Sulfuric acid bleaching of kraft pulp 1: Bleaching of hardwood and softwood kraft pulps     

Tsutomu Ikeda  Shuji Hosoya  Yoichi Tomimura  Kengo Magara  Isao Takano 《Journal of Wood Science》1999,45(3):233-237

To develop a new nonchlorine bleaching technology, hardwood and softwood kraft pulps, before and after oxygen-alkali predelignification, were treated with dilute sulfuric acid solutions (pH 1.0-1.8) at 100°C for 1 h and then extracted with aqueous sodium hydroxide at 70°C for l h. Hardwood kraft pulp was successfully bleached. The delignification selectivity was similar to that seen with oxygen-alkali bleaching; and it was greatly enhanced by the addition of sodium nitrate and sodium nitrite. The sulfuric acid bleaching can replace the presently adopted oxygen and chlorine stages if the additives are allowed. This bleaching process was also effective for oxygen-bleached hardwood kraft pulp, but it was less effective for softwood kraft pulp and oxygen-bleached softwood kraft pulp. The effectiveness of the addition of sodium nitrate and sodium nitrite was more apparent for softwood kraft pulp than for hardwood kraft pulp.Part of this report was presented at the 7th International Symposium on Wood and Pulping Chemistry, Beijing, July 1993  相似文献   

Physicochemical Properties and Molecular Structures of Starches from Millet (Pennisetum typhoides) and Sorghum (Sorghum bicolor L. Moench) Cultivars in Nigeria     

Terna Gaffa  Yasushi Yoshimoto  Isao Hanashiro  Osamu Honda  Sadamichi Kawasaki  Yasuhito Takeda 《Cereal Chemistry》2004,81(2):255-260

Some physicochemical properties and molecular structures of starches from millet (Pennisetum typhoides, Doro and Gero) and sorghum (Sorghum bicolor, red and white) in Nigeria were examined. Starch granules of millet and sorghum were 3–14 μm and 4–26 μm in diameter, respectively. Millet cultivars had similar peak viscosities (204–205 RVU) on pasting, while sorghum showed similar minimum viscosities (155–156 RVU). The actual amylose content (%) calculated from iodine affinity (IA, g/100 g) was 20.1 and 21.4 for sorghum and 21.3 for millet. The IA of amylopectin was high (1.27–1.42) and its average chain lengths were 20–21 with β‐amylolysis limit of 56%. Amylopectins showed a polymodal molecular weight distribution on a molar basis. The distributions differed among the samples with a higher amount of larger molecules in Doro and red sorghum. Weight‐ and molar‐based distributions of debranched amylopectins on HPSEC were polymodal with weight‐based distribution showing presence of long chains. Peak DP values for A+B₁ and B₂+B₃ chain fractions were 13–16 and 42–43, respectively. The (A+B₁)/(B₂+B₃) ratio on molar basis (9.0–11.5) was similar to maize and rice amylopectins. Peak DP on molar‐based distribution for white sorghum and millet amyloses were similar (490–540) and the DP_n range was narrow (1,060–1,300), but weight‐based distribution profiles differed. The average chain lengths were 260–270 with 3.9–4.8 chains per molecule.  相似文献   

How commercial fishing effort is managed     

Christopher M. Anderson  Melissa J. Krigbaum  Martin C. Arostegui  Megan L. Feddern  John Zachary Koehn  Peter T. Kuriyama  Christina Morrisett  Caitlin I. Allen Akselrud  Melanie J. Davis  Courtney Fiamengo  Ava Fuller  Qi Lee  Katherine N. McElroy  Maite Pons  Jessica Sanders 《Fish and Fisheries》2019,20(2):268-285

Wild capture fisheries produce 90 million tonnes of food each year and have the potential to provide sustainable livelihoods for nearly 40 million people around the world ( http://www.fao.org/3/a-i5555e.pdf ). After decades of overfishing since industrialization, many global fish stocks have recovered, a change brought about through effective management. We provide a synthetic overview of three approaches that managers use to sustain stocks: regulating catch and fishing mortality, regulating effort and regulating spatial access. Within each of these approaches, we describe common restrictions, how they alter incentives to change fishing behaviour, and the resultant ecological, economic and community‐level outcomes. For each approach, we present prominent case‐studies that illustrate behaviour and the corresponding performance. These case‐studies show that sustaining target stocks requires a hard limit on fishing mortality under most conditions, but that additional measures are required to generate economic benefits. Different systems for allocation allow stakeholder communities to strike a locally acceptable balance between profitability and employment.  相似文献   

