1,384 research outputs found
Testing Static Trade-off Against Pecking Order Models of Capital Structure
This paper tests traditional capital structure models against the alternative of a pecking order model of corporate financing. The basic pecking order model, which predicts external debt financing driven by the internal financial deficit, has much greater explanatory power than a static trade-off model which predicts that each firm adjusts toward an optimal debt ratio. We show that the power of some usual tests of the trade-off model is virtually nil. We question whether the available empirical evidence supports the notion of an optimal debt ratio.
Soil diversity under semi-natural grassland within the forest-steppe zone - examples from Transylvania (Romania)
In the Transylvanian Basin, extensively managed hay meadows with a particular biodiversity could survive until today. Under a temperate-continental climate of the forest steppe and within the colline zone, they are situated on north-facing slopes with an erratic ondulated relief, dominated by small slumpings. A mosaic of different site conditions is illustrated by a patchy distribution of wet meadow, dry- and semi-dry grassland sites. However, little is still known about the edaphic properties of these ecosystems. Precise pedological studies, even less entire soil sequences, are nonexistent. Therefore, the presented findings are a first approach to outline the distribution of different soil types under such semi-natural grasslands. As preliminary results, they are embedded into a pedological-morphodynamic study about the regional grassland-dependent landscape development.
Two northern exposed hay meadows were investigated through the application of catenas. Soil description was done according to 'Bodenkundliche Kartieranleitung' (KA 5), based on data gathered from cores, test pits, and laboratory analysis.
Several different soil types were detected: On the upper slope and on exposed positions, driest conditions and lowest clay contents led to the formation of subtypes of 'Pararendzina', 'Tschernosem', and 'Kalktschernosem'. Along more inclined parts of the slope, 'Tschernosem' and 'Pelosol' occur with accented processes of soil creep. Within colluvial infillings of punctually distributed small depressions, highest clay- and SOM-amounts were recorded. Especially in 'Pelosol'-subtypes occuring there, intense seasonal waterlogging and desiccation dominates soil formation.
Along the investigated slopes, the generally deep, clay- and organic matter-rich soil cover reveals a small-scale mosaic of different soil types, reflecting the variety of site conditions. The specific soil features further let assume a long lasting constancy of semi-natural grassland on these potentially forested sites within the forest steppe
Magnetic & Spectral Studies on Ni(II) & Cu(II) Complexes of N-(Salicylidene)phenylhydrazine
536-53
Multiple bilateral submandibular gland sialolithiasis
Sialolithiasis accounts for the most common etiology of salivary gland obstruction which leads to recurrent painful swelling of the involved gland which often exacerbates while eating. Stones may be encountered in any of the salivary glands but most frequently in the submandibular gland and its duct. Simultaneous sialolithiasis in more than one salivary gland is rare, occurring in fewer than 3% of cases. Seventy to 80% of cases feature solitary stones; only about 5% of patients have three or more stones, the case report which we are presenting here had three submandibular sialoliths involving both the submandibular glands which were removed by intraoral approach and no post‑operative complications were noted.Key words: Bilateral, multiple, sialolithiasis, submandibula
Effects of the glutamate carboxypeptidase II (GCP2 1561C>T) and reduced folate carrier (RFC1 80G>A) allelic variants on folate and total homocysteine levels in kidney transplant patients
Effects of the glutamate carboxypeptidase II (GCP2 1561C>T) and reduced folate carrier (RFC1 80G>A) allelic variants on folate and total homocysteine levels in kidney transplant patients.BackgroundThe effect of the glutamate carboxypeptidase II GCP2 1561C>T and the reduced folate carrier 1 RFC1 80G>A polymorphisms on folate and total homocysteine (tHcy) plasma levels of kidney transplant patients are unknown.MethodsIn a cross-sectional study of 730 kidney allograft recipients, GCP2 1561C>T, RFC1 80G>A, folate, and tHcy plasma levels were analyzed using linear regression models that allowed dependent covariates to follow a gamma distribution for univariate and multivariate analyses.ResultsThe allele frequency for GCP2 1561C>T was 0.05, and 0.43 for RFC1 80G>A. Heterozygosity or homozygosity for GCP2 1561C>T was associated with higher folate plasma levels compared to patients without mutation (P < 0.0001), while RFC1 80G>A showed no influence. Multiple testing, also including MTHFR 677C>T and MTHFR 1298A>C, revealed no interaction between the different genotypes and the folate plasma concentration. Neither GCP2 1561C>T nor RFC1 80G>A showed an association with tHcy plasma levels.ConclusionWe conclude that GCP2 1561C>T is associated with elevated folate levels. GCP2 1561C>T and RFC1 80G>A are no major determinants of tHcy plasma levels in kidney transplant patients
Noncommutative Dynamics of Random Operators
We continue our program of unifying general relativity and quantum mechanics
in terms of a noncommutative algebra on a transformation groupoid
where is the total space of a principal fibre bundle
over spacetime, and a suitable group acting on . We show that
every defines a random operator, and we study the dynamics of
such operators. In the noncommutative regime, there is no usual time but, on
the strength of the Tomita-Takesaki theorem, there exists a one-parameter group
of automorphisms of the algebra which can be used to define a state
dependent dynamics; i.e., the pair , where is a state
on , is a ``dynamic object''. Only if certain additional conditions
are satisfied, the Connes-Nikodym-Radon theorem can be applied and the
dependence on disappears. In these cases, the usual unitary quantum
mechanical evolution is recovered. We also notice that the same pair defines the so-called free probability calculus, as developed by
Voiculescu and others, with the state playing the role of the
noncommutative probability measure. This shows that in the noncommutative
regime dynamics and probability are unified. This also explains probabilistic
properties of the usual quantum mechanics.Comment: 13 pages, LaTe
Effects of TCN2 776C>G on vitamin B12, folate, and total homocysteine levels in kidney transplant patients
Effects of TCN2 776C>G on vitamin B12, folate, and total homocysteine levels in kidney transplant patients.BackgroundControversy exists regarding the possible associations between a single nucleotide polymorphism of the transcobalamin II encoding gene (TCN2 776C>G) and plasma levels of vitamin B12, folate, or total homocysteine.MethodsIn a cross-sectional study of 732 kidney allograft recipients, patients were categorized by TCN2 776C>G genotype. In univariate and multivariate linear regression models that allowed the outcome variables vitamin B12, folate, and total homocysteine plasma levels to follow a gamma distribution, we tested for possible associations of allelic variants of the TCN2 776C>G gene and these three dependent variables.ResultsThe allele frequency for TCN2 776C>G was 0.46. Heterozygosity or homozygosity for TCN2 776C>G was not associated with plasma levels of vitamin B12 (776CG, P = 0.22; 776GG, P = 0.89), folate (776CG, P = 0.91; 776GG, P = 0.84), or total homocysteine (776CG, P = 0.11; 776GG, P = 0.33) even after adjustment for several possible confounders.ConclusionWe conclude from this largest study on the subject thus far that there are no associations between allelic variants of TCN2 776C>G and plasma vitamin B12, folate, or total homocysteine plasma levels in kidney transplant patients
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