bluuebunny/crossref_metadata_2025 huggingface dataset:
Dimension, multiplicity, holonomic modules, and an analogue of the inequality of Bernstein for rings of differential operators in prime characteristic
Authors: Bavula V.
Published: May 2009

Let

K
K

be an arbitrary field of characteristic

p
>
0

p>0

and

D

(

P
n

)

\mathcal D (P_n)

the ring of differential operators on a polynomial algebra

P
n

P_n

in

n
n

variables. A long anticipated analogue of the inequality of Bernstein is proved for the ring

D

(

P
n

)

\mathcal D (P_n)

. In fact, three different proofs are given of this inequality (two of which are essentially characteristic free): the first one is based on the concept of the filter dimension, the second, on the concept of a set of holonomic subalgebras with multiplicity, and the third works only for finitely presented modules and follows from a description of these modules (obtained in the paper). On the way, analogues of the concepts of (Gelfand-Kirillov) dimension, multiplicity, holonomic modules are found in prime characteristic (giving answers to old questions of how to find such analogs). The idea is very simple to find characteristic free generalizations (and proofs) which in characteristic zero give known results, and in prime characteristic, generalizations. An analogue of Quillen’s Lemma is proved for simple finitely presented

D

(

P
n

)

\mathcal D (P_n)

-modules. Moreover, for each such module

L
L

,

End

D

(

P
n

)

(
L
)

\textrm {End}_{\mathcal D (P_n)}(L)

is a finite separable field extension of

K
K

and

dim
K

⁡
(

End

D

(

P
n

)

(
L
)
)

\dim _K(\textrm {End}_{\mathcal D (P_n)}(L))

is equal to the multiplicity

e
(
L
)

e(L)

of

L
L

. In contrast to the characteristic zero case where the Gelfand-Kirillov dimension of a nonzero finitely generated

D

(

P
n

)

\mathcal D (P_n)

-module

M
M

can be any natural number from the interval

[
n
,
2
n
]

[n,2n]

, in the prime characteristic, the (new) dimension

Dim

(
M
)

\textrm {Dim}(M)

can be any real number from the interval

[
n
,
2
n
]

[n,2n]

. It is proved that every holonomic module has finite length, but in contrast to the characteristic zero case it is not true that neither a nonzero finitely generated module of dimension

n
n

is holonomic nor that a holonomic module is finitely presented. Some of the surprising results are:

(
i
)

(i)

each simple finitely presented

D

(

P
n

)

\mathcal D (P_n)

-module

M
M

is holonomic having the multiplicity which is a natural number (in characteristic zero rather the opposite is true, i.e.

GK

(
M
)
=
2
n
−
1

\textrm {GK}\,(M)=2n-1

, as a rule),

(
i
i
)

(ii)

the dimension

Dim

(
M
)

\textrm {Dim}(M)

of a nonzero finitely presented

D

(

P
n

)

\mathcal D (P_n)

-module

M
M

can be any natural number from the interval

[
n
,
2
n
]

[n,2n]

,

(
i
i
i
)

(iii)

the multiplicity

e
(
M
)

e(M)

exists for each finitely presented

D

(

P
n

)

\mathcal D (P_n)

-module

M
M

and

e
(
M
)
∈

Q

e(M)\in \mathbb {Q}

, the multiplicity

e
(
M
)

e(M)

is a natural number if

Dim

(
M
)
=
n

\textrm {Dim}(M)=n

, and can be an arbitrarily small rational number if

Dim

(
M
)
>
n

\textrm {Dim}(M)>n

.
An active registry for bioinformatics web services
Authors: Pettifer S. , Thorne D. , McDermott P. , Attwood T. , Baran J. , Bryne J. C. , Hupponen T. , Mowbray D. , Vriend G.
Published: May 2009

Summary: The EMBRACE Registry is a web portal that collects and monitors web services according to test scripts provided by the their administrators. Users are able to search for, rank and annotate services, enabling them to select the most appropriate working service for inclusion in their bioinformatics analysis tasks.

Availability and implementation: Web site implemented with PHP, Python, MySQL and Apache, with all major browsers supported. (www.embraceregistry.net)

Contact:  steve.pettifer@manchester.ac.uk
N,N′-Di-8-quinolyladipamide
Authors: Wang Shi-Ying , Xie Xing-Lei , Huang Qing-Hua , Lin Yu-Sheng
Published: May 2009

The complete molecule of the title compound, C24H22N4O2, is generated by a crystallographic inversion centre located at the mid-point of the central C—C bond. The quinoline ring system and the hexyl chain are both essentially planar, and the dihedral angle between them is 46.30 (2)°. Intramolecular N—H...N and C—H...O hydrogen bonds form five- and six-numbered rings, respectively. The crystal packing is stabilized by short C—H...O interactions.
α-D-Tagatopyranose
Authors: Punzo Francesco , Watkin David J. , Fleet George W. J.
Published: May 2009

The title compound, C6H12O6, also known as D-Tagatose, occurs in its furanose and pyranose forms in solution, but only the α-pyranose form crystallizes out. In the crystal, the molecules form hydrogen bonded chains propagating in [100] linked by O—H...O interactions. Further O—H...O bonds cross-link the chains.
2-Hydroxy-N′-(4-isopropylcyclohexylcarbonyl)-3-methylbenzohydrazide. Corrigendum
Authors: Shu Tian-Pin , Zhou Yu , Wen Jun-Long , Chen Su-Zhen , Lei Ke-Wei
Published: May 2009

The author list in the paper by Shu, Wen, Chen & Lei [Acta Cryst. (2009), E65, o575] is corrected.
PhenylN-phenylcarbamate
Authors: Shahwar Durre , Tahir M. Nawaz , Mughal M. Sharif , Khan Muhammad Akmal , Ahmad Naeem
Published: May 2009

In the title compound, C13H11NO2, the aromatic rings are oriented at a dihedral angle of 42.52 (12)°. The crystal structure is stabilized by intermolecular N—H...O hydrogen bonds, which form infinite one-dimensional polymeric chains extending along theaaxis. C—H...π interactions between the aromatic rings are also present.
RbCa2Nb3O10from X-ray powder data
Authors: Liang Zhen-Hua , Tang Kai-Bin , Chen Qian-Wang , Zheng Hua-Gui
Published: May 2009

