Phasic firing and coincidence detection by subthreshold negative feedback: divisive or subtractive or, better, both

Phasic neurons typically fire only for a fast-rising input, say at the onset of a step current, but not for steady or slow inputs, a property associated with type III excitability. Phasic neurons can show extraordinary temporal precision for phase locking and coincidence detection. Exemplars are found in the auditory brain stem where precise timing is used in sound localization. Phasicness at the cellular level arises from a dynamic, voltage-gated, negative feedback that can be recruited subthreshold, preventing the neuron from reaching spike threshold if the voltage does not rise fast enough. We consider two mechanisms for phasicness: a low threshold potassium current (subtractive mechanism) and a sodium current with subthreshold inactivation (divisive mechanism). We develop and analyze three reduced models with either divisive or subtractive mechanisms or both to gain insight into the dynamical mechanisms for the potentially high temporal precision of type III-excitable neurons. We compare their firing properties and performance for a range of stimuli. The models have characteristic non-monotonic input-output relations, firing rate vs. input intensity, for either stochastic current injection or Poisson-timed excitatory synaptic conductance trains. We assess performance according to precision of phase-locking and coincidence detection by the models' responses to repetitive packets of unitary excitatory synaptic inputs with more or less temporal coherence. We find that each mechanism contributes features but best performance is attained if both are present. The subtractive mechanism confers extraordinary precision for phase locking and coincidence detection but only within a restricted parameter range when the divisive mechanism of sodium inactivation is inoperative. The divisive mechanism guarantees robustness of phasic properties, without compromising excitability, although with somewhat less precision. Finally, we demonstrate that brief transient inhibition if properly timed can enhance the reliability of firing.Postprint (published version

China's New Third Board Market: Opportunities and Challenges

AbstractThe New Third Board Market is China's OTC market, established in 2006. Compared to China's Main Board Market and the Second Board Market, it attracts a lot of start-up companies needing financing with lower listing requirements. Meanwhile, it is full of opportunities and challenges that appeal to numerous securities traders and investors with the rapid development momentum. This paper is intended to build a comprehensive and systematic knowledge framework of China's New Third Board Market for those enterprises and individuals interested in it, and to provide a research base for future researchers

Type III excitability, slope sensitivity and coincidence detection

Some neurons in the nervous system do not show repetitive firing for steady currents. For time-varying inputs, they fire once if the input rise is fast enough. This property of phasic firing is known as Type III excitability. Type III excitability has been observed in neurons in the auditory brainstem (MSO), which show strong phase-locking and accurate coincidence detection. In this paper, we consider a Hodgkin-Huxley type model (RM03) that is widely-used for phasic MSO neurons and we compare it with a modification of it, showing tonic behavior. We provide insight into the temporal processing of these neuron models by means of developing and analyzing two reduced models that reproduce qualitatively the properties of the exemplar ones. The geometric and mathematical analysis of the reduced models allows us to detect and quantify relevant features for the temporal computation such as nearness to threshold and a temporal integration window. Our results underscore the importance of Type III excitability for precise coincidence detection.Postprint (published version

Analysis on the Trading Path of Carbon Emission Rights of Village-level Photovoltaic Poverty Alleviation Power Stations in China

Photovoltaic poverty alleviation is a pioneering initiative in the organic combination of China’s poverty alleviation and new energy development. As a landmark project of China’s targeted poverty alleviation, it is characterized with rapid effects, steady profits, precise poverty alleviation and environmental-friendliness. Developing the photovoltaic poverty alleviation power station project into a greenhouse gas emission reduction project that meets the national requirements is not only an innovative measure to consolidate and expand the achievements of poverty alleviation, and continuously promote rural revitalization, but also an effective way to practice green and low-carbon development and promote “Carbon Peak•Carbon Neutrality”. Based on the summaries and analysis of the development of China’s photovoltaic poverty alleviation and carbon trading market and the situation of carbon emission trading pilot, this paper sorts out the relevant policies of poverty alleviation’s participation in carbon trading, studies the participation mode and trading process of village-level photovoltaic poverty alleviation power station, scientifically calculates the additional economic benefits brought by Chinese Certified Emission Reduction (CCER) trading for village-level photovoltaic poverty alleviation power station, and puts forward some policy recommendations on rationally optimizing carbon trading procedures and improving work efficiency. Keywords: Photovoltaic poverty alleviation, Carbon market, Carbon trading, Implementation path DOI: 10.7176/PPAR/11-5-01 Publication date:June 30th 202

