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Climate is critically affected by aerosols, which alter cloud lifecycles and precipitation distribution through radiative and microphysical effects. In this study, aerosol and cloud property datasets from MODIS (Moderate Resolution Imaging Spectroradiometer), onboard the Aqua satellite, and surface observations, including aerosol concentrations, raindrop size distribution, and meteorological parameters, were used to statistically quantify the effects of aerosols on low-level warm-cloud microphysics and drizzle over northern Taiwan during multiple fall seasons (from 15 October to 30 November of 2005–2017). Our results indicated that northwestern Taiwan, which has several densely populated cities, is dominated by low-level clouds (e.g., warm, thin, and broken clouds) during the fall season. The observed effects of aerosols on warm clouds indicated aerosol indirect effects (i.e., increased aerosol loading caused a decrease in cloud effective radius (CER)), an increase in cloud optical thickness, an increase in cloud fraction, and a decrease in cloud-top temperature under a fixed cloud water path. Quantitatively, aerosol–cloud interactions (ACI=-∂ln⁡CER∂ln⁡α|CWP, changes in CER relative to changes in aerosol amounts) were 0.07 for our research domain and varied between 0.09 and 0.06 in the surrounding remote (i.e., ocean) and polluted (i.e., land) areas, respectively, indicating aerosol indirect effects were stronger in the remote area. From the raindrop size distribution analysis, high aerosol loading resulted in a decreased frequency of drizzle events, redistribution of cloud water to more numerous and smaller droplets, and reduced collision–coalescence rates. However, during light rain (≤1 mm h−1), high aerosol concentrations drove raindrops towards smaller droplet sizes and increased the appearance of drizzle drops. This study used long-term surface and satellite data to determine aerosol variations in northern Taiwan, effects on clouds and precipitation, and observational strategies for future research on aerosol–cloud–precipitation interactions.

Holistic processing (HP) has long been considered a characteristic of right hemisphere (RH) processing. Indeed, holistic face processing is typically associated with left visual field (LVF)/RH processing advantages. Nevertheless, expert Chinese character recognition involves reduced HP and increased RH lateralization, presenting a counterexample. Recent modeling research suggests that RH processing may be associated with an increase or decrease in HP, depending on whether spacing or component information was used respectively. Since expert Chinese character recognition involves increasing sensitivity to components while deemphasizing spacing information, RH processing in experts may be associated with weaker HP than novices. Consistent with this hypothesis, in a divided visual field paradigm, novices exhibited HP only in the LVF/RH, whereas experts showed no HP in either visual field. This result suggests that the RH may flexibly switch between part-based and holistic representations, consistent with recent fMRI findings. The RH's advantage in global/low spatial frequency processing is suggested to be relative to the task relevant frequency range. Thus, its use of holistic and part-based representations may depend on how attention is allocated for task relevant information. This study provides the first behavioral evidence showing how type of information used for processing modulates perceptual representations in the RH.

Operational scenario for diverted plasmas has been developed in Versatile Experiment Spherical Torus (VEST) not only for improving plasma performance but also for preparing upcoming experiments on advanced divertor concepts such as snowflake and x-point divertor. Diverted discharge scenario is designed using an in-house simulation code and experimentally realized by adjusting turn-on time of two partial solenoid (PF2) coils located at both ends of the center stack. With the diverted scenario, we achieve the improvement in plasma duration by ∼20% compared to the limited plasma operation, mainly due to the mitigation of impurity influxes from the center stack made of tungsten. Indeed, the impurity O-I line is observed to be decreased to 50% of the limited plasma operation. Fast camera images and equilibrium reconstruction based on magnetic diagnostics clearly shows the successful generation of diverted plasmas as well. This paper presents the first results on the diverted plasma operation in VEST and future plan for the experiments on the advanced divertor concept.

Previous research on cross-culture comparisons found that Western cultures tend to value independence and the self is construed as an autonomous individual, while Eastern cultures value interdependence and self-identity is perceived as embedded among friends and family members (Markus and Kitayama, 1991). The present experiment explored these cultural differences in the context of a paradigm developed by Sui et al. (2012), which found a bias toward the processing of self-relevant information using perceptual matching tasks. In this task, each neutral shape (i.e., triangle, circle, square) is associated with a person (i.e., self, friend, stranger), and faster and more accurate responses were found to formerly neutral stimuli tagged to the self compared to stimuli tagged to non-self. With this paradigm, the current study examined cross-cultural differences in the self-bias effect between participants from Hong Kong and the United Kingdom. Results demonstrated a reliable self-bias effect across groups consistent with previous studies. Importantly, a variation was identified in a larger self-bias toward stranger-associated stimuli in the United Kingdom participants than the Hong Kong participants. This suggested the cultural modulation of the self-bias effect in perceptual matching.

