Modulating sphingolipid biosynthetic pathway rescues photoreceptor degeneration

Mutations in proteins of the Drosophila phototransduction cascade, a prototypic guanine nucleotide-binding protein-coupled receptor signaling system, lead to retinal degeneration and have been used as models to understand human degenerative disorders. Here, modulating the sphingolipid biosynthetic pathway rescued retinal degeneration in Drosophila mutants. Targeted expression of Drosophila neutral ceramidase rescued retinal degeneration in arrestin and phospholipase C mutants. Decreasing flux through the de novo sphingolipid biosynthetic pathway also suppressed degeneration in these mutants. Both genetic backgrounds modulated the endocytic machinery because they suppressed defects in a dynamin mutant. Suppression of degeneration in arrestin mutant flies expressing ceramidase correlated with a decrease in ceramide levels. Thus, enzymes of sphingolipid metabolism may be suitable targets in the therapeutic management of retinal degeneration.     

Effectiveness of an elemental sulfur fertilizer in an oilseed‐cereal‐legume rotation on the Canadian prairies

Adequate sulfur (S) nutrition is critical for sustaining yields in crop rotation systems. Because of slow oxidation of elemental S (S°), research on S° fertilizers has emphasized improving the short‐term availability, while the long‐term effects of S° have been overlooked. The effectiveness of a dispersible granule S° fertilizer (SF: Sulfer95), consisting of S° particles smaller than any S° fertilizer reported in literature (< 44 μm in diameter), was compared to gypsum (CS: CaSO₄) and ammonium sulfate [AS: (NH₄)₂SO₄] in a three‐year experiment (1997—1999) on a moderately S deficient Black Chernozem soil (Typic Cryoboroll). The three S fertilizers were applied to canola (Brassica rapa L.) at 20, 40, and 80 kg S ha^‐1, supplemented with corresponding rates of nitrogen (N) fertilizer in the first year. The control treatment (CT) received N only. Barley (Hordeum vulgare L.) and peas (Pisum sativum L.) were grown in the second and third years to test the availability of residual S. Although the yield of canola in SF fertilized treatments was only slightly higher than in CT, available S provided by SF produced a higher physiological S efficiency (PSE). Superior yields with residual SF were obtained in the second and third years by barley and peas at the rate of 80 kg S ha^‐1 applied in the first year, indicating that slow oxidation of SF was beneficial to the crops subsequently grown. Over three years, the total crop S uptake was 21, 4.0, and 15% higher with SF than with CT, CS, and AS, respectively.     

Determining fertilizer-induced NO emission ratio from soils by a statistical distribution model

To reduce uncertainties in the highly variable estimates of NO emission from N fertilizer, we compiled and analyzed available reports of field measurements on fertilizer-induced NO emission. Three statistical distribution models, lognormal, gamma and Weibull, were used to fit the observation data. Results show that while all three models fit the observation data statistically, the lognormal model is not applicable to this data set. A mean fertilizer-induced NO emission ratio of 0.71% was derived from a Weibull distribution, which is the besting fitting model.     

Photic and circadian regulation of self-feeding activity in ayu

ABSTRACT:   The self-feeding rhythms of ayu Plecoglossus altivelis altivelis were examined. Individual ayu (mean body weight 40 g) were held in 60-L glass tanks equipped with self-feeders. Six of 14 fish learned self-feeding during the experiment. Under two different light–dark (LD) conditions (16 h:8 h and 8 h:16 h LD), self-feeding was synchronized to the LD cycle, and feeding occurred almost exclusively during the light phase. During exposure to constant light (LL), circadian feeding rhythms were observed. These results indicate self-feeding rhythms in ayu are restricted to the light phase under LD conditions and are controlled by the circadian clock under LL conditions.     

Toxicity of wild juvenile “komonfugu” Takifugu flavipterus in the Bay of Sanriku Coast,Tohoku Area,Northern Japan

To clarify the mechanism of tetrodotoxin (TTX) accumulation in pufferfish, we compared the toxicity of two sets of wild juvenile “komonfugu” Takifugu flavipterus. The first set was sampled from Onisawa Fishing Port (FP) located in Okirai Bay, the Pacific Coast of Sanriku, Tohoku Area, Northern Japan. The second set was collected from the Onisawa FP and reared in an outdoor laboratory tank supplied with different seawater (Yoshihama Bay). The fish were sampled regularly and on the same days. The amount of TTX (mouse unit (MU)/fish) in the fish at Onisawa FP increased until 20 days and thereafter it did not change, while the amount of TTX in the fish in the laboratory tank remained low, and the TTX concentration (MU/g fish) decreased. Next, we compared the toxicity of wild juvenile T. flavipterus collected from Okirai Bay (Onisawa FP and Okirai FP) and Yoshihama Bay (Yoshihama FP). Large differences in TTX levels were observed among the fish from the three FPs. The amounts and concentrations of TTX in the fish at Onisawa FP were higher than those in the fish from the other two FPs. These results indicate that a large variation in toxic activity exists in the juvenile T. flavipterus in the bay of the Sanriku Coast.