Growth of giant tiger prawn, <Emphasis Type="Italic">Penaeus monodon</Emphasis> Fabricius,under co-culture with a discarded filamentous seaweed, <Emphasis Type="Italic">Chaetomorpha ligustica</Emphasis> (Kützing) Kützing,at an aquarium-scale     

Isao Tsutsui  Poonmanee Kanjanaworakul  Prapansak Srisapoome  Dusit Aue-umneoy  Kaoru Hamano 《Aquaculture International》2010,18(4):545-553

Growth of juvenile giant tiger prawn, Penaeus monodon Fabricius, was evaluated at an aquarium-scale in co-culture with a discarded filamentous seaweed, Chaetomorpha ligustica (Kützing) Kützing. Juveniles at different ages in days were examined, designated as J 16, J 44, J 58, J 93 and J 128, where a 1-day-old juvenile (J 1) is equivalent to a 20-day-old post-larva (PL 20)). Juveniles at every age group grazed directly on live C. ligustica, even those fed an artificial shrimp diet to satiation. Mean specific growth rate (SGR: % day⁻¹) was higher in early age juveniles. Compared to mono-culture, significant differences in growth were observed at J 16 (4.44% day⁻¹) and J 44 (1.60% day⁻¹); however, no significant differences were recorded at J 58 (1.16% day⁻¹), J 93 (0.75% day⁻¹) or J 128 (0.45% day⁻¹). It was concluded that co-culture of giant tiger prawn with C. ligustica has a dietary advantage, especially in early age juveniles.  相似文献   

Induced Ovarian Maturation of Penaeus vannamei by Implantation of Lobster Ganglion   总被引：3，自引：0，他引：3  

Isao  Yano Brian  Tsukimura James N.  Sweeney James A.  Wyban 《Journal of the World Aquaculture Society》1988,19(4):204-209

Induction of ovarian maturation in Penaeus vannamei , by implantation of ganglion prepared from female lobster, Homarus americanus , with developing ovaries was investigated under tank culture conditions. Four of six females with thoracic ganglion implants were maturing while only two of thirteen females of the control groups with abdominal ganglion or no implant matured. Two ripe stage V were found 18 days after implantation of lobster's thoracic ganglion. This indicates that ovarian maturation of P. vannumei in tanks can be induced and accelerated by implantation of thoracic ganglion prepared from maturing females of another species. Ovarian maturation may be induced by a gonad-stimulating hormone, secreted by the thoracic ganglion of maturing females. This gonnd-stimdating hormone is not species specific in activity in the shrimp and lobster.  相似文献   

Fruit and vegetable consumption and risk of colorectal cancer in Japan: The Miyagi Cohort Study     

Sato Y  Tsubono Y  Nakaya N  Ogawa K  Kurashima K  Kuriyama S  Hozawa A  Nishino Y  Shibuya D  Tsuji I 《Public health nutrition》2005,8(3):309-314

OBJECTIVE: Adequate fruit and vegetable intake has been suggested to protect against colorectal cancer. However, several recent prospective studies have reported no association. We therefore examined the association between fruit and vegetable intakes and the risk of colorectal cancer in a prospective cohort study in Japan. DESIGN: Between June and August 1990, 47 605 Japanese men and women completed a self-administered questionnaire, including a food-frequency questionnaire. We divided the subjects into quartiles based on their self-reported fruit and vegetable consumption. There were 165 colon cancer and 110 rectal cancer incidences identified during 7 years of follow-up, to the end of December 1997. We used Cox proportional hazards models to estimate the relative risk (RR) of developing colorectal cancer according to the level of fruit and vegetable consumption, applying adjustments for potential confounders. RESULTS: No statistically significant association was observed between fruit and vegetable consumption and the risk of colorectal cancer. The multivariate RR of colon cancer in the highest quartile of fruit and vegetable intake compared with the lowest was 1.13 (95% confidence interval (CI) 0.73-1.75), the RR for vegetables alone was 1.24 (95% CI 0.79-1.95) and that for fruit alone was 1.45 (95% CI 0.85-2.47). The corresponding multivariate RRs for rectal cancer were 1.12 (95% CI 0.67-1.89), 1.14 (95% CI 0.67-1.93) and 1.41 (95% CI 0.73-2.73). CONCLUSIONS: We found no association between the consumption of fruit and vegetables and the risk of colorectal cancer among the Japanese population.  相似文献   

A simulation study for a linear measurement error model when error variances vary between measurements     

Yasutaka?ChibaEmail author  Yutaka?Matsuyama  Tosiya?Sato  Isao?Yoshimura 《Journal of Agricultural, Biological & Environmental Statistics》2005,10(1):118-130