Mitigation of heat flux impinging on divertor plates is a critical engineering issue even for the fusion reactor adopting innovative super-X divertor. In this work, we are exploring the possibility for resolving this problem by converting a substantial portion of thermal energy of ions into electricity in front of the divertor plates. Since successful energy conversion is followed by the separation of electrons from the plasma, the rigorous investigation for the conditions of efficient charge separation is essential. Considering that the charge separation is affected by intricate relations between plasma density, drift velocity, Larmor radius, and field curvature, we have recently designed and constructed a new linear plasma device at Seoul National University for studying the feasibility of the charge separation by curved magnetic field. The device consists of the driving section including a typical electron cyclotron resonance (ECR) plasma source operating at 2.45 GHz wave frequency and the diffusion section where a cylindrical chamber is surrounded by a pair of solenoid coils for generating various curved magnetic field structures. The plasma density in the experimental region is measured to be around the middle of 1015 m−3 for the optimum ECR field, depending on the gas pressure and microwave power. The preliminary results clearly show that the charged particles in the plasma with a density range of 1015 m−3 can be separated quite well by an extremely slanted cusp magnetic field. We are planning to increase the microwave power to increase the plasma density up to 1017 m−3, making it possible to investigate charge separation at higher density condition.

Transition of thermodynamic behavior for the electrons in a magnetically expanding collisionless plasma is experimentally observed by local measurement using an axially movable cylindrical Langmuir probe. The polytropic indexes which are deduced from the correlations among the plasma potential, effective electron temperature, and electron density seem to have a quite different value of $3 \pm 0.2$ and $1.17 \pm 0.03$ near the nozzle throat and far from the nozzle, respectively. The transition of polytropic index can be explained by a theoretical calculation of effective polytropic index depending on the double-adiabatic laws and the thermal energies for magnetized anisotropic plasmas1. The results show that the significant electron cooling near the nozzle throat is caused by nearly one-dimensional adiabatic expansion along almost parallel strong magnetic field. With increasing the distance from the nozzle throat, the magnetic field strength decreases and the electron cooling rate is also decreased. The present study demonstrates that a sufficiently high and nearly longitudinal magnetic field configuration can enhance the electron cooling near the nozzle throat significantly. It also means that the ion acceleration can be enhanced through high potential drop generated by high electron cooling rate. Ion demagnetization is correlated with the change in the thermodynamic property of electrons along the distance from the magnetic nozzle.

A deep understanding of the kinetic properties of the electrons in a magnetic nozzle (MN), which is attracting attention as an acceleration stage for thrusters, is of great significance as it directly contributes to the development of the MN performance. In the sense that a conversion of the electron momentum to the ion kinetic energy determines the characteristics of the MN, fundamental research on the kinetic feature of a magnetically expanding plasma has focused on the spatial distribution of the electron properties and proposed directions to the desired application. Unlike the common perception of this importance, various research groups have proposed contradictory arguments based on their theoretical approaches regarding the ion beam acceleration from the viewpoint of heat flow of electrons. We point out that the main reason for the absence of a theoretical consensus for the nozzle efficiency improvements arises from the lack of the clear interpretation of the plasma properties by focusing only on the final state of the electrons. In this Letter, time-resolved measurement of the electron energy distributions has been performed to grasp a detailed series of expansion processes. It has been revealed that the effective potential well gradually formed by the self-generated electric field acts as a limiting factor in the motion of electrons; this effect attributes to the changes of the electron energy distribution represented as the accumulation of the trapped electrons. The accumulation over the entire region diminishes the degree of the cooling rate of a system and decreases the electric field in the downstream region initially generated by the adiabatic expansion. The present study emphasizes that the kinetic features of an MN are strongly affected by the non-stationary motion of the trapped electrons; thus, the temporal behavior of the trapped electrons must be considered for prediction and analysis of nozzle performances.

