Chemiluminescence detection in analytical chemistry

Chemiluminescence as a consequence of biological processes and — more recently — in organic chemical reactions has long been known, though the mechanisms involved are still not fully understood. In recent years chemiluminescence has become the basis of a number of fast and exceedingly sensitive artificial techniques: it is, for example, the preferred method for ATP determination.     

Controlling fruit-shedding in the oil palm

The oil palm is a major factor in the economy of much of South East Asia and maximising the harvest is of major consequence. One important source of loss is the shedding of ripe fruit from the bunches before they reach the factories. Study of the course of abscission reveals unusual processes in the oil palm — and in a few other plantation crops such as dates and coconuts — which suggest practical means of achieving better harvesting regimes and regulation of fruit shedding.     

Vitamins: essential dietary constituents discovered

Until a century or more ago disease was generally attributed to the presence of some undesirable feature. The realization that disease could be due to the absence of a desirable factor was revolutionary. During the 18th and 19th centuries, however, foundations were laid for the recognition in the 20th century that to prevent some diseases certain ‘accessory substances’—the vitamins—were essential in the diet. This article tells the story of their discovery, their current significance, and future trends in vitamin research.     

The role of meat in the Roman diet

Of the animal artifacts encountered by archaeologists, bones and teeth are the ones most commonly found. Systematic study of these — particularly of their distribution and the different species involved —can throw much light on the diet and eating habits of people in the past.     

The Chinese river dolphin, Lipotes vexillifer

The river dolphins, of which there are now five species, are among the world's most endangered animals. This article describes the steps that have been taken — based on systematic study of its anatomy, ecology, and breeding and behavioural habits — to preserve the rare Chinese river dolphin. This is now limited to about 300 individuals in the middle and lower reaches of the Changjiang River.     

An innovation research perspective on information system implementation

This paper analyses information system implementation from an innovation research perspective. The basic assumption is that information systems can be regarded as special types of innovation, so that the results of research concerning innovations may be of value within information system implementation research. The paper gives a brief overview of innovation research, identifying the characteristics of innovations as its most distinctive research area. Principal attention is paid to the analysis of four characteristics — complexity, radicalness, originality and divisibility — as factors influencing the implementability of innovations and information systems.     

The European molecular biology laboratory

The need for collaborative ventures in Europe has long been stressed in the editorial pages of this journal, and more than ten years ago (Endeavour, 28, 54, 1969) we gave strong support for a proposal to establish a European Laboratory of Molecular Biology. For this we then incurred some criticism, on the ground that such a laboratory would weaken national academic institutes striving to establish themselves in this rapidly developing field. Nevertheless, we continued to maintain (30, 2, '71) ‘the great political and scientific importance of this [concept]—and of other such collaborative enterprises—if Europe is to maintain the initiative in fields where the great institutions of the United States have established a dominant position.’ In the event, the Laboratory was established at Heidelberg in 1974, though not formally opened until 1978. The Director-General, Sir John Kendrew, here surveys the policy and achievements of this important new institute.     

Data-driven estimates of global nitrous oxide emissions from croplands

Croplands are the single largest anthropogenic source of nitrous oxide (N₂O) globally, yet their estimates remain difficult to verify when using Tier 1 and 3 methods of the Intergovernmental Panel on Climate Change (IPCC). Here, we re-evaluate global cropland-N₂O emissions in 1961–2014, using N-rate-dependent emission factors (EFs) upscaled from 1206 field observations in 180 global distributed sites and high-resolution N inputs disaggregated from sub-national surveys covering 15593 administrative units. Our results confirm IPCC Tier 1 default EFs for upland crops in 1990–2014, but give a ∼15% lower EF in 1961–1989 and a ∼67% larger EF for paddy rice over the full period. Associated emissions (0.82 ± 0.34 Tg N yr^–1) are probably one-quarter lower than IPCC Tier 1 global inventories but close to Tier 3 estimates. The use of survey-based gridded N-input data contributes 58% of this emission reduction, the rest being explained by the use of observation-based non-linear EFs. We conclude that upscaling N₂O emissions from site-level observations to global croplands provides a new benchmark for constraining IPCC Tier 1 and 3 methods. The detailed spatial distribution of emission data is expected to inform advancement towards more realistic and effective mitigation pathways.     

