Two complementary molecular energy decomposition schemes: the Mayer and Ziegler-Rauk methods in comparison

In the present paper we discuss and compare two different energy decomposition schemes: Mayer's Hartree-Fock energy decomposition into diatomic and monoatomic contributions [Chem. Phys. Lett. 382, 265 (2003)], and the Ziegler-Rauk dissociation energy decomposition [Inorg. Chem. 18, 1558 (1979)]. The Ziegler-Rauk scheme is based on a separation of a molecule into fragments, while Mayer's scheme can be used in the cases where a fragmentation of the system in clearly separable parts is not possible. In the Mayer scheme, the density of a free atom is deformed to give the one-atom Mulliken density that subsequently interacts to give rise to the diatomic interaction energy. We give a detailed analysis of the diatomic energy contributions in the Mayer scheme and a close look onto the one-atom Mulliken densities. The Mulliken density ρA has a single large maximum around the nuclear position of the atom A, but exhibits slightly negative values in the vicinity of neighboring atoms. The main connecting point between both analysis schemes is the electrostatic energy. Both decomposition schemes utilize the same electrostatic energy expression, but differ in how fragment densities are defined. In the Mayer scheme, the electrostatic component originates from the interaction of the Mulliken densities, while in the Ziegler-Rauk scheme, the undisturbed fragment densities interact. The values of the electrostatic energy resulting from the two schemes differ significantly but typically have the same order of magnitude. Both methods are useful and complementary since Mayer's decomposition focuses on the energy of the finally formed molecule, whereas the Ziegler-Rauk scheme describes the bond formation starting from undeformed fragment densities

Vitae sanctorum.

Abdo et Sennes (262-263v) ; Acisclus et Victoria (163-165) ; Adrianus (72v-77) ; Affra (45v) ; Amancius (122-125v) ; Andochius (90v-92v) ; Andreas (186-194v) ; Antoninus (68v-70v, 221v) ; Apollinaris (1bis-1bis v); Audardus (254-259) ; Augustinus (231-232v) ; Bartholomeus (55v-59v) ; Bricius Turonensis (162v-163) ; Caprasius (107-108) ; Caprasius et Fides (218-219v) ; Cassianus (48v) ; Cecilia (168v-174v) ; Christina (12-16v) ; Christoforus (22-24) ; Ciricus et Julita (2v-6, 260v-262) ; Cirillus (2-2v) ; Ciprianus (47v-48v) ; Claudius, Asterius, Neo (54v-55v) ; Clemens (174v-176) ; Cosmas et Damianus (97v-98v) ; Crisantus et Daria (179-182v) ; Crucis exaltatio (83-84) ; Cucufas (24-25) ; Dalmacius Rutenae urbis (131-132v) ; Desiderius Caturcensis (207v-217v) ; Dionisius (105-106v) ; Donatus (263v-265v) ; Eleazarus (38-38v) ; Eptadius (59v-61v) ; Eufemia (84-86) ; Eugenia (78-83) ; Eulalia (195v-199) ; Eustachius (125v-129v) ; Fabius (34v-36v) ; Fausta (52-53v) ; Faustus, Januarius et Marcialis (106v-107) ; Felix (36v-38) ; Felix Nolensis ep. (25-27) ; Filibertus (227v-231) ; Genesius Arelatensis (61v-62v) ; Germanus Autissiodorensis (33-34) ; Gervasius et Protasius (259v-260v) ; Gregorius papa (222-224v) ; Grisogonus (176v-178) ; Jacobus major (20v-21v) ; Jeronimus (100-102) ; Johannis Baptistae decollatio (66v-68v) ; Johannes et Paulus (227-227v) ; Julia (11-12) ; Julianus (64-64v) ; Julianus, auct. Gregorio Turonense (265v-272) ; Julius (178-178v) ; Justa et Rufina (6v-7) ; Justina et Ciprianus (92v-97v) ; Justus et Pastor (44v-45) ; Laurianus (167v-168v) ; Leochadia (195-195v) ; Leodegarius (102-104v) ; Licerius (62v-64) ; Longinus (195) ; Lucia (199-200v) ; Machabei (34-34v) ; Mammes (45v-47v) ; Marcellinus et Petrus (259-259v) ; Marcellus (114) ; Marcellus Cavalonis (219v-220) ; Marcellus Kavilonensis (1v-1bis) ; Marcus (224v-225) ; Marciana (129v-131) ; Marcianus (206-206v) ; Margarita (7-11) ; Mariae assumptio (48v-51) ; Martinus, auct. Sulpicio Severo (133-160v) ; Matheus (86-89) ; Mauricius (89-90v) ; Mauricius, Exuperius, Candidus, Innocentius, Victor cum sociis eorum (272-272v) ; Maurinus (245-247v) ; Maximus (241-244v) ; Medardus (225-227) ; Mennas (160v-162v) ; Michael (98v-100) ; Mimius (39v-40) ; Nazarius et Celsus (27-31v) ; Omnes Sancti (118v-122) ; Pantaleo (31v-32v) ; Petri cathedra (220-221v, 249-250) ; Petrus, ep. Alexandriae (248-249) ; Procopius (39-39v) ; Quintinus (114-118v) ; Regina (70v-72v) ; Reparata (104v-105) ; Romanus (165-167) ; Sabina (64v-66v) ; Salvius (77-78) ; Saturninus et Sisinnius (178v) ; Saturninus Tolosanensis (182v-185v, 232v-239) ; Segolena (16v-20v) ; Servandus et Germanus (108-109) ; Sixtus, Laurentius et Ypolitus (40-44v); Symo et Judas (109-112v) ; Symphorianus (53v-54v) ; Teodota (38v-39) ; Terencianus (239-241) ; Theodardus Narbonensis (250-254) ; Thomas (200v-206) ; Valerianus (206v-207) ; Vamnes (51-52) ; Vincentius et Savina (112v-114). Le f. 220v contient un catalogue ancien de la bibliothèque de Moissac.

