Outline of a dynamical inferential conception of the application of mathematics

We outline a framework for analyzing episodes from the history of science in which the application of mathematics plays a constitutive role in the conceptual development of empirical sciences. Our starting point is the inferential conception of the application of mathematics, recently advanced by Bueno and Colyvan (2011). We identify and discuss some systematic problems of this approach. We propose refinements of the inferential conception based on theoretical considerations and on the basis of a historical case study. We demonstrate the usefulness of the refined, dynamical inferential conception using the well-researched example of the genesis of general relativity. Specifically, we look at the collaboration of the physicist Einstein and the mathematician Grossmann in the years 1912–1913, which resulted in the jointly published “Outline of a Generalized Theory of Relativity and a Theory of Gravitation,” a precursor theory of the final theory of general relativity. In this episode, independently developed mathematical theories, the theory of differential invariants and the absolute differential calculus, were applied in the process of finding a relativistic theory of gravitation. The dynamical inferential conception not only provides a natural framework to describe and analyze this episode, but it also generates new questions and insights. We comment on the mathematical tradition on which Grossmann drew, and on his own contributions to mathematical theorizing. The dynamical inferential conception allows us to identify both the role of heuristics and of mathematical resources as well as the systematic role of problems and mistakes in the reconstruction of episodes of conceptual innovation and theory change.     

新西兰政府科技投资现状概述

近年来新西兰政府大力调整其科技政策，在建设知识社会的蓝图下，建构了科技投资的基本框架，凸显了知识、经济、环境、社会四大目标，另外通过对投资决策、运行和监督的改革，使政府科技投资的机制更为科学有效，本文还给出了新西兰政府近年来科技投资的分配比例状况，阐明了其投资的重点领域。     

羟甲基化对合成木质素改性酚醛胶粘剂性能的影响

采用羟甲基化技术对碱木质素进行活化,对比了羟甲基化前后未质素改性酚醛树脂胶的粘结强度、残留甲醛、贮存稳定性和热稳定性等性能,为木质素的高值应用探讨新的途径.试验结果表明在木质素对笨酚的替代率低于30%务件下,以分离提纯后的木质素可直接应用于酚醛树脂胶粘剂的改性;而当替代率大于50%后,木质素的羟甲基化展示对木质素改性酚醛树脂的胶结强度、热稳定性具有良好的促进作用.但木质素的羟甲基化作用同时也导致木质素改性酚醛树脂中残留甲醛含量增加,进而导致制备的胶粘荆的贮存稳定性降低,可以通过改变合成过程中甲醛和碱的用量来达到降低酚醛树脂中残留甲醛含量.     

Specificity of action of phospholipases of rat intestinal mucosa]

The total homogenate of rat intestine is devoid of C or D phospholipase activity. At pH 6,5 in the presence of phosphatidylcholines, it exhibits a B phospholipase activity and in the presence of exogen lysophosphatidylcholines an A1 lysophospholipase activity. At pH 8,5 the intestinal mucous membrane of a rat shows an isolated A2 phospholipase activity.     

Hypotensive activity of histidine-containing analogues of C-terminal hexapeptide of Substance P

Summary Four new hexapeptide analogues of C-terminal Substance P fragment with increased solubility in aqueous solutions are described. The peptides contain histidine in positions 6, 8, 9 and 10, respectively. The effect of the structural changes on the hypotensive activity and antigenic properties of analogues was compared. It was found that substitution of amino acid residues in various positions in the C-terminal hexapeptide of Substance P resulted in different effects on the hypotensive and antigenic properties, respectively. Only the [His⁶] SP_6-11 analogue had an unchanged antigenic structure when compared with the C-terminal region of Substance P, but it showed an almost total loss of hypotensive activity. The [His⁹] SP_6-11 analogue retained 50% of the hypotensive activity of the C-terminal hexapeptide but showed a markedly reduced expression of the antigenic epitope localized in this region of Substance P.     

Effect of light adaptation on electrical responses of the retinas of four species of bats

Summary The levels of light adaptation at which the retinas of 4 species of microchiropteran bats became unable to generate electroretinograms were progressively ordered. The order correlated well with light preferences based on activity patterns of the 4 species. These results suggest that the ability of the retina to function in ambient light may govern some natural behaviors of these bats.This work was supported in part by grant No. EY 01228 from the U.S.P.H.S. and was facilitated by equipment provided by Bob Hope Fight for Sight Award No. G522 and a grant from Research to Prevent Blindness, Inc. Portions of this work were presented at the Fifth International Bat Research Conference, Albuquerque, New Mexico, USA, August, 1978.     

