Dietary Deficiency of Essential Amino Acids Rapidly Induces Cessation of the Rat Estrous Cycle

Reproductive functions are regulated by the sophisticated coordination between the neuronal and endocrine systems and are sustained by a proper nutritional environment. Female reproductive function is vulnerable to effects from dietary restrictions, suggesting a transient adaptation that prioritizes individual survival over reproduction until a possible future opportunity for satiation. This adaptation could also partially explain the existence of amenorrhea in women with anorexia nervosa. Because amino acid nutritional conditions other than caloric restriction uniquely alters amino acid metabolism and affect the hormonal levels of organisms, we hypothesized that the supply of essential amino acids in the diet plays a pivotal role in the maintenance of the female reproductive system. To test this hypothesis, we examined ovulatory cyclicity in female rats under diets that were deficient in threonine, lysine, tryptophan, methionine or valine. Ovulatory cyclicity was monitored by daily cytological evaluations of vaginal smears. After continuous feeding of the deficient diet, a persistent diestrus or anovulatory state was induced most quickly by the valine-deficient diet and most slowly by the lysine-deficient diet. A decline in the systemic insulin-like growth factor 1 level was associated with a dietary amino acid deficiency. Furthermore, a paired group of rats that were fed an isocaloric diet with balanced amino acids maintained normal estrous cyclicity. These disturbances of the estrous cycle by amino acid deficiency were quickly reversed by the consumption of a normal diet. The continuous anovulatory state in this study is not attributable to a decrease in caloric intake but to an imbalance in the dietary amino acid composition. With a shortage of well-balanced amino acid sources, reproduction becomes risky for both the mother and the fetus. It could be viewed as an adaptation to the diet, diverting resources away from reproduction and reallocating them to survival until well-balanced amino acid sources are found

Comparative Study of Japanese Derivative Processing Using PCFG

In Japanese language, derivative word consists of a noun and some following suffixes, and those components are concatenated into a sequence without separators. This construction often cause ambiguity in parsing or Kana-Kanji conversion. Some methods to treat derivatives have been developed; 1) recognizing arbitrary combination of any noun and any suffix, 2) registering collected derivative words directly into the word dictionary, and 3) using semantic category to enable selectional restriction. However, these methods have too simple mechanism to derive correct analysis. In our previous paper, we proposed 4) an example-based method in which collected sample words are generalized for wider coverage of derivative words. In this paper, we compare these methods through experiments. To realize fair comparison, all methods were represented in Probabilistic Context Free Grammar (PCFG) and equally tuned with the same training method Maximum Likelihood Estimate. The results show that our method is superior to the methods 1) and 3), under the condition that the grammar learned more than 80,000 generalized examples

Progress and Prospects of X-Ray Laser Research in QST

Recent progress made in the development of coherent x-ray sources and their applications in material science and laser processing in the National Institutes for Quantum and Radiological Science and Technology (QST) is presented herein. The upgrade of Ti:Sapphire laser for a grazing incidence pumping (GRIP) scheme was started, to further develop a coherent x-ray source. Investigating the applications of x-ray lasers, we observed temporal evolution of metal surface ablation using an x-ray laser probe, and the damage to an EUV mirror structure by the x-ray pulse irradiation

Surface processing by femtosecond EUV laser

We have demonstrated the surface processing by use of single and multiple EUV-FEL irradiations. Ablation threshold of silica glass against femtosecond EUV pulse is 20 times smaller than that of near-IR pulse. On the surface, damage free structures are found in interaction region. We have also investigated physical process of EUV-FEL induced ablation. Damage threshold of silicon increases with absorption coefficient. From the theoretical consideration based on the experimental result, the energy sink effect may help to avoid unwanted hydrodynamic motions. As the results, we conclude that the femtosecond EUV laser is a suitable tool for highly precise processing on materials.SACLA Users\u27 Meeting 201