Males usually come into conflict due to competition for territories and females. However, interference competition can also occur between males of congeneric species when their ecological requirements are overlapping. Using acoustic playback experiments, we investigated male-male interactions within and between Grasshopper (Locustella naevia; GW) and River Warbler (L.
View Article and Find Full Text PDFSibling cannibalism is relatively common in nature, but its evolution in birds and certain other vertebrates with extended parental care had been discarded. Here, however, we demonstrate its regular occurrence in two European populations of the Eurasian hoopoe () and explore possible adaptive and non-adaptive explanations. Results showed that sibling cannibalism was more frequently detected in Spain (51.
View Article and Find Full Text PDFHeatwaves exert disproportionately strong and sometimes irreversible impacts on forest ecosystems. These impacts remain poorly understood at the tree and species level and across large spatial scales. Here, we investigate the effects of the record-breaking 2018 European heatwave on tree growth and tree water status using a collection of high-temporal resolution dendrometer data from 21 species across 53 sites.
View Article and Find Full Text PDFAtmospheric carbon dioxide (CO2) has increased substantially since the industrial revolution began, and physiological responses to elevated atmospheric CO2 concentrations reportedly alter the biometry and wood structure of trees. Additionally, soil nutrient availability may play an important role in regulating these responses. Therefore, in this study, we grew 288 two-year-old saplings of sessile oak (Quercus petraea (Matt.
View Article and Find Full Text PDFTop dieback in 40-60 years old forest stands of Norway spruce [Picea abies (L.) Karst.] in southern Norway is supposed to be associated with climatic extremes.
View Article and Find Full Text PDFObjectives: Dihydropyridine calcium channel blockers have some disadvantages such as light sensitivity and relatively short plasma half-lives. Stability of dihydropyrimidines analogues could be of advantage, yet they remain less well characterized. We aimed to test four newly synthesized Biginelli-type dihydropyrimidines for their calcium channel blocking activity on rat isolated aorta.
View Article and Find Full Text PDFA synthesis of novel pyrazolopyridine, benzopyranopyrazolopyridine, and oxygen-bridged pyrazolo-, tetrazolo-, benzimidazo-, and thiazolopyrimidines via Hantzsch- and Biginelli-like condensations has been developed. The ability of these compounds to inhibit Eg5 activity has been examined. The results indicate that synthetic manipulations in the monastrol thiourea moiety are inefficient.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
May 2010
The title compound, C(12)H(13)NO(2), represents a conformationally restricted 2-pyridone analogue of 1,4-dihydro-pyridine-type calcium antagonists and was selected for a crystal structure determination in order to explore some aspects of drug-receptor inter-action. In the mol-ecule, two stereogenic centres are of opposite chirality, whereas a racemate occurs in the crystal. It was found that the formally aminic N atom of the heterocycle is essentially sp(2)-hybridized with the lone-pair electrons partially delocalized through conjugation with the adjacent carbonyl bond.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
December 2010
There are two crystallographically independent mol-ecules in the asymmetric unit of the title compound, C(21)H(18)N(4)O(4). The substituted benzopyran portion of one of the independent mol-ecules exhibits disorder [occupancy 0.5248 (18):0.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
April 2009
In the title compound, C(11)H(10)N(2)O(2), a potential inhibitor of the cyclo-oxygenase-2 isoenzyme, the pyrazoline ring exists in a flat-envelope conformation while the puckering of the central oxazine ring is more severe. As a result, the mol-ecule as a whole is non-planar. The formal sp(3) pyrazoline N atom is sp(2) hybridized, with the lone-pair electrons delocalized through conjugation with the carbonyl group rather than the double bond of the pyrazoline ring.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
October 2009
The title compound, C(13)H(14)N(2)OS, crystallizes as a racemate in a non-chiral space group. It represents a conformationally restricted analogue of so-called Biginelli compounds known to exhibit multiple pharmacological activities and was selected for a single-crystal X-ray analysis in order to probe the chemical and spatial requirements of some kinds of activity. It was found that the state of hybridization of the formally aminic nitro-gen of the heterocycle is between sp(2) and sp(3) with the lone-pair electrons partially delocalized through conjugation with the sulfur atom rather than the double bond of the pyrimidine nucleus.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
May 2008
The title compound, C(17)H(20)N(2)O(6), belongs to the monastrol-type of anti-cancer agents and was selected for crystal structure determination in order to confirm its mol-ecular structure and explore some aspects of its structure-activity relationships. The central tetra-hydro-pyrimidine ring has a flat-envelope conformation. The 4-hydroxy-phenyl group occupies a pseudo-axial position and is inclined at an angle of 87.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
February 2008
In the title compound, C(18)H(16)N(2)O(3), a potential inhibitor of the cyclo-oxygenase-2 isoenzyme, the pyrazoline ring exists in a flattened envelope conformation with one C atom deviating by 0.463 Å from the mean plane of the remaining four atoms. The puckering of the central oxazine ring is more severe, with one N atom and one C atom displaced by 0.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
August 2008
The title compound, C(15)H(16)N(2)O(5), belongs to the class of monastrol-type anti--cancer agents and was selected for crystal structure determination in order to determine the conformational details needed for subsequent structure-activity relationship studies. The central tetra-hydro-pyrimidine ring has a flat-envelope conformation. The 4-phenyl group occupies a pseudo-axial position and is inclined at an angle of ca 90° to the mean plane of the heterocyclic ring.
View Article and Find Full Text PDFIn the title compound, C(16)H(18)N(6)O, an N-carbonylimidazole derivative of pyrazoline-1-carboximidamide, the pi-electron density of the N atom in the 1-position on the pyrazoline ring is delocalized through the amidine moiety and the adjacent carbonyl group. The imidazole ring, though coplanar with the rest of the molecule, is deconjugated. The pyrazoline ring adopts a flat-envelope conformation, having the substituted phenyl ring oriented perpendicular to the mean plane of the heterocycle.
View Article and Find Full Text PDFThe reaction between 4-(4-methylphenyl)but-3-en-2-one and aminoguanidine produced an unexpected product of formula C(12)H(15)N(3)O, consisting of a carboxamide moiety joined to a substituted pyrazoline ring at one of the N atoms. The pyrazoline ring adopts a flat-envelope conformation and the substituted phenyl ring is oriented almost perpendicular to the heterocycle. The carbonyl O atom has partial anionic character as a result of the transfer of pi density from the two adjacent sp(2) N atoms and is involved in an intermolecular hydrogen bond with the amide group.
View Article and Find Full Text PDFThe X-ray structure analysis of the unexpected product of the reaction between 4-(4-methylphenyl)but-3-en-2-one and aminoguanidine revealed the title compound, C(12)H(17)N(4)(+) x -C(2)H(3)O(2)(-) x 0.5C(3)H(6)O, consisting of a protonated amidine moiety joined to a substituted pyrazoline ring at the N1 atom. The amidine group is protonated and the positive charge is delocalized over the three C[bond]N bonds in a similar manner to that found in guanidinium salts.
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