Factors affecting the biodiversity of historical landscape elements: detailed analyses from three case studies in Slovakia.

A direct, positive correlation between biodiversity and the traditional agricultural landscape is evident on the national or regional scale. It is mostly conditioned by higher landscape diversity and less intensive farming. We have carried out research on a detailed scale at plot level (productive plots of arable lands, grasslands, vineyards, orchards, and unproductive agrarian landforms (mostly field margins) such as terraced slopes, terraced steps, heaps, mounds, and unconsolidated walls) in three traditional agricultural landscapes: the mountain village Liptovská Teplicka, the vineyard landscape in Svätý Jur, and dispersed settlements in a submontane area in Hrinová. We determined the statistical significance of the impact of the selected landscape ecological factors (a set of factors concerning land use and management, agrarian landforms and relief properties) on the distribution of vegetation and selected invertebrate groups (spiders, millipedes, grasshoppers, and crickets). We also explored whether maintaining traditional land use and traditional management helped to enhance the biodiversity. We found that the management regime is the most important factor determining the species composition of vascular plants and all studied animal groups. Also, present land use and agrarian landforms character (type, skeleton content, continuity) are significant factors. Our expectation of a positive relationship between biodiversity and the maintaining traditional land use and traditional management was, in general, not confirmed: such a relation was only found in Svätý Jur for biodiversity of spiders.

Diagnostic confidence and image quality of CT pulmonary angiography at 100 kVp in overweight and obese patients.

AIM: To compare image quality and diagnostic confidence of 100 kVp CT pulmonary angiography (CTPA) in patients with body weights (BWs) below and above 100kg. MATERIALS AND METHODS: The present retrospective study comprised 216 patients (BWs of 75-99kg, 114 patients; 100-125kg, 88 patients; >125kg, 14 patients), who received 100 kVp CTPA to exclude pulmonary embolism. The attenuation was measured and the contrast-to-noise ratio (CNR) was calculated in the pulmonary trunk. Size-specific dose estimates (SSDEs) were evaluated. Three blinded radiologists rated subjective image quality and diagnostic confidence. Results between the BW groups and between three body mass index (BMI) groups (BMI <25kg/m(2), BMI = 25-29.9kg/m(2), and BMI ≥30kg/m(2), i.e., normal weight, overweight, and obese patients) were compared using the Kruskal-Wallis test. RESULTS: Vessel attenuation was higher and SDDE was lower in the 75-99kg group than at higher BWs (p-values between <0.001 and 0.03), with no difference between the 100-125 and >125kg groups (p = 0.892 and 1). Subjective image quality and diagnostic confidence were not different among the BW groups (p = 0.225 and 1). CNR was lower (p < 0.006) in obese patients than in normal weight or overweight subjects. Diagnostic confidence was not different in the BMI groups (p = 0.105). CONCLUSION: CTPA at 100 kVp tube voltage can be used in patients weighing up to 125kg with no significant deterioration of subjective image quality and confidence. The applicability of 100 kVp in the 125-150kg BW range needs further testing in larger collectives.

First-principles atomistic study of surfaces of Fe-rich Fe-Cr.

The surface properties of Fe-rich ferromagnetic Fe-Cr alloys are investigated using a first-principles quantum-mechanical method. In dilute alloys, the surfaces are dominated by Fe, whereas the Cr-containing surfaces become favorable when the bulk Cr concentration exceeds the limit of ∼ 10 atomic per cent. The abrupt change in the surface behavior is the consequence of complex competing magneto-chemical interactions between the alloying atoms. Considering the quantities of various features: equilibrium surface profiles, chemical potentials, segregation energies, surface energies, magnetic moments, mixing energies and pair interactions, within a wider range of bulk and surface concentrations enables us to build a comprehensive picture of the physics of Fe-Cr surfaces. Using the present achievements many previously controversial results can now be merged into a consistent model of Fe-rich Fe-Cr alloys.

Compressive surface stress in magnetic transition metals.