Structured RNAs in the ENCODE selected regions of the human genome

Functional RNA structures play an important role both in the context of noncoding RNA transcripts as well as regulatory elements in mRNAs. Here we present a computational study to detect functional RNA structures within the ENCODE regions of the human genome. Since structural RNAs in general lack characteristic signals in primary sequence, comparative approaches evaluating evolutionary conservation of structures are most promising. We have used three recently introduced programs based on either phylogenetic–stochastic context-free grammar (EvoFold) or energy directed folding (RNAz and AlifoldZ), yielding several thousand candidate structures (corresponding to ∼2.7% of the ENCODE regions). EvoFold has its highest sensitivity in highly conserved and relatively AU-rich regions, while RNAz favors slightly GC-rich regions, resulting in a relatively small overlap between methods. Comparison with the GENCODE annotation points to functional RNAs in all genomic contexts, with a slightly increased density in 3′-UTRs. While we estimate a significant false discovery rate of ∼50%–70% many of the predictions can be further substantiated by additional criteria: 248 loci are predicted by both RNAz and EvoFold, and an additional 239 RNAz or EvoFold predictions are supported by the (more stringent) AlifoldZ algorithm. Five hundred seventy RNAz structure predictions fall into regions that show signs of selection pressure also on the sequence level (i.e., conserved elements). More than 700 predictions overlap with noncoding transcripts detected by oligonucleotide tiling arrays. One hundred seventy-five selected candidates were tested by RT-PCR in six tissues, and expression could be verified in 43 cases (24.6%).

Absence of delta-9-tetrahydrocannabinol dysphoric effects in dynorphin-deficient mice

The involvement of dynorphin on Delta-9-tetrahydrocannabinol (THC) and morphine responses has been investigated by using mice with a targeted inactivation of the prodynorphin (Pdyn) gene. Dynorphin-deficient mice show specific changes in the behavioral effects of THC, including a reduction of spinal THC analgesia and the absence of THC-induced conditioned place aversion. In contrast, acute and chronic opioid effects were normal. The lack of negative motivational effects of THC in the absence of dynorphin demonstrates that this endogenous opioid peptide mediates the dysphoric effects of marijuana.

Cannabinoid withdrawal syndrome is reduced in pre-proenkephalin knock-out mice

The functional interactions between the endogenous cannabinoid and opioid systems were evaluated in pre-proenkephalin-deficient mice. Antinociception induced in the tail-immersion test by acute Delta9-tetrahydrocannabinol was reduced in mutant mice, whereas no difference between genotypes was observed in the effects induced on body temperature, locomotion, or ring catalepsy. During a chronic treatment with Delta9-tetrahydrocannabinol, the development of tolerance to the analgesic responses induced by this compound was slower in mice lacking enkephalin. In addition, cannabinoid withdrawal syndrome, precipitated in Delta9-tetrahydrocannabinol-dependent mice by the injection of SR141716A, was significantly attenuated in mutant mice. These results indicate that the endogenous enkephalinergic system is involved in the antinociceptive responses of Delta9-tetrahydrocannabinol and participates in the expression of cannabinoid abstinence.

THC prevents MDMA neurotoxicity in mice

The majority of MDMA (ecstasy) recreational users also consume cannabis. Despite the rewarding effects that both drugs have, they induce several opposite pharmacological responses. MDMA causes hyperthermia, oxidative stress and neuronal damage, especially at warm ambient temperature. However, THC, the main psychoactive compound of cannabis, produces hypothermic, anti-inflammatory and antioxidant effects. Therefore, THC may have a neuroprotective effect against MDMA-induced neurotoxicity. Mice receiving a neurotoxic regimen of MDMA (20 mg/kg ×4) were pretreated with THC (3 mg/kg ×4) at room (21°C) and at warm (26°C) temperature, and body temperature, striatal glial activation and DA terminal loss were assessed. To find out the mechanisms by which THC may prevent MDMA hyperthermia and neurotoxicity, the same procedure was carried out in animals pretreated with the CB1 receptor antagonist AM251 and the CB2 receptor antagonist AM630, as well as in CB1, CB2 and CB1/CB2 deficient mice. THC prevented MDMA-induced-hyperthermia and glial activation in animals housed at both room and warm temperature. Surprisingly, MDMA-induced DA terminal loss was only observed in animals housed at warm but not at room temperature, and this neurotoxic effect was reversed by THC administration. However, THC did not prevent MDMA-induced hyperthermia, glial activation, and DA terminal loss in animals treated with the CB1 receptor antagonist AM251, neither in CB1 and CB1/CB2 knockout mice. On the other hand, THC prevented MDMA-induced hyperthermia and DA terminal loss, but only partially suppressed glial activation in animals treated with the CB2 cannabinoid antagonist and in CB2 knockout animals. Our results indicate that THC protects against MDMA neurotoxicity, and suggest that these neuroprotective actions are primarily mediated by the reduction of hyperthermia through the activation of CB1 receptor, although CB2 receptors may also contribute to attenuate neuroinflammation in this process.