendicular mass were divided into two groups of 30 each. Group I included patients who underwent emergency appendicectomy, while Group II consisted of patients who were managed conservatively. Results:In this study, patients' mean age was 27.58 yrs with a male to female ratio of 2.66:1. Intraoperative ndings in Group I - 20(70%) cases had simple mass, 8(26.66%) had adhesions and loculated pus in 2(6%). In Group II, 14(53.84%) patients had normal ndings, 4(15.38%) cases had simple mass, 6(23%) had adhesions, 1(3.84%) had loculated pus and adhesive intestinal obstruction. Postoperatively, In Group I, 3(10%) patients had wound infection, and 1(3.33%) patient developed fecal stula, which was managed conservatively. In Group II, 2(6.66) patients had wound infection, 4(13.33%) had failure of conservative treatment, four had lost follow-up, 3 had respiratory tract infection, and one patient developed intestinal obstruction due to adhesions. Mean length of hospital stay was 5.3 days in Group I and 8.5 days in Group II. Fewer complications, reduced number of days of parenteral medication, and reduced duration of total hospital stay were noted in Group I compared to Group II, indicating that emergency appendicectomy is a safe and feasible method of managing patients with appendicular mass.

A large accessory protein interactome is rewired across environments

To characterize how protein-protein interaction (PPI) networks change, we quantified the relative PPI abundance of 1.6 million protein pairs in the yeast Saccharomyces cerevisiae across nine growth conditions, with replication, for a total of 44 million measurements. Our multi-condition screen identified 13,764 pairwise PPIs, a threefold increase over PPIs identified in one condition. A few ‘immutable’ PPIs are present across all conditions, while most ‘mutable’ PPIs are rarely observed. Immutable PPIs aggregate into highly connected ‘core’ network modules, with most network remodeling occurring within a loosely connected ‘accessory’ module. Mutable PPIs are less likely to co-express, co-localize, and be explained by simple mass action kinetics, and more likely to contain proteins with intrinsically disordered regions, implying that environment-dependent association and binding is critical to cellular adaptation. Our results show that protein interactomes are larger than previously thought and contain highly dynamic regions that reorganize to drive or respond to cellular changes.