Residual effects of natural Zn chelates on navy bean response, Zn leaching and soil status

greenhouse experiment was conducted on weakly acidic and calcareous soils to evaluate the aging and residual effects of three natural organic Zn chelates [Zn-ethylenediaminedisuccinate (Zn-EDDS), Zn-polyhydroxyphenylcarboxylate and Zn-aminelignosulfonate] each administered in a single application to a first navy bean (Phaseolus vulgaris L.) crop at several different Zn application rates. In a second navy bean crop, we determined the following parameters: the extent of Zn leaching, the amount of available Zn remaining in soils, the amount of easily leachable Zn, the size of Zn fractions in soils, the pH and redox potential, the dry matter yield, and the soluble and total Zn concentrations in plants. The residual effect after 2 years of Zn fertilization mainly depended on the aging effect of Zn chelates and losses due to Zn leaching. The data relating to the evolution from the first to the second crop showed that the aging effect was noticeable in the calcareous soil. In the latter soil, the Zn-S,S-EDDS treatments showed greater decreases in the Zn uptake by plants than the other Zn treatments and the greatest Zn uptake by plants occurred when Zn was applied as Zn-aminelignosulfonate (10 mg Zn kg−1 rate, 6.85 mg Zn per lysimeter; 5 mg Zn kg−1 rate, 3.36 mg Zn per lysimeter). In contrast, in the calcareous soil, the maximum amount of Zn uptake, for the three chelates was 0.82 mg Zn per lysimeter. Consequently, a further application of Zn would be needed to prevent Zn deficiencies in the plants of a subsequent crop. The behaviour of the pH and Eh parameters in the soils and leachates did not depend on the natural Zn sources applied. In this study, the easily leachable Zn estimated by BaCl2 extraction was not adequate to predict Zn leaching from the soils in subsequent crops

Intracranial chondroma arising from the cranial vault: CT and MR appearance

A case of intracranial chondroma arising from the right parietal bone in a 37-year-old woman is presented. CT and MRI findings as well as the differential diagnosis of the lesion are discussed

Compensatory Intracranial Arterial Dilatation in Extracranial Carotid Atherosclerosis: The Northern Manhattan Study

BACKGROUND: There is a scarcity of data supporting the association between atherosclerosis and dolichoectasia (DE) in unbiased samples. AIMS: To test the hypothesis that the association between DE and extracranial carotid atherosclerosis depends on the degree of collateral circulation. METHODS: The Northern Manhattan Study MRI substudy consists of 1290 participants who remained stroke-free at the time of MRI. Arterial diameters were collected in all participants with available MRA. Dolichoectasia was defined as a head-size adjusted diameter > 2 SD for each artery. Carotid Doppler was used to evaluate for carotid atherosclerosis (carotid plaque, maximum plaque thickness [MCPT] and intima media thickness [cIMT]). RESULTS: We included 994 participants with available Doppler and MRA data (mean age 63 years, 60% female). Any DE was reported in 16% of participants, 54% had at least one carotid plaque and the mean cIMT was 0.92 ± 0.09 mm. After adjusting for demographic and clinical characteristics, there was no association between markers of carotid atherosclerosis and DE. However, stratifying by collaterals, it was observed that DE was more likely in the anterior and posterior circulations when collaterals were available among participants with carotid atherosclerosis. These associations were confirmed by noting an increment in arterial diameters in the corresponding arteries ipsilateral and contralateral to each carotid as well as in the posterior circulation. CONCLUSIONS: We did not find an association of extracranial carotid atherosclerosis with DE. However, we found that DE is more frequent when intracranial collaterals are available suggesting a compensatory process that needs further investigation