Epidemiology of breast cancer in women based on diagnosis data from oncologists and senologists in Algeria

BACKGROUND

Breast cancer (BC) is a major health issue threatening women's life. No reliable epidemiological data on BC diagnosed by oncologists/senologists are available in Algeria.

METHODS

The BreCaReAl study, a non-interventional prospective cohort study, included adult women with confirmed BC in Algeria. Disease incidence, patients and disease characteristics, treatment patterns, and mortality rate were recorded up to 12 months of follow-up.

RESULTS

Overall, 1,437 patients were analysed: median age was 48 [41;57] years and 337 (23.5%) women had a family history of BC. BC incidence was 22.3 (95% CI: 21.5; 23.2) cases per 100,000 inhabitants over 8 months. Delayed diagnosis was reported in 400 (29.2%) patients. First line of treatments were mainly chemotherapy and surgery. Twenty-eight serious adverse events were reported including 10 (37.0%) events which led to death. Mortality rate reached 3.2% at 12 months CONCLUSION: A delayed diagnosis highlights the importance of implementing more effective screening strategies.

Electromagnetic instability in plasmas heated by a laser field

Electromagnetic instability is investigated in homogeneous plasmas heated by a laser wave in the range α=v_{0}^{2}/v_{t}^{2}≤2, where v_{0} is the electron quiver velocity and v_{t} is the thermal velocity. The anisotropic electron distribution function that drives unstable quasistatic electromagnetic modes is calculated numerically with the Vlasov-Landau equation in the high ion charge number approximation. A dispersion relation of electromagnetic waves which accounts for further nonlinear terms on v_{0}^{2} from previous results is derived. In typical simulation with ion charge number Z=13, a temperature T=5keV, a density n=9.8×10^{20}cm^{-3}, and a laser wavelength λ_{laser}=1.06μm, growth rates larger than 10^{12}s^{-1} in the quasicollisionless wave-number range were found for α≥1. In the same physical conditions and in the mildly collisional range a growth rate about 10^{11}s^{-1} was also obtained. The extent of the growth wave-number region increases significantly with increasing α.

Anisotropic electron-distribution function in inverse-bremsstrahlung-heated plasmas

The electron-distribution function in homogeneous plasmas heated by a high-frequency laser field is calculated in velocity space from the Vlasov-Landau equation. The kinetic model is valid for moderate laser intensity defined by the relevant parameter α=v_{0}^{2}/v_{t}^{2}<0.5 where v_{0} and v_{t} are the peak velocity of oscillation in the high-frequency electric field and the thermal velocity, respectively. The results obtained constitute an improvement of the results reported in the literature devoted to weak electric field intensities. The electron-distribution function is calculated solving the kinetic equation with the use of the Legendre polynomial expansion within the laser field dipole approximation. It results in an infinite set of equations for the isotropic component f_{0}(v) and the anisotropic components f_{n≥1}(v) that we have solved numerically with appropriate truncation. For the second anisotropy f_{2}(v), we found that its maximum increases from the weak electric field intensity (α<0.01) to a moderate one (α=0.5) by a factor f_{2max}(α=0.5)/f_{2max}(α=0.01)≈48. Applications to the radiation pressure, electromagnetic instabilities, and photoabsorption are also considered.

Time-dependent closure relations for relativistic collisionless fluid equations

Linear fluid equations for relativistic and collisionless plasmas are derived. Closure relations for the fluid equations are analytically computed from the relativistic Vlasov equation in the Fourier space (ω,k), where ω and k are the conjugate variables of time t and space x variables, respectively. The mathematical method used is based on the projection operator techniques and the continued fraction mathematical tools. The generalized heat flux and stress tensor are calculated for arbitrary parameter ω/kc where c is the speed of light, and for arbitrary relativistic parameter z=mc²/T , where m is the particle rest mass and T, the plasma temperature in energy units.

Linear transport equations valid for arbitrary collisionality: comparison with the Chapman-Enskog expansion

Recently we proposed a method to solve the perturbed Boltzmann equation modeled by the Bhatnagar-Gross-Krook operator [Phys. Rev. E 74, 041204 (2006)]. In this work we use this method to derive linear transport equations in the whole collisionality range. A comparison of the closure relations derived up to the third order in the Knudsen number (super-Burnett) yields the same results as the Chapman-Enskog expansion. The contribution of the projection operators to the transport is investigated. It is pointed out that their contributions are not negligible in the super-Burnett equations and very significant in the collisionless range. The test of stability of the super-Burnett equations is also performed. It is shown that the stability problem can be related to the positivity of the generalized transport coefficients. Using the Padé approximants, nonlocal transport coefficients are proposed which present the desirable stability properties.

