Day 5 vitrified blastocyst transfer versus day 6 vitrified blastocyst transfer in oocyte donation program.

The superiority of day 5 blastocysts compared to day 6 blastocysts in fresh cycle transfers was previously demonstrated and attributed mainly to endometrial asynchrony. Data from frozen blastocysts transfers showed conflicting results, possibly due to heterogeneous patient population and embryo quality. The aim of this study was to compare clinical pregnancy rate (CPR) and live birth rate (LBR) between transfers of vitrified day 5 blastocysts and day 6 blastocysts in oocyte donation, blastocyst-only cycles. In a retrospective, multi-center study, with a single oocyte donation program, a total of 1840 frozen embryo transfers (FET's) were analyzed, including 1180 day 5 blastocysts and 660 day 6 blastocysts transfers. Day 5 blastocyst transfers had better embryonic development and significantly higher CPRs (34.24% vs. 20.15%, P < 0.0001), higher LBRs (26.89% vs. 14.77%, P < 0.0001), less cycles to LBR (1.83 ± 0.08 vs. 2.39 ± 0.18, P = 0.003) and shorter time to LBRs (76.32 ± 8.7 vs. 123.24 ± 19.1 days, P = 0.01), compared to day 6 transfers, respectively. A multivariate stepwise logistic regression indicated, that day 5 transfer was an independent factor for CPRs (OR 1.91; 95% CI 1.43-2.54, P < 0.001) and LBRs (OR 2.26; 95% CI 1.19-4.28, P = 0.01), regardless of embryo quality, compared to day 6. In conclusion, day 5 blastocysts in oocyte donation program have significantly higher CPRs and LBRs, and present shorter time to delivery, compared to day 6 blastocysts, regardless of embryo quality.

Fetal Brain MRI: Novel Classification and Contribution to Sonography.

PURPOSE: 1) To evaluate and classify the indications for fetal brain MRI in a tertiary referral center. 2) To assess the contribution of fetal brain MRI to fetal neurosonography. MATERIALS AND METHODS: A retrospective study in a tertiary medical center during a two-year period (2011 - 2012) included pregnant women who underwent fetal brain MRI. MRI was implemented at 32 weeks of gestation unless a severe abnormality possibly requiring earlier medical intervention was suspected. RESULTS: 633 patients were included, 40 (6.3%) underwent repeated examinations with a total of 733 fetal MRI scans. Patients were classified to three main indication cohorts: Suspected primary brain anomaly (52.9%), non-CNS disorders (32.5%) and obstetrical complications (14.6%). These cohorts were further divided into 16 separate groups with lateral ventricle abnormalities being the most common (23.7%), followed by exposure to TORCH (17.5%) and cerebral cortex abnormalities (13%). 149 (19.3%) fetal MRI scans demonstrated additional findings. Repeated examinations were commonly implemented in complicated monochorionic-biamniotic (MCBA) twin pregnancies (34.6%) and in cases of supra-tentorial cysts (19%). The average gestational age for MRI scan in the MCBA group was 26 ±â€Š5 weeks in comparison to ≥ 31st weeks in all other groups (p < 0.001). CONCLUSION: The current study describes a detailed picture of fetal brain MRI indications. Most patients were referred because of CNS anomalies. The impressive diversity of 16 separate entities emphasizes the expanding use of fetal brain MRI. Complicated MCBA pregnancies, which may have dramatic events, constitute a unique challenge due to early and repetitive MRI examinations and may serve as a role model for the contribution of fetal MRI during antenatal evaluation. The contribution of MRI to prenatal evaluation in various indications is discussed.

Prenatal Brain Imaging in Isolated vs. Complicated Club Foot: A Cohort Study.

Purpose: Talipes equinovarus (TEV) is a common birth defect. Differentiation between isolated and complex TEV is fundamental due to its effect on prognosis. Association between TEV and poor neurological outcome is more prominent in complex cases and highlights the significance of brain evaluation. The aim of the current study was to evaluate the contribution of fetal brain MRI to sonographic evaluation. Materials and Methods: In this retrospective study we evaluated charts of all pregnant patients referred for fetal brain MRI due to fetal TEV between 1/1/2011 and 12/31/14 in a single tertiary referral center. Isolated and complex TEV were differentiated according to associated anomalies. Brain US and MRI results were compared. Results: 28 pregnant patients were included with an average gestation and parity of 2.5 and 1.5, respectively. Both isolated and complicated TEV groups included 14 fetuses after initial TEV diagnosis on anatomical survey. Brain sonography and MRI were normal among 12/14 patients with isolated TEV while two patients were later diagnosed with mild ventriculomegaly. US brain evaluation has revealed pathologic findings in 4 (28.6 %) cases in the complicated TEV group, while MRI demonstrated abnormal findings in 8 (57.1 %) fetuses with notable severity diversity. In 6 cases, MRI diagnosed additional pathologies which were not demonstrated by US. Conclusion: Brain fetal MRI is an efficient tool during antenatal evaluation of complicated TEV with a high percentage of additional findings not demonstrated songraphically while its efficacy in isolated cases is in doubt. The current study expands the relevance of fetal brain MRI in cases of non-CNS anomalies.

