Recasting the mode of production

Robert Briglio is a human-rights lawyer and a student of Anthropology at the New School for Social Research.     

Penicillin production and its mode of inheritance inAspergillus nidulans

Previous workers have shown that some strains ofAspergillus nidulans produce penicillin-like substances. In the present studies, shake-flask cultures of 101 wild-type strains ofA. nidulans, representatives of 18 different heterokaryon-compatible groups, were examined and filtrates of most found to inhibit the growth of a strain ofBacillus subtilis sensitive to penicillin, although members of two of these groups had no detectable antibiotic activity. Five strains with antibacterial properties were chosen for detailed investigation as well as two genetically labelled derivatives obtained from one of these after ultraviolet light treatments; one derivative had a similar antibiotic yield to its original wild-type parent but the other was selected as having increased antibiotic yield. The antibiotic produced by these seven strains was by all tested criteria, including chromatographic and electrophoretic behaviour, indistinguishable from penicillin. A heterokaryon test between the two mutants indicated that antibiotic productivity was under nuclear control.     

Caffeine inhibition of aflatoxin production: mode of action.

Evaluation of caffeine and a number of related methylxanthines indicated that the ability of the compound to inhibit growth and aflatoxin production by Aspergillus parasiticus is highly specific and does not involve an inhibition of cyclic AMP phosphodiesterase. Supplementation of the culture medium with purine bases, nucleosides, and nucleotides suggested that the inhibition of fungal growth could be partially overcome by adenine or guanine but that the purines had little effect on the inhibition of aflatoxin production. Likewise, increasing the levels of trace minerals did not overcome the inhibition of toxin production. Electron microscopic evaluation of caffeine-treated and -untreated cultures indicated that the compound produced observable changes in the ultrastructure of the fungus.     

甘肃景电灌区枸杞与玉米生产模式的能值分析

灌区由于不合理的生产以及不完善的灌排设施,土地盐碱化成为普遍存在的现象,景电灌区治理盐碱地的典型代表村-红跃村在盐碱地种植枸杞取得了良好的生态效益和经济效益.应用能值分析法,对该村枸杞生产模式与原有的玉米生产模式进行了系统分析.枸杞生产模式与玉米生产模式的各项能值指标的比值是:能值投资率3.78 ,净能值产出率2.24 、环境负载率0.27 、能值可持续性指数8.19 .结果表明:枸杞生产模式使得红跃村落后、封闭的生态经济系统变得开放、活跃,增强了可持续发展的潜力.为进一步完善绿洲经济生态系统,应优化生产结构,加强绿洲防护林体系建设.     

应用年龄结构产量模型评估印度洋黄鳍金枪鱼资源

利用年龄结构产量模型(Age structured production model,ASPM)评估了印度洋黄鳍金枪鱼资源状况,同时结合亲体量-补充量曲线陡度系数和年龄组自然死亡系数的敏感性分析,描述了黄鳍金枪鱼资源的发展趋势、判断了开发状况。研究认为,陡度系数设在0.6-0.8才可能使亲体量产生出最大可持续产量(Maximum sustainable yield,MSY)的水平。采用美洲热带金枪鱼委员会推荐的自然死亡系数值时,评估结果最接近渔业现状。研究发现,随着捕捞努力量的增加,总资源量和亲体量呈逐年下降趋势,但总资源量自1990年后趋向稳定,维持在195.9-263.2万t,平均为221万t;亲体量在1994年后下降到100万t以下,1997年以后处在维持MSY所需亲体量的水平之下,目前仍呈下降趋势。补充量在渔业初期呈现大幅度波动,1978年后趋于稳定,并维持在3258.36-6583.35×106尾,平均为4687.66×106尾。未成熟鱼的数量总体较为稳定,但成熟鱼的数量出现剧减,从渔业初期的246.51×106尾减少到2005年的19.02×106尾。模型估计的总捕捞死亡系数从渔业初期开始逐渐上升,1991年后出现大幅度上升,处于0.334-0.456间,2003年时超过FMSY,捕捞产量也于2003年超过MSY。分析认为,2003年以来印度洋黄鳍金枪鱼的持续高产量被认为是不可持续,根据ASPM估算,2003-2006年均产量46.4万t,超过了MSY(36.4万t);S/SMSY为0.76;Fall/FMSY为1.39,由此判断现阶段印度洋黄鳍金枪鱼正处于过度捕捞状态。     