Because of the increased electron density within the surface layer, metal surfaces are generally expected to have tensile surface stress. Here, using first-principles density functional calculations, we demonstrate that in magnetic 3d metals surface magnetism can alter this commonly accepted picture. We find that the thermodynamically stable surfaces of chromium and manganese possess compressive surface stress. The revealed negative surface stress is shown to be ascribed to the enhanced magnetic moments within the surface layer relative to the bulk values.

Surface relaxation and stress for 5d transition metals.

Using the density functional theory, we present a systematic theoretical study of the layer relaxation and surface stress of 5d transition metals. Our calculations predict layer contractions for all surfaces, except for the (111) surface of face centered cubic Pt and Au, where slight expansions are obtained similarly to the case of the 4d series. We also find that the relaxations of the close packed surfaces decrease with increasing occupation number through the 5d series. The surface stress for the relaxed, most closely packed surfaces shows similar atomic number dependence as the surface energy. Using Cammarata's model and our calculated surface stress and surface energy values, we examine the possibility of surface reconstructions, which is in reasonable agreement with the experimental observations.

Anomalous bismuth-stabilized (2x1) reconstructions on GaAs(100) and InP(100) surfaces.

First-principles phase diagrams of bismuth-stabilized GaAs- and InP(100) surfaces demonstrate for the first time the presence of anomalous (2x1) reconstructions, which disobey the common electron counting principle. Combining these theoretical results with our scanning-tunneling-microscopy and photoemission measurements, we identify novel (2x1) surface structures, which are composed of symmetric Bi-Bi and asymmetric mixed Bi-As and Bi-P dimers, and find that they are stabilized by stress relief and pseudogap formation.

Assessment of hydraulic restoration of San Pablo Marsh, California.

Inter-tidal marshes are dynamic diverse ecosystems at the transition zone between terrestrial and ocean environments. Geomorphologically, inter-tidal salt marshes are vegetated land-forms at elevations slightly greater than mean tidal levels that have distributed channels formed under ebb (drainage) tidal flows that widen and deepen in the seaward direction. The drainage channels enable tidal flows to circulate sediments and nutrients through the marsh system during normal tidal events, while depositing sediments during storm or seismic events. This dynamic system encourages considerable biodiversity while simultaneously providing water quality enhancement features that service marsh terrestrial life and marine life in the estuary. Reservoir creation limiting sediment transport, anticipated large increases in sea levels as well as agricultural and urban development have resulted in significant loss of inter-tidal marshes and subsequent adverse impacts on waterfowl, infauna and fisheries. The complex and continuously changing marsh channel hydraulics and sedimentary processes have severely constrained quantitative modeling of these marsh systems such that restoration/creation efforts remain something of an empirical science and further assessments are needed. The purpose of this paper is to outline current understanding of salt marsh hydrodynamics, sediment accretion processes and subsequent response of marsh vegetation to set the stage for assessment of a marsh restoration effort along San Pablo Bay near San Francisco, California. Several kilometers of drainage channels were constructed in a 624 ha disturbed salt marsh to restore tidal circulation and vegetation so as to enhance habitat for threatened species (e.g. clapper rail, harvest mouse, delta smelt and potentially anadromous fish species). Two distinct drainage channel systems ('east' and 'west') were installed having similar channel dimensions common to salt marshes in the region, but having design bankfull tidal prism volumes differing by a factor of two. Following channel excavation, main channel tidal flows and sediment loads as well as marsh sediment accretion rates were monitored to assess the relative success of the excavation in restoring tidal circulation and vegetation (Salicornia spp.) to the marsh. Annual aerial surveys corroborated with ground-truthing indicated that marsh vegetation rapidly expanded, from 40 to 85% coverage several years following excavation. The 'east' channel intake was nearly completely silted in within three years. However, channel surveys and flow measurements indicated that the 'east' channel system tidal prism was only about 1200 m3, more than an order of magnitude less than that of the stable 'west' channel system. Marsh sediment accretion rates were on the order of 7-8 mm yr(-1), a rate common to the Pacific coast region that exceeds estimated sea level rise rates of approximately 2 mm yr(-1). East channel network siltation resulted in storm and spring tidal flood ponding such that marsh vegetation coverage decreased to 51% of the marsh area and related habitat expansion decreased. These results are considered in terms of the primary inter-tidal marsh factors affecting possible restoration/creation strategies.