A születő szélsőjobboldaliság mint nemzedéki életérzés: [Gyurgyák János: Magyar fajvédők. Eszmetörténetri tanulmány. Osiris, Budapest, 2012. 272 o.]

Recenzió Gyurgyák János: Magyar fajvédők című könyvérő

Dependence on the structure and surface polarity of ZnS photocatalytic activities of water splitting: first-principles calculations

It has been reported that phase structure and surface polarity largely affect the photocatalytic efficiency of semiconductor nanostructures. To understand the chemical activity of ZnS at the electronic level, we investigate electron structures and carrier transportation ability for bulk intrinsic zinc blende (ZB) and wurtzite (WZ) ZnS, as well as the reaction pathway of hydrogen generation from water splitting on Zn- and S-terminated polar surfaces. The electron structure calculations prove that the WZ phase possesses a higher reducing ability than the ZB phase. The conductivity of the bulk ZB phase surpasses that of the WZ phase at or above room temperature. As the temperature increases, the asymptotic conductivity ratio of WZ/ZB is close to the Golden Ratio, 0.62. Reaction kinetics studies indicate that Zn-terminated polar surfaces are more chemically active than S-terminated polar surfaces in the reaction of hydrogen generation from water splitting. The calculation results suggest that the first H splitting from water on Zn-terminated polar surfaces can occur with ground state electronic structures, while photo-assistance is necessary for the first H splitting on the S-terminated surfaces. Electronic triplet states calculations further show that Zn-terminated surfaces are more photosensitive than S-terminated surfaces

Discovery of Fe_2 =P-Type Ti(Zr/Hf)_2O_6 Photocatalysts toward Water Splitting

We report the discovery of Fe_2P-type TiO_2-based photocatalysts, TiZr_2O_6 and TiHf_2O_6, through first-principle calculations. Appearing as the solid solutions of TiO_2 and Zr(Hf)O_2 at 150 GPa, Ti (Zr/Hf)_2O_6 unit cells are constructed by replacing two Ti atoms with Zr or Hf atoms in the pure Fe_2P-type TiO_2 lattice. The two compounds are mechanically and dynamically stable at ambient conditions. The electronic structure calculations predict direct bandgaps of 2.29 and 2.65 eV for TiZr_2O_6 and TiHf_2O_6, respectively. Significant evidence in the electronic properties prove both TiZr_2O_6 and TiHf_2O_6 to be attractive photocatalysts in the visible light region, but TiZr_2O_6 is more promising in the application of hydrogen generation by water splitting. Thus, instead of element doping, we narrow the bandgap of TiO_2 by developing intrinsic stable semiconductors from scratch. The rational design in this work of predicting high-pressure phases and stabilizing them open a way for prompting photoelectrochemical activities of photocatalysts

Trimester-and Assay-Specific Thyroid Reference Intervals for Pregnant Women in China

Objective. The guidelines of the American Thyroid Association (ATA) recommend an upper limit reference interval (RI) of thyroid stimulating hormone (TSH) of 2.5 mIU/L in the first trimester of pregnancy and 3.0 mIU/L in subsequent trimesters, but some reported ranges in China are significantly higher. Our study aimed to establish trimester-and assay-specific RIs for thyroid hormones in normal pregnant Chinese women. Methods. In this cross-sectional study, 2540 women with normal pregnancies (first trimester, = 398; second trimester, = 797; third trimester, = 1345) and 237 healthy nonpregnant control subjects were recruited. Serum TSH, free thyroxin (FT4), thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb) levels were determined by automated chemiluminescence with an Immulite 2000 system (Siemens, Erlangen, Germany). After outliers were excluded, the 2.5-97.5th percentiles were used to define the RIs. Results. The RIs of thyroid function in the first, second, and third trimesters of pregnancy and in nonpregnant controls were 0. .61 pmol/L for FT4, respectively. Conclusion. The trimester-and assay-specific RIs of thyroid function during pregnancy differed between trimesters, which suggests that it is advisable to detect and avoid misclassification of thyroid dysfunction during pregnancy for women in Henan, China