The asiatic mode of production: Problems of conceptualising state and economy

Conclusion The tendency on the part of Kosambi, Joshi and Alavi to characterise pre-colonial India as predominantly feudal can be appreciated in the context of a critique of colonialism. The problem of the transformation of the AMP has been left largely unanswered by Marx who vacillates between two accounts of this question. In the New York Daily Tribune articles the AMP is perceived as inherently static and it is this statism that legitimates the colonial intervention. By contrast, in the Grundrisse and Capital I, a more dynamic view is expressed in which the AMP gives way to other modes. Marx's primary thesis provides an indirect justification of colonialism and imperialism, but that justification cannot be upheld if it is established that the prevailing mode in the immediate pre-British India era was feudal rather than Asiatic. By claiming a feudal heritage, Kosambi, Joshi and Alavi can maintain a position in line with Marxist analysis while rejecting Marx's legitimation of imperialism. If, however, it can be established that the AMP does have an inherent dynamic then the defence of the feudal view is weakened. Arguably, the maintenance of massive standing armies — which consumed two thirds of the surplus product but were essential for the reproduction of the mode —constitute the location of such a dynamic. The point at which the maintenance of armies becomes prohibitive is the point at which the mode must start to disintegrate since its reproduction can no longer be guaranteed. In the case of the AMP, unlike the capitalist mode of production, there are no offsetting factors.The explicitly ideological and geographical connotations of the term Asiatic, which are central to Melotti's characterisation of Marx's analysis, are both misleading and unessential. It is difficult to a) reject the term Asiatic without b) negating the mode to which that term has been applied. The rejection of the term, however, does not necessarily entail the negation of the mode. For Marx it is the tribute-raising state which appropriates the surplus product from the direct producer and which stands in the same objectively antagonistic relationship to that producer as does the slave-owner to the slave, the feudal lord to the serf, and the capitalist to the wage labourer. Thus, it is the means whereby the surplus product is appropriated which sets apart the mode in question — which may legitimately be designated tributary — from other modes. This is the sense in which the tax/rent couplet does have theoretical validity. However, while the tax/rent couplet may constitute the dominant mode of appropriation of the surplus product in a particular geographical location — Asiatic or otherwise — and at a specific point in time, this does not justify the conflation of mode and society.Kate Currie is Lecturer in Sociology at the University of Lancaster, Lancaster, Great Britain.

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Suppression of testosterone production by ethyl alcohol. Possible mode of action

Intragastric administration of ethyl alcohol (1.24 g/kg body weight) to adult male mice caused a drastic decrease in the concentration of testosterone (T) in peripheral plasma. The depression of plasma T levels was significant at 30, 60 and 90 minutes after alcohol administration, but by 120 min, the normal T levels were re-established. This transient decrease in peripheral T levels was probably due to a reduction in testicular T production, because at 1 hr after alcohol administration, the concentration of T in the testis was also significantly depressed. The ability of the testes of alcohol-treated mice to produce T in response to gonadotropic stimulation in vitro was not affected. Addition of 5, 10, 20 or 50 microliter of alcohol per ml of the medium used for the incubation of decapsulated testes had no significant effect on the accumulation of T, but similar doses of acetaldehyde caused a pronounced inhibition of T production. The decrease in plasma T levels observed after administration of ethyl alcohol in vivo may be related to a direct inhibition of testicular T production by acetaldehyde derived from the metabolism of alcohol.     

圆红冬孢酵母两阶段培养法生产微生物油脂

为缩短发酵时间,减少原料消耗,采用细胞增殖和油脂积累分离的两阶段模式,培养圆红冬孢酵母Rhodosporidium toruloides AS 2.1389生产微生物油脂。结果表明,细胞增殖阶段获得的R.toruloides AS 2.1389细胞,重悬接种在葡萄糖溶液中,可快速积累油脂,菌体油脂含量超过自身干重的55%。增殖阶段细胞的菌龄越高,产油能力越强。油脂积累阶段使用高浓度葡萄糖溶液或未灭菌的葡萄糖溶液,油脂合成可以有效进行。油脂中脂肪酸成分以含16和18个碳原子的长链脂肪酸为主,可作为制备生物柴油的新型原料。     

Reflector based chlorophyll production by Spirulina platensis through energy save mode

The present study suggests that the effect of silver coated polyester film fixed in culture racks serves as a reflector of light intensity on Spirulina platensis cultivation, using of KNO₃ and urea as nitrogen sources. The use of light reflector (LR) gave light intensity of 4.8-6.0 klux and the reduction in number of tube light with reflector gave 2.5 klux of light intensity and its effect was studied on S. platensis. Total chlorophyll productions were observed for the cultivation at light intensity of two lights with reflector. This improvement is simple, inexpensive and saves 50% electric energy by reducing the number of lights, and thus contributes to energy conservation.     

Ovarian structure and mode of egg production in the seaweed pipefish Syngnathus schlegeli (Syngnathidae)

This study investigated ovarian structure and mode of egg production in the seaweed pipefish, Syngnathus schlegeli. The ovary had a rolled sheet-like structure where developing follicles were arranged serially in sequence according to their development, with a single germinal ridge running along the edge of the sheet. Oocytes of various developmental stages were concomitantly present in the ovary, and the number of mature eggs increased continuously over time, indicating that egg production is asynchronous. This would be a physiological basis for multiple spawning within a short time span associated with polygamy in this fish.     