Muon spin relaxation and susceptibility studies of the pure and diluted spin 1/2 kagomé-like lattice system (CuxZn(1-x))3V2O7(OH2) 2H2O.

Muon spin relaxation and magnetic susceptibility measurements have been performed on the pure and diluted spin 1/2 kagomé system (CuxZn(1-x))3V2O7(OH)2 2H2O. In the pure x=1 system we found a slowing down of Cu spin fluctuations with decreasing temperature towards T approximately 1 K, followed by slow and nearly temperature-independent spin fluctuations persisting down to T=50 mK, indicative of quantum fluctuations. No indication of static spin freezing was detected in either of the pure (x=1.0) or diluted samples. The observed magnitude of fluctuating fields indicates that the slow spin fluctuations represent an intrinsic property of kagomé network rather than impurity spins.

Spotting neural spike patterns using an adversary background model.

The detection of a specific stochastic pattern embedded in an unknown background noise is a difficult pattern recognition problem, encountered in many applications such as word spotting in speech. A similar problem emerges when trying to detect a multineural spike pattern in a single electrical recording, embedded in the complex cortical activity of a behaving animal. Solving this problem is crucial for the identification of neuronal code words with specific meaning. The technical difficulty of this detection is due to the lack of a good statistical model for the background activity, which rapidly changes with the recording conditions and activity of the animal. This work introduces the use of an adversary background model. This model assumes that the background "knows" the pattern sought, up to a first-order statistics, and this "knowledge" creates a background composed of all the permutations of our pattern. We show that this background model is tightly connected to the type-based information-theoretic approach. Furthermore, we show that computing the likelihood ratio is actually decomposing the log-likelihood distribution according to types of the empirical counts. We demonstrate the application of this method for detection of the reward patterns in the basal ganglia of behaving monkeys, yielding some unexpected biological results.

Detecting precise firing sequences in experimental data.

A precise firing sequence (PFS) is defined here as a sequence of three spikes with fixed delays (up to some time accuracy Delta), that repeat excessively. This paper provides guidelines for detecting PFSs, verifying their significance through surrogate spike trains, and identifying existing PFSs. The method is based on constructing a three-fold correlation among spikes, estimating the expected shape of the correlation by smoothing, and detecting points for which the correlations significantly protrude above the expected correlation. Validation is achieved by generating surrogate spike trains in which the time of each of the real spikes is randomly jittered within a small time window. The method is extensively tested through application to simulated spike trains, and the results are illustrated with recordings of single units in the frontal cortex of behaving monkeys. Pitfalls which may cause false detection of PFSs, or loss of existing PFSs, include searching for PFSs in which the same neuron participates more than once, and attempting to produce a surrogate with some fixed statistical property.

Cortical activity flips among quasi-stationary states.

Parallel recordings of spike trains of several single cortical neurons in behaving monkeys were analyzed as a hidden Markov process. The parallel spike trains were considered as a multivariate Poisson process whose vector firing rates change with time. As a consequence of this approach, the complete recording can be segmented into a sequence of a few statistically discriminated hidden states, whose dynamics are modeled as a first-order Markov chain. The biological validity and benefits of this approach were examined in several independent ways: (i) the statistical consistency of the segmentation and its correspondence to the behavior of the animals; (ii) direct measurement of the collective flips of activity, obtained by the model; and (iii) the relation between the segmentation and the pair-wise short-term cross-correlations between the recorded spike trains. Comparison with surrogate data was also carried out for each of the above examinations to assure their significance. Our results indicated the existence of well-separated states of activity, within which the firing rates were approximately stationary. With our present data we could reliably discriminate six to eight such states. The transitions between states were fast and were associated with concomitant changes of firing rates of several neurons. Different behavioral modes and stimuli were consistently reflected by different states of neural activity. Moreover, the pair-wise correlations between neurons varied considerably between the different states, supporting the hypothesis that these distinct states were brought about by the cooperative action of many neurons.

An effect of linguistic experience. Auditory word discrimination by native and non-native speakers of English.

In this study, the effect of linguistic experience on the auditory discrimination of words has been examined. 18 subjects, including 6 native and 12 non-native speakers of English, were tested with CID auditory test W-22 in quiet and in the presence of white noise at the signal-to-noise (S/N) ratios of +12, +6 and 0 dB. The non-native speakers of English included 6 with 1 year of experience and 6 with 3-4 years of experience speaking Enligsh in the USA. In the absence of noise, the results were essentially equivalent for all three groups. As noise level increased, word discrimination deteriorated for all three groups with non-native speakers of English obtaining results significantly poorer than native speakers of English. Linguistic experience and noise levels were significant at the 0.001 level fo confidence. It appears that at 0 dB S/N, individual variability of non-native speakers of English, regardless of their original linguistic background, was much smaller than that found for native speakers of English. The results of the study tend to indicate that a limited linguistic experience results in a persistent deterioration of auditory word discrimination under impoverished conditions of audition.