Rubidium dicalcium triniobate(V), RbCa2Nb3O10, has been synthesized by solid-state reaction and its crystal structure refined from X-ray powder diffraction data using Rietveld analysis. The compound is a three-layer perovskite Dion–Jacobson phase with the perovskite-like slabs derived by termination of the three-dimensional CaNbO3perovskite structure along theabplane. The rubidium ions (4/mmmsymmetry) are located in the interstitial space.
Bis[μ-2-(2-carboxylatophenyl)acetato]-κ3O1,O1′:O2;κ3O2:O1,O1′-bis[aqua(1,10-phenanthroline-κ2N,N′)nickel(II)]
Authors: Li Feng , Zeng Huifang , Yan Zhaowei , Li Taohai
Published: May 2009

The title compound, [Ni2(C9H6O4)2(C12H8N2)2(H2O)2], is isostructural with the ZnIIanalogue. Each NiIIatom is coordinated in a distorted octahedral geometry by three O atoms from two homophthalate anions, one aqua O atom and two 1,10-phenanthroline N atoms. The two NiIIatoms are linked by two bridging homophthalate dianions into a centrosymmetric dinuclear unit. The dinuclear units are linked into one-dimensional ladder-like chains along [100] by O—H...O hydrogen bonds between the coordinated water molecules and one of the O atoms of the carboxylatomethyl group.
(Z)-3-(9-Anthryl)-1-(4-bromophenyl)-2-(4-nitro-1H-imidazol-1-yl)prop-2-en-1-one
Authors: Lu Yi-Hui , Wang Guang-Zhou , Zhou Cheng-He , Zhang Yi-Yi
Published: May 2009

In the title molecule, C26H16BrN3O3, the anthracene and benzene mean planes make dihedral angles of 63.79 (2) and 14.67 (2)°, respectively, with the plane of the imidazole ring. In the crystal structure, weak intermolecular C—H...O hydrogen bonds link molecules to form centrosymmetric dimers. Weak π–π stacking interactions, with centroid–centroid distances of 3.779 (2) and 3.826 (2) Å, supply additional stabilization. The crystal packing also exhibits short intermolecular contacts between the nitro groups and Br atoms [Br...O = 3.114 (2) Å].
Dibromido[(tert-butylamino)dimethyl(piperidin-1-ylmethyl)silane-κ2N,N′]zinc(II)
Authors: Colquhoun Victoria P. , Strohmann Carsten
Published: May 2009

The title compound, [ZnBr2(C12H28N2Si)], is an example of a neutral coordination compound of a bidentate ligand to a metal centre with the Zn atom being coordinated by two Br and two N atoms, yielding a slightly distorted tetrahedral coordination environment.
9-O-Butylberberrubinium bromide
Authors: Chen Zhu , Li Xue-Gang , Xie Yong-Sheng , Ye Xiao-Li
Published: May 2009

In the title compound, C23H24NO4+·Br−, the butyl chain is disordered between two conformations; the occupancies refined to 0.735 (7) and 0.265 (7). The dihedral angle between the naphthalene ring system and the phenyl ring is 11.6 (2)°. In the crystal structure, the cations are packedviaπ–π interactions into stacks propagating in the [010] direction. Weak intermolecular C—H...O and C—H...Br hydrogen bonds contribute further to the crystal packing stability.
(7R,8S,8aS)-8-Hydroxy-7-phenylperhydroindolizin-3-one
Authors: Švorc Ľubomír , Vrábel Viktor , Marchalín Štefan , Šafář Peter , Kožíšek Jozef
Published: May 2009

In the title compound, C14H17NO2, the six-membered ring of the indolizine system adopts a chair conformation. In the crystal, molecules form chains parallel to thebaxisviaintermolecular O—H...O hydrogen bonds. The absolute molecular configuration was assigned from the synthesis.
Bis[μ-2-(2H-benzotriazol-2-yl)-4-methylphenolato]bis[dimethylaluminium(III)]
Authors: Li Chen-Yu , Lin Chia-Her , Ko Bao-Tsan
Published: May 2009

The title complex, [Al2(CH3)4(C13H10N3O)2], is dimeric, bridged through the O atoms of the phenolate anions. The asymmetric unit contains one half of the molecule and there is a crystallographic inversion centre in this molecule. Each Al atom is pentacoordinated by one N atom and two bridging O atoms of twoN,O-bidentate benzotriazolylphenolate ligands and by two C atoms from two methyl groups, forming a distorted trigonal–bipyramidal environment.
3-[(1H-Benzimidazol-2-yl)sulfanylmethyl]benzonitrile
Authors: Lin Jin Rui , He Jia , Qian Yang , Zhao Hong
Published: May 2009

In the title compound, C15H11N3S, the dihedral angle between the benzimidazole ring system and the benzene ring is 51.8 (2)°. The crystal structure exhibits intermolecular N—H...N hydrogen bonds which lead to the formation ofC(4) chains along the [001] direction.
{2-Hydroxy-3-[4-(2-methoxyethyl)phenoxy]propyl}isopropylammonium hemisuccinate
Authors: Bartolucci Gianluca , Bruni Bruno , Coran Silvia A. , Di Vaira Massimo
Published: May 2009

Metoprolol, a widely used adrenoreceptor blocking drug, is commonly administered as the succinate or tartrate salt. The structure of metoprolol succinate, C15H26NO3+·0.5C4H4O42−, is characterized by the presence of ribbons in which cations, generated byN-protonation of the metoprolol molecules, are hydrogen bonded to succinate anions. The dicarboxylic acid transfers its H atoms to two metoprolol molecules; the asymmetric unit contains one cation and half an anion, the latter possessing twofold rotational symmetry. There are localized nets of O—H...O and N—H...O hydrogen bonds along a ribbon, within centrosymmetric arrangements formed by pairs of metoprolol cations and pairs of anions, each of the latter contributing with one of its carboxyl groups to the localized net. This arrangement is repeated along the ribbon by the operation of the twofold axis bisecting the anion, as well as by the lattice translation.
2-Bromo-4,4-dimethyl-1-(2,4,5-trimethoxyphenyl)pentan-3-one
Authors: Tang Lin-Lin , Ye Jiao , Liu Qi-Xing , Hu Ai-Xi
Published: May 2009

