Impact of Magnetic Field Configuration on Heat Transport in Stellarators and Heliotrons.

We assess the magnetic field configuration in modern fusion devices by comparing experiments with the same heating power, between a stellarator and a heliotron. The key role of turbulence is evident in the optimized stellarator, while neoclassical processes largely determine the transport in the heliotron device. Gyrokinetic simulations elucidate the underlying mechanisms promoting stronger ion scale turbulence in the stellarator. Similar plasma performances in these experiments suggests that neoclassical and turbulent transport should both be optimized in next step reactor designs.

Development of new experimental setup focusing on long-pulse magnetic reconnection by using rotating magnetic field technique.

A new closed-type experimental setup to achieve a long-pulse magnetic reconnection in weakly ionized plasmas was developed by using a rotating magnetic field (RMF) technique. The experimental setup has a cylindrical vacuum vessel in which two sets of four antennas are equipped to generate RMF which drives steady azimuthal electron current in two torus plasmas. This device provided a quasi-steady magnetic reconnection condition in weakly ionized plasmas with ionization fraction of less than 1%. The proposed experimental setup will extend the research area of laboratory reconnection experiments and be helpful to comprehend the reconnection process in weakly ionized plasmas such as solar chromosphere.

Recovery from disturbance requires resynchronization of ecosystem nutrient cycles.

Nitrogen (N) and phosphorus (P) are tightly cycled in most terrestrial ecosystems, with plant uptake more than 10 times higher than the rate of supply from deposition and weathering. This near-total dependence on recycled nutrients and the stoichiometric constraints on resource use by plants and microbes mean that the two cycles have to be synchronized such that the ratio of N:P in plant uptake, litterfall, and net mineralization are nearly the same. Disturbance can disrupt this synchronization if there is a disproportionate loss of one nutrient relative to the other. We model the resynchronization of N and P cycles following harvest of a northern hardwood forest. In our simulations, nutrient loss in the harvest is small relative to postharvest losses. The low N:P ratio of harvest residue results in a preferential release of P and retention of N. The P release is in excess of plant requirements and P is lost from the active ecosystem cycle through secondary mineral formation and leaching early in succession. Because external P inputs are small, the resynchronization of the N and P cycles later in succession is achieved by a commensurate loss of N. Through succession, the ecosystem undergoes alternating periods of N limitation, then P limitation, and eventually co-limitation as the two cycles resynchronize. However, our simulations indicate that the overall rate and extent of recovery is limited by P unless a mechanism exists either to prevent the P loss early in succession (e.g., P sequestration not stoichiometrically constrained by N) or to increase the P supply to the ecosystem later in succession (e.g., biologically enhanced weathering). Our model provides a heuristic perspective from which to assess the resynchronization among tightly cycled nutrients and the effect of that resynchronization on recovery of ecosystems from disturbance.

Open clinical study of eye-drops containing tetrapeptides derived from substance P and insulin-like growth factor-1 for treatment of persistent corneal epithelial defects associated with neurotrophic keratopathy.

BACKGROUND/AIMS: Loss of corneal sensation results in the development of persistent corneal epithelial defects. The combination of a substance P-derived peptide (FGLM-amide) and an insulin-like growth factor-1 (IGF-1)-derived peptide (SSSR) stimulates rabbit corneal epithelial migration in vitro and rabbit corneal epithelial wound closure in vivo. The clinical efficacy of eye-drops containing FGLM-amide and SSSR for the treatment of persistent corneal epithelial defects in individuals with neurotrophic keratopathy was examined in a prospective open study. METHODS: Twenty-five consecutive patients (26 eyes) with persistent corneal epithelial defects associated with neurotrophic keratopathy were treated by administration of eye-drops containing FGLM-amide and SSSR. The course of epithelial healing was monitored by slit-lamp examination. RESULTS: Epithelial defects resurfaced completely in 19 of the 26 eyes (73%) within 4 weeks after treatment initiation. Complete resurfacing of epithelial defects was apparent in 18 of 22 (82%) or in one of four (25%) eyes without or with limbal stem cell deficiency, respectively. No adverse effects of treatment were observed in any subject. CONCLUSION: Eye-drops containing FGLM-amide and SSSR induced the rapid resurfacing of persistent epithelial defects in stem cell-positive individuals with neurotrophic keratopathy.

Tai Chi Chuan practice as a tool for rehabilitation of severe head trauma: 3 case reports.

Rehabilitation after severe head trauma is a complex process that can be long and frustrating. New, more holistic methods for rehabilitation are constantly sought. We present the cases of 3 patients who had severe head injury and whose rehabilitation was facilitated by Tai Chi Chuan (TCC) therapy. TCC therapy should be taught only by a qualified TCC therapist and under close medical supervision.

