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The Underutilization of Lifestyle Modifications in Primary Care Medicine
Jean-Marc Lucas(Jean-Marc Lucas ),Karl F. Kozlowski(Karl F. Kozlowski ) 사피엔시아 2019 Exercise Medicine Vol.3 No.-
Chronic disease accounts for the majority of deaths in the United States and is often attributed to obesity. A sedentary lifestyle and poor nutrition are primary contributing factors to the development of obesity and thus chronic disease. Primary care providers are optimally positioned to prescribe exercise and nutrition (lifestyle medicine) as a treatment for chronic disease. Unfortunately, this opportunity seems to be regularly lost. Primary care providers often rely too heavily on weight loss pharmaceuticals and bariatric surgeries to treat obesity. This treatment approach however also does little to prevent and treat the accumulation of chronic diseases. The purpose of this review was to evaluate the efficacy of conventional medical weight loss treatments and determine why primary care providers may not prescribe exercise and nutrition more frequently. Our findings suggest that some primary care providers may be uncomfortable prescribing lifestyle medicine as they receive little formal education in this field. In conclusion, prescription of exercise and nutrition by primary care providers may elicit greater long-term weight loss than current medical weight management practices. Medical management is most likely effective when combined with lifestyle medicine. We propose that primary care providers be better trained in lifestyle medicine through their formal and clinical education. Rates of chronic disease accumulation may potentially decrease if providers prescribe lifestyle medical treatments more frequently.
BERTRAND CURVES IN NON-FLAT 3-DIMENSIONAL (RIEMANNIAN OR LORENTZIAN) SPACE FORMS
Lucas, Pascual,Ortega-Yagues, Jose Antonio Korean Mathematical Society 2013 대한수학회보 Vol.50 No.4
Let $\mathbb{M}^3_q(c)$ denote the 3-dimensional space form of index $q=0,1$, and constant curvature $c{\neq}0$. A curve ${\alpha}$ immersed in $\mathbb{M}^3_q(c)$ is said to be a Bertrand curve if there exists another curve ${\beta}$ and a one-to-one correspondence between ${\alpha}$ and ${\beta}$ such that both curves have common principal normal geodesics at corresponding points. We obtain characterizations for both the cases of non-null curves and null curves. For non-null curves our theorem formally agrees with the classical one: non-null Bertrand curves in $\mathbb{M}^3_q(c)$ correspond with curves for which there exist two constants ${\lambda}{\neq}0$ and ${\mu}$ such that ${\lambda}{\kappa}+{\mu}{\tau}=1$, where ${\kappa}$ and ${\tau}$ stand for the curvature and torsion of the curve. As a consequence, non-null helices in $\mathbb{M}^3_q(c)$ are the only twisted curves in $\mathbb{M}^3_q(c)$ having infinite non-null Bertrand conjugate curves. In the case of null curves in the 3-dimensional Lorentzian space forms, we show that a null curve is a Bertrand curve if and only if it has non-zero constant second Frenet curvature. In the particular case where null curves are parametrized by the pseudo-arc length parameter, null helices are the only null Bertrand curves.
Lucas Rabelo Crunivnel,Gregorio Sandro Vieira,Juliano Geraldo Ribeiro Neto 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.6
Due to the wide variety of cross-sections and their good mass/strength ratio, cold-formed steel (CFS) components are gaining prominence among steel structures, although this material is more susceptible to local, distortional, and global buckling. The design procedure based on the direct strength method (DSM) presented in some codes as the Brazilian, the American Iron and Steel Institute, and the Australia/New Zealand (AS/NZ), have been well accepted for estimating simply and safely the moment capacity of beams subject to distortional buckling. However, more recent studies show that DSM design can lead to unsafe moment capacity for beams with a high slenderness factor of distortional buckling. This study analyzes the results from 64 models developed using the fi nite element analyses (FEA) with the Abaqus software to determine the distortional moment capacity of CFS rack type beams. The selection of the specimens in which the distortional buckling mode is predominant (modal participation analysis) was performed through a linear stability analysis using the GBTul software. The nonlinear elastoplastic fi nite element model was created, including initial imperfections, and a parametric study was developed to investigate the infl uence of the slenderness factor of distortional buckling on CFS rack beams' moment capacity. The FEA results were compared with DSM results to verify the accuracy of this method to predict distortional moment capacity. It is shown that, for CFS rack beams subject to uniform bending and distortional buckling with slenderness factor of distortional buckling higher than 1.0, the DSM overestimates the moment capacity.