The three methoxy groups of the title compound, C16H23BrO4, are almost coplanar with the attached aromatic ring, forming dihedral angles of 7.19 (13), 2.48 (13) and 7.24 (12)°. The crystal structure shows an intramolecular and an intermolecular C—H...O interaction.
catena-Poly[potassium-di-μ-aqua-μ-4-(5-tetrazolio)pyridine]
Authors: Cui Li-Jing
Published: May 2009

The title compound, [K(C6H4N5)(H2O)2]n, was synthesized by hydrothermal reaction of KOH with 4-(5-tetrazolio)pyridine. The K atom has a distorted octahedral coordination environment and is coordinated by two axial N atoms from the organic ligand and by four water molecules in the equatorial plane. The molecules as a whole are located on crystallographic mirror planes; the K atom is also located on an inversion center. Both the water molecules and the organic ligands act as bridges to link symmetrically the adjacent K atoms into polymeric chains parallel to thecaxis. O—H...N hydrogen bonds involving the water O atoms and aromatic π–π interactions [centroid–centroid distance 3.80 (2) Å] between the pyridine and tetrazole rings build up an infinite three-dimensional network.
4-{2-[4-(Dimethylamino)phenyl]ethylidene}benzonitrile
Authors: Moreno-Fuquen Rodolfo , Dvries Richard , Theodoro Jahyr , Ellena Javier
Published: May 2009

In the crystal of the title compound, C17H16N2, molecules are linked by C—H...N hydrogen bonds, forming rings of graph-set motifsR21(6) andR22(10). The title molecule is close to planar, with a dihedral angle between the aromatic rings of 0.6 (1)°. Torsion angles confirm a conformationaltransstructure.
3-[1-(3-Hydroxybenzyl)-1H-benzimidazol-2-yl]phenol
Authors: Eltayeb Naser Eltaher , Teoh Siang Guan , Fun Hoong-Kun , Jebas Samuel Robinson , Adnan Rohana
Published: May 2009

In the title molecule, C20H16N2O2, the benzimidazole mean plane forms dihedral angles of 56.55 (3) and 81.65 (4)° with the two benzene rings. In the crystal structure, intermolecular O—H...O and O—H...N hydrogen bonds link the molecules into layers parallel to the (101) plane. The crystal packing also exhibits weak intermolecular C—H...O and C—H...π interactions.
Bis(di-2-pyridylmethanediol-κ3N,O,N′)nickel(II) dinitrate
Authors: Yu Seung Man , Song Young Joo , Kim Kang Chul , Kim Cheal , Kim Youngmee
Published: May 2009

The title compound, [Ni(C11H10N2O2)2](NO3)2, consists of an NiIIatom coordinated by two tridentate chelating di-2-pyridylmethanediol [(2-py)2C(OH)2] ligands. The NiIIatom is located on an inversion center. The geometry around the NiIIatom is distorted octahedral. Thegem-diol (2-py)2C(OH)2ligand adopts the coordination mode η1:η1:η1. The Ni—N and Ni—O bond lengths are typical for high-spin NiIIin an octahedral environment [Ni—N = 2.094 (2) and 2.124 (3) Å, and Ni—O = 2.108 (3) Å]. One of the hydroxy H atoms is split over two positions which both interact with the nitrate anion. The occurence of different O—H...O hydrogen bonds leads to the formation of a layer parallel to the (101) plane.
2-Chloro-N-(2,4-dichlorophenyl)acetamide
Authors: Gowda B. Thimme , Foro Sabine , Terao Hiromitsu , Fuess Hartmut
Published: May 2009

The structure of the title compound, C8H6Cl3NO, contains two molecules in the asymmetric unit. In each independent molecule, the conformation of the N—H bond is almostsynto theortho-chloro substituent and the conformation of the C=O bond isantito the N—H bond. The molecules in the crystal structure are linked into supramolecular chains through N—H...O hydrogen bonding along theaaxis.
4-[2-(1-Acetyl-2-oxopropylidene)hydrazino]-N-(pyrimidin-2-yl)benzenesulfonamide
Authors: Rai Priyanka , Upadhyay Shalini , Nethaji M. , Upadhyay K. K.
Published: May 2009

In the title compound, C15H15N5O4S, the dihedral angle between the pyrimidine and benzene rings is 84.56 (2)°. Intramolecular hydrazine–carbonyl N—H...O and intermolecular sulfonamide–pyridimine N—H...N hydrogen bonds stabilize the molecular and crystal structures, respectively.
4,5-Diphenyl-2-p-tolyl-1H-imidazol-3-ium nitrate
Authors: Cui Li-Jing
Published: May 2009

In the cation of the title compound, C22H19N2+·NO3−, the N atom in the 3-position of the imidazole is protonated. The three pendant aromatic rings are twisted from the plane of the imadazolium ring by dihedral angles of 38.1 (1), 43.74 (9) and 20.4 (1)°. In the crystal structure, N—H...O and N—H...(O,O) hydrogen bonds link the molecules to form an infinite one-dimensional chain parallel to thecaxis.
2-(2-Thienyl)-4,5-dihydro-1H-imidazole. Corrigendum
Authors: Kia Reza , Fun Hoong-Kun , Kargar Hadi
Published: May 2009

Consideration of a previous unrecognized twinning of the original investigated crystal of the title compound [Kiaet al.(2009).Acta Cryst.E65, o301] led to improved reliability factors and to a slightly higher precision for all geometric parameters. The crystal under investigation was twinned by pseudo-merohedry with [100, 0\overline{1}0, 00\overline{1}] as the twin matrix and a refined twin domain fraction of 0.9610 (5):0.0390 (5). The results of the new crystal structure refinement are given here.
2-Butyl-5-pentylbenzene-1,3-diol
Authors: Jumpathong Juangjun , Retailleau Pascal , Abdalla Muna Ali , Ouazzani Jamal , Lumyong Saisamorn
Published: May 2009

