Rapid and accurate quantitative analysis of fermentation gases by Raman spectroscopy

Raman spectroscopy was employed for the precise quantitative analysis of a gaseous mixture. The band ratio between the Raman band of the target gas and that of the external standard was calculated and found to be proportional to the pressure of the target gas. The linearity of the calibration curves was very good (higher than 0.999). The mole fractions of atmospheric nitrogen and atmospheric oxygen were determined from their partial pressures. The average molar fraction of atmospheric nitrogen was calculated to be 0.790, similar to the literature value. Those of methane, hydrogen, and carbon dioxide, which are produced by fermentation, were also determined from the Raman spectrum. The values were identical to those obtained from the measured volume of each gas. The possibility of quantifying gas molecules by Raman spectroscopy is demonstrated.     

Resting Heart Rate Variability and the Effects of Biofeedback Intervention in Women with Low-Risk Pregnancy and Prenatal Childbirth Fear

Anxiety about labor in women at the end of pregnancy sometimes reaches levels that are clinically concerning. We investigated whether low-risk pregnant women with childbirth fear during the last trimester demonstrate specific findings with regard to resting heart rate variability (HRV) and examined whether HRV biofeedback can reduce this fear and alter resting HRV. We measured the levels of childbirth fear (Wijma delivery expectancy/experience questionnaire, W-DEQ) and resting HRV indexes in 97 low-risk pregnant women in their 32nd–34th week of gestation and advised women with W-DEQ scores of ≥?66 (n?=?40) to practice HRV biofeedback (StressEraser) at home. We then reassessed these measures 3–4 weeks later in the 36th–37th week of gestation regardless of whether the women practiced the method. We found that childbirth fear had no significant effect on resting HRV indexes when the W-DEQ cutoff was conventionally set at ≥?66. However, women with W-DEQ scores of ≥?90 (n?=?5) had a significantly lower high-frequency power than their counterparts (p?=?0.028). The W-DEQ scores reduced significantly in women who performed HRV biofeedback (n?=?18, p?<?0.001), but there was no change in those who did not perform the method (n?=?20). These findings suggested that very high W-DEQ scores (≥?90), but not the conventional criteria (W-DEQ score?≥?66), of the fear of childbirth were associated with low parasympathetic activity among low-risk pregnant women and that HRV biofeedback intervention can effectively decrease the fear of childbirth in these women.     

Lycodes nishimurai, a new deep-sea eelpout (Teleostei: Zoarcidae) from the Sea of Japan

A new zoarcid fish, Lycodes nishimuari, is described on the basis of four specimens from the Yamato Bank, the Sea of Japan, at depths of 642–669 m. Although this species resembles Lycodes diapterus, L. hubbsi, L. pectoralis, L. macrochir, and L. nakamurae in having a deep notch in the pectoral fin and a single lateral line on the body, it is distinguished from them by the following combination of characters: no scales on pectoral fin base; scales on dorsum before dorsal fin origin; suborbital, preopercular, and last postorbital pores with risen rim; whitish lips; no whitish transverse bars on body; pectoral fin membrane and anterior part of dorsal fin membrane without black spots; basal color of vertical fins black. Supplementary material to this paper is available in electronic format at .     

美西螈胚胎鳃神经发育的形态学

在约25℃温度下孵化并选用第30～44期的美西螈(Ambystoma mexicanum)胚胎标本,用4%多聚甲醛溶液固定,进行整体标本免疫染色,体视显微镜观察.结果显示,胚胎30期,可观察到鳃神经节短小的鳃神经本干;胚胎35期,已能观察到较明显的部分分支和交通支;胚胎37期,形成上颌神经及下颌神经;胚胎38期,可观察到舌咽神经的背支、咽头支;胚胎40期,可观察到舌咽神经的鳃裂前支.因而,美西螈鳃神经在胚胎早期遵循祖先型排列的特点,之后随胚胎的发育,出现随鳃器官演化而重新分布的趋势;其舌咽神经基本保持了鳃神经的原始形态特点.     

Postnatal development of the ovarian bursa of the golden hamster (Mesocricetus auratus): its complete closure and morphogenesis of lymphatic stomata

The golden hamster ovarian bursa was studied by light and electron microscopy to clarify the process of its complete closure and the development of lymphatics that leads to morphogenesis of stomata. The results were as follows. 1) The bursa completely closed at 9 days of age primarily due to development of the mesotubarium superius. 2) With the closure, the ovary and bursa became closely apposed, and most of the original bursal cavity disappeared. 3) Between 9 and 12 days of age U-shaped folds of the bursal mesothelium began to invade the connective tissue of the bursa. 4) Widening of the internal angle of the U-shaped folds contributed to reappearance of the bursal cavity, and thus separation of the bursa from the ovary. It also contributed to future geometrical proximity of lymphatics to the cavity of the bursa. 5) The separation of the bursa from the ovary began as early as 12 days of age in the cephalic half of the bursa. It occurred remarkably late in the caudal half. Juxtaposition of the window portion of the bursa to the ovary remained in some adult animals. 6) Development of lymphatics in the cephalic half of the bursa was divided into two stages, before and after days 21-24 of life. In the first stage, lymphatics grew in the submesothelial connective tissue, and the framework of lymphatics was formed. In the second stage, lymphatics extended small branches to form the submesothelial plexus or lymphatic lacuna. 7) Intercellular junctions between contiguous lymphatic endothelial cells were mostly tight and desmosomelike. Open junctions were, if they occurred at all, rare. (8) A smooth-surfaced area lined with the lymphatic endothelium was found in the bursa on day 27 of life, before the initiation of ovulation. Valvelike stomal orifices were absent before the initiation of ovulation and extremely rare even after the first ovulation. They were commonly present in the bursae after the fourth ovulation, however. The process of complete closure of the ovarian bursa is very complex and may be related to the later development of the bursal mesothelium and lymphatics. Some liplike stomal orifices are of purely developmental origin. However, all valvelike stomal orifices are assumed to be formed as a result of damage to the bursal mesothelium, as well as to the submesothelial connective tissue and lymphatics, by repetition of ovulation. It is possible that liplike stomal orifices may be formed in the process of repairing the damage.     

Multiple Pathways Suppress Non-Allelic Homologous Recombination during Meiosis in Saccharomyces cerevisiae

Recombination during meiosis in the form of crossover events promotes the segregation of homologous chromosomes by providing the only physical linkage between these chromosomes. Recombination occurs not only between allelic sites but also between non-allelic (ectopic) sites. Ectopic recombination is often suppressed to prevent non-productive linkages. In this study, we examined the effects of various mutations in genes involved in meiotic recombination on ectopic recombination during meiosis. RAD24, a DNA damage checkpoint clamp-loader gene, suppressed ectopic recombination in wild type in the same pathway as RAD51. In the absence of RAD24, a meiosis-specific recA homolog, DMC1, suppressed the recombination. Homology search and strand exchange in ectopic recombination occurred when either the RAD51 or the DMC1 recA homolog was absent, but was promoted by RAD52. Unexpectedly, the zip1 mutant, which is defective in chromosome synapsis, showed a decrease, rather than an increase, in ectopic recombination. Our results provide evidence for two types of ectopic recombination: one that occurs in wild-type cells and a second that occurs predominantly when the checkpoint pathway is inactivated.