DNA topoisomerase II enzyme activity appears in mouse sperm heads after fertilization

Sperm suspensions of 4 male mice (A, B, C and D), having an initial motility grade of 3.5 were used to examine the presence of DNA topoisomerase II (top 2) activity in sperm heads. The initial percentage motile of male A was 75%, male B was 80%, male C was 70% and male D was 60%. Top 2 activity was examined by testing the effect of etoposide (ETO), a specific top 2 blocker, on sperm motility, fertilizing ability and formation of the male pronuclei. Sperm suspension drops (0.5 ml) and fertilization drops (0.4 ml) were made from TYH medium with 50 μg/ ml ETO (treatments) or TYH without ETO (controls). Sperm suspensions were made from epididymal sperms of the above males in treatments and controls and incubated for 3 h. Mature mouse oocytes (n = 461) were co-cultured with capacitated sperms in the treatments fertilization drops for 5 h. Other oocytes (n= 437) were co-cultured with capacitated sperms in the controls fertilization drops. The oocytes were further cultured for 24 h in KSOM with ETO (for treatments) and KSOM without ETO (for controls). Six sperm motility indexes (SMI) for each male were recorded at 30 min interval according to the formula, SMI = (grade)2 × % motile. The fertilization rates and nuclear events were assessed by observing the pronuclei under an inverted microscope and finding the sperm heads in whole mounts from the oocytes that failed to make pronuclei. The SMI of the treatments and the controls increased gradually and reached peak values after 2 h of incubation. No differences (p > 0.05) were observed among SMI of the treatments and the controls. However, treatment reduced (p < 0.05) the fertilization rate and completely inhibited the formation of the pronuclei. All the oocytes fertilized in treatments (n = 412) failed to form pronuclei and all had enlarged or decondensed sperm heads, whereas 92.6% of the oocytes fertilized in the controls (n= 378) had pronuclei and only 30 (7.4%) oocytes had enlarged or decondensed sperm heads. Neither sperm motility nor fertilization were inhibited with ETO. However, the formation of the pronuclei was blocked. It was concluded that ETO has no effect on sperm capacitation and top 2 activity appears in mouse sperm heads after oocyte penetration.Key words: DNA topoisomerase II, sperm, treatment, mice

Model-based kernel sum rule: kernel Bayesian inference with probabilistic model

Kernel Bayesian inference is a principled approach to nonparametric inference in probabilistic graphical models, where probabilistic relationships between variables are learned from data in a nonparametric manner. Various algorithms of kernel Bayesian inference have been developed by combining kernelized basic probabilistic operations such as the kernel sum rule and kernel Bayes’ rule. However, the current framework is fully nonparametric, and it does not allow a user to flexibly combine nonparametric and model-based inferences. This is inefficient when there are good probabilistic models (or simulation models) available for some parts of a graphical model; this is in particular true in scientific fields where “models” are the central topic of study. Our contribution in this paper is to introduce a novel approach, termed the model-based kernel sum rule (Mb-KSR), to combine a probabilistic model and kernel Bayesian inference. By combining the Mb-KSR with the existing kernelized probabilistic rules, one can develop various algorithms for hybrid (i.e., nonparametric and model-based) inferences. As an illustrative example, we consider Bayesian filtering in a state space model, where typically there exists an accurate probabilistic model for the state transition process. We propose a novel filtering method that combines model-based inference for the state transition process and data-driven, nonparametric inference for the observation generating process. We empirically validate our approach with synthetic and real-data experiments, the latter being the problem of vision-based mobile robot localization in robotics, which illustrates the effectiveness of the proposed hybrid approach

Observation of thundercloud-related gamma rays and neutrons in Tibet

During the 2010 rainy season in Yangbajing (4300 m above sea level) in Tibet, China, a long-duration count enhancement associated with thunderclouds was detected by a solar-neutron telescope and neutron monitors installed at the Yangbajing Comic Ray Observatory. The event, lasting for ∼40  min, was observed on July 22, 2010. The solar-neutron telescope detected significant γ-ray signals with energies >40  MeV in the event. Such a prolonged high-energy event has never been observed in association with thunderclouds, clearly suggesting that electron acceleration lasts for 40 min in thunderclouds. In addition, Monte Carlo simulations showed that >10  MeV γ rays largely contribute to the neutron monitor signals, while >1  keV neutrons produced via a photonuclear reaction contribute relatively less to the signals. This result suggests that enhancements of neutron monitors during thunderstorms are not necessarily clear evidence for neutron production, as previously thought

Relationship of Glucose Variability and Daily Lifestyle by Continuous Glucose Monitoring (CGM)

Authors and collaborators have continued diabetic practice and research on low carbohydrate diet (LCD), continuous glucose monitoring (CGM), and so on. The case is a 64-year-old male with type 2 diabetes mellitus (T2DM) treated with multiple daily insulin injections (MDI). When his HbA1c was 8.2% before, he changed to take tofu instead of rice and bread. HbA1c decreased to 7.1% and 4kg of weight reduction in 2 months. Tofu is a traditional Japanese food made from soybeans, which is a suitable LCD with Protein:Fat:Carbohydrate (PFC) ratio=40:45:15 in this case. His HbA1c is recently unstable, then glucose variability was investigated by CGM using FreeStyle Libre. The glucose pattern was different due to his lifestyle, including working day, off day, playing golf, respectively. The average glucose was 143-167 mg/dL and the estimated HbA1c was 7.1%, whereas HbA1c in outclinic was 8.1%, respectively. This report will hopefully become reference data for future research