In the title compound, C15H24O2, a natural dialkylresorcinol commonly named stemphol, the molecules are linked intoC(6) andC22(4) chains andR44(16) rings by intermolecular O—H...O hydrogen bonds, creating molecular sheets parallel to the (010) plane. The alkyl chains are directed orthogonally away from these planes in almost complete extension.
(±)-trans-6,7-Dimethoxy-1-oxo-3-(2-thienyl)isochroman-4-carboxylic acid
Authors: Akkurt Mehmet , Baktır Zeliha , Bogdanov Milen G. , Svinyarov Ivan V. , Büyükgüngör Orhan
Published: May 2009

The title compound, C16H14O6S, was synthesized by the reaction of 6,7-dimethoxyhomophthalic anhydride with thiophene-2-carbaldehyde in the presence of 4-(dimethylamino)pyridine (DMAP) as a basic catalyst. The thiophene ring of the title molecule is disordered over two sites with occupancies of 0.877 (3) and 0.123 (3). The disorder corresponds to an approximate 180° rotation of the thiophene ring with respect to the C—C bond linking it to the rest of the molecule. The six-membered ring of the 3,4-dihydroisochromanone ring system is not planar [puckering parametersQT= 0.571 (2) Å, θ = 115.2 (2)° and φ = 99.1 (2)°]. The benzene ring of the 3,4-dihydroisochromanone ring system makes dihedral angles of 75.0 (2) and 77.2 (5)° with the disordered thiophene rings. Intermolecular O—H...O and C—H...O hydrogen bonds, as well as C—H...π interactions, lead to the observed supramolecular structure.
2α-Acetoxy-5α-methoxycaryophyll-8(15)-en-3-one
Authors: Zhang Wen , Duan Hong-Quan
Published: May 2009

The title compound, C18H28O4, crystallizes with two molecules in the asymmetric unit. Both molecules have similar conformations of nine-membered rings, which aretrans-fused with cyclobutane fragments. The puckering amplitudes (q2) of the cyclobutane rings are 0.2451 (2) and 0.2526 (2) Å.
Propylamine–borane
Authors: Gainsford Graeme J. , Bowden Mark E.
Published: May 2009

The title compound, C3H12BN, was solved using data collected from a multiple crystal (note incomplete data shell). The cell packing is dominated by bifurcated attractive N—Hδ+...δ−H—B interactions.
Methyl 4-anilino-3-nitrobenzoate
Authors: Li Hao-Yuan , Wu Yong-Zhong , Liu Bo-Nian , Tang Shi-Gui , Guo Cheng
Published: May 2009

In the molecule of the title compound, C14H12N2O4, the aromatic rings are oriented at a dihedral angle of 51.50 (4)°. An intramolecular N—H...O interaction results in the formation of a six-membered ring having an envelope conformation. In the crystal structure, intermolecular N—H...O interactions link the molecules into centrosymmetric dimers. π–π contacts between the benzene rings [centroid–centroid distance = 3.708 (1) Å] may further stabilize the structure.
2-(3-Pyridinio)benzimidazolium pentachloridoantimonate(III) monohydrate
Authors: Cui Li-Jing , Xu Hai-Jun , Pan Ke-Ji
Published: May 2009

In the title compound, (C12H11N3)[SbCl5]·H2O, the SbIIIcentre is surrounded by five Cl atoms and displays a distorted square-pyramidal coordination geometry. The dihedral angle formed by the plane of the imidazole ring system with the pyridine ring is 4.380 (15)°. The crystal structure is stabilized by N—H...Cl, O—H...Cl and N—H...O hydrogen bonds, forming a three-dimensional network.
Triclinic modification ofN-[(1,1-dimethylethoxy)carbonyl]-3-[(R)-prop-2-en-1-ylsulfinyl]-(R)-alanine ethyl ester at 120 (1) K
Authors: Singh Suneel P. , Verdu Marcus J. , Lough Alan J. , Schwan Adrian L.
Published: May 2009

There are two independent molecules in the asymmetric unit of the title compound, C13H23NO5S. In the crystal structure, intermolecular N—H...O hydrogen bonds link molecules into two independent one-dimensional chains along [100]. The crystal studied was found to be a non-merohedral twin with a ratio of 0.615 (6):0.385 (1) for the refined components. At 200 (1) K [Singhet al.(2009).Acta Cryst. E65, o1385–o1386] the crystal structure of the title compound contains one disordered molecule in the asymmetric unit of a monoclinic unit cell.
Monoclinic modification ofN-[(1,1-dimethylethoxy)carbonyl]-3-[(R)-prop-2-en-1-ylsulfinyl]-(R)-alanine ethyl ester at 200 (1) K
Authors: Singh Suneel P. , Verdu Marcus J. , Lough Alan J. , Schwan Adrian L.
Published: May 2009

In the monoclinic polymorph of the title compound, C13H23NO5S, intermolecular N—H...O hydrogen bonds link molecules into one-dimensional chains along [100]. The atoms of the terminal propenyl group are disordered over two sets of sites with refined occupancies of 0.69 (2) and 0.31 (2).
(S)-2-(2-Pyrrolidinio)-1H-benzimidazol-3-ium dichloride monohydrate
Authors: Jing Dai
Published: May 2009

In the title compound, C11H15N32+·2Cl−·H2O, one N atom of the imidazole ring and the N atom of the pyrrolidine ring are protonated. The crystal structure is stabilized by aromatic π–π interactions between the benzene rings of neighbouring benzimidazole systems [centroid–centroid duistance = 3.712 (2) Å]. The crystal structure is further stabilized by intermolecular N—H...Cl, O—H...Cl and N—H...O hydrogen bonds.
4-Methoxy-N′-(2-methoxybenzylidene)benzohydrazide
Authors: Zhang Xinyou
Published: May 2009

In the title compound, C16H16N2O3, the two benzene rings are inclined to one another by 75.4 (2)°, and the molecule adopts anEconfiguration about the C=N bond. In the crystal structure, symmetry-related molecules are linkedviaintermolecular N—H...O hydrogen bonds, forming chains running parallel to thecaxis.
Sr5(VIVOF5)3F(H2O)3refined from a non-merohedrally twinned crystal
Authors: Le Bail Armel , Mercier Anne-Marie , Dix Ina
Published: May 2009

