1,230 research outputs found
Well-posedness for a class of nonlinear degenerate parabolic equations
In this paper we obtain well-posedness for a class of semilinear weakly
degenerate reaction-diffusion systems with Robin boundary conditions. This
result is obtained through a Gagliardo-Nirenberg interpolation inequality and
some embedding results for weighted Sobolev spaces
Multiplicative controllability for nonlinear degenerate parabolic equations between sign-changing states
In this paper we study the global approximate multiplicative controllability
for nonlinear degenerate parabolic Cauchy problems. In particular, we consider
a one-dimensional semilinear degenerate reaction-diffusion equation in
divergence form governed via the coefficient of the \-reaction term (bilinear
or multiplicative control). The above one-dimensional equation is degenerate
since the diffusion coefficient is positive on the interior of the spatial
domain and vanishes at the boundary points. Furthermore, two different kinds of
degenerate diffusion coefficient are distinguished and studied in this paper:
the weakly degenerate case, that is, if the reciprocal of the diffusion
coefficient is summable, and the strongly degenerate case, that is, if that
reciprocal isn't summable. In our main result we show that the above systems
can be steered from an initial continuous state that admits a finite number of
points of sign change to a target state with the same number of changes of sign
in the same order. Our method uses a recent technique introduced for uniformly
parabolic equations employing the shifting of the points of sign change by
making use of a finite sequence of initial-value pure diffusion pro\-blems. Our
interest in degenerate reaction-diffusion equations is motivated by the study
of some \-energy balance models in climatology (see, e.g., the Budyko-Sellers
model) and some models in population genetics (see, e.g., the Fleming-Viot
model).Comment: arXiv admin note: text overlap with arXiv:1510.0420
Exact controllability for quasi-linear perturbations of KdV
We prove that the KdV equation on the circle remains exactly controllable in
arbitrary time with localized control, for sufficiently small data, also in
presence of quasi-linear perturbations, namely nonlinearities containing up to
three space derivatives, having a Hamiltonian structure at the highest orders.
We use a procedure of reduction to constant coefficients up to order zero,
classical Ingham inequality and HUM method to prove the controllability of the
linearized operator. Then we prove and apply a modified version of the
Nash-Moser implicit function theorems by H\"ormander.Comment: 39 page
Well-posedness of 2D and 3D swimming models in incompressible fluids governed by Navier--Stokes equations
We introduce and investigate the wellposedness of two models describing the
self-propelled motion of a "small bio-mimetic swimmer" in the 2D and 3D
incompressible fluids modeled by the Navier-Stokes equations. It is assumed
that the swimmer's body consists of finitely many subsequently connected parts,
identified with the fluid they occupy, linked by the rotational and elastic
forces. The swimmer employs the change of its shape, inflicted by respective
explicit internal forces, as the means for self-propulsion in a surrounding
medium. Similar models were previously investigated in [15]-[19] where the
fluid was modeled by the liner nonstationary Stokes equations. Such models are
of interest in biological and engineering applications dealing with the study
and design of propulsion systems in fluids and air.Comment: 28 pages, 5 figures, Corresponding author: Alexandre Khapalov,
Department of Mathematics, Washington State University, USA (email:
[email protected]
TEACHING VOCABULARY BY USING PICTURES TO THE FIRST GRADE STUDENTS IN SDN DUWET 01 BAKI SUKOHARJO
ABSTRACT
Linggar Floridia. 2013 .Teaching Vocabulary by Using Pictures to The First
Grade Students In SDN Duwet 01 Baki Sukoharjo. English Diploma
Program, Faculty of Letters and Fine Arts, Sebelas Maret University.
This final project report was written based on the job training in SDN
Duwet 01 Baki Sukoharjo on February 4th to April 2nd2013. The objectives of this
report are to describe the process of teaching English vocabulary by using pictures
for the first grade students of SDN Duwet 01, to find out the problems of teaching
English vocabulary by using pictures and to provide the solution to the problems
of teaching English vocabulary by using pictures.
In the job training, I did some activities such as class observation and
made a lesson plan. I use the pictures as media to teach the vocabulary to the
students. The process of teaching vocabulary consists of building knowledge of
the field, modeling of the text, joint construction, independent construction and
closing.
