Miscellaneous earthworm types in the Natural History Museum, London (Annelida: Oligochaeta: Megadrilacea: Eudrilidae, Lumbricidae, Megascolecidae, Moniligastridae, Octochaetidae)

Recently restored Lumbricus terrestris Linnaeus, 1758 neotype (NHM Register No. 1973.1.1) is described in greater detail. A lectotype is designated for Amynthas morrisi (Beddard, 1892) and an informal A. morrisi clonal speciescomplex is proposed. Once combined under A. gracilis (Kinberg, 1867), the nominal taxon is revised since its restoration and representation of A. morrisi species-group sensu Sims & Easton (1972), now unwieldy with forty or so members. A restricted A. morrisi sensu stricto is proposed with re-evaluation of its erstwhile synonyms based on types. Limited DNA COI barcode comparisons are appended. A lectotype for A. barbadensis (Beddard, 1892) now becomes a junior synonym of Amynthas gracilis removing it from nomenclatural consideration. Lectotypes of contenders, A. mauritianus (Beddard, 1892) itself closer to A. gracilis, and A. insulae (Beddard, 1896) appear separate from A. morrisi. Next, A. pallidus (Michaelsen, 1892) is restored with retention of some of its synonyms, but A. loveridgei (Gates, 1968) syntype is maintained. An exotic species from Queensland, Australia is a new member of A. morrisi species-group described as Amynthas talus sp. nov. Taxonomic ‘housekeeping’ of Queensland taxa requires re-allocation of Terrisswalkerius leichhardti Jamieson, McDonald et James, 2013 to prior Perionychella Michaelsen, 1907. New Zealand’s possibly extinct Tokea? orthostichon (Schmarda, 1861) and imperfectly known Anisochaeta antarctica (Baird, 1871) are revised in new combinations with slight revision of the genus Tokea Benham, 1904. Samples labelled as Hamburg syntypes of Japanese Metaphire hilgendorfi (Michaelsen, 1892) are briefly noted as are various other megadriles, such as divers pheretimoids and lumbricids, some also on loan, in the Museum’s collection

Darwin’s earthworms (Annelida, Oligochaeta, Megadrilacea) with review of cosmopolitan Metaphire peguana–species group from Philippines.

A chance visit to Darwin allowed inspection of and addition to Northern Territory (NT) Museum’s earthworm collection. Native Diplotrema zicsii sp. nov. from Alligator River, Kakadu NP is described. Town samples were dominated by cosmopolitan exotic Metaphire bahli (Gates, 1945) herein keyed and compared morpho-molecularly with M. peguana (Rosa, 1890) requiring revision of allied species including Filipino Pheretima philippina (Rosa, 1891), P. p. lipa and P. p. victorias sub-spp. nov. A new P. philippina-group now replaces the dubia-group of Sims & Easton, 1972 and Amynthas carinensis (Rosa, 1890) further replaces their sieboldi-group. Lumbricid Eisenia fetida (Savigny, 1826) and Glossoscolecid Pontoscolex corethrurus (Müller, 1857) are confirmed introductions to the NT. mtDNA barcodes newly include Metaphire houlleti (Perrier, 1872) and Polypheretima elongata (Perrier, 1872) spp.-complexes from the Philippines. Pithemera philippinensis James & Hong, 2004 and Pi. glandis Hong & James, 2011 are new synonyms of Pi. bicincta (Perrier, 1875) that is common in Luzon. Vietnamese homonym Pheretima thaii Nguyen, 2011 (non P. thaii Hong & James, 2011) is replaced with Pheretima baii nom. nov. Two new Filipino taxa are also described: Pleionogaster adya sp. nov. from southern Luzon and Pl. miagao sp. nov. from western Visayas

The perception of self-produced sensory stimuli in patients with auditory hallucinations and passivity experiences: evidence for a breakdown in self-monitoring