Tilted post arrays for separating long DNA

Recent simulations by Chen and Dorfman [Electrophoresis 35, 405–411 (2014)] suggested that “tilting” the electric field with respect to the lattice vectors of a hexagonal post array would lead to a substantial improvement in electrophoretic DNA separations therein. We constructed such an array where the electric field is applied at an angle equidistant between the two lattice vectors. This tilted array leads to (i) baseline resolution of 20 kbp DNA and λ DNA (48.5 kbp) in a 4 mm channel and (ii) measurable separation resolutions for electric fields up to 50 V/cm, both of which are improvements over untilted post arrays of the same post density. The predicted time required to reach a resolution of unity is approximately 5 min, independent of electric field. The separations are more reproducible at higher fields.     

Sourcing technological knowledge through corporate acquisition: Evidence from an international sample of high technology firms

We investigate the prevalence of the motive to source technological knowledge externally through corporate acquisition. Drawing on make-or-buy and organizational learning theories, we infer the implications of this explanation for the acquirers' pre-acquisition innovative characteristics. Using an international sample of 6106 high technology acquisitions during 1984–2000, we assess the contribution of innovative characteristics to the acquisition likelihood. For firms acquiring small private firms and former subsidiaries—but not public targets—the evidence is consistent with three propositions: (1) A firm's commitment to internal R&D is negatively affected by the decision to acquire; (2) Low R&D productivity increases the likelihood of acquisition; (3) A large knowledge stock predisposes firms to acquire because they perceive they are capable of selecting and absorbing targets. We conclude that acquisitions of small private firms and former subsidiaries are a viable R&D strategy to explore a range of potential future innovation trajectories for large public firms.     

Innovation regimes, R&D and radical innovations in telecommunications

By introducing the concept of innovation regimes, the aim of this article is to show how the rapid pace of technological development in the telecom sector may be explained by the close links between the sector's own R&D and the creation of numerous innovations, many of which are radical. In contemporary innovation theory, a theoretical antinomy exists: Whereas, the creation of incremental innovations is variously explained in terms of «rational» responses to markets, dynamics of technological regimes, dominant design, etc., radical innovations, in contrast, are explained in terms of serendipity, chance or haphazard scientific discoveries. Evidence from analysis of innovations in the telecom sector suggests that innovation regimes have provided a capability of coordination, direction and leadership in the creation of many of the radical technological innovations that have emerged in the sector. Thus, one may claim that the strong innovation regimes and high R&D intensity of the telecom sector, at least until recently, have provided a capability of creating innovations on purpose — for a purpose. The policy implications of this contradict some of the assumptions on which the prevailing market-oriented R&D governance models and policies are based — and which are supported by contemporary innovation theories.     

Concerted breeding in fungi and its biotechnological application

The biotechnological exploitation of fungi is becoming more and more important both for industrial purposes and in the field of cultivation of edible mushrooms. In the past, breeding of fungi was restricted mainly to selection of better strains after spontaneous or induced mutations. Today, the inclusion of genetic recombination—based on better knowledge of how to handle fungi under controlled conditions, of their life cycles, and of their breeding systems—has given the possibility of ‘concerted breeding’. In addition, some recent basic research provides means of preventing ageing and death of fungal strains, by either genetic alterations or therapeutic treatment. Examples of the application of these ideas and results are given.     

Mohenjo-Daro, city of the Indus Valley

The Harappan civilization, the world's fourth great civilization after those of Egypt, Mesopotamia, and China flourished in the valley of the Indus three thousand years ago. As yet little is known about it, but one enormous town — Mohenjo-Daro — has survived. This has been only partially excavated and has yielded just a few scraps of information which have provided the basis for some fanciful theories. The author of this article had developed an interesting new approach. Combining a re-examination of the documentation that has accumulated over the past 50 years with an investigation of the actual remains, he has obtained some exciting results which shed new light on the overall planning, architecture, and development of the town over the centuries, thus providing a fresh understanding of the Harappan civilization itself.     

Multi-candidate reduction: Sentence compression as a tool for document summarization tasks

This article examines the application of two single-document sentence compression techniques to the problem of multi-document summarization—a “parse-and-trim” approach and a statistical noisy-channel approach. We introduce the multi-candidate reduction (MCR) framework for multi-document summarization, in which many compressed candidates are generated for each source sentence. These candidates are then selected for inclusion in the final summary based on a combination of static and dynamic features. Evaluations demonstrate that sentence compression is a valuable component of a larger multi-document summarization framework.     

