Continuous visual properties explain neural responses to nonsymbolic number

Nonsymbolic number and its continuous visual properties are confounded in everyday life: When number changes, its continuous visual properties also change. It could therefore be efficient to rely on the visual properties to judge number. The current consensus, however, holds that number is processed independent of its visual properties. In this study, we pitched these two opposing theories against each other. We used electroencephalography to look at the components suggested to process number. The first experiment showed that number and visual cues affect the N1 and/or the P2 component. To disentangle number and visual processes, we controlled the visual cues in the second experiment. Now, no number‐related effects were present. When the data were reorganized according to visual cue instead of number size, N1 and P2 effects emerged. These results argue against the idea that number is processed independent of its continuous visual variables.     

Congenital talipes equinovarus: comparison of outcome between a prenatal diagnosis and a diagnosis after delivery

OBJECTIVES: To establish the impact on outcome of prenatally versus postnatally detected talipes equinovarus (TEV). METHODS: The prenatal group was represented by pregnancies with sonographically detected TEV of which 18 were isolated and 39 were complex. The postnatal group contained 64 infants with an isolated and 10 infants with a complex TEV detected at birth. Treatment consisted of redressement followed by surgical postero-lateral or postero-medial release at the University Paediatric Orthopaedic Centre. The postnatal isolated TEV group underwent redressement treatment at the University Centre (subset A, n = 39) or at a regional general hospital (subset B, n = 25). RESULTS: For isolated TEV, statistically significant difference existed for the surgical procedure (p < 0.001), age at surgery (p < 0.01) and admission time (p < 0.001) between the prenatal and postnatal subset B and between the postnatal subsets A and B. For the complex TEV, no significant difference was found for these variables between the six surviving infants of the prenatal group and the postnatal group. CONCLUSION: Prenatal detection of isolated TEV results in earlier and less complicated postnatal surgery and a shorter admission time, provided treatment is arranged at a paediatric orthopaedic centre. After prenatal detection of a complex TEV, survival is low and determined by associated anomalies.     

Tel2 structure and function in the Hsp90-dependent maturation of mTOR and ATR complexes

We reported previously that the stability of all mammalian phosphatidylinositol 3-kinase-related protein kinases (PIKKs) depends on their interaction with Tel2, the ortholog of yeast Tel2 and Caenorhabditis elegans Clk-2. Here we provide evidence that Tel2 acts with Hsp90 in the maturation of PIKK complexes. Quantitative immunoblotting showed that the abundance of Tel2 is low compared with the PIKKs, and Tel2 preferentially bound newly synthesized ATM, ATR, mTOR, and DNA-PKcs. Tel2 complexes contained, in addition to Tti1–Tti2, the Hsp90 chaperone, and inhibition of Hsp90 interfered with the interaction of Tel2 with the PIKKs. Analysis of in vivo labeled nascent protein complexes showed that Tel2 and Hsp90 mediate the formation of the mTOR TORC1 and TORC2 complexes and the association of ATR with ATRIP. The structure of yeast Tel2, reported here, shows that Tel2 consists of HEAT-like helical repeats that assemble into two separate α-solenoids. Through mutagenesis, we identify a surface patch of conserved residues involved in binding to the Tti1–Tti2 complex in vitro. In vivo, mutation of this conserved patch affects cell growth, levels of PIKKs, and ATM/ATR-mediated checkpoint signaling, highlighting the importance of Tti1–Tti2 binding to the function of Tel2. Taken together, our data suggest that the Tel2–Tti1–Tti2 complex is a PIKK-specific cochaperone for Hsp90.     

Acetylcholine-binding proteins

Acetylcholine-binding protein (AChBP) is a water-soluble protein released from molluscan glial cells and modulates ACh-mediated synaptic transmission. Acetylcholine-binding protein (AChBP) is a water-soluble homolog of the ligand-binding domain of nicotinic receptors and other members of the pharmaceutically important family of pentameric ligand-gated ion channels (LGICs), GABAA, GABAC, 5-HT3 serotonin, and glycine receptors. The crystal structure of AChBP from Lymnaea stagnalis has become an established model for the extracellular domain of the pentameric LGICs, and homology models have been generated to analyze receptor-ligand interactions. AChBP has pharmacological properties similar to the homomeric alpha7 subtype of nicotinic ACh receptors (nAChRs), with relatively weak affinity for ACh and a 10-fold higher affinity for nicotine.     

Object representation in the human auditory system

One important principle of object processing is exclusive allocation. Any part of the sensory input, including the border between two objects, can only belong to one object at a time. We tested whether tones forming a spectro-temporal border between two sound patterns can belong to both patterns at the same time. Sequences were composed of low-, intermediate- and high-pitched tones. Tones were delivered with short onset-to-onset intervals causing the high and low tones to automatically form separate low and high sound streams. The intermediate-pitch tones could be perceived as part of either one or the other stream, but not both streams at the same time. Thus these tones formed a pitch 'border' between the two streams. The tones were presented in a fixed, cyclically repeating order. Linking the intermediate-pitch tones with the high or the low tones resulted in the perception of two different repeating tonal patterns. Participants were instructed to maintain perception of one of the two tone patterns throughout the stimulus sequences. Occasional changes violated either the selected or the alternative tone pattern, but not both at the same time. We found that only violations of the selected pattern elicited the mismatch negativity event-related potential, indicating that only this pattern was represented in the auditory system. This result suggests that individual sounds are processed as part of only one auditory pattern at a time. Thus tones forming a spectro-temporal border are exclusively assigned to one sound object at any given time, as are spatio-temporal borders in vision.     

