Effects of nitrogen-deficiency on efficiency of light-harvesting apparatus in radish

Nitrogen starvation has been stated to reduce chlorophyll a and accessory pigments, decrease photosynthetic efficiency, as well as modify chloroplast thylakoid membranes. However, the impact of N-deficiency on light-dependent reactions of photosynthesis has not been well understood. In this study, efficiency and structure of light-harvesting complex under N-deficiency conditions were investigated in two radish cultivars (Raphanus sativus var. sativus 'Fluo HF1' and 'Suntella F1'). Light-dependent reactions of photosynthesis were investigated by measuring in vivo chlorophyll a prompt fluorescence signal. Acquired data were utilised in two ways: by plotting fast induction curves and calculating OJIP-test biophysical parameters. Detailed analysis of difference curves as well as OJIP-test results showed that major disturbances were associated with photosystem II and its subunits, including decoupling of light-harvesting complexes, dysfunction of oxygen-evolving complex, and reaction centres inactivation. The maximum quantum yield of photosystem II primary photochemistry was severely restricted, causing an inhibition in electron transport through successive protein complexes in the thylakoid membrane. Structural changes were demonstrated by recording images using Transmission Electron Microscopy (TEM). TEM investigations showed intensive starch accumulation under N-deficiency. Rare thylakoid stacks distributed in tiny layers of stroma around grains and chloroplast periphery were observed in cells of N-deficient plants. The application of principal component analysis (PCA) on OJIP-test results allowed characterizing the dynamics of stress response and separating parameters according to their influence on plants stress response. 'Suntella F1' genotype was found to be more sensitive to nitrogen deficiency as compared to 'Fluo HF1' genotype.

In situ measurements of the physical characteristics of Titan's environment

On the basis of previous ground-based and fly-by information, we knew that Titan's atmosphere was mainly nitrogen, with some methane, but its temperature and pressure profiles were poorly constrained because of uncertainties in the detailed composition. The extent of atmospheric electricity ('lightning') was also hitherto unknown. Here we report the temperature and density profiles, as determined by the Huygens Atmospheric Structure Instrument (HASI), from an altitude of 1,400 km down to the surface. In the upper part of the atmosphere, the temperature and density were both higher than expected. There is a lower ionospheric layer between 140 km and 40 km, with electrical conductivity peaking near 60 km. We may also have seen the signature of lightning. At the surface, the temperature was 93.65 +/- 0.25 K, and the pressure was 1,467 +/- 1 hPa.

[A case of coexistence of polycystic ovary syndrome and ovarian carcinoma]

There was a case of carcinoma of the ovary that coexisted with PCO syndrome in young, 25 years old woman. After clinical examination and USG doctors suspected PCO syndrome and hydrosalpings that is why the patient underwent an operation. In intraoperative histopathological examination bilateral adenocarcinoma were found. In prophylactic examination of patient's mother ovarian tumour was found that is also turned out to be an adenocarcinoma.

[The use of ultrasonographic studies in the early detection of ovarian tumors]

In this report the authors have analyzed and presented the results of his 7 years-long research focused on estimating the usefulness of ultrasonography in diagnosing adnexal pathology. Special attention was devoted to: 1. specifying location of change, establishing whether it covered one or two of the ovaries, 2. asserting the extend of change, 3. finding whether the tumor was well capsuled or not and whether the papillary projections were present and if so, establishing if they were endo- or egzofitic, 4. estimating its structure (cystic, solid, partly cystic partly solid) and establishing the presence of calcification, 5. evaluating metastases presence (in uterus, true pelvis, omentum, liver and the lymph nodes), 6 ascites assessment. There were 341 females who underwent examination before operation between 1991-1997 who were suspected of ovarian tumors and whose status was operationally verified. Results of this research were statistically analyzed. This analysis covered the calculating of mean and standard deviation, the frequency of special category presence and conducting evaluation of malignant tumors' presence frequency. On the basis of research results obtained and the statistical analyses performed, the following conclusions have been formulated: 1. Malignant tumors characistically co-exist more frequently with the following ultrasonographics traits: thick capsule of diversified thickness, with irregular outline, solid or partly solid partly cystic structure, unhomogenous internal echogenisity and multilocular character. 2. Ultrasonography is complementary to gynecological examination but allows for earlier detection of small and soft tumors.