Local-field-correction effects on the electron response functions and on the electrical conductivity in a hydrogen plasma

In a one-component plasma constituted by electrons with a uniform positive background, the correlations are studied in the framework of the Singwi, Tosi, Land, and Sjölander (STLS) model. The local-field corrections (LFCs) are calculated with electron density ranging from 10;{19}to10;{26}cm;{-3} and with a temperature of 10;{4}K . Then, a dielectric formalism is used to deduce the potential energy of a positive test charge (a proton) imbedded in the electron medium. A significant departure of this potential from the random phase approximation (RPA) one has been found. In particular, as the density increases, the discrepancy between the two potentials grows up to reach a maximum correlated to the maximum of the electron coupling parameter. In addition, it is found that in both high and low density limits, the STLS and RPA approaches yield similar results. On the other hand, the effect of the LFC on the electrical conductivity is also estimated in hydrogen plasmas.

Generalized linear transport theory in dilute neutral gases and dispersion relation of sound waves

The transport processes in dilute neutral gases are studied by using the kinetic equation with a collision relaxation model that meets all conservation requirements. The kinetic equation is solved keeping the whole anisotropic part of the distribution function with the use of the continued fractions. The conservative laws of the collision operator are taken into account with the projection operator techniques. The generalized heat flux and stress tensor are calculated in the linear approximation, as functions of the lower moments, i.e., the density, the flow velocity and the temperature. The results obtained are valid for arbitrary collision frequency nu with the respect to kv(t) and the characteristic frequency omega, where k(-1) is the characteristic length scale of the system and v(t) is the thermal velocity. The transport coefficients constitute accurate closure relations for the generalized hydrodynamic equations. An application to the dispersion and the attenuation of sound waves in the whole collisionality regime is presented. The results obtained are in very good agreement with the experimental data.

[Factors associated with neonatal, infant and child mortality. Results of a national survey in Algeria]

BACKGROUND

The immediate medical causes of childhood death in developing countries are low birthweight, inadequate nutrition and serious infectious diseases. This report describes the main diseases causing infant mortality in Algeria.

POPULATION AND METHODS

1% of Algerian household was investigated in December 1989 in a cross-sectional single-interview survey. Sampling was simple random stratified based on the population dispersion, with a second degree cluster for district and household. Questionnaires included 6 data on the deaths: birthdate, day of death, sex, associated factors, diagnosis of the mother, and diagnosis of the survey team.

RESULTS

32,945 births were registered between 1985 and 1989. There were 1,608 deaths. The main factors linked to these deaths were acute diarrhea (18.4%), acute respiratory diseases (13.8%), premature birth (11.6%). Premature birth was the main factor (31.9%) linked to mortality before the age of 1 month. Factors linked to mortality were not influenced by sex but were influenced by population dispersion. The mortality rate and the factors linked to it remained unchanged between 1985 and 1989.

CONCLUSIONS

These results will help target the national program to reduce infant mortality.

The sella turcica in Sheehan's syndrome: computerized tomographic study in 54 patients

A CT scan study of the sella turcica and its contents was conducted in patients with Sheehan's syndrome with a search for correlation between the radiological data and the degree of endocrine insufficiency on one hand, and the time course of the disease on the other. Fifty-four patients with Sheehan's syndrome were included: 32 with complete anterior hypopituitarism, 22 with at least one spared pituitary function. Subgroups of equal size were obtained with a cut-off of 9 years evolution. The CT scan appearance of the pituitary was never normal in Sheehan's syndrome. The sella turcica was totally empty in 39 patients. A pituitary remnant was visible in 15 patients, more frequently in those with incomplete hypopituitarism (p less than 0.005) and those with short evolution (p less than 0.025). The size of this pituitary residue never exceeded one third of the normal pituitary gland. The pituitary stalk was always visualized. On the other hand, the size of the fossa was significantly (p less than 0.001) smaller in the patients, as compared to a 12-female control group, matched for age and number of pregnancies. Among the patients there was no difference when considering the disease duration nor the degree of hypopituitarism. An empty or partially empty sella of normal or reduced size is a constant feature of Sheehan's syndrome. The presence of a pituitary remnant is inversely correlated to the duration and extension of the disease. Arachnoid herniation alone does not induce a dilatation of the fossa.

[X-ray computed tomography of hydatid cyst of the liver: symptomatology and classification. Apropos of 157 cases including 146 surgically confirmed]

Computed tomography (CT) and in most cases ultrasonography imaging was carried out in 157 patients with suspected hydatid cyst of liver (HCL), and the diagnosis was confirmed on operation in 146 cases. Findings enabled enrichment of CT semiology, proposals for a classification of HCL and precision concerning the value of CT for diagnosis of this affection. The CT scan was observed to provide data on the lesions and to establish the diagnosis of HCL in almost all patients (only one false positive in the 146 cases operated upon). It appeared to be a more reliable method than other exploratory examinations, particularly ultrasonography, in a good number of cases. The indications for CT are defined and the place of this examination in overall investigatory procedures discussed.