A periodization of research technologies and of the emergency of genericity

According to the historian and sociologist of science Terry Shinn, the creator of the concept of ‘research technologies’: “Research technologies may sometimes generate promising packets of instrumentation for yet undefined ends. They may offer technological answers to questions that have hardly been raised. Research technologists׳s instruments are then generic in the sense that they are base-line apparatus which can subsequently be transformed by experimenters into products tailored to specific economic ends or adapted by experimenters to further cognitive ends in academic research.”¹ Genericity thus manifests one of three fundamental characteristics of research technologies. At the same time, however, each research technology emerges out of the specific disciplinary context in which it is initially developed with entirely concrete aims. Consequently, genericity does not exist from the outset but first has to form, along a path that remains to be clarified. It is produced or constructed by the actors on two levels: as an instrument in the laboratory and as a way of speaking at the representational level. This issue yields the structure of this paper. Three options for the transition of a specific technique into a generic research technology are compared. One of them proves to be the most frequent pattern of this dynamic. This is explored further, taking as paradigmatic examples ‘computed tomography’ (CT), ‘nuclear magnetic resonance׳ (NMR) and its application known as ‘magnetic resonance imaging’ (MRI), together with several additional examples.     

Effects of fluoride on glycosaminoglycan of cancellous and cortical bone of rabbits

Summary The present report deals with the effect of excessive ingestion of fluoride on glycosaminoglycan (GAG). Increase in fluoride deposition in bone, and in circulating levels of fluoride in serum, are also reported. Among the 3 constituents of GAG investigated; hexosamine, uronic acid and sulphate, the content remained unaltered except for sulphate.Acknowledgment. The authors wish to acknowledge the Department of Science and Technology (DST), Government of India, for the financial aid. One of us (M.J.) acknowledges the receipt of a Junior Research Fellowship from DST, during the tenure of which the investigations were carried out.     

超高频RFID物联网前端感知系统的设计

介绍了一种基于超高频RFID的物联网前端感知系统的设计和实现,以及主要模块的功能,然后分别从硬件结构,工作流程和软件设计三个方面进行了详细阐述.本系统的工作频率在860～960 MHz可调节,能支持EPC Gen2和ISO/IEC 18000-6B/6C标准.它的射频前端是以射频芯片AS3992为核心,使用内部集成的功放,外加一系列外围电路实现.其优点是体积小、重量轻、集成度高和功耗低.实验结果表明,该系统的读写距离能达到2.5m,能够满足实际应用的需要.     

Hypotensive activity of histidine-containing analogues of C-terminal hexapeptide of substance P

Four new hexapeptide analogues of C-terminal Substance P fragment with increased solubility in aqueous solutions are described. The peptides contain histidine in positions 6, 8, 9 and 10, respectively. The effect of the structural changes on the hypotensive activity and antigenic properties of analogues was compared. It was found that substitution of amino acid residues in various positions in the C-terminal hexapeptide of Substance P resulted in different effects on the hypotensive and antigenic properties, respectively. Only the [His6] SP6-11 analogue had an unchanged antigenic structure when compared with the C-terminal region of Substance P, but it showed an almost total loss of hypotensive activity. The [His9] SP6-11 analogue retained 50% of the hypotensive activity of the C-terminal hexapeptide but showed a markedly reduced expression of the antigenic epitope localized in this region of Substance P.     

巷道布置对围岩稳定性影响的数值模拟

采用理论分析不同应力场下巷道轴线与最大水平主应力方向夹角的最佳角度,利用数值模拟不同夹角情况下,巷道围岩应力分布、正前方应力分布及变形特征。得出：1）最大水平主应力σH〉最小水平主应力σh〉垂直主应力σr时,最佳角度为0°;σt〉σH〉σh时,最佳角度为90°;σH〉σa〉σA时,最佳夹角为α0.2）巷道开挖后,水平应力在两帮出现应力降低区,在顸、底板出现应力集中区;垂直应力在两帮出现应力集中区,在顶、底板出现应力降低区;随角度变化,应力变化区均有明显变化,正前方断面的最大主应力变化明显。3）巷道达到最佳角度时,围岩变形相对较小,最大主应力围绕在巷道周边,呈环状或类环状分布;其它角度时,围岩变形相对较大,最大主应力逐渐向顶、底板的四角或两帮发展。     

Implication of GABA in the spatial organization of the receptive fields of retinal ganglia cells of frogs]

An histoautoradiographic study of the Chicken and Frog retinae was made following an intravitreal injection if tritiated GABA. This amino acid was especially fixed at the amacrine and horizontal cell level. It has been suggested (Werblin, 1974) that horizontal cells might be responsible for the spatial organization of the receptive fields of retinal ganglion cells. GABA could thus be involved in bringing about of the centre-surround arrangement of the latter receptive fields. We have shown that picrotoxin, a specific GABA-antagonist, does indeed provoke marked changes in the activity of retinal ganglion cells. It provokes a decrease in the response threshold, a facilitation of spontaneous activities, and a marked increase in the receptive field area of the ON-OFF ganglion cells: from 12 at the start, it reaches 24 under the effect of picrotoxin.     

