An On-Line Cross-Sectional Questionnaire to Assess Knowledge of COVID-19 Pandemic among Citizens Tested for the SARS-CoV-2 Virus in Quito and Ibarra, Ecuador

Several public health measures have been implemented to contain the SARS-CoV-2 outbreak. The adherence to control measures is known to be influenced by people’s knowledge, attitudes and practices with regard to the disease. This study aimed at assessing COVID-19 knowledge in individuals who were tested for the virus. An online cross-sectional survey of 32 items, adapted to the national context, was conducted among 1656 Ecuadorians. The mean knowledge score was 22.5 ± 3 out of 28, with significant differences being observed with regard to educational attainment. People with postgraduate training scored higher than those with college, secondary and elementary instruction. Indeed, multiple linear regression revealed that lower scores were associated significantly with the latter three levels of education. Interviewees were knowledgeable about the symptoms, detection, transmission and prevention of the disease. However, they were less assertive regarding the characteristics of the virus as well as the usefulness of traditional and unproven treatments. These outcomes indicated a lack of knowledge in fundamental aspects of virus biology, which may limit the effectiveness of further prevention campaigns. Conclusively, educational and communicational programs must place emphasis on explaining the basic molecular characteristics of SARS-CoV-2; such information will certainly contribute to improve the public’s adherence to control measures.

College Students’ Reasons for Using JUULs

Purpose: To identify reasons that college students use JUUL and explore associations between reasons for using JUUL and social and behavioral (tobacco use) factors. Design: On-line, cross-sectional survey. Setting: Large southwestern university in the US. Subjects: Undergraduate students (n = 605) who owned JUUL and used it weekly. Measures: The study measured age of JUUL initiation, JUUL dependence, and use of other e-cigarettes and other tobacco products. Participants described reasons for JUUL use as brief open-ended responses. Analysis: Responses were categorized by 2 researchers using an inductive procedure. Logistic regressions examined associations between demographics and use frequency and categorized reasons for using JUUL. Results: Four reasons for using JUUL emerged: self-help (48.4%), social (30.4%), experience (42.8%), and substance use/addiction (42.3%). Daily JUUL users were 1.66 (95% CI: 1.05-2.63) times as likely to use JUUL for self-help than those who used JUUL 1-3 days/week. Those who had never tried a cigarette were twice (OR = 2.08; 95% CI: 1.22-3.54) as likely as cigarette-first users to use JUUL for social reasons. Males (OR = 1.87; 95% CI: 1.32-2.65) had higher odds of using JUUL for the experience than females, and JUUL and other e-cigarettes users were 4.37 (95% CI: 1.83-10.45) times as likely as JUUL-only users to use JUUL due to substance use/addiction. Conclusion: JUUL users report unique reasons for use (e.g., addiction) not previously reported for older models of e-cigarette devices.

Wideband Band-Pass Filter Design Using Coupled Line Cross-Shaped Resonator

In this paper, a wideband bandpass filter with a coupled line cross-shaped resonator (CLCSR) is proposed. The proposed bandpass filter is composed of two open-end parallel coupled lines, one short-end parallel coupled line, one branch microstrip line, and the parallel coupled line feed structure. With the use of the even and odd mode approach, the transmission zeros and transmission poles of the proposed bandpass filter are analyzed. The coupling coefficient of the parallel coupled line feed structure is big, so the distance between the parallel coupled line is too small to be processed. A three microstirp lines coupled structure is used to realize strong coupling and cross coupling. This structure also can reduce the return loss in passband and increase the out-of-band rejection. The transmission zeros can be adjusted easily by varying the lengths of the open-end parallel coupled line or the short-end parallel coupled line. The proposed bandpass filter is fabricated and measured. The simulated results agree well with the measured ones, which shows that the design method is valid.