Uterine and fetal umbilical artery flow velocity waveforms in normal first trimester pregnancies

In 85 normal singleton pregnancies between 8 and 13 weeks gestation, Doppler flow velocity waveform recordings were attempted from the left and right uterine artery and fetal umbilical artery. Acceptable waveforms were obtained from the uterine arteries in 83 and from the fetal umbilical artery in 61 of the 85 pregnancies. There was virtually no difference between the left and right uterine artery on average. The marked decrease in pulsatility (PI) and resistance (RI) indices from both uterine arteries reflects the ongoing process of secondary trophoblast invasion into the muscular part of the spiral arteries. Absent end-diastolic velocities were observed in 59 of 61 fetal umbilical artery flow velocity waveform recordings. PI values from the fetal umbilical artery suggest unaltered umbilical placental vascular resistance during the first trimester of pregnancy.     

Toxoplasma gondii infection in animal-friendly pig production systems

PURPOSE: Consumption of undercooked pork meat products has been considered a major risk factor for contracting toxoplasmosis in humans. Indoor farming and improved hygiene have drastically reduced Toxoplasma infections in pigs over the past decades. Whether introduction of animal-friendly production systems will lead to a reemergence of Toxoplasma infections in pigs is not yet known. Investigating this possibility was the purpose of this study. METHODS: Blood was obtained from pigs raised for slaughter and tested for Toxoplasma antibodies by using latex agglutination and indirect immunofluorescence testing, with confirmation by immunoblotting. RESULTS: None of the slaughter pigs (n = 621) from conventional farms (n = 30) were positive, whereas 38 (2.9%) of 1295 animals from animal-friendly systems tested positive (n = 33 farms; 13 [39%] farms positive). CONCLUSIONS: The following conclusions may be derived from this study: Conventionally (indoors) raised pigs are free from Toxoplasma infection, and (2) animal-friendly production systems may lead to a reemergence of Toxoplasma infections, although many of these farms remain Toxoplasma free. Slaughterhouse monitoring of pigs from animal-friendly production systems combined with on-farm prevention strategies should be applied to ensure safety for consumers of the meat products obtained from these animals.     

Ovarian function with a novel combined contraceptive vaginal ring

BACKGROUND: NuvaRing is a combined contraceptive vaginal ring designed for 3 weeks continuous use followed by a 1 week ring-free period. The present study evaluated ovarian function in women who were instructed to either adhere to, or deviate from, the recommended regimen of use. METHODS: In this open-label, randomized study, 45 women aged between 18 and 35 years used NuvaRing for one cycle in which the ring was used according to the recommended regimen. Women in group A (n = 15) then continued with a 'normal' 3 week period of ring use after which the restoration of ovarian function-i.e. the time to ovulation-for each woman was determined by daily vaginal ultrasound and serum hormone levels. For women in group B (n = 15), the second cycle consisted of only 3 consecutive days of ring use, after which each woman was monitored until ovulation. Women in group C (n = 15) were not permitted to start a second 'normal' cycle until a follicle with a diameter of 13 mm was observed by vaginal ultrasound; subsequently, the development of these follicles during the second cycle of ring use was monitored daily. RESULTS: Irrespective of the length of the second cycle, 3 weeks (group A) versus 3 days (group B), a new cohort of follicles needed to be recruited and the time to ovulation after ring removal was similar (19 versus 17 days). The median time needed to develop a follicle up to 13 mm in diameter (group C) was 11 days (range 8-21 days); none of the women ovulated after insertion of the second ring. CONCLUSION: NuvaRing is a highly effective, reversible method of hormonal contraception. Ovulation, at least until the stage of a 13 mm dominant follicle, is prevented and as little as 3 consecutive days of NuvaRing use interferes with follicle growth.     

Hemispheric lateralization of cerebral blood-flow changes during selective listening to dichotically presented continuous speech

Regional cerebral blood flow (rCBF) was measured with positron emission tomography (PET) while subjects were selectively listening to continuous speech delivered to one ear and ignoring concurrent speech delivered to the opposite ear, as well as concurrent text or letter strings running on a screen. rCBF patterns associated with selective listening either to the left-ear or right-ear speech message were compared with each other and with rCBF patterns in two visual-attention conditions in which the subjects ignored both speech messages and either read the text or discriminated the meaningless letter strings moving on the screen. Attention to either speech message was associated with enhanced activity in the superior temporal cortex of the language-dominant left hemisphere, as well as in the superior and middle temporal cortex of the right hemisphere suggesting enhanced processing of prosodic features in the attended speech. Moreover, enhanced activity during attention to either speech message was observed in the right parietal areas known to have an important role in directing spatial attention. Evidence was also found for attentional tuning of the left and right auditory cortices to select information from the contralateral auditory hemispace.