Measurement of cyclic AMP in the islets of Langerhans of newborn rats. Effect of amino acids]

Radioimmunoassay of cyclic AMP (cAMP) in the islets of Langerhans from 48-64 h old Rats was performed after succinylation of the samples. cAMP was detected at 0.03 nM. The cAMP content of islets increases when L-arginine, L-lysine and L alanine are added together in the incubation medium at a concentration of 5-10 mM each. When phosphodiesterase is inhibited by theophylline the three amino acids considerably increase the cAMP content of islets. Thus an increase in cAMP content of the islets was observed with a concentration of amino acids which is efficient in stimulating the insulin and glucagon secretion.     

Redox-sensitivity of the dimerization of occludin

Occludin is a self-associating transmembrane tight junction protein affected in oxidative stress. However, its function is unknown. The cytosolic C-terminal tail contains a coiled coil-domain forming dimers contributing to the self-association. Studying the hypothesis that the self-association is redox-sensitive, we found that the dimerization of the domain depended on the sulfhydryl concentration of the environment in low-millimolar range. Under physiological conditions, monomers and dimers were detected. Masking the sulfhydryl residues in the domain prevented the dimerization but affected neither its helical structure nor cylindric shape. Incubation of cell extracts containing full-length occludin with sulfhydryl reagents prevented the dimerization; a cysteine/alanine exchange mutant also did not show dimer formation. This demonstrates, for the first time, that disulfide bridge formation of the domain is involved in the occludin dimerization. It is concluded that the redox-dependent dimerization of occludin may play a regulatory role in the tight junction assembly under physiological and pathological conditions.     

有限元法在电机温度场仿真中的运用

运行的超声电机会产生温升,过高的温升对超声电机的机械特性及使用寿命都有较大影响。本文首先通过实验证明压电陶瓷元件发热和摩擦层摩擦发热是超声电机温升的主要热源;然后,分别以压电陶瓷元件发热和摩擦层摩擦发热为热源,建立其相应的温度场热分布模型。并用有限元软件分别对压电陶瓷元件发热场和接触摩擦发热场进行仿真计算。计算结果表明,压电陶瓷片发热源部分,热量最大处为压电陶瓷片粘贴面的内圈;接触摩擦发热中,摩擦产生的热量集中在接触表面。     

国外工程院情况研究

自从1919年10月世界上最早的工程院——瑞典皇家工程科学院成立以来，已有大约40多个国家和地区相继成立了工程院或类似的组织，它们各具特色，开展了各种各样的活动，推动了工程科学技术的进步、促进了经济的繁荣并造福人类。本文对国外工程院各方面的情况进行了综合的分析。     

Effect of light adaptation on electrical responses of the retinas of four species of bats.

The levels of light adaptation at which the retinas of 4 species of microchiropteran bats became unable to generate electroretinograms were progressively ordered. The order correlated well with light preferences based on activity patterns of the 4 species. These results suggest that the ability of the retina to function in ambient light may govern some natural behaviors of these bats.     

Quantitative determination of the activity of acid peptidases of industrial origin]

Reagent ninhydrine-Cd++, reacts with free alpha and epsilon amino groups of proteins. Horse-heart apomyoglobin was subjected to exhaustive succinylation, rendering the product non reactive to ninhydrine. The succinylglobin was submitted to enzyme digestion at pH 2.0, 4.0, 4.7 and 6.0. The commercially available enzymes contain mainly pepsin-like and chymosin-like enzymes. The enzymatic digests of succinyl-globin contain new free alpha-amino groups reacting with ninhydrin. Enzymatic digestion was performed under various condition (ratio E/S, pH). The results were compared to those obtained with synthetic substrate: PRO-HIS-LEU-SER-PHE(NO2)-NLEU-ALA-LEU-OME. The price of the synthetic substrate used, was more than 100 times the cost of succinyl-globin, thus the use of this substrate is a valuable tool for the quantitative estimation of peptidase activity in commercially available (pepsin, chymosin-like) enzymes.     

Stereospecificity of hydrogen transfer of aldehyde reductase

Summary Aldehyde reductase from human liver catalyzes the hydrogen transfer from the pro-4R position on the dihydronicotinamide ring of the coenzyme to there face of the carbonyl carbon atom of the substrate.     

Age-dependent response of lactate dehydrogenase of pituitary of rat to testosterone

Summary The effects of time and various doses of testosterone on the responsiveness of lactate dehydrogenase of pituitary of 7-, 38- and 78-week-old rats were studied. The activity of the enzyme increases in 78-week-old rats. Castration decreases the enzyme activity at all ages. Maximum increase in the enzyme activity is seen with 50 and 100 g of testosterone 4 h after administration of hormone to castrated rats. No further time and dose-dependent effect is observed. The magnitude of increase for the enzyme is higher at the age of 38 weeks and decreases in 78-week-old rats.To whom all correspondence should be addressed. The authors are grateful to Professor M.S. Kanungo, Biochemistry Laboratory, Department of Zoology, Banaras Hindu University for the suggestions and encouragement. K.V.G. thanks the PL-480 for a research fellowship.