The title compound, pentastrontium tris[pentafluoridooxidovanadate(IV)] fluoride trihydrate, was obtained under hydrothermal conditions. Its crystal structure has been refined from intensity data of a non-merohedrally twinned crystal. Two domains in almost equal proportions are related by a −180° rotation along the reciprocal [101]* vector. The structure may be considered as a derivative of the fluorite structure type, adopted here by SrF2. In the title compound, fluorite-like large rods are recognized, built up from a group of 16 Sr atoms of which 6 are substituted by V atoms, leading to [Sr10V6]∞units. These rods extend infinitely along thebaxis and are interconnected by the three water molecules. Each of the water molecules is shared by two different Sr atoms belonging to two different rods. The rods are also interconnected by an `independent' F atom in a distorted triangular [FSr3] coordination and by hydrogen-bonding interactionsviadonor water molecules. The acceptors are either F atoms or the O atoms of the vanadyl ion, VO2+, that is part of the [VOF5] isolated octahedron.
Influence of ABCB1 gene polymorphisms on the pharmacokinetics of verapamil among healthy Chinese Han ethnic subjects
Authors: Zhao Li‐Mei , He Xiao‐Jing , Qiu Feng , Sun Ya‐Xin , Li‐Ling Jesse
Published: May 2009

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• The pharmacokinetics of verapamil have been assessed in a number of studies.

• As a substrate of P‐glycoprotein (P‐gp), verapamil shows a large inter‐individual variability in terms of plasma concentrations.

• It has been confirmed that polymorphisms of the ABCB1 gene at positions 2677 and 3435 are related to the expression and function of P‐gp.

WHAT THIS STUDY ADDS

• This study has confirmed that polymorphisms of ABCB1 gene may influence the pharmacokinetics of verapamil among healthy Chinese Han ethnic subjects.

AIMS

To assess the association between polymorphisms of the ABCB1 gene and the pharmacokinetics of verapamil among healthy Chinese Han ethnic subjects.

METHODS

Based on polymorphisms of the ABCB1 gene at positions 2677 and 3435, 24 healthy male participants were divided into three groups: 2677GG/3435CC (n = 6), 2677GT/3435CT (n = 12) and 2677TT/3435TT (n = 6). Each subject had received a single oral dose of verapamil (80 mg) under fasting conditions. Multiple blood samples were collected over 24 h, and plasma concentrations of verapamil were determined by HPLC. Pharmacokinetic characteristics were compared between the different genotypic groups.

RESULTS

The pharmacokinetics parameters of verapamil differed significantly among the three genotypic groups. AUC(last) was significantly lower among individuals with the 2677TT/3435TT (159.5 ± 79.0 ng ml−1 h) and 2677GT/3435CT (189.3 ± 73.1 ng ml−1 h) genotypes than those with the 2677GG/3435CC genotype (303.1 ± 83.7 ng ml−1 h) (P= 0.004 and P= 0.008, respectively). However, the CL/F value was higher among subjects with the 2677TT/3435TT (523.0 ± 173.7 l h−1) genotype than those with the 2677GT/3435CT (452.2 ± 188.6 l h−1) or 2677GG/3435CC (265.4 ± 72.8 l h−1) genotypes. A significant difference was also found between the latter two groups (P= 0.034). In addition, the Cmax tended to be higher among subjects with the 2677GG/3435CC genotype than those with the 2677GT/3435CT or 2677TT/3435TT genotypes (42.2 ± 3.9 vs 32.2 ± 16.2 vs 38.1 ± 13.7 ng ml−1).

CONCLUSIONS

Our study showed for the first time that verapamil pharmacokinetics may be influenced by particular genetic polymorphisms of the ABCB1 gene among healthy Chinese Han ethnic subjects. An individualized dosage regimen design incorporating such information may improve the efficacy of the drug whilst reducing adverse reactions.
Effect of in vitro aspirin stimulation on basophils in patients with aspirin‐exacerbated respiratory disease
Authors: Çelik G. E. , Schroeder J. T. , Hamilton R. G. , Saini S. S. , Adkinson N. F.
Published: May 2009

Background
Basophil activation has been implicated in the pathogenesis of aspirin‐exacerbated respiratory disease (AERD). However, a comprehensive analysis of basophil responses to aspirin in terms of mediator release, cytokine secretion and increased expression of surface activation markers has not been performed.

Objective
To study the in vitro effects of aspirin on the concurrent release of histamine, leukotriene C4 (LTC4) and IL‐4 from human basophils and to also evaluate changes in surface activation markers (CD63, CD69 and CD203c) expressed by these cells.

Methods
Basophil‐enriched cell suspensions from 10 patients with AERD and 10 healthy volunteers were incubated with lysine‐aspirin for up to 3 h. Cells were analysed for expression of CD63, CD69 and CD203c using flow cytometry. Cell‐free supernatants were evaluated for histamine, and LTC4 release and for IL‐4 secretion.

Results
Aspirin‐induced expression of CD63, CD69 and CD203c yielded 30%, 80% and 70% sensitivity, respectively, but with poor specificity. There was no significant difference in LTC4 synthesis between groups. None of the patients with AERD (or controls) released IL‐4 in response to aspirin. A higher dose of 5 mg/mL aspirin‐mediated non‐specific effects on basophils.

Conclusion
Basophil responses to in vitro aspirin challenge are poor indicators of clinical sensitivity. Aspirin activates some basophils by means of mechanisms that differ from the classical IgE‐mediated pathway. Our study also shows that the use of 27 mm of aspirin (5 mg/mL) by previous investigators causes non‐specific basophil activation, thereby eliminating its usefulness in a cell‐based diagnostic test for AERD. Evaluation of in vitro basophil activation has low clinical value in identifying aspirin‐induced respiratory reactions.
Pulmonary periarterial inflammation in fatal asthma
Authors: Shiang C. , Mauad T. , Senhorini A. , De Araújo B. B. , Ferreira D. S. , Da Silva L. F. F. , Dolhnikoff M. , Tsokos M. , Rabe K. F. , Pabst R.
Published: May 2009

Background
To date, little information has been available about pulmonary artery pathology in asthma. The pulmonary artery supplies the distal parts of the lungs and likely represents a site of immunological reaction in allergic inflammation. The objective of this study was to describe the inflammatory cell phenotype of pulmonary artery adventitial inflammation in lung tissue from patients who died of asthma.