     

Preventive effect of Kaempferia parviflora ethyl acetate extract and its major components polymethoxyflavonoid on metabolic diseases

Previously, we reported that rhizome powder of Kaempferia parviflora Wall. Ex. Baker prevented obesity and a range of metabolic diseases. In this study, to clarify which molecular mechanisms and active ingredients of K. parviflora have an anti-obesity effect, we investigated the effect of ethyl acetate extract of K. parviflora (KPE) on TSOD mice, a spontaneously obese Type II diabetes model, and on pancreatic lipase. In the TSOD groups, KPE showed a suppressive effect on body weight increase and visceral fat accumulation and also showed preventive effects on symptoms related to insulin resistance, hypertension and fatty liver. In addition, KPE also suppressed body weight increase and food intake in TSNO mice groups, which served as reference animals, at an early stage of administration. Searching for the ingredients in KPE revealed that KPE contains at least 12 kinds of polymethoxyflavonoid (PMF). Furthermore, KPE and its component PMFs showed an inhibitory effect on pancreatic lipase. The above results suggest that KPE has a preventive effect on obesity and various metabolic diseases. The mechanisms of action probably involve inhibition of pancreatic lipase by the PMFs in KPE.     

Effect of the Y chromosome on testis weight in mice

We investigated the effect of the Y chromosome on testis weight in (B6.Cg-A^y × Y-consomic mouse strain) F₁ male mice. We obtained the following results: (1) Mice with the Mus musculus domesticus-type Y chromosome had significantly heavier testis than those with the M. m. musculus-type Y chromosome. (2) Variations in Usp9y and the number of CAG repeats in Sry were significantly associated with testes weight. The A^y allele was correlated with a reduced testis weight, and the extent of this reduction was significantly associated with a CAG repeat number polymorphism in Sry. These results suggest that Y chromosome genes not only influence testis weight but also modify the effect of the A^y allele in mediating this phenomenon.     

Further characterization of diabetes mellitus and body weight loss in males of the congenic mouse strain DDD.Cg-Ay

The A^y allele at the agouti locus causes obesity and promotes linear growth in mice. However, body weight gain stops between 16 and 17 weeks after birth, and then, body weight decreases gradually in DDD.Cg-A^y male mice. Body weight loss is a consequence of diabetes mellitus, which is genetically controlled mainly by a quantitative trait locus (QTL) on chromosome 4. This study aimed to further characterize diabetes mellitus and body weight loss in DDD.Cg-A^y males. The number of β-cells was markedly reduced, and plasma insulin levels were very low in the DDD.Cg-A^y males. Using a backcross progeny of DDD × (B6 × DDD.Cg-A^y) F₁-A^y, we identified one significant QTL for plasma insulin levels on distal chromosome 4, which was coincidental with QTL for hyperglycemia and lower body weight. The DDD allele was associated with decreased plasma insulin levels. When the DDD.Cg-A^y males were housed under three different housing conditions [group housing (4 or 5 DDD.Cg-A^y and DDD males), individual housing (single DDD.Cg-A^y male) and single male housing with females (single DDD.Cg-A^y male with DDD.Cg-A^y or DDD females)], diabetes mellitus and body weight loss were most severely expressed in individually housed mice. Thus, the severity of diabetes and body weight loss in the DDD.Cg-A^y males was strongly influenced by the housing conditions. These results demonstrate that both genetic and nongenetic environmental factors are involved in the development of diabetes mellitus and body weight loss in the DDD.Cg-A^y males.     

Japan,Monsoon Asia and the global agricultural revolution in the 21st century

The world knows little about Monsoon Asia's agriculture, which feeds 60% of the world's population by using only 30% of the arable land. By approximately 40 years after World War II, most Asian countries had achieved self-sufficiency in rice and built up the foundation of the East Asian Miracle in the early 1990s through the integration of agricultural processing and marketing. This paper consists of nine figures and tables focusing on specific thematic headings with concise explanations rather than the full written format used in most research articles. It is hoped that these materials contribute to the realization of the global agricultural revolution in the 21st century. Electronic Publication     

Markov-Switching Linked Autoregressive Model for Non-continuous Wind Direction Data

In this paper, a Markov-switching linked autoregressive model is proposed to describe and forecast non-continuous wind direction data. Due to the influence factors of geography and atmosphere, the distribution of wind direction is disjunct and multi-modal. Moreover, for a number of practical situations, wind direction is a time series and its dependence on time provides very important information for modeling. Our model takes these two points into account to give an accurate prediction of this kind of wind direction. A simulation study shows that our model has a significantly higher prediction accuracy and a smaller mean circular prediction error than three existing models and it is illustrated to be effective by analyzing real data. Supplementary materials accompanying this paper appear online.