In this work, we introduced a highly selective and sensitive lithium ion sensor constituted of graphite electrode modified with a chromium doped spinel type manganese oxide (Li1·0Cr0·05Mn1·95O4). The metal ion doped spinel manganese oxide was synthesised by mechanochemical activation and characterised by XRD and SEM analysis. The sensor response to lithium ions was linear with a slope of 111 mV/decade over a wide pH 10 in Tris buffer and was linear in the concentration range 6·5×10−6–1·0×10−1 mol L−1 with a detection limit of 5·2×10−6 mol L−1.

A lithium (Li) vapor injector for boundary control has been developed. A diverter covered with lithium is expected to reduce particle recycling. Recycling reduction is considered to be one of the triggers for the L–H transition. In this paper, the method of lithium dispersion is investigated under the assumption that the experiment is carried out in the Large Helical Device in National Institute for fusion Science, Japan (LHD). A performance test is performed on a prototype of the vapor injector. The amount of injected lithium was approximately 1% of the value expected from the vapor pressure data, due to the generation of lithium oxide. It is also found that nozzle temperature is quite important to suppress the Li dispersion.

Electrostatic probe measurements for low-pressure inductively coupled SF 6 plasmas are performed. From the current–voltage ( I – V ) curves of the probe, the saturation currents of the positive ions, the electron density, and the electron temperature are measured. The electronegativity and the positive ion density are obtained by several different methods (the ion saturation current at the floating potential, the positive and negative current balances at the floating potential, and the three pressure point method). They are compared with the positive ion density obtained by the orbital-motion-limited theory.

We investigated efficiency of removal of NO and NOx for applied voltage, repetition frequency and energy according to reactor type (wire-plate and wire-cylinder type reactor). Characteristics of Re...

We have theoretically investigated and compared the thermal characteristics of γ ∼ 10.6 μm InGaAs/InAlAs/InP buried heterostructure (BH) quantum cascade lasers (QCLs) with different heat-sinking configurations by a steady-state heat-transfer analysis. The heat-source densities were obtained from laser threshold power densities measured experimentally under room-temperature continuous-wave mode. The two-dimensional anisotropic heat-dissipation model was used to calculate the temperature distribution, heat flux, and thermal conductance (Gth) inside the device. For good thermal characteristics, the QCLs in the long-wavelength infrared region require the relatively narrow BH structure in combination with epilayer-down bonding due to thick active core/cladding layers and high insulator losses. The single-ridge BH structure results in slightly higher thermal conductance by ∼2–4% than the double-channel (DC) ridge BH structure. For W = 12 μm with 5 μm thick electroplated Au, the single-ridge BH laser with epilayer-down bonding exhibited the highest Gth value of 201.9 W/K cm2, i.e. increased by nearly 36% with respect to the epilayer-up bonded DC ridge waveguide laser. This value is improved by ∼50% and ∼62% with respect to the single-ridge BH laser and DC ridge waveguide laser with W = 20 μm in the epilayer-up bonding scheme, respectively. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

We have theoretically investigated the thermal characteristics of double-channel ridge–waveguide InGaAs/InAlAs/InP quantum cascade lasers (QCLs) using a two-dimensional heat dissipation model. The temperature distribution, heat flow, and thermal conductance (Gth) of QCLs were obtained through the thermal simulation. A thick electroplated Au around the laser ridges helps to improve the heat dissipation from devices, being good enough to substitute the buried heterostructure (BH) by InP regrowth for epilayer-up bonded lasers. The effects of the device geometry (i.e., ridge width and cavity length) on the Gth of QCLs were investigated. With 5 μm thick electroplated Au, the Gth is increased with the decrease of ridge width, indicating an improvement from Gth=177 W/K⋅cm2 at W=40 μm to Gth=301 W/K⋅cm2 at W=9 μm for 2 mm long lasers. For the 9 μm×2 mm epilayer-down bonded laser with 5 μm thick electroplated Au, the use of InP contact layer leads to a further improvement of 13% in Gth, and it was totally raised by 45% corresponding to 436 W/K⋅cm2 compared to the epilayer-up bonded laser with InGaAs contact layer. It is found that the epilayer-down bonded 9 μm wide BH laser with InP contact layer leads to the highest Gth=449 W/K⋅cm2. The theoretical results were also compared with available obtained experimentally data.