Trimester- and Assay-Specific Thyroid Reference Intervals for Pregnant Women in China

Objective. The guidelines of the American Thyroid Association (ATA) recommend an upper limit reference interval (RI) of thyroid stimulating hormone (TSH) of 2.5 mIU/L in the first trimester of pregnancy and 3.0 mIU/L in subsequent trimesters, but some reported ranges in China are significantly higher. Our study aimed to establish trimester- and assay-specific RIs for thyroid hormones in normal pregnant Chinese women. Methods. In this cross-sectional study, 2540 women with normal pregnancies (first trimester, n=398; second trimester, n=797; third trimester, n=1345) and 237 healthy nonpregnant control subjects were recruited. Serum TSH, free thyroxin (FT4), thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb) levels were determined by automated chemiluminescence with an Immulite 2000 system (Siemens, Erlangen, Germany). After outliers were excluded, the 2.5–97.5th percentiles were used to define the RIs. Results. The RIs of thyroid function in the first, second, and third trimesters of pregnancy and in nonpregnant controls were 0.07–3.96, 0.27–4.53, 0.48–5.40, and 0.69–5.78 mIU/L for TSH and 9.16–18.12, 8.67–16.21, 7.80–13.90, and 8.24–16.61 pmol/L for FT4, respectively. Conclusion. The trimester- and assay-specific RIs of thyroid function during pregnancy differed between trimesters, which suggests that it is advisable to detect and avoid misclassification of thyroid dysfunction during pregnancy for women in Henan, China

Nicotine aggravates vascular adiponectin resistance via ubiquitin-mediated adiponectin receptor degradation in diabetic Apolipoprotein E knockout mouse

There is limited and discordant evidence on the role of nicotine in diabetic vascular disease. Exacerbated endothelial cell dysregulation in smokers with diabetes is associated with the disrupted adipose function. Adipokines possess vascular protective, anti-inflammatory, and anti-diabetic properties. However, whether and how nicotine primes and aggravates diabetic vascular disorders remain uncertain. In this study, we evaluated the alteration of adiponectin (APN) level in high-fat diet (HFD) mice with nicotine (NIC) administration. The vascular pathophysiological response was evaluated with vascular ring assay. Confocal and co-immunoprecipitation analysis were applied to identify the signal interaction and transduction. These results indicated that the circulating APN level in nicotine-administrated diabetic Apolipoprotein E-deficient (ApoE−/−) mice was elevated in advance of 2 weeks of diabetic ApoE−/− mice. NIC and NIC addition in HFD groups (NIC + HFD) reduced the vascular relaxation and signaling response to APN at 6 weeks. Mechanistically, APN receptor 1 (AdipoR1) level was decreased in NIC and further significantly reduced in NIC + HFD group at 6 weeks, while elevated suppressor of cytokine signaling 3 (SOCS3) expression was induced by NIC and further augmented in NIC + HFD group. Additionally, nicotine provoked SOCS3, degraded AdipoR1, and attenuated APN-activated ERK1/2 in the presence of high glucose and high lipid (HG/HL) in human umbilical vein endothelial cells (HUVECs). MG132 (proteasome inhibitor) administration manifested that AdipoR1 was ubiquitinated, while inhibited SOCS3 rescued the reduced AdipoR1. In summary, this study demonstrated for the first time that nicotine primed vascular APN resistance via SOCS3-mediated degradation of ubiquitinated AdipoR1, accelerating diabetic endothelial dysfunction. This discovery provides a potential therapeutic target for preventing nicotine-accelerated diabetic vascular dysfunction