Acetazolamide as a vasodilatory stimulus in cerebrovascular diseases and in conditions affecting the cerebral vasculature.

Pathologic processes affecting the brain vessels may damage cerebral vasodilatory capacity. Early detection of cerebral dysfunction plays an important role in the prevention of cerebrovascular diseases. In recent decades acetazolamide (AZ) has frequently been used for this purpose. In the present work the mechanism of action and the previous studies are reviewed. The authors conclude that AZ tests are useful in cerebrovascular research. Further investigations are recommended to prove how impaired reserve capacity and reactivity influence the stroke risk in patients and whether these tests may indicate therapeutic interventions.

Is every sharply defined, symmetrical, necrotic-demyelinating lesion in the corpus callosum an actual manifestation of Marchiafava-Bignami disease?

Neuroimaging of a 75-year-old lady demonstrated the characteristic pathological features of the Marchiafava-Bignami disease (MBD), which develops usually in chronic alcoholics. The onset of the neurological symptoms and signs were abrupt and similar to those seen in common ischemic vascular lesions. Our patient denied that she had consumed alcoholic beverage during her life. Laboratory results showed her liver enzymes were not elevated and a subsequent abdominal ultrasound examination revealed no liver pathology. The attack responded fairly well to anti-ischemic therapy and a complete recovery was observed within a week. In this sense, her pathology cannot be considered as a true MBD in spite of the presence of the CT and MRI findings of MBD. Our case seems to show that the CT and MRI findings in MBD are not specific because new imaging procedures reveal edematous, necrotic lesions that may have the appearance of MBD.

Parametrization of perovskite structures: an ab initio study.

An overview of the pressure, temperature and chemical composition dependence of the lattice distortion in orthorhombic ABO(3) perovskite structures is presented. Within the framework of the so-called global parametrization method (GPM) [Thomas (1998). Acta Cryst. B54, 585--599] an improved description for the position of the A cation in terms of the AO(12) and BO(6) polyhedral volume ratio is proposed. The relationship is derived from an extensive ab initio study based on the density functional theory. The applicability of the improved GPM in combination with ab initio total energy calculations in the prediction of changes in the structural distortion under increasing hydrostatic pressure is investigated. Test calculations are performed for the geophysically important magnesium silicate perovskite and the results are compared with the available theoretical and experimental data.

Lack of gender difference in acetazolamide-induced cerebral vasomotor reactivity in patients suffering from type-1 diabetes mellitus.

The aim of the present work was to investigate the impact of gender on resting cerebral blood flow velocity and cerebrovascular reserve capacity among diabetic patients. Middle cerebral artery mean blood flow velocity (MCAV) was measured in 72 patients suffering from type 1 diabetes mellitus at rest and 5, 10, 15 and 20 min after intravenous administration of 1 g acetazolamide. Cerebrovascular reserve was calculated as the maximal percent increase in MCAV after acetazolamide. Resting MCAV and cerebrovascular reserve capacity were compared between males and females. Resting cerebral blood flow velocity was higher in diabetic females than in males (men, 55.0+/-17.0 cm/s; women, 64.4+/-12.6 cm/s, p=0.0094). Cerebrovascular reserve capacity was similar in diabetic women and men (men, 44.0%+/-18.6%; women, 52.6%+/-32.9%, p=0.17). Comparing MCAV and cerebrovascular reserve capacity among the diabetic subgroups with disease duration < or = 10 years and >10 years, we did not detect any differences between women and men. Duration of diabetes was an important factor in determining cerebrovascular reserve capacity in both sexes: long-term diabetic women and men showed lower CRC values than diabetics with < or = 10 years disease duration. Cerebrovascular reserve capacity is similar in diabetic women and men. Taking into consideration that cerebrovascular reserve is normally higher among women, our finding indicates a relatively more serious worsening of cerebral vasodilatory responses in women suffering from type 1 diabetes.