Lucas Polo Fonseca 한국고분자학회 2023 Macromolecular Research Vol.31 No.3
Amphiphilic hyperbranched polyurethanes (HPUs) based on PEG and PCL are promising for several biomedical applications. However, the lack of control over the molar mass and composition hinders a deep understanding of the aqueous self-assembly of HPUs. In this paper, the control over the HPU molar mass and composition was provided by dynamic urea bond-mediated polymerization (DUBMP), enabling a careful evaluation of their aqueous self-assembly by 1H NMR, DLS, and Cryo-TEM. HPUs containing a single PCL block per chain self-assemble into nanoaggregates (Rh ≈ 10 nm) in water up to its cloud-point temperature (Tcp) of 34 °C. On the other hand, HPUs with more than one PCL block per chain self-assemble into nanoaggregates and their clusters below Tcp. In this case, the solution behavior can be tuned by the HPU molar mass. Increasing Mw from 4 to 19 kDa, HPUs of similar composition can form colloidally stable cluster suspensions (Mw = 4 kDa) and phase separate into a denser liquid aggregate–cluster phase (Mw = 7 kDa) or into a highly viscous aggregate-network phase (Mw = 19 kDa). This type of control over the hierarchical aggregation of HPUs was reported for the first time and is interesting for biomedical applications.
Lucas de Paula Lopes Rosado,Izabele Sales Barbosa,Sibele Nascimento de Aquino,Rafael Binato Junqueira,Francielle Silvestre Verner 대한영상치의학회 2019 Imaging Science in Dentistry Vol.49 No.3
Purpose: To compare the diagnostic ability of undergraduate dental students to detect maxillary sinus abnormalities in panoramic radiographs (PR) and cone-beam computed tomography (CBCT). Materials and Methods: This was a retrospective study based on the evaluation of PR and CBCT images. A pilot study was conducted to determine the number of students eligible to participate in the study. The images were evaluated by 2 students, and 280 maxillary sinuses were assessed using the following categories: normal, mucosal thickening, sinus polyp, antral pseudocyst, nonspecific opacification, periostitis, antrolith, and antrolith associated with mucosal thickening. The reference standard was established by the consensus of 2 oral radiologists based on the CBCT images. The kappa test, receiver operating characteristic curves, and 1-way analysis of variance with the Tukey-Kramer post-hoc test were employed. Results: Intraobserver and interobserver reliability showed agreement ranging from substantial (0.809) to almost perfect (0.922). The agreement between the students’ evaluations and the reference standard was reasonable (0.258) for PR and substantial (0.692) for CBCT. Comparisons of values of sensitivity, specificity, and accuracy showed that CBCT was significantly better (P<0.05). Conclusion: CBCT was better than PR for the detection of maxillary sinus abnormalities by dental students. However, CBCT should only be requested after a careful analysis of PR by students and more experienced professionals.
SLANT HELICES IN THE THREE-DIMENSIONAL SPHERE
Lucas, Pascual,Ortega-Yagues, Jose Antonio Korean Mathematical Society 2017 대한수학회지 Vol.54 No.4
A curve ${\gamma}$ immersed in the three-dimensional sphere ${\mathbb{S}}^3$ is said to be a slant helix if there exists a Killing vector field V(s) with constant length along ${\gamma}$ and such that the angle between V and the principal normal is constant along ${\gamma}$. In this paper we characterize slant helices in ${\mathbb{S}}^3$ by means of a differential equation in the curvature ${\kappa}$ and the torsion ${\tau}$ of the curve. We define a helix surface in ${\mathbb{S}}^3$ and give a method to construct any helix surface. This method is based on the Kitagawa representation of flat surfaces in ${\mathbb{S}}^3$. Finally, we obtain a geometric approach to the problem of solving natural equations for slant helices in the three-dimensional sphere. We prove that the slant helices in ${\mathbb{S}}^3$ are exactly the geodesics of helix surfaces.