There were some problems in teaching vocabulary by using pictures to the
first grade students in SDN Duwet 01 Baki. The problems were the size of
pictures, the difficulty in pronouncing and memorizing English words, and the
lack of teaching materials. The solution to solve the problems were giving clear
pictures, telling the instruction of the way to answer relate to the pictures and
bringing some pictures related to the topic. From the discussion in this final
project, the readers would know that using picture is necessary and effective for
teaching vocabularies especially to the first grade students of SDN Duwet 01 Baki
Sukoharjo
Backbone switch to abacavir/lamivudine fixed-dose combination: implications for antiretroviral therapy optimization
Current guidelines recommend treatment optimization in virologically suppressed patients through switching/ simplification strategies to minimize long-term toxicities and improve adherence. The assessment of inflammation/ coagulation profiles may support therapeutic decisions. We undertook a prospective, non-randomized study to evaluate the efficacy and safety of switching to ABC/3TC from ZDV/3TC or TDF/FTC backbones, in 40 HIV-1 infected patients with HIV-RNA levels 24 months). Main endpoints were viral load levels, CD4+ T cells and toxicities after 48 weeks. Serum inflammation/coagulation markers (ESR, CRP, D-dimer and fibrinogen) and pro-inflammatory cytokines (IL-6, TNF-α, adiponectin, resistin) were evaluated. Baseline characteristics were similar in the two arms, with significantly lower values of e-GFR in patients on TDF/FTC. Markers of inflammation/ coagulation and cytokine profile were also similar, except for higher values of resistin in patients on TDF/ FTC. During follow up, CD4+ T cells increased and viral load remained undetectable in both groups. Patient from ZDV/3TC had significantly greater changes in total cholesterol and serum creatinine. Markers of inflammation/ coagulation remained unchanged. Adiponectin significantly increased in patients from ZDV/3TC. Switching to ABC/3TC was effective and safe. Inflammatory markers remained low in both groups. Some changes in metabolic, kidney and cytokine profiles were apparently specific for baseline cART treatment
Recent records of spiders (Arachnida : Araneae) from Malta
Two spider species are recorded from Malta, one for the first time (Zora sp., Family Zoridae) and one for the second time (Aphantaulax cincta, Family Gnaphosidae). Observations and other information about the species together with photographs are provided.peer-reviewe
Usefulness of calcaneal quantitative ultrasound stiffness for the evaluation of bone health in HIV-1-infected subjects: Comparison with dual X-ray absorptiometry
Objectives: With the development of effective treatments and the resulting increase in life expectancy, bone mineral density (BMD) alteration has emerged as an important comorbidity in human immunodeficiency virus type-1 (HIV-1)-infected individuals. The potential contributors to the pathogenesis of osteopenia/osteoporosis include a higher prevalence of risk factors, combined antiretroviral therapy (cART)-exposure, HIV-1 itself and chronic immune activation/inflammation. Dual-energy X-ray absorptiometry (DXA) is the “gold standard” technique for assessing bone status in HIV-1 population. Methods: We conducted a cross-sectional study to investigate bone mineral status in a group of 158 HIV-1-infected subjects. The primary endpoint was the feasibility of calcaneal quantitative ultrasound (QUS) as a screening tool for BMD. All subjects were receiving stable cART and were virologically suppressed (HIV-RNA <37 copies/mL) from at least 12 months. Calcaneal QUS parameters were analyzed to obtain information on bone mass and microarchitecture. The results were compared with those obtained by DXA. Results: No correlations were found between DXA/QUS parameters and demographic or HIV-1-specific characteristics, also including cART strategies. In the univariate analyses BMD, QUS indexes, and Fracture Risk Assessment Tool scores conversely showed significant associations with one or more demographic or HIV-1-related variables. Moreover, a significant relationship between calcaneal quantitative ultrasound index/stiffness and femoral/lumbar BMD values from DXA was described. The multivariate analysis showed an independent association between calcaneal quantitative ultrasound index/stiffness and body mass index, higher CD4+T-cell numbers and low 25-OH D2/D3 vitamin D levels <10 ng/mL (P-values: 0.004, 0.016, and 0.015, respectively). Conclusion: As an alternative and/or integrative examination to DXA, calcaneal QUS could be proposed as a useful screening in HIV-1-infected patients for assessing bone health impairment. In fact, the results obtained confirm that calcaneal QUS may be useful for monitoring bone status, being a noninvasive and inexpensive technique, especially in those subjects with the classical traditional risk factors for bone damage that were observed earlier in HIV-1 population
Interior degenerate/singular parabolic equations in nondivergence form: well-posedness and Carleman estimates
We consider non smooth general degenerate/singular parabolic equations in non
divergence form with degeneracy and singularity occurring in the interior of
the spatial domain, in presence of Dirichlet or Neumann boundary conditions. In
particular, we consider well posedness of the problem and then we prove
Carleman estimates for the associated adjoint problem.Comment: Accepted in Journal of Differential Equations. arXiv admin note: text
overlap with arXiv:1507.0778
- …
