Biomechanical, biochemical, and morphological mechanisms of heat shock-mediated germination in Carica papaya seed.

Carica papaya (papaya) seed germinate readily fresh from the fruit, but desiccation induces a dormant state. Dormancy can be released by exposure of the hydrated seed to a pulse of elevated temperature, typical of that encountered in its tropical habitat. Carica papaya is one of only a few species known to germinate in response to heat shock (HS) and we know little of the mechanisms that control germination in tropical ecosystems. Here we investigate the mechanisms that mediate HS-induced stimulation of germination in pre-dried and re-imbibed papaya seed. Exogenous gibberellic acid (GA3 ≥250 µM) overcame the requirement for HS to initiate germination. However, HS did not sensitise seeds to GA3, indicative that it may act independently of GA biosynthesis. Seed coat removal also overcame desiccation-imposed dormancy, indicative that resistance to radicle emergence is coat-imposed. Morphological and biomechanical studies identified that neither desiccation nor HS alter the physical structure or the mechanical strength of the seed coat. However, cycloheximide prevented both seed coat weakening and germination, implicating a requirement for de novo protein synthesis in both processes. The germination antagonist abscisic acid prevented radicle emergence but had no effect on papaya seed coat weakening. Desiccation therefore appears to reduce embryo growth potential, which is reversed by HS, without physically altering the mechanical properties of the seed coat. The ability to germinate in response to a HS may confer a competitive advantage to C. papaya, an opportunistic pioneer species, through detection of canopy removal in tropical forests

One analysis for the Ordinance on Respect for Sexual Diversity Sexual Diversity Positioning and Initiatives in Local Governments

http://purl.org/coar/resource_type/c_650

Multi log-normal density structure in Cygnus-X molecular clouds: A fitting for N-PDF without power-law

We studied the H$_2$ column density probability distribution function (N-PDF) based on molecular emission lines using the Nobeyama 45-m Cygnus X CO survey data. Using the DENDROGRAM and SCIMES algorithms, we identified 124 molecular clouds in the $^{13}$CO data. From these identified molecular clouds, an N-PDF was constructed for 11 molecular clouds with an extent of more than 0.4 deg$^2$. From the fitting of the N-PDF, we found that the N-PDF could be well-fitted with one or two log-normal distributions. These fitting results provided an alternative density structure for molecular clouds from a conventional picture. We investigated the column density, dense molecular cloud cores, and radio continuum source distributions in each cloud and found that the N-PDF shape was less correlated with the star-forming activity over a whole cloud. Furthermore, we found that the log-normal N-PDF parameters obtained from the fitting showed two impressive features. First, the log-normal distribution at the low-density part had the same mean column density ($\sim$ 10$^{21.5}$ cm$^{-2}$) for almost all the molecular clouds. Second, the width of the log-normal distribution tended to decrease with an increasing mean density of the structures. These correlations suggest that the shape of the N-PDF reflects the relationship between the density and turbulent structure of the whole molecular cloud but is less affected by star-forming activities.Comment: 14 pages, 7 Figures, Accepted in MNRA

Orange Juice and Its Component, Hesperidin, Decrease the Expression of Multidrug Resistance-Associated Protein 2 in Rat Small Intestine and Liver

We investigated the effects of orange juice (OJ) or hesperidin, a component of OJ, on the pharmacokinetics of pravastatin (PRV) and the expression of both protein and mRNA of multidrug resistance-associated protein 2 (Mrp2) in the rat small intestine and liver. Eight-week-old male Sprague-Dawley rats were used in this study. OJ or a 0.079% hesperidin suspension was administered orally for 2 days. Tap water was given as a control. A single dose of PRV at 100 mg/kg p.o. was administered after 2 days of OJ, hesperidin, or tap water ingestion. The AUC, Cmax, and t1/2 values of PRV were significantly increased in OJ group. Mrp2 protein and mRNA levels in the small intestine and liver, respectively, were significantly decreased after the ingestion of OJ. The same results were obtained with hesperidin. These results suggest that the changes in PRV pharmacokinetic parameters and the decrease in Mrp2 expression caused by OJ are due to hesperidin in the juice

A Thermo-labile Process in Dark Germination of New York Lettuce Seeds (A. NATURAL SCIENCE)

A thermo-labile process, that determines the level of dark germination of New York lettuce seeds, was separated from the other miscellaneous processes during germination. It began 2hr after the start of imbibition, and completed several hr before the radicle protrusion at 15℃. The optimum temperature of the process was 15℃, and the activity of the process was zero at 28℃. Secondary dormancy may by induced by the reversible inactivation of the process at high temperature. It was suggested that the physiological role of the process is the generation of the growth potential of embryonic axes in order to overcome the restraint imposed by seed coats

マルチコンパートメント解析における解の信頼限界について(A. 理学)

マルチコンパートメント解析における代謝回転率の信頼限界を求める方法について, 再検討した。実験が最低5回くり返して行える場合には, スチューデント分布を利用した一般的方法が適用できるが, 1回の実験のみの場合には, 理論的根拠の明確な方法が適用できないことが明らかとなった。1回の実験の場合には, データのばらつきを反映した「相対偏差」を導入することにより, 求めた代謝回転率の分布の巾を知ることができ, モデル実験により, くり返し実験によって求めた代謝回転率の標準偏差と, それぞれの実験の「相対偏差」とは, ほぼ対応していることが明らかとなった

マルチコンパートメント解析の非定常系への適用(A. 理学)

マルチコンパートメント解析を非定常系へ適用した場合, データと定常系の近似モデルとの間に系統的なずれが確認でき, このことから, 系の状態が判定できることが明らかとなった。この他, 2つのコンパートメントを1つとみなして解析した場合, 可逆系に適用した場合について検討した

Identification and Replication of Loci Involved in Camptothecin-Induced Cytotoxicity Using CEPH Pedigrees

To date, the Centre d'Etude Polymorphism Humain (CEPH) cell line model has only been used as a pharmacogenomic tool to evaluate which genes are responsible for the disparity in response to a single drug. The purpose of this study was demonstrate the model's ability to establish a specific pattern of quantitative trait loci (QTL) related to a shared mechanism for multiple structurally related drugs, the camptothecins, which are Topoisomerase 1 inhibitors. A simultaneous screen of six camptothecin analogues for in vitro sensitivity in the CEPH cell lines resulted in cytotoxicity profiles and orders of potency which were in agreement with the literature. For all camptothecins studied, heritability estimates for cytotoxic response averaged 23.1±2.6%. Nonparametric linkage analysis was used to identify a relationship between genetic markers and response to the camptothecins. Ten QTLs on chromosomes 1, 3, 5, 6, 11, 12, 16 and 20 were identified as shared by all six camptothecin analogues. In a separate validation experiment, nine of the ten QTLs were replicated at the significant and suggestive levels using three additional camptothecin analogues. To further refine this list of QTLs, another validation study was undertaken and seven of the nine QTLs were independently replicated for all nine camptothecin analogues. This is the first study using the CEPH cell lines that demonstrates that a specific pattern of QTLs could be established for a class of drugs which share a mechanism of action. Moreover, it is the first study to report replication of linkage results for drug-induced cytotoxicity using this model. The QTLs, which have been identified as shared by all camptothecins and replicated across multiple datasets, are of considerable interest; they harbor genes related to the shared mechanism of action for the camptothecins, which are responsible for variation in response