Diphyllobothrium dendriticum (Cestoda: Pseudophyllidea) from Tasmania

Adult cestodes recovered from the small intestines of water rats (Hydromys chrysogaster) in Northern Tasmania were identified, on the basis of their morphology and the developmental requirements of their coracidia, as non-marine members of the genus Diphyllobothrium. The exact taxonomic position of this diphyllobothriid is not known. It differs in some respects from Stephens' (1908) description of a parasite (Diphyllobothrium parvum) obtained from the same locality, but could not be clearly differentiated from D. dendriticum. Thus, until more information is available about the full life cycle of this parasite, we consider it to be D. dendriticum. ac]1986072

A See-Saw Mechanism With Light Sterile Neutrinos

The usual see-saw mechanism for the generation of light neutrino masses is based on the assumption that all of the flavours of right-handed (more properly, sterile) neutrinos are heavy. If the sterile Majorana mass matrix is singular, one or more of the sterile neutrinos will have zero mass before mixing with the active (left-handed) neutrinos and be light after that mixing is introduced. In particular, a rank 1 sterile mass matrix leads naturally to two pseudo-Dirac pairs, one very light active Majorana neutrino and one heavy sterile Majorana neutrino. For any pattern of Dirac masses, there exists a region of parameter space in which the two pseudo-Dirac pairs are nearly degenerate in mass. This, in turn, leads to large amplitude mixing of active states as well as mixing into sterile states.Comment: 12 pages, no figures. Contributed to the XX International Symposium on Lepton and Photon Interactions at High Energies, Rome, July 2001, and to the International Europhysics Conference on High Energy Physics, Budapest, July 2001. v2: Report-no added, misprints correcte

Ecstasy analogues found in cacti

Human interest in psychoactive phenethylamines is known from the use of mescaline-containing cacti and designer drugs such as Ecstasy. From the alkaloid composition of cacti we hypothesized that substances resembling Ecstasy might occur naturally. In this article we show that lophophine, homopiperonylamine and lobivine are new minor constituents of two cactus species, Lophophora williamsii (peyote) and Trichocereus pachanoi (San Pedro). This is the first report of putatively psychoactive phenethylamines besides mescaline in these cacti. A search for further biosynthetic analogues may provide new insights into the structure-activity relationships of mescaline. An intriguing question is whether the new natural compounds can be called "designer drugs."</p

Comparison between the urinary alcohol markers EtG, EtS, and GTOL/5-HIAA in a controlled drinking experiment

5-hydroxyindole-3-acetic acid (GTOL/5-HIAA) are all suggested as biomarkers for recent alcohol ingestion with longer detection times than measurement of ethanol itself. The aim of this controlled study was to compare the sensitivities and detection times of EtG, EtS, and GTOL/5-HIAA, after a single ingestion of ethanol. Methods: 0.5 g ethanol/kg body weight was ingested by 10 healthy male volunteers in a fasted state. Ethanol, EtG, EtS, and GTOL/HIAA levels were measured in urine samples collected during a 45–50 h period. The total amount of ethanol excreted as EtG and EtS was also determined. Results: Urinary EtG, EtS, and GTOL/5-HIAA showed 100 % sensitivity as biomarkers for recent drinking. Compared to ethanol testing in urine, the detection times for GTOL/5-HIAA were ∼5 h longer and for EtG and EtS ∼25 h longer. The maximum EtG concentrations were higher than for EtS in all subjects, and a higher fraction of the ethanol dose was excreted as EtG (median 0.019%) compared with EtS (median 0.011%). Conclusions: This study is the first controlled experiment comparing the time-courses for ethanol, EtG, EtS, and GTOL/5-HIAA in urine. In cases where surveillance of alcohol relapse is needed, measurements of urinary EtG and EtS are sensitive and specific alternatives to ethanol testing. The GTOL/5-HIAA ratio is equally sensitive but with a much shorter window of detection