In this paper, we investigated the electrical properties of triisopropylsilyl (TIPS) pentacene organic thin-film transistor (OTFT) depending on solvent type. We spin coated TIPS pentacene by using chlorobenzene, p-xylene, chloroform, and toluene as solvents. Fabricated OTFT with chlorobenzene shows field-effect mobility of 1.0×10?² ㎠/Vㆍs, on/off ratio of 4.3×10³ and threshold voltage of 5.5 V. In contrast, with chloroform, the mobility is 5.8×10?? ㎠/Vㆍs, on/off ratio of 1.1×10² and threshold voltage of 1.7 V. Moreover we measured the grain size of each TIPS pentacene solvent by atomic force microscopy (AFM). From these results, it can be concluded that a solvent with higher boiling point results in better electrical characteristics due to large grain size and high crystallinity of TIPS pentacene layer. In this paper TIPS pentacene with chlorobenzene shows the best electrical properties.

For the analysis of atomic processes such as recombination and ionization in the divertor plasmas, a new fluid model on the ion collection to a probing object in magnetized plasma is developed including electron-ion recombination, molecular activated recombination and ionization. Density profiles and ratio of ion saturation currents are presented with ionization and recombination for the application to the Mach probe. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

For the analysis of atomic processes such as recombination and ionization in the divertor plasmas, we have developed a fast-scanning multiple probe system, which is composed of single, Mach and emissive probes along with Thomson scattering system at the material and plasma (MAP)-II divertor simulator with low magnetic field (about 200 G). Measured spatial variations of electron density, electron temperature, flow velocity and plasma potential will be given in comparison with those by Thomson scattering method. To analyze the data, a new fluid model on the ion collection to a probing object in un-magnetized plasmas is developed including electron–ion recombination, molecular activated recombination and ionization. This system is applied to another divertor simulator, divertor plasma simulator (DiPS), with higher magnetic field (up to 2 kG).

The strain-relief and structural properties of GaSb films with thin AlSb islands and thick AlSb buffer layers grown on GaAs (0 0 1) substrate at low temperature (LT) by molecular beam epitaxy are investigated by atomic force microscopy and transmission electron microscopy. The strain arising from depositing the buffer layer onto the GaAs substrate was relieved by a periodic array of the 90° misfit dislocations with the Burgers vector of 1/2a 〈1 1 0〉 for the thin AlSb islands buffer, but by both 60° and 90° misfit dislocations for the thick rough-and-flat AlSb buffer. The 90°-misfit dislocation array of AlSb/GaAs interface had an average spacing of 4.80 nm. The mean roughness of the GaSb film on the thin AlSb islands buffer layer was found to be less than 1 nm. These results clearly demonstrate that the presence of a thin, LT AlSb islands initiation layer is very useful for improving the quality of GaSb crystals grown on GaAs substrates.

A classification scheme for patients with hemophilia B has been devised. Assessment of factor IX antigen and factor IX coagulant activity has confirmed the genetic heterogeneity of hemophilia B and has shown that some affected patients have normal amounts of factor IX-like protein. An abnormal factor IX, factor IX Chapel Hill, has been isolated from one of these variants and compared structurally and functionally to the purified normal human factor IX molecule. The major difference between factor IX Chapel Hill and normal human factor IX appears to be defective activation of the abnormal molecule by factor XIa and calcium.

LiF-based thermoluminescence (TL) materials have been widely used for radiation dosimetry due to their attractive features. LiF:Mg,Cu,P is one of the most sensitive tissue-equivalent TL materials, approximately 40 times more sensitive than LiF:Mg,Ti (TLD-100), but it has two main drawbacks: a thermal loss of the TL sensitivity when annealed at temperatures>240 degrees C, and a relatively high-residual signal. Recently, LiF:Mg,Cu,Na,Si TL material was developed to overcome these drawbacks at the Korea Atomic Energy Research Institute, but it provided only marginal improvements in reducing the residual signal. The newly developed LiF:Mg,Cu,Si TL material has a significantly lower residual signal and a better stability to thermal treatments. In this article, the preparation method and some dosimetric properties (sensitivity and residual signal) of the new LiF:Mg,Cu,Si TL material are presented. At the end of the preparation procedures, a dual-step annealing method is introduced and this has proved as a very efficient method to reduce the high-temperature peak and is the cause of residual signal. Therefore, the high-temperature peak in the glow curve was significantly reduced. The sensitivity is approximately 20 times higher than that of TLD-100 and the residual signal was estimated to be approximately 0.04%.