Methods
We quantified the different inflammatory cell types in the periarterial region of small pulmonary arteries in lung tissue from 22 patients who died of asthma [fatal asthma (FA)] and 10 control subjects. Using immunohistochemistry and image analysis, we quantified the cell density for T lymphocytes (CD3, CD4, CD8), B lymphocytes (CD20), eosinophils, mast cells (chymase and tryptase), and neutrophils in the adventitial layer of pulmonary arteries with a diameter smaller than 500 μm.

Results
Our data (median/interquartile range) demonstrated increased cell density of mast cells [FA=271.8 (148.7) cells/mm2; controls=177.0 (130.3) cells/mm2, P=0.026], eosinophils [FA=23.1 (58.6) cells/mm2; controls=0.0 (2.3) cells/mm2, P=0.012], and neutrophils [FA=50.4 (85.5) cells/mm2; controls=2.9 (30.5) cells/mm2, P=0.009] in the periarterial space in FA. No significant differences were found for B and T lymphocytes or CD4+ or CD8+ subsets. Chymase/tryptase positive (MCCT) mast cells predominated over tryptase (MCT) mast cells in the perivascular arterial space in both asthma patients and controls [MCCT/(MCCT+MCT)=0.91 (0–1) in FA and 0.75 (0–1) in controls, P=0.86].

Conclusions
Our results show that the adventitial layer of the pulmonary artery participates in the inflammatory process in FA, demonstrating increased infiltration of mast cells, eosinophils, and neutrophils, but not of T and B lymphocytes.
Effects of hydropower generation and opportunities for environmental flow management in Swedish riverine ecosystems
Authors: RENÖFÄLT BIRGITTA MALM , JANSSON ROLAND , NILSSON CHRISTER
Published: May 2009

1. Hydropower is often presented as a clean and renewable energy source that is environmentally preferable to fossil fuels or nuclear power. Hydropower production, however, fundamentally transforms rivers and their ecosystems by fragmenting channels and altering river flows. These changes reduce flow velocity and the number of rapids, and reduce or alter wetland, floodplain and delta ecosystems. Dams disrupt dispersal of riverine organisms and sediment dynamics and may alter riverine biodiversity composition and abundance. Freshwater ecosystems now belong among the world’s most threatened ecosystems.

2. Water managers are beginning to recognise the need to combine demands for social and economic development with the protection of the resource base on which socio‐economic benefits rely. Environmental flows can help to balance ecosystem and human needs for water, both when constructing new dams and in re‐licensing existing dams.

3. We briefly review the impacts of hydropower generation on freshwater ecosystems by discussing different types of dams and development, and by providing examples from Sweden of how environmental effects of hydropower production could be mitigated. Special emphasis is given to flow regulation through re‐operation of dams.

4. Regulated rivers in Sweden were developed with little consideration of ecological effects, with most dams lacking migration pathways or minimum flow releases. There is thus a substantial potential for improvement of ecological conditions, such as naturalisation of flow regimes and reestablishment of connectivity, in regulated river reaches but technical hurdles imply major challenges for rehabilitation and mitigation. Most regulated rivers consist of cascades of consecutive reservoirs and impoundments, further constraining possible actions to improve ecological conditions.

5. Most environmental mitigation measures require flow modifications to serve ecosystems, implying reduced power production. An important challenge for river management is to identify situations where measures involving relatively small production losses can have major ecological advantages.

6. Climate change during the 21st century is expected to increase runoff in northern and central Sweden and make the annual hydrograph more similar to variation in electricity demand, i.e. a lower spring flood and increased run‐off during winter months. This could provide opportunities for operating dams and power stations to the benefit of riverine ecosystems. On the other hand, demands to produce hydropower are likely to increase as fossil fuels are phased out, leading to increased pressures on free‐flowing rivers and aquatic ecosystems.
The effect of long‐term frozen storage on the quality of frozen and thawed mashed potatoes with added cryoprotectant mixtures
Authors: Fernández Cristina , Canet Wenceslao , Dolores Alvarez María
Published: May 2009

Cryoprotectant mixtures were added to frozen/thawed (F/T) mashed potatoes in the form of amidated low‐methoxyl (ALM) pectin and xanthan gum (XG), kappa‐carrageenan (κ‐C) and XG and sodium caseinate (SC) and XG, and the effect of frozen storage was examined. F/T mashed potatoes without added biopolymers had higher storage modulus G′ after freezing and frozen storage, associated with sponge formation due to amylose retrogradation. Oscillatory measurements indicated weakening of the structure of mashed potatoes without biopolymers and with added κ‐C/XG and SC/XG mixtures at the end of storage due to ice recrystallisation, whereas the structure of samples with added ALM/XG mixtures was reinforced by increasing time in storage. Mashed potatoes with added mixtures exhibited water‐holding capacity for 1 year. Samples with added κ‐C/XG mixtures were more structured, although when both κ‐C/XG and SC/XG mixtures were included in mashed potato, very acceptable sensory quality was maintained in usual frozen storage conditions.
Volatile composition and proteolysis in traditionally produced mature Kashar cheese
Authors: Hayaloglu Ali Adnan
Published: May 2009