Physiological significance of short-loop feedback of prolactin in female mice.

Twice daily subcutaneous injections of 1 mg human placental lactogen for 1 week to female mice significantly suppressed the pituitary prolactin synthesis, which was measured by the in vitro incorporation of [14C]leucine into prolactin. On the other hand, 2 isologous pituitary grafting affected neither synthesis nor release of prolactin in the in situ pituitary even after 8 weeks, while the grafting resulted in the constant elevation of circulating prolactin to the proestrous level, the highest under normal physiological conditions, and induced marked mammary growth. Based on these observations, the significance of short-loop feedback of prolactin is discussed.

Failure of ovulation after neonatal administration of 5 alpha-dihydrotestosterone to female rats.

Wistar female rats were injected with testosterone (T) or 5 alpha-dihydrotestosterone (5 alpha-DHT) from the day of birth (= day 1) to day 5. Neonatal treatment with 1 mg of T resulted in anovulatory persistent estrous syndrome in 100% of the animals. In the females treated with 1 mg of 5 alpha-DHT, 88.2% of the treated rats were sterile at 120 days of age. Treatment with 0.5 mg 5 alpha-DHT was also effective in inducing anovulatory sterility, the incidence of sterility being 71.4%. In the females injected with 0.1 mg 5 alpha-DHT, 42.9% of the animals were anovulatory at 120 days of age. These results suggest that non-aromatizable androgen, 5 alpha-DHT, can permanently suppress the development of female type of neuroendocrine regulation.

Long-term effects of perinatal exposure to 5 alpha-dihydrotestosterone on normal and neoplastic mammary development in mice.

Daily subcutaneous injection of 200 microgram 5 alpha-dihydrotestosterone to SHN female mice for the first 5 days of postnatal life resulted in the stimulation of normal and neoplastic mammary development at advanced ages and it also induced the ovarian anovulatory syndrome and stimulated pituitary prolactin secretion. Daily subcutaneous injections of 1 mg 5 alpha-dihydrotestosterone to pregnant mice from day 12 to day 15 of pregnancy (prenatal treatment) had no effects on their offspring. Long-term effects of 5 alpha-DHT on normal and neoplastic mammary development in mice were generally not so marked as those observed previously with 5 beta-dihydrotestosterone which is biologically inactive in the adult.

Induction of anovulatory sterility by neonatal treatment with 5 beta-dihydrotestosterone in female rats.

Wistar female rats were injected with testosterone (T) or 5 beta-dihydrotestosterone (5 beta-DHT) for the first 5 days of life. Neonatal treatment with 1 mg of T resulted in anovulatory persistent oestrous syndrome in 100% of the animals. In the females injected with 1 mg of 5 beta-DHT, 74% of the treated rats became sterile at 120 days of age. In addition, 0.5 mg 5 beta-DHT was also effective in inducing anovulatory persistent oestrus; the incidence of sterility was 10 and 80% at 60 and 120 days of age, respectively. When daily dose of 5 beta-DHT was reduced to 0.1 mg, however, only 33% of the rats resulted in sterility. These results suggest that the free form of T and non-aromatizable androgen, 5 beta-DHT, can permanently suppress the development of female type of neuroendocrine regulation. The possible participation of the process other than the central aromatization in androgenization will be discussed.

Effects of hormones on prolactin binding to normal mammary glands and pregnancy-dependent mammary tumors in GR/A female mice near parturition.

Pregnancy-dependent mammary tumors in GR/A female mice are different from normal mammary glands in hormone responsiveness and prolactin binding near parturition. The binding was modified by several hormones. Thus, prolactin binding under the hormonal conditions favorable for the progression of tumors was compared between normal and neoplastic mammary glands. Slices of the glands were incubated in 1 ml Medium 199 containing 125I-labeled ovine prolactin and the radioactivity incorporated was counted as the index of binding. Prolactin binding to either normal or neoplastic glands on day 19 of pregnancy was low and not affected by ovariectomy on day 15, and by daily injections of progesterone alone or in combination with estradiol benzoate between days 14 and 19 of pregnancy. One day after parturition (litter was removed immediately after parturition), the binding to tumors was raised significantly, while, the binding to normal glands remained low. Injections of progesterone alone or in combination with human placental lactogen twice a day from 1 day before parturition induced little changes in the binding to either normal or neoplastic glands. These results suggest no alteration of mammary response for prolactin binding to exogenous hormones in the process of transformation of the glands from normal to neoplastic states, and low predictability of membrane prolactin receptors for tissue responsiveness to the hormone.