With direct evidence that iron is the chemical limitation of phytoplankton growth, particularly in the Southern Ocean, it is increasingly important to develop new tools that provide direct measurement of the bioavailable iron fraction in oceanic waters. Here we report the development of a fluorescence quenching-based siderophore biosensor capable of the in situ measurement of this ultratrace Fe(III) fraction at ambient pH ( approximately 8). Parabactin was extracted from cultures of Paracoccus denitrificans. The purified siderophore was encapsulated within a spin-coated sol-gel thin film, which was subsequently incorporated in a flow cell system. The parabactin biosensor has been fully characterized for the detection of Fe(III) in seawater samples. The biosensor can be regenerated by lowering the pH of the flowing solution, thereby releasing the chelated Fe(III), enabling multiple use. The LOD of the biosensor was determined to be 40 pM, while for an Fe(III) concentration of 1 nM, a reproducibility with a RSD of 6% (n = 10) was obtained. The accuracy of the biosensing system has been determined through analysis of a certified seawater reference sample. Samples from the Atlantic Ocean have been analyzed using the parabactin biosensor providing a concentration vs depth profile for the bioavailable Fe(III) fraction in the 50 pM-1 nM range.

The intensity ratios of He I emission lines are used to determine electron density and temperature in Diversified Plasma Simulator (DiPS). The Hel line ratios are measured by optical emission spectroscopy and are calculated using the collisional-radiative equilibrium (CRE) model. The measured He I line ratios are 706.52 nm / 728.13 nm for electron temperature and 728.13 nm / 667.82 nm for electron density determination, respectively. The results obtained from the collisional-radiative equilibrium model are crosschecked with those of electrical probe measurement.

DiPS (Diversified Plasma Simulator), a new versatile linear machine (length=3400 mm, diameter=200-600 mm), is developed for the simulations of divertor, space and processing plasmas with various electric probes: fast-scanning systems with single, triple, and Mach Probes, slow-scanning water-cooled single probe, gridded-energy analyzer (GEA), and several fixed single probes. For the verification of current probe theories and the development of new theories with magnetic vector field, collisional effects, various particle sources, and wide range of plasma parameters, two different plasma sources are installed: (1) For a stable high density dc plasma, a LaB 6 disk is used as the thermal electron emission source with 5 kW graphite heater. Initial plasma density of the LaB 6 source is 5 x 10 12 cm -3 , electron temperature is 8-10 eV with magnetic field around 1 kG. The electron density would be decreased severely, i.e., to 10 6 - 10 8 cm -3 with grid, and expanded into space simulation region without magnetic field; (2) Helicon plasma source is also installed for a processing simulation in DiPS and for the space propulsion study with magnetic expansion, which generates the plasma with density of 2 × 10 13 cm -3 and electron temperature 3-4 eV for the rf power of 2.5 kW at optimum pressure of 7.5 mTorr. As a unique feature for the diversified uses of sources and divertor simulator experiments, space and processing simulation chambers can be detached from and attached to the divertor simulation chamber on the rail. Initial data of various electric probes (single, triple, emissive, mach probes, GEA, etc.) are introduced for the the following conditions of DiPS with B= 1 kG, P= 130 mTorr at source region, P= 2 mTorr at divertor simulation region, n e = 1 × 10 12 - 1 x 10 14 cm -3 , T e = 2 - 3 eV, T i = 0.2 eV with laser induced fluorescence (LIF) (Ar gas), The = 1 × 10 12 - 1 × 10 13 cm -3 , Te =5 - 6 eV (He gas) at divertor simulation region, T i = 0.47 - 0.74 eV with GEA at space simulation region and υ d = 500 - 600 m/s.

Although theory of the triple probe for Maxwellian plasma is well known, analysis with ion beams has not been established. Since plasma parameters, especially electron temperature, are distorted severely in the presence of supersonic ion beams, a new model for deducing electron temperature is introduced by solving the governing equations of the triple probe including the beam currents to three probe tips through simple assumptions. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Using MLV (murine leukemia virus)-based retrovirus vectors encapsidated with VSV-G (vesicular stomatitis virus G glycoprotein), we tried to make transgenic chickens carrying the transferred genes in their chromosomes. Twenty one days after virus injection beneath the blastoderms of unincubated chicken embryos (stage X, at laying), DNA isolated from the hatched chicks were analyzed by PCR with two sets of primers specific for EGFP (enhanced green fluorescence protein) gene or Neo R (E. coli neomycin resistant) gene. Among sixty-seven embryos injected with retrovirus, four of them were identified to carry the EGFP genes in their genomes. Remarkably, one transgenic chick showed presence of the retrovirus vector sequences in all organs differentiated from one of endoderm, mesoderm, and ectoderm. Expression of EGFP gene was not detected, however, the stable germ line transmission of transgene was verified in spermatozoa from the founder chicken and 50% of F 1 progenies.