BACKGROUND: To test the hypothesis that certain psychotic symptomatology is due to a defect in self-monitoring, we investigated the ability of groups of psychiatric patients to differentiate perceptually between self-produced and externally produced tactile stimuli. METHODS: Responses to tactile stimulation were assessed in three groups of subjects: schizophrenic patients; patients with bipolar affective disorder or depression; and normal control subjects. Within the psychiatric groups subjects were divided on the basis of the presence or absence of auditory hallucinations and/or passivity experiences. The subjects were asked to rate the perception of a tactile sensation on the palm of their left hand. The tactile stimulation was either self-produced by movement of the subject's right hand or externally produced by the experimenter. RESULTS: Normal control subjects and those psychiatric patients with neither auditory hallucinations nor passivity phenomena experienced self-produced stimuli as less intense, tickly and pleasant than identical, externally produced tactile stimuli. In contrast, psychiatric patients with these symptoms did not show a decrease in their perceptual ratings for tactile stimuli produced by themselves as compared with those produced by the experimenter. This failure to show a difference in perception between self-produced and externally produced stimuli appears to relate to the presence of auditory hallucinations and/or passivity experiences rather than to the diagnosis of schizophrenia. CONCLUSIONS: We propose that auditory hallucinations and passivity experiences are associated with an abnormality in the self-monitoring mechanism that normally allows us to distinguish self-produced from externally produced sensations

Contralateral manual compensation for velocity-dependent force perturbations

It is not yet clear how the temporal structure of a voluntary action is coded allowing coordinated bimanual responses. This study focuses on the adaptation to and compensation for a force profile presented to one stationary arm which is proportional to the velocity of the other moving arm. We hypothesised that subjects would exhibit predictive coordinative responses which would co-vary with the state of the moving arm. Our null hypothesis is that they develop a time-dependent template of forces appropriate to compensate for the imposed perturbation. Subjects were trained to make 500 ms duration reaching movements with their dominant right arm to a visual target. A force generated with a robotic arm that was proportional to the velocity of the moving arm and perpendicular to movement direction acted on their stationary left hand, either at the same time as the movement or delayed by 250 or 500 ms. Subjects rapidly learnt to minimise the final end-point error. In the delay conditions, the left hand moved in advance of the onset of the perturbing force. In test conditions with faster or slower movement of the right hand, the predictive actions of the left hand co-varied with movement speed. Compensation for movement-related forces appeared to be predictive but not based on an accurate force profile that was equal and opposite to the imposed perturbatio

The major megadrile families of th e World reviewed again on their taxonomic types (Annelida: Oligochaeta: Megadrilacea)

A critique of recent clado-molecular phylogenies notes shortcomings of starting materials, methods applied, and,therefore, their conclusions; hence this review. A new group, Exquisiclitellata, is newly defined as those ‘non-crassiclitellate’members of the superorder Megadrilacea (viz., Moniligastridae Claus, 1880, plus Alluroididae Michaelsen, 1900 andSyngenodrilidae Smith & Green, 1919). Support for restitution and elevation of American Diplocardiinae Michaelsen, 1900and Argilophilini Fender & McKey-Fender, 1990 are again raised. ICZN priority requires revival of Typhoeus Beddard, 1883over synonym Eutyphoeus Michaelsen, 1900 and the sub-family Typhoeinae (corr. of Typhaeinae Benham, 1890) is reestablished.Hoplochaetellinae sub-family nov. is proposed as a development of Octochaetidae s. lato in India.Wegeneriellinae sub-fam. nov. accommodates the holoic members of a restricted Neogastrini Csuzdi, 1996 from W. Africaand S. America. Caribbean family Exxidae Blakemore, 2000 and related Trigastrinae Michaelsen, 1900 are both retained. Acontingency table of Megascolecidae s. stricto sub-families and types is presented with some revived and a few new subfamiliesproposed, particularly from Australasia. These are Diporochaetinae, Megascolidesinae, Celeriellinae, andWoodwardiellinae sub-fams. nov. Synonymy of Perichaetidae Claus, 1880 over Megascolecidae Rosa, 1891 is deferred forreasons of nomenclatural stability. For the large African family Eudrilidae Claus, 1880, a new sub-family, Polytoreutinae, isadvanced and the status of abandoned Teleudrilini Michaelsen, 1891 and overlooked Hippoperidae Taylor, 1949 are noted