Twelve samples of raw milk mature Kashar cheese at different stages of ripening were collected from retail outlets. The average pH, moisture, fat‐in‐dry matter, protein, salt‐in‐dry matter and titratable acidity contents of the samples were 5.33, 39.39%, 45.20%, 27.33%, 6.62% and 0.65% (as lactic acid), respectively. Indices of proteolysis varied from 10.72% to 23.75% and 7.09% to 12.26% for pH 4.6‐soluble and 12% trichloroacetic acid‐soluble nitrogen fractions, respectively, and total free amino acid concentrations ranged from 6.36 to 36.03 mg Leu g−1 of cheese. The cheeses were analysed for volatile compounds by Solid Phase Microextraction and Gas Chromatography‐Mass Spectrometry (GC‐MS). A total of 113 compounds were detected and identified belonging to the following chemical groups: acids (eleven), esters (sixteen), ketones (sixteen), aldehydes (six), alcohols (twenty‐seven), sulphur compounds (seven), terpenes (seven) and miscellaneous compounds (twenty‐three). The potential effect of each compound on the flavour profile of Kashar cheese is discussed. Acids, esters, ketones and alcohols were found at considerable levels in the samples. Kashar cheeses obtained from different retail outlets displayed some differences in terms of chemical composition, proteolysis and patterns of aroma compounds; and may be attributed to their production technologies and age‐related variations.
Infectious haematopoietic necrosis virus genogroup‐specific virulence mechanisms in sockeye salmon, Oncorhynchus nerka (Walbaum), from Redfish Lake, Idaho
Authors: Purcell M K , Garver K A , Conway C , Elliott D G , Kurath G
Published: May 2009

Characterization of infectious haematopoietic necrosis virus (IHNV) field isolates from North America has established three main genogroups (U, M and L) that differ in host‐specific virulence. In sockeye salmon, Oncorhynchus nerka, the U genogroup is highly virulent, whereas the M genogroup is nearly non‐pathogenic. In this study, we sought to characterize the virus–host dynamics that contribute to genogroup‐specific virulence in a captive stock of sockeye salmon from Redfish Lake in Idaho. Juvenile sockeye salmon were challenged by immersion and injection with either a representative U or M viral strain and sampled periodically until 14 days post‐infection (p.i.). Fish challenged with each strain had positive viral titre by day 3, regardless of challenge route, but the fish exposed to the M genogroup virus had significantly lower virus titres than fish exposed to the U genogroup virus. Gene expression analysis by quantitative reverse transcriptase PCR was used to simultaneously assess viral load and host interferon (IFN) response in the anterior kidney. Viral load was significantly higher in the U‐challenged fish relative to M‐challenged fish. Both viruses induced expression of the IFN‐stimulated genes (ISGs), but expression was usually significantly lower in the M‐challenged group, particularly at later time points (7 and 14 days p.i.). However, ISG expression was comparable with 3 days post‐immersion challenge despite a significant difference in viral load. Our data indicated that the M genogroup virus entered the host, replicated and spread in the sockeye salmon tissues, but to a lesser extent than the U genogroup. Both virus types induced a host IFN response, but the high virulence strain (U) continued to replicate in the presence of this response, whereas the low virulence strain (M) was cleared below detectable levels. We hypothesize that high virulence is associated with early in vivo replication allowing the virus to achieve a threshold level, which the host innate immune system cannot control.
Improved fireblight diagnostics using quantitative real‐time PCR detection of Erwinia amylovora chromosomal DNA
Authors: Pirc M. , Ravnikar M. , Tomlinson J. , Dreo T.
Published: May 2009

Specific and sensitive TaqMan real‐time PCR assays were developed targeting chromosomal DNA of Erwinia amylovora (amsC gene and ITS region). These assays increased the reliability of detection of E. amylovora strains, regardless of their plasmid profile, and have the ability to differentiate between Erwinia spp. strains from Hokkaido, Erwinia pyrifoliae and Erwinia spp. isolated from necrotic pear blossoms in Spain. The assays were used for testing the efficiency of three different extraction methods to remove plant‐based PCR inhibitors. Combined with an automated DNA‐extraction method based on magnetic beads (QuickPick™), the real‐time PCR assays reliably detected at least 103 cells mL−l (c. four cells per reaction) of the pathogen from blighted woody plant material. In testing of symptomless samples, absolute quantification of E. amylovora before and after enrichment in liquid media provided proof of E. amylovora viability and its ability to multiply, including in cases when subsequent isolation in pure culture was unsuccessful.
Variation among Colletotrichum gloeosporioides isolates from infected coffee berries at different locations in Vietnam
Authors: Nguyen T. H. P. , Säll T. , Bryngelsson T. , Liljeroth E.
Published: May 2009

Isolates of Colletotrichum gloeosporioides associated with anthracnose disease on coffee berries in Vietnam were characterized by morphological and molecular methods. Random amplified polymorphic DNA (RAPD) and microsatellite‐primered PCR (MP‐PCR) analyses were employed to investigate the genetic variation among 38 and 51 isolates of C. gloeosporioides, respectively. According to both methods, the isolates mainly grouped in accordance with geographical origins. Higher genetic variation (H = 0·312 and 0·335) in the northern population of C. gloeosporioides than in the southern population (H = 0·261 and 0·186), according to the RAPD and MP‐PCR markers, respectively, was indicative of a difference between the northern and southern populations. Moderate gene differentiation (Gst = 0·1) between populations from the north and the south was found. However, there was no differentiation between locations within the northern or southern populations, indicating significant gene flow. A four‐gamete test indicated a high level of recombination, particularly in the south. The geographic differences may be explained by different histories of coffee cultivation in different parts of Vietnam. The symptoms caused by the Vietnamese isolates on both hypocotyls and green berries were less severe than symptoms caused by the reference CBD (coffee berry disease; Colletotrichum kahawae) isolates originating from Africa.
Western Grenville Province holds key to midcontinental Granite‐Rhyolite Province enigma
Authors: Slagstad T. , Culshaw N. G. , Daly J. S. , Jamieson R. A.
Published: May 2009