Tropical guppies, Poecilia reticulata, collected from the canal of La Laguna Los Patos were acclimated over a four-week period at local water temperatures of 24–33 °C to determine their critical thermal maxima (CTM) and death points (DP), as criteria of thermal tolerance. In addition, individual thermal tolerance times at a lethal temperature of 38.5 °C were measured over 12 days for upward acclimation from 24 to 30 °C and over 16 days for downward acclimation from 30 to 24 °C to determine acclimation rate just before and after changing the acclimation temperatures. The CTM ranged from 38.95 to 40.61 °C and the average DP varied from 41.22 to 42.86 °C. Positive relationships were apparent between thermal tolerance and acclimation temperatures, and thus heat tolerance criteria (CTM and DP) were significantly different among acclimation temperatures. Individual heat tolerance times increased most rapidly during the first 6 hours of upward acclimation after transfer from 24 to 30 °C, continued to increase another 5 days and fluctuated after initial acclimation was completed. The heat tolerance times of fish transferred from 30 to 24 °C declined steadily over times, reaching a minimum at 14–16 days after transfer.

We present results of grazing incidence X-ray diffraction studies concerning the effect of pH (and thus, of headgroup dissociation) on Langmuir monolayers of fatty acids, in the absence of any divalent cations in the aqueous subphase. An increase in pH transforms the distorted-hexagonal S phase first to the partially disordered Rotator-I phase with less distortion, and then to the completely disordered Rotator-II phase with an undistorted hexagonal structure. The S−Rotator-I and Rotator-I−Rotator-II transitions are pushed to lower temperatures with increase in pH. The fact that the effects of pH increase are almost identical to the effects of increasing temperature indicates the important role of headgroup−headgroup interactions in these monolayer phases.

Enhanced production of ΛΛ pairs, above levels predicted by a two-step process model, has been observed near threshold (in the mass range 2.23-2.26 GeV/c2) in the 12C(K−,K+) reaction at 1.66 GeV/c using a scintillating fiber target. The differential cross section for ΛΛ production in the momentum region 0.95≤pK+≤1.3 GeV/c averaged over the range 2.3o≤θK+≤14.7o was found to be 7.6±1.3 ±0.9 μ b/sr, and that for the enhancement was found to be approximately 3 μ b/sr.

Radial profiles of plasma density and electron temperature have been measured by a fast-scanning probe (FSP) system with various neutral pressures in the MAP-II and DIPS linear devices for the divertor simulation. The probe system is made of three probe tips, two of which is for a Mach probe consisting of two opposite-directional probes, and one is for an emissive probe installed on the pneumatically driven fast-scanning system with stroke of 30 cm. In MAP-II, density at the center has been varied from 1.5 × 10 13 cm -3 to 0.7 x 10 13 cm -3 with pressures of 5.5 to 112 mtorr, while that of DiPS varied from 3.5 × 10 12 cm -3 to 9 × 10 12 cm -3 with pressures of 0.8 to 50 mtorr. Relation of density profile with the working pressure/magnetic field is analyzed by using a simple fluid model. Electron temperature at the center is also measured by the Thomson scattering method and compared with those of FSP, which is varied from 0.6 to 6.5 eV.

Enhanced production of ΛΛ pairs, above the prediction of a two-step process model, is observed near threshold (around the masses of 2.23 – 2.26 GeV/c2) in the12C(K−,K+) reaction at PK− = 1.66GeV/c using a scintillating fiber target. The differential cross section for the ΛΛ production averaged over 2.3° ≤ $$K + ≤ 14.7° in the momentum region 0.95 ≤ pK + ≤ 1.3GeV/c was found to be 7.6 ± 1.3 μb/sr, and that for the enhancement approximately 3 μb/sr.

Cascade hypernuclei have been studied in the ${(K}^{\ensuremath{-}}{,K}^{+})$ reaction on a scintillating fiber target. The experimental result is compared with a theoretical calculation in order to extract information concerning the ${\ensuremath{\Xi}}^{\ensuremath{-}}$ nucleus potential.