Relation among concentrations of incorporated Mn atoms, ionized Mn acceptors, and holes in p-(Ga,Mn)As epilayers

The amount of ionized Mn acceptors in various p-type Mn-doped GaAs epilayers has been evaluated by electrochemical capacitance-voltage measurements, and has been compared systematically with concentrations of incorporated Mn atoms and holes for wide range of Mn concentration (10^17 ~ 10^21 cm^-3). Quantitative assessment of anomalous Hall effect at room temperature is also carried out for the first time.Comment: 8 pages, 4 figures, tabl

Risk-taking to obtain reward: sex differences and associations with emotional and depressive symptoms in a nationally representative cohort of UK adolescents

BACKGROUND: Cognitive mechanisms that characterize or precede depressive symptoms are poorly understood. We investigated cross-sectional and longitudinal associations between risk taking to obtain reward and adolescent depressive symptoms in a large prospective cohort, using the Cambridge Gambling Task (CGT). We also explored sex differences. METHODS: The Millennium Cohort Study (MCS) is an ongoing UK study, following the lives of 19 000 individuals born 2000/02. The CGT was completed at ages 11 (n = 12 355) and 14 (n = 10 578). Our main exposure was the proportion of points gambled, when the odds of winning were above chance (risk-taking to obtain reward). Outcomes were emotional symptoms (Strengths and Difficulties Questionnaire, SDQ) at age 11 and depressive symptoms (short Mood and Feelings Questionnaire, sMFQ) at age 14. We calculated cross-sectional and longitudinal associations, using linear regressions. RESULTS: In univariable models, there was evidence of cross-sectional associations between risk-taking and SDQ/sMFQ scores, but these associations disappeared after we adjusted for sex. Longitudinally, there was weak evidence of an association between risk-taking and depressive symptoms in females only [a 20-point increase in risk-taking at age 11 was associated with a reduction of 0.31 sMFQ points at age 14 (95% CI -0.60 to -0.02)]. At both time-points, females were less risk-taking than males. CONCLUSIONS: We found no convincing evidence of a relationship between risk-taking to obtain reward and depressive symptoms. There were large sex differences in risk-taking, but these do not appear to contribute to the female preponderance of depressive symptoms in adolescence

Stochastic Dynamics of Magnetosomes in Cytoskeleton

Rotations of microscopic magnetic particles, magnetosomes, embedded into the cytoskeleton and subjected to the influence of an ac magnetic field and thermal noise are considered. Magnetosome dynamics is shown to comply with the conditions of the stochastic resonance under not-too-tight constraints on the character of the particle's fastening. The excursion of regular rotations attains the value of order of radian that facilitates explaining the biological effects of low-frequency weak magnetic fields and geomagnetic fluctuations. Such 1-rad rotations are effectively controlled by slow magnetic field variations of the order of 200 nT.Comment: LaTeX2e, 7 pages with 3 figure

Magnetic irreversibility and Verwey transition in nano-crystalline bacterial magnetite

The magnetic properties of biologically-produced magnetite nanocrystals biomineralized by four different magnetotactic bacteria were compared to those of synthetic magnetite nanocrystals and large, high quality single crystals. The magnetic feature at the Verwey temperature, $T_{V}$, was clearly seen in all nanocrystals, although its sharpness depended on the shape of individual nanoparticles and whether or not the particles were arranged in magnetosome chains. The transition was broader in the individual superparamagnetic nanoparticles for which $T_{B}<T_{V}$, where $T_{B}$ is the superparamagnetic blocking temperature. For the nanocrystals organized in chains, the effective blocking temperature $T_{B}>T_{V}$ and the Verwey transition is sharply defined. No correlation between the particle size and $T_{V}$ was found. Furthermore, measurements of $M(H,T,time)$ suggest that magnetosome chains behave as long magnetic dipoles where the local magnetic field is directed along the chain and this result confirms that time-logarithmic magnetic relaxation is due to the collective (dipolar) nature of the barrier for magnetic moment reorientation