A novel method of macropathologic and arteriographic examination of carotid specimens obtained from autopsy.

Twenty carotid bifurcations were examined. During autopsy, carotid bifurcations were removed in toto. Unfixed carotids were ligated and cannulated for injection of an angiographic contrast medium followed by injection of a tissue-embedding medium at physiologic pressure and temperature. The carotid bifurcation was frozen and cut manually in 3-mm cross-sections. Photographs were then taken of every slice. Angiography, filling with tissue-embedding material, and sectioning were successful in all cases. In the macropathologic sections, the extent, configuration and location of atherosclerotic lesions could be identified.

[Immunohistologic determination of extracellular matrix components in granuloma annulare]. / Imunohistologické stanovenie zloziek extracelulárnej matrix u granuloma anulare.

BACKGROUND: The histological diagnosis of granuloma annulare is based on assessment of a palisade-like granuloma and necrobiosis. The authors attempt to make a more accurate diagnosis of the disease based on immunohistological assessment of components of the extracellular matrix. METHODS AND RESULTS: In a group of 15 patients with granuloma annulare the authors assessed, using the immunoperoxidase method, collagens type I, III and V and fibronectin. An increased amount of collagens type III and V was found within the palisade-like granuloma and its neighbourhood resp. In the area of the necrobiosis the findings of the mentioned collagens depended on the degree of necrobiotic changes (12 of 15 patients). An increased occurrence of collagen type I was only indicated in the vicinity of granulomas or within the palisade-like granuloma in 7 of 15 patients. Larger amounts of fibronectin were found in the area of the necrobiosis and in the area of the granulomatous palisade-like infiltrate resp. (12 of 15 patients). CONCLUSIONS: In the author's opinion the higher incidence of collagens types III and V in the neighbourhood of the palisade-like granulomatous infiltrate and its size resp, as well as the finding of fibronectin in the area of necrobiosis and the granulomatous infiltrate justify the use of immunohistological assessment of the above constituents of the extracellular matrix as a supplementary examination in the diagnosis of the above disease.

Screening for depressive symptoms in the acute phase of stroke.

Depressive symptoms can often be observed after stroke. We prospectively evaluated patients at a stroke unit in order to determine the occurrence and severity of depressive symptoms in the acute phase of stroke in 82 patients 7 +/- 2 days after admission to the stroke unit. Severity of stroke was evaluated by the Scandinavian and Orgogozo scales and the Barthel index. Severity of depressive symptoms was measured by the 13-item Beck scale. Mean age of the patients was 65.8 years. No gender difference was observed in the severity of stroke or depressive symptoms. DSM-IV criteria of adjustment disorder with depressed mood were fulfilled by 27% of the patients. In this group, stroke was significantly more severe by the Barthel, Orgogozo, and Scandinavian scales (p < 0.001). Whereas Beck score was at least 10 in 19.5%, severe depressive symptoms (Beck score > or = 15) occurred in less than 5% of patients with acute stroke. Those who could not walk by themselves or who were aphasic had significantly higher mean Beck scores (6.3 +/- 5.1 vs 2.4 +/- 3.1, p < 0.001, and 7.0 +/- 5.8 vs 3.4 +/- 3.9, p = 0.002). Significant correlation was found between the severity of stroke and that of the depressive symptoms (r = -0.56, -0.58, and -0.54 for the Scandinavian, Orgogozo, and Barthel scales, p < 0.001).

Screening of vascular cognitive impairment on a Hungarian cohort.