When predicting scores in the Draize eye irritation test based on measurements of in vitro alternative tests, we are often faced with estimating parameters in a linear measurement error model with heterogeneous error variances. This article proposes a new statistical method for parameter estimation to address this issue. The proposed method is an extension of an earlier proposal that applied a linear measurement error model with homogeneous error variances, to cases with heterogeneous error variances. A simulation study to examine the performance of the proposed method was conducted in a framework that was adaptable to the data, which was obtained in a validation study of alternative methods to animal experiments conducted in Japan. The proposed method reduced the biases of estimates in comparison with an ordinary regression analysis method and three other methods under the assumption of homogeneous error variances. Although the proposed method did not fit the real data well, the resulting prediction formula was far better than those obtained by other methods.  相似文献   

Sequence and polymerase chain reaction–restriction fragment length polymorphism analysis of the large subunit rRNA gene of bivalve: Simple and widely applicable technique for multiple species identification of bivalve larva     

Masatomi  HOSOI  Shoko  HOSOI-TANABE  Hideki  SAWADA  Masahiro  UENO  Haruhiko  TOYOHARA  Isao  HAYASHI 《Fisheries Science》2004,70(4):629-637

ABSTRACT:   One of the biggest and long-standing difficulties in investigation of larval ecology in the field is species-level identification. In the present study, we developed polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) analysis based on the large subunit (LSU) rRNA gene (rDNA) D1/D2/D3 region for identification of multiple species of bivalve larvae using 14 species of bivalve collected from Maizuru Bay. The LSU rDNA D1/D2/D3 region of all analyzed species could be amplified by PCR using bvD1f/bvD3r primers, and RFLP analysis by Hae III digestion on the PCR products showed species-specific fragment patterns. Furthermore, this analysis applied to single bivalve larvae in Maizuru Bay revealed efficient amplification of the target region and the species-specific pattern from 80% of the larvae, 75% of which showed a pattern that matched a certain pattern of the adult bivalves. In addition, the analysis of inter- and intraspecies variation of the LSU rDNA D1/D2/D3 region using the sequence data of the genus Crassostrea from the DDBJ database showed high applicability of this RFLP analysis on closely related species. Because of the wide applicability and technical simplicity, this method can become the standard for the identification of bivalve larvae species once the sequence data of the LSU rDNA D1/D2/D3 region of many bivalve species have been accumulated.  相似文献   

Measuring the ecological value of the forests around the kushiro marsh: An empirical study of choice experiments     

Koichi Kuriyama 《Journal of Forest Research》2000,5(1):7-11

This paper estimates the ecological value of the forests around the Kushiro marsh using data from choice experiments (CE). CE is one of the environmental valuation techniques and asks individuals to pick from a set of resource management alternatives. The total sample surveyed was 845. Conditional logit and conditional probit models analyzed the CE data for five management plans of the wetland. The results are as follows: (1) The average willingness to pay is 137 dollars / year / household and the aggregate willingness to pay is 301 million dollars / year, when all the land around the wetland (151,361 ha) is protected for the ecosystem. (2) Cost benefit analysis shows that the optimal protection area is Q₄ (91,361 ha). This means that it is important in terms of social welfare to protect not only the wetland itself, but also the forest around the wetland.  相似文献   

Structural and Retrogradation Properties of Rice Endosperm Starch Affect Enzyme Digestibility of Steamed Milled-Rice Grains Used in Sake Production     

Masaki Okuda  Isao Aramaki  Takuya Koseki  Naoyoshi Inouchi  Katsumi Hashizume 《Cereal Chemistry》2006,83(2):143-151

Structural and physicochemical characteristics of endosperm starch from milled rice grains of seven Japanese cultivars used in sake production were examined. Amylose content was 15.2–20.2%, number-average degree of polymerization (DP_n) of amylose was 900–1,400, and the ratio of short-to-long chain amylopectin was 2.7–3.5, respectively. The degree of retrogradation of purified starch stored for seven days at 4°C after gelatinization was 20–31%. The degree of retrogradation correlated negatively with the ratio of short-to-long chain amylopectin. The effect of holding time after steaming on enzyme digestibility and starch retrogradation of steamed rice grains was investigated. The longer the holding time after steaming, the greater the extent of retrogradation, and the less the degree of enzymatic digestibility. The decreased rate of enzyme digestibility correlated with amylopectin chain length distribution. Samples with short-chain amylopectin exhibited a slow decrease in enzyme digestibility. It was determined that the structure and retrogradation properties of endosperm starch in Japanese rice cultivars affect the decreasing rate of enzyme digestibility of the steamed, milled rice grains.  相似文献