Enhancement of phenolic compound production in Spirulina platensis by two-step batch mode cultivation

Phenolic compounds regarded as important pharmaceuticals with various biological activities are found in low amounts in microalgae. The objective of this study was to increase the amount of phenolic compounds in Spirulina platensis by a two-step batch mode cultivation. The evaluation of the effect of the sudden shift from low light to high light on phenolic compound production, antioxidant activity, growth, and biomass composition of S. platensis was undertaken. The amount of phenolic compounds was significantly increased by approximately eightfold (p?<?0.01) by the light treatment. There were also increases in total amounts of carbohydrate, phycocyanin, carotenoid, malondialdehyde, and antioxidant activities while there were significant decreases in total protein amounts (p?<?0.05). The relationships between antioxidant activities and total amounts of phenolic compounds were significantly correlated at the 99% confidence level (p?<?0.01) indicating that phenolic compounds were major contributors of antioxidant activities.     

不同培养方式对细菌纤维素产量和结构性质的影响

考察了自行筛选的Acetobacter xylinum NUST4.2在静置培养和发酵罐培养获得的细菌纤维素(BC)的产量、基本结构和性能的差异。结果表明:静置培养时产纤维素7.5g/L,产率为0.052g/L/h,在机械搅拌发酵罐中培养3d产量达3.13g/L,产率达0.043g/L/h;SEM分析显示静置培养和发酵罐培养得到的纤维素均具有网状结构,但静置获得的纤维素丝带相互缠绕且层状重叠,更加致密,丝带更细;FT-IR分析知搅拌不改变纤维素的化学结构,但能减弱分子间氢键,和XRD结合分析可知静置培养的纤维素具有更高结晶指数,更高Iα含量和更大晶粒尺寸,但不改变晶型,仍为纤维素I型,说明搅拌会干扰纤维素初始纤丝的结晶,有利于形成更小的晶粒和较Iα稳定的Iβ。与棉纤维素相比,静置培养获得的纤维素的热稳定性更好,而发酵罐培养获得的纤维素则阻燃性更好。     

Recombinant production of docosahexaenoic acid in a polyketide biosynthesis mode in Escherichia coli

The docosahexaenoic acid (DHA) biosynthesis gene cluster (pDHA3) from the DHA-producing Moritella marina strain MP-1 includes the genes pfaA, pfaB, pfaC, and pfaD, which are similar to the genes of polyketide biosynthesis. When this cluster was co-expressed in Escherichia coli with M. marina MP-1 pfaE, which encodes phosphopantetheinyl transferase, DHA was biosynthesized. The maximum production of DHA (5% of total fatty acids) was observed at 15°C. This is the first report of the recombinant production of DHA in a polyketide biosynthesis mode.     

The tempo and mode of gopher mound production in a tallgrass prairie remnant

To gain better insight into how small-scale disturbances might affect ecological processes, such as the maintenance of plant species diversity, we conducted a two-year study characterizing spatio-temporal patterns of gopher mound production on a tallgrass prairie remnant located at Anderson Prairie, Iowa. USA. The locations of all newly produced gopher mounds were mapped on two 80 × 80 m permanent plots. We used these data to characterize spatio-temporal patterns of mound production across a range of scales. We found that mound production was highly clustered at scales of < 8 m over short periods of time (< 2 weeks), but shifted in location over a 3–4 weeks time period, resulting in a clustered pattern at scales of < 20 m over longer time periods (up to the 2 yr of the study). We also found that patterns of mound production at intermediate spatial scales (> 20 m) remained fairly static over time, although they differed significantly from site to site. The results of this study suggest that small-scale patterns of variability in mound production may increase habitat variability over very short spatial scales, possibly providing a mechanism that can enhance the development and maintenance of species diversity.     

Investigation of continuous-batch mode of two-stage culture of Nannochloropsis sp. for lipid production

Microalgal lipid induction through nitrogen stress often suffers from a contradiction between biomass productivity and lipid content, i.e., either high biomass productivity with low lipid content or vice versa. A two-stage nitrogen-replete and nitrogen-deplete (NR–ND) culture was suggested to be an option to attain high lipid productivity. In this study, the effects of culture conditions and modes on biomass productivity and lipid productivity of Nannochloropsis sp. in the two stages were comprehensively investigated. The optimal culture conditions for the two stages, aiming to high biomass productivity and lipid productivity respectively, were consistent, i.e., CO₂ content in aeration (1 %), phosphorus concentration in medium (181 μmol/L), incident light intensity (150 μE/(m²s)), temperature (25 °C). Different culture modes of the two stages were compared. The overall lipid productivity of the two-stage continuous-batch mode achieved 0.123 g/(L day), which was 60.3, 48.2, 34.9 and 13.5 % higher than that of single nitrogen-replete batch, single nitrogen-limited batch, continuous nitrogen-replete culture and two-stage batch–batch culture, respectively, and also higher than most reported values. This contribution provides fundamental data for the two-stage NR–ND cultivation process design of Nannochloropsis sp.