Laboratory Experiment of Two-Degree-of-Freedom Vortex-Induced Vibrations of Circular Cylinder in Regular Waves

This paper presents new laboratory experiments of two-degree-of-freedom vortex-induced vibration of a flexibly mounted vertical circular cylinder in regular waves. A new experimental model has been developed and tested in the Wind, Wave & Current Tank at Newcastle University. The system mass ratio is close to 3 and the cylinder aspect ratio based on its submerged length is close to 27. The Stokes first-order wave theory is considered to describe the depth-dependent, horizontal velocity amplitude of the wave flow in the circulating water tank. This wave theory is satisfactorily validated by the wave probe measurement. The effects of cylinder stiffness affecting system natural frequencies are also investigated by using a combination of different spring setups in in-line and cross-flow directions. For each set of springs, VIV tests are performed in regular waves, with flow frequency ranging from 0.4 to 1 Hz and amplitude from 0.01 to 0.09 m. The associated Reynolds number at the water surface is in a range of 1.7 × 103–1.5 × 104. The surface Keulegan-Carpenter number (KC) is in the range of 2 < KC < 28 while the surface reduced velocity (Vr) is in the range of 0.5 < Vr < 16 depending on the implemented spring stiffness. Combined in-line/cross-flow oscillations of the cylinder are measured using two non-intrusive Qualisys cameras and the associated data acquisition system. The spring forces are also acquired using four load cells. Results reveal that, depending on KC and Vr, the cylinder primarily oscillates at the flow frequency in the in-line direction and at an integer (mainly 2, 3 and 4) multiple of the flow frequency in the cross-flow direction. Such occurrence of multi frequencies corroborates other experimental and numerical results in the literature. Several peculiar trajectories are observed, including infinity, butterfly, S and V shapes. The present experimental data of vibration amplitudes and oscillation frequencies in in-line/cross-flow directions as well as response patterns provide new results and improved understanding of VIV in oscillatory flows. These will be useful for the development of an industrial tool in predicting offshore structural responses in waves.

The March of the Beetles: Epistatic Components Dominate Divergence in Dispersal Tendency in Tribolium castaneum

The genetic underpinnings of traits are rarely simple. Most traits of interest are instead the product of multiple genes acting in concert to determine the phenotype. This is particularly true for behavioral traits, like dispersal. Our investigation focuses on the genetic architecture of dispersal tendency in the red flour beetle, Tribolium castaneum. We used artificial selection to generate lines with either high or low dispersal tendency. Our populations responded quickly in the first generations of selection and almost all replicates had higher dispersal tendency in males than in females. These selection lines were used to create a total of 6 additional lines: F1 and reciprocal F1, as well as 4 types of backcrosses. We estimated the composite genetic effects that contribute to divergence in dispersal tendency among lines using line cross-analysis. We found variation in the dispersal tendency of our lines was best explained by autosomal additive and 3 epistatic components. Our results indicate that dispersal tendency is heritable, but much of the divergence in our selection lines was due to epistatic effects. These results are consistent with other life-history traits that are predicted to maintain more epistatic variance than additive variance and highlight the potential for epistatic variation to act as an adaptive reserve that may become visible to selection when a population is subdivided.

Reflection-Like Maps in High-Dimensional Euclidean Space

In this paper, we introduce reflection-like maps in n-dimensional Euclidean spaces, which are affinely conjugated to θ : ( x 1 , x 2 , … , x n ) → 1 x 1 , x 2 x 1 , … , x n x 1 . We shall prove that reflection-like maps are line-to-line, cross ratios preserving on lines and quadrics preserving. The goal of this article was to consider the rigidity of line-to-line maps on the local domain of R n by using reflection-like maps. We mainly prove that a line-to-line map η on any convex domain satisfying η ∘ 2 = i d and fixing any points in a super-plane is a reflection or a reflection-like map. By considering the hyperbolic isometry in the Klein Model, we also prove that any line-to-line bijection f : D n ↦ D n is either an orthogonal transformation, or a composition of an orthogonal transformation and a reflection-like map, from which we can find that reflection-like maps are important elements and instruments to consider the rigidity of line-to-line maps.