Cerebrovascular disease is a major public health problem in Eastern European countries. A Hungarian post-stroke population was examined to estimate the rate of dementia, the risk factors for cognitive impairment, and the applicability of a recently established Canadian diagnostic checklist in this cohort. Chronic cerebrovascular outpatients were screened for cognitive impairment with a combined checklist: the Diagnostic Checklist for Vascular Dementia established by the Consortium of Canadian Centres for Clinical Cognitive Research using the Mini Mental State Examination instead of the detailed neuropsychological part of the Checklist. Of the 247 consecutive patients at a cerebrovascular outpatient unit, 176 had cerebrovascular disorder diagnosed either by computed tomography (CT; n=126) or by the clinical signs. Of these, 15% were cognitively impaired and 5% fulfilled the criteria of dementia. The mean age of the patients with cognitive impairment was significantly higher than that of patients with normal cognition (68.2+/-10.2 and 60.5+/-10.5 years, P<0.001). The Barthel index was significantly lower in the cognitively affected group than in non-affected patients (92.4+/-16.0 and 97.1+/-8.7, P=0.027). Diabetes and more than two subcortical infarcts on CT or magnetic resonance imaging were more frequent in patients with cognitive loss (P=0.043 and P=0.013, respectively). Cognitive performance was also influenced by the level of education. Higher age, diabetes, motor deficits, and multiple subcortical infarcts are risk factors for cognitive impairment after stroke. The combined checklist appears to be a practical screening test for cognitive impairment in patients with chronic cerebrovascular diseases.

Complete coding sequence of bovine aggrecan: comparative structural analysis.

The previously available sequence for bovine aggrecan included only the KS domain, the C-terminal portion of the CS-2 domain, and the entire CS-3 and G3 domains. We have isolated cDNA clones for previously uncharacterized portions of the bovine aggrecan sequence, and, when we combined them with previously published incomplete sequences, have obtained a complete sequence for the entire core protein. The bovine aggrecan sequence, which is a composite of new sequence data and previously published incomplete sequences, is 2327 residues in length. Although there is significant conservation of G1, G2, and G3 globular domains between species, there are differences in the length of the interglobular domain, in the number of KS domain hexapeptide repeats and CS domain repeats, and in alternative splicing within the G3 domain. The bovine aggrecan KS domain contains 24 repeats of a hexapeptide motif. The largely uncharacterized CS-1 domain of bovine aggrecan was found to contain 27 variable repeats of a 21-residue consensus sequence. A notable feature of the bovine CS-1 domain is in the distribution of single Ser-Gly dipeptides, the majority of which are separated by 7 or 8 amino acids, compared to the human, where discrete pairs of Ser-Gly dipeptides are separated by 13 amino acids. The CS-2 domain contains a total of six "homology domains" with 4 complete and 2 partial approximately 100-residue repeats. Each "homology domain" contains a "nodal" region with few sites for CS chain addition that is highly conserved between species, suggesting a possible role in aggrecan biosynthesis or catabolism.

[Cerebral positron emission tomographic study in systemic lupus erythematosus]. / Agyi pozitron emissziós tomográfiai vizsgálatok systemás lupus erythematosusban.

The cerebral glucose metabolism in eight patients with systemic lupus erythematosus (SLE) and in five healthy controls were examined by positron emission tomography (PET) using 18-F-labeled deoxy-glucose (FDG) as tracer. One of the eight patients had no abnormality by magnetic resonance imaging (MRI), three of them had cerebral atrophy and four patients had multiple white matter hyperintensities and vascular infarcts in the striatum as assessed by MRI. With FDG-PET, inhomogeneous multifocal cerebral glucose hypometabolism was detected, more frequently in the temporal lobe of right hemisphere. The PET findings did not correlate always with the neurological symptoms. Abnormalities in brain metabolism can be detected more frequently by PET, than morphological changes by MRI, indicating the involvement of the central nervous system.

[Angiographical evaluation of extracranial carotid artery: comparison between Japanese and Hungarian].

We investigated the cervical level of carotid bifurcation, diameter of common carotid artery (CCA) and internal carotid artery (ICA) in 147 Japanese patients (150 arteries, range of age 31-79) and in 490 Hungarian patients (517 arteries, range of age 12-77). The cervical level of carotid bifurcation was determined by comparison with cervical vertebra. The carotid bifurcation of Japanese was most frequent at the lower part of 3rd cervical vertebra but in Hungarian the bifurcation was most frequent at the middle part of 4th cervical vertebra. Japanese carotid bifurcation was high-positioned compared with Hungarian. The mean CCA diameter in Japanese was 7.47 mm in male and 7.07 mm in female, in Hungarian 9.24 mm in male and 7.80 mm in female. The mean ICA diameter in Japanese was 4.96 mm in male and 4.83 mm in female, in Hungarian 8.56 mm in male and 7.66 mm in female. CCA and ICA diameter were larger in male than in female. The diameter of CCA had a significantly positive correlation with age (p < 0.002) but ICA had no similar correlation.