The effects of propranolol, a β-adrenergic blocker, and epinephrine on cortical granule exocytosis and polyspermic penetration in the pig were determined. Pig oocytes precultured in medium containing 1 and 10 μM propranolol had an increased (P

The double strangeness exchange reaction ( K − , K + ) is investigated with respect to the sub-threshold production of scalar and vector mesons ( f 0 / a 0 / φ ) decaying into K + K − and the two-step processes induced by intermediate mesons and Ξ − hyperons at p k − = 1.66 GeV/ c using a scintillating fiber active target. The differential cross section ( 〈 dσ dΩ L 〉) averaged over the angular interval (2.3° ⩽ θ K + L ⩽ 14.7°) for the sub-threshold f 0 / a 0 / φ meson production with the K + K − decay is 11 ± 6 μ b/sr at 0.6 ⩽ p K 1 c . The present result differs significantly from the theoretical calculation which predicts the contribution of the f 0 / a 0 / φ meson production to be predominant in the ( K − , K + ) reaction below p K + = 0.95 GeV/ c . We found a sizable contribution from two-step ( K − , K + processes, characterized by production of two S = −1 hyperons, consistent with the result of the intra-nuclear cascade (INC) model calculation with respect to the meson-induced hyperon (or hyperon resonance) pair production in the momentum region 0.6 ⩽ p K + c . The observed enhancement of the cross section for the two-step ΛΛ production beyond the prediction of the INC model at p K + ⋍ 1.1 GeV /c could be due to the Ξ − p → ΛΛ reaction in 12 C.

The objective of this study was to determine the effects of fetal calf serum (FCS), non-essential MEM amino acids, MEM vitamins and insulin on blastocoel formation, expansion and hatching in porcine embryos developing in vitro. Addition of 20% FCS to the NCSU 23 medium significantly (P0.05) decreased by the compaction and blastocoel formation of 1- to 2-cell embryos developing in vitro. In contrast, more 1- to 2-cell embryos commenced hatching in the media containing amino acids than in control medium (25.7 vs 2.6%, P0.01). Amino acids and insulin synergistically enhanced the incidence of blastocoel formation and hatching of porcine embryos developing in vitro (P0.05). When early compacted embryos which developed in vitro in NCSU 23 medium were cultured in BSA-free NCSU 23 medium supplemented with 20% FCS, the incidence of hatching was significantly increased compared with that of the control groups (35.7 vs 4.1%, P0.01). However, addition of amino acids, vitamins or insulin to the NCSU 23 medium did not enhance the development of early morulae to the hatched embryos (P0.1). When either in vivo or IVM/IVF-derived 1- to 2-cell stage embryos were cultured 4 d in the modified NCSU 23 and an additional 4 days in the modified NCSU 23 supplemented in the FCS, the percentages (61.8 and 17.8%, in vivo- and IVM/TVF-derived, respectively) of hatched blastocysts were significantly higher (P0.01) than in the control groups (2.9 and 0%, in vivo and IVM/IVF-derived, respectively). These results suggested that dual culture conditions are required to optimize an in vitro culture system for the development of the porcine embryo in vitro.

Potassium (K(+)) concentration in the mammalian oviduct and uterus is particularly interesting due to its unusually high concentration (12 to 25 mM) compared with that in the blood stream (3 to 6 mM). In this study we examined the effects of various K(+) concentrations in the fertilization medium on polyspermy and subsequent in vitro development of porcine oocytes. In the absence of K(+) in the fertilization medium, sperm penetration was not observed. The incidence of polyspermy was significantly higher in the fertilization medium that contained 6 or 12 mM K(+) as compared with 3 mM K(+). The mean number of sperm penetrated in oocytes in medium with 6 and 12 mM K(+) was higher than in medium with 3 mM K(+). The addition of 3, 6 or 12 mM K(+) to the fertilization medium did not significantly affect the proportion of zygotes that developed to the blastocyst stage (14.1, 12.4 and 15.0%, respectively). Chlorotetracycline (CTC) analysis was used to determine the capacitation and acrosome reaction of spermatozoa incubated for 3 h with various concentrations of K(+). The number of acrosome reacted spermatozoa decreased with increasing K(+) concentration. These results suggest that extracellular K(+) in the fertilization medium affects sperm acrosome reaction which may be related to the sperm penetration.