Abnormal negative feedback processing in first episode schizophrenia: evidence from an oculomotor rule switching task

Background. Previous studies have shown that patients with schizophrenia are impaired on executive tasks, where positive and negative feedbacks are used to update task rules or switch attention. However, research to date using saccadic tasks has not revealed clear deficits in task switching in these patients. The present study used an oculomotor ‘ rule switching ’ task to investigate the use of negative feedback when switching between task rules in people with schizophrenia. Method. A total of 50 patients with first episode schizophrenia and 25 healthy controls performed a task in which the association between a centrally presented visual cue and the direction of a saccade could change from trial to trial. Rule changes were heralded by an unexpected negative feedback, indicating that the cue-response mapping had reversed. Results. Schizophrenia patients were found to make increased errors following a rule switch, but these were almost entirely the result of executing saccades away from the location at which the negative feedback had been presented on the preceding trial. This impairment in negative feedback processing was independent of IQ. Conclusions. The results not only confirm the existence of a basic deficit in stimulus–response rule switching in schizophrenia, but also suggest that this arises from aberrant processing of response outcomes, resulting in a failure to appropriately update rules. The findings are discussed in the context of neurological and pharmacological abnormalities in the conditions that may disrupt prediction error signalling in schizophrenia

Root Fracture in Immature Tooth: Report of a Case

Root fracture injuries affect 0.5–7% of permanent teeth. Although this type of injury is rarely seen in teeth with immature root formation, the prognosis is generally good depending on the site of the fracture. A case report of horizontal root fracture in maxillary central incisor of an 8-year and 3-month-old girl and its treatment was presented

Anaerobic digestion as a tool to eliminate animal parasites and weed seeds

Anaerobic digestion of residual materials from animals and crops offers an opportunity to simultaneously produce bioenergy and plant fertilizers at single farms and in farm communities where input substrate materials and resulting digested residues are shared among member farms. A surplus benefit from this praxis may be the suppressing of propagules from harmful biological pest like animal parasites, pathogens, and weed seeds. In the BIOCONCENS project (http://www.icrofs.dk/Sider/Forskning/foejoIII_bioconcens.html) batch experiments were performed, where survival of six species of weeds and the pigs large roundworm Ascaris suum (non-embryonated eggs) was assessed under conditions similar to biogas plants managed at meso- (37°C) and thermophilic (50°C) conditions. Cattle manure was used as digestion substrate and experimental units were sampled destructively during time. Regarding survival of A. suum, the effect of thermophilic conditions was highly significant as no eggs survived more than 3 h of incubation at 50°C. Incubation at 37°C did not affect egg survival during the first 48 h and it took up to 10 days before total elimination was reached. Similarly, at 50°C complete mortality of weed seeds, irrespective of species, was reached after less than two days. At mesophilic conditions, seeds of Avena fatua, Sinapsis arvensis, Solidago Canadensis had completely lost germination ability, while Brassica napus, Fallopia convolvulus and Amzinckia micranta still maintained low levels (~1%) of germination ability after one week. Chenopodium album was the only weed species which survived one week at substantial levels (7%) although after 11 d germination ability was totally lost. In general, anaerobic digestion in biogas plants seems an efficient way (thermophilic more efficient than mesophilic) to treat organic farm wastes in a way that suppresses animal parasites and weeds so that the digestates can be applied without risking the spread of these pests

Second Overtone Pulsators Among Delta Scuti Stars

We investigate the modal stability of stellar models at masses and luminosity levels corresponding to post main sequence luminous delta scuti pulsators. The envelope models have been computed at fixed mass value, luminosity level and chemical composition (Y=0.28, Z=0.02). According to a nonlinear approach to radial oscillations the present investigation predicts the occurrence of stable second overtone pulsators for the first time. The shape of both light and velocity curves are presented and discussed, providing a useful tool for the identification of second overtone pulsators among the known groups of radially pulsating stars. The period ratios of mixed mode pulsators obtained by perturbing the first and the second overtone radial eigenfunctions are in agreement with observative values. Finally, the physical structure and the dynamical properties of second overtone pulsators are discussed in detail. The role played by the nodal lines in the destabilization of second overtone pulsators is also pointed out.Comment: 20 pages, 11 Postscript figures, uses aaspp4.sty and tighten.st

NIR spectroscopy of the Sun and HD20010 - Compiling a new linelist in the NIR

Context: Effective temperature, surface gravity, and metallicity are basic spectroscopic stellar parameters necessary to characterize a star or a planetary system. Reliable atmospheric parameters for FGK stars have been obtained mostly from methods that relay on high resolution and high signal-to-noise optical spectroscopy. The advent of a new generation of high resolution near-IR spectrographs opens the possibility of using classic spectroscopic methods with high resolution and high signal-to-noise in the NIR spectral window. Aims: We aim to compile a new iron line list in the NIR from a solar spectrum to derive precise stellar atmospheric parameters, comparable to the ones already obtained from high resolution optical spectra. The spectral range covers 10 000 {\AA} to 25 000 {\AA}, which is equivalent to the Y, J, H, and K bands. Methods: Our spectroscopic analysis is based on the iron excitation and ionization balance done in LTE. We use a high resolution and high signal-to-noise ratio spectrum of the Sun from the Kitt Peak telescope as a starting point to compile the iron line list. The oscillator strengths (log gf) of the iron lines were calibrated for the Sun. The abundance analysis was done using the MOOG code after measuring equivalent widths of 357 solar iron lines. Results: We successfully derived stellar atmospheric parameters for the Sun. Furthermore, we analysed HD20010, a F8IV star, from which we derived stellar atmospheric parameters using the same line list as for the Sun. The spectrum was obtained from the CRIRES- POP database. The results are compatible with the ones found in the literature, confirming the reliability of our line list. However, due to the quality of the data we obtain large errors.Comment: 9 pages and 9 figure