[First Hungarian experiences with positron emission tomography (PET) studies. Members of the PET working group]. / Elsö hazai tapasztalatok pozitron emissziós tomográfiás (PET) vizsgálatokkal. PET munkacsoport tagjai.

Diagnostic investigations commenced on the 28th of June 1994 in Hungary's and Central Europe's first PET Centre at the University Medical School of Debrecen. The Centre is equipped with a GE 4096 Plus whole body PET scanner. A metabolic tracer, 18F-deoxy-D-glucose (FDG), was used in the investigations. During the first 15 months 249 PET investigations were made in the Centre of which 242 were diagnostic and 7 normal subjects served as control for the patient studies with brain scans. The number of oncological indications (intra- and extracranial tumours, Hodgkin's lymphomas) was n = 105 (43.4% of the 242 diagnostic examinations), neurological investigations (without intracranial tumours) formed the dominant group (n = 117; 48.3%), whereas the number of cardiological indications was 20 (8.3%). The oncological studies included those of intracranial tumours (n = 76; 31.4%); thyroid tumours (n = 9; 3.7%); Hodgkin's lymphomas (n = 7; 2.9%) and other extracranial tumours (n = 13; 5.4%). The distribution of different neurological and psychiatric investigations was as follows: localization of focal epileptogen zone (n = 60; 24.8%); differential diagnosis of dementias (n = 30; 12.4%); exploration of cerebrovascular diseases (n = 10; 4.1%); and other neurological diseases (n = 17; 7.0%). The main objective of the cardiological PET investigations was the exploration of viable myocardium. The present paper overviews both the procedures (including administrative issues, as well) and the results of the first 249 FDG-PET investigations.

[Levels of Lp(a) and apolipoproteins in vegetarians and their informative value in hyperlipidemia]. / Hladiny Lp(a) a apolipoproteínov u vegetariánov a ich informatívna hodnota o hyperlipidémii.

BACKGROUND: An increased level of Lp(a) and unphysiological, even risk levels of apolipoproteins (apo) are currently considered to represent more significant markers of the premature development of atherosclerosis than that of increased serum lipids. AIM AND OBJECTIVES: The aim of our study was to detect the changes in Lp(a), apo A-I, apo A-II, apo B and lipids (TCH, TG, LDL-CH, HDL-CH, non HDL-CH) levels in 54 middle-aged vegetarians (V). METHODS: In addition to vegetarians, 40 persons, all middle-aged workers of a chemical firm with hyperlipidaemia B and C (HLP) were examined. The control group was constituted of 23 healthy people, normolipidaemics with common dietary patterns (K). Their age was mutually comparable within the examined groups. The apo A-I, apo A-II and Lp(a) levels were assessed by means of the radial immunodiffusion method, and apo B levels were detected by electroimmunoprecipitation method. RESULTS: The vegetarians yielded the lowest Lp(a) level, as well as an excellent lipid profile including apolipoproteins. The workers with HLP yielded significantly increased levels of apo B (p < 0.001), Lp(a) (p < 0.01), and values of the atherogenic index of apo B/apo A/I (p < 0.001) with simultaneous hypoapolipoproteinaemia apo A-I (p < 0.05) and apo A-II (p < 0.001). CONCLUSION: Physiological levels of lipids and apolipoproteins including the significantly lower levels of apo B, Lp(a) and levels of the index of apo B/apo A-I in persons with a high intake of fiber and minimal consumption of unsaturated fat give evidence of the decisive role of nutrition regarding the maintenance of optimal levels of lipids and lipoproteins and therefore represent the guarantee of protection from a premature development of atherosclerosis. (Tab. 1, Fig. 10, Ref. 11.)