The Mesoproterozoic Granite‐Rhyolite Provinces in North America consist of A‐type granitic and rhyolitic rocks, and their formation is commonly ascribed to continental `extension' or `rifting'. The tectonic environment of the extension is, however, poorly understood. New Sm–Nd isotopic data from the Central Gneiss Belt, Grenville Province, Ontario, suggest that rocks compositionally and temporally similar to those in the Granite‐Rhyolite Provinces formed in and behind an active continental arc undergoing intra‐arc and back‐arc extension. Basaltic underplating accompanied extension, providing heat and juvenile material. Source rocks vary from juvenile within the arc, to more mature with increasing distance behind the arc. Recent investigations from SW Baltica show that the Rjukan Group, a proposed Granite‐Rhyolite Province correlative, also formed inboard of an active continental arc. A tectonically and temporally similar, and probably recurrent, evolution along the vast Laurentia–Baltica margin points to active continental‐margin processes as first‐order controls on back‐arc granite‐rhyolite magmatism.
Evidence for oceanic subduction at the NE Gondwana margin during Permo‐Triassic times
Authors: Liu Yan , Liu Hongfei , Theye Thomas , Massonne Hans‐Joachim
Published: May 2009

Blueschist was recently recognized within the Lhasa terrane, which is one of the NE Gondwana blocks. In this rock, the Mn and Mg contents of garnet enclosing aegirine‐rich clinopyroxene, rutile and quartz decrease and increase, respectively, from core to rim. Amphibole changes from glaucophane through Na–Ca amphibole to Ca amphibole. The Si contents of phengite are high in the centre but low along the rim. The P–T path, starting above 2.5 GPa–450 °C and showing subsequently first a temperature increase to 500 °C and then a pressure release via blueschist conditions to 0.6 GPa, was reconstructed using a P–T pseudosection calculated for the P–T range 0.4–2.8 GPa and 250–650 °C. This path points to deep subduction of a cold oceanic crust probably beneath the NE Gondwana margin during Permo‐Triassic times. This finding contributes to a better understanding of the pre‐Cenozoic history of major terranes of NE Gondwana.
200‐m‐deep earthquake swarm in Tricastin (lower Rhône Valley, France) accounts for noisy seismicity over past centuries
Authors: Thouvenot François , Jenatton Liliane , Gratier Jean‐Pierre
Published: May 2009

In the lower Rhône Valley (France), the Tricastin area was struck in 2002–2003 by an earthquake swarm with a maximumML‐magnitude of 1.7. These shocks would have gone unnoticed if they had not occurred beneath habitations and close to the surface, some events being only 200‐m deep. A several months’ monitoring of the seismic activity by a 16‐station mobile network showed that earthquakes clustered along a N–S‐trending, at least 5‐km long, shallow rupture zone, with no corresponding fault mapped in the surface. Half of the seismic events occurred in a massive,c. 250‐m‐thick, Lower Cretaceous limestone slab that outcrops near by. Since the late eighteenth century, several much more severe earthquake swarms have struck Tricastin. The 1772–1773 and 1933–1936 swarms were prolific and protracted, with reports of numerous detonations and even damage. Obviously, the abnormal noises that caused panic in the past centuries can be explained by the shallowness of the phenomena, a 200‐m focal depth being perhaps a record value for tectonic earthquakes.
The Cimmerian Orogeny in northern Iran: tectono‐stratigraphic evidence from the foreland
Authors: Wilmsen Markus , Fürsich Franz T. , Seyed‐Emami Kazem , Majidifard Mahmoud Reza , Taheri Jafar
Published: May 2009

From the Permian onwards, the Gondwana‐derived Iran Plate drifted northward to collide with Eurasia in the Late Triassic, thereby closing the Palaeotethys. This Eo‐Cimmerian Orogeny formed the Cimmeride fold‐and‐thrust belt. The Upper Triassic–Middle Jurassic Shemshak Group of northern Iran is commonly regarded as the Cimmerian foreland molasse. However, our tectono‐stratigraphic analysis of the Shemshak Group resulted in a revised and precisely dated model for the Triassic–Jurassic geodynamic evolution of the Iran Plate: initial Cimmerian collision started in the Carnian with subsequent Late Triassic synorogenic peripheral foreland deposition (flysch, lower Shemshak Group). Subduction shifted south in the Norian (onset of Neotethys subduction below Iran) and slab break‐off around the Triassic–Jurassic boundary caused rapid uplift of the Cimmerides followed by Liassic post‐orogenic molasse (middle Shemshak Group). During the Toarcian–Aalenian (upper Shemshak Group), Neotethys back‐arc rifting formed a deep‐marine basin, which developed into the oceanic South Caspian Basin during the Late Bajocian–Late Jurassic.
Strong inbreeding depression in male mating behaviour in a poeciliid fish
Authors: ALA‐HONKOLA O. , UDDSTRÖM A. , PAULI B. DIAZ , LINDSTRÖM K.
Published: May 2009

The magnitude of inbreeding depression is often larger in traits closely related to fitness, such as survival and fecundity, compared to morphological traits. Reproductive behaviour is also closely associated with fitness, and therefore expected to show strong inbreeding depression. Despite this, little is known about how reproductive behaviour is affected by inbreeding. Here we show that one generation of full‐sib mating results in a decrease in male reproductive performance in the least killifish (Heterandria formosa). Inbred males performed less gonopodial thrusts and thrust attempts than outbred males (δ = 0.38). We show that this behaviour is closely linked with fitness as gonopodial performance correlates with paternity success. Other traits that show inbreeding depression are offspring viability (δ = 0.06) and maturation time of males (δ = 0.19) and females (δ = 0.14). Outbred matings produced a female biased sex ratio whereas inbred matings produced an even sex ratio.
Occurrence and distribution pattern of Palaemon spp. shrimps in a shallow submarine cave environment: a study case in South‐eastern Italy
Authors: Denitto Francesco , Moscatello Salvatore , Belmonte Genuario
Published: May 2009

The common shrimps of the genus Palaemon are often reported as living in Mediterranean submarine caves. The present study quantifies the distribution pattern of a Palaemon spp. populations throughout 1 year of observations in a shallow submarine cave in South‐eastern Italy, Ionian Sea. The cave was subdivided into six sectors from the entrance towards the inner portion of the ‘blind cave’ and 16 dives (four per season, during both day and night) were performed with SCUBA equipment. The population was estimated in situ using visual census. Four different species of Palaemon were identified. This study has shown that Palaemon spp. assemblages live throughout the year in submarine caves. Moreover, the results suggest submarine caves play an important role in the biology of Palaemon spp. populations, by providing refuge, juvenile recruitment and food resources.