Technological learning and entrepreneurial behaviour: A taxonomy of the chemical industry in Venezuela

This paper presents a taxonomy of entrepreneurial behaviour vis-à-vis technology, derived from empirical research on a specific sector, that of the chemicals industry in Venezuela. The research focuses heavily on the accumulation of minor innovations through which enterprises acquire their technical knowledge and know how, their technological learning. We have tried to give a precise empirical meaning to that notion in order to understand which are the most important variables that affect the technical learning process. Both the process of technological learning and the technical external linkages — in particular with foreign firms — of Venezuelan companies seem to be the fundamental factors in understanding the development of a new competitive industry which adopts a new products-oriented strategy. But not all firms do respond to such a scheme and it is thus necessary to develop a taxonomy of the industrial sector both for scholarly reasons as well as a policy guide.     

The processes involved in the solid-to-liquid phase transition

The detailed study of crystals and the dynamics of the melting process in two and three dimensions is a fundamental and interesting research topic, which is important for increasing our knowledge of solid state physics. In natural crystals, structure information can be obtained principally by Bragg-scattering of neutrons, electrons or photons on the crystal, followed by an analysis in Fourier space. Dynamical aspects cannot be investigated in these systems. Recently, a new crystalline system was discovered whose properties are such that the melting transition can be investigated in great detail — the ‘plasma crystal’. This article presents the results of such an investigation and shows evidence for the existence of intermediate phases between the solid, liquid and gaseous phases. The observed ‘structured’ phase transition may be specific for plasma crystals but, alternatively, it may indicate the existence of intermediate stages in the melting transition more generally.     

Precision measurement of the Newtonian gravitational constant

The Newtonian gravitational constant G, which is one of the most important fundamental physical constants in nature, plays a significant role in the fields of theoretical physics, geophysics, astrophysics and astronomy. Although G was the first physical constant to be introduced in the history of science, it is considered to be one of the most difficult to measure accurately so far. Over the past two decades, eleven precision measurements of the gravitational constant have been performed, and the latest recommended value for G published by the Committee on Data for Science and Technology (CODATA) is (6.674 08 ± 0.000 31) × 10⁻¹¹ m³ kg⁻¹ s⁻² with a relative uncertainty of 47 parts per million. This uncertainty is the smallest compared with previous CODATA recommended values of G; however, it remains a relatively large uncertainty among other fundamental physical constants. In this paper we briefly review the history of the G measurement, and introduce eleven values of G adopted in CODATA 2014 after 2000 and our latest two values published in 2018 using two independent methods.     

The convergence of Moore's/Mooers' law's

A four-stage hypothesis of information systems development is presented. The stages derive from the application of Moore's Law—that the number of elements that can be integrated onto a chip is doubling roughly every year—the expression of the very rapid exponential rate of growth of information systems technology, and the application of Mooers' Law—that an information system will only be used when it is more trouble not to use it than it is to use it—the quintessential expression of the importance of human factors. It is argued that we are now roughly halfway along this developmental process, about to make the transition from Stage II to Stage 111, and that from that conclusion we can make some useful projections for and about the future.     

A re-examination of relevance: toward a dynamic, situational definition*

Although relevance judgments are fundamental to the design and evaluation of all information retrieval systems, information scientists have not reached a consensus in defining the central concept of relevance. In this paper we ask two questions: What is the meaning of relevance? and What role does relevance play in information behavior? We attempt to address these questions by reviewing literature over the last 30 years that presents various views of relevance as topical, user-oriented, multidimensional, cognitive, and dynamic. We then discuss traditional assumptions on which most research in the field has been based and begin building a case for an approach to the problem of definition based on alternative assumptions. The dynamic, situational approach we suggest views the user — regardless of system — as the central and active determinant of the dimensions of relevance. We believe that relevance is a multidimensional concept; that it is dependent on both internal (cognitive) and external (situational) factors; that it is based on a dynamic human judgment process; and that it is a complex but systematic and measurable phenomenon.     

In search of insights into the generation of techno-economic trends: Micro- and macro-constituencies in the microprocessor industry

In the field of technology policy, few challenges are more intriguing than understanding the nature of technical and market trends. This paper deals with this problem by using the sociotechnical constituencies approach in order to integrate the treatment of “micro”/“macro” issues — from product to industry. The case study is that of the microprocessor industry where at present a Risc (reduced instruction set computer) technology is emerging in a field where a powerful and far-from-exhausted Cisc (complex instruction set computer) technology tends to occupy almost every segment of the market. The analysis reveals how emerging product-constituencies do implement pro-active trend-creating strategies in order to establish themselves as industrial trends, and, by so doing, they simultaneously re-define the existing content of the “macro” industrial level. The study also reveals the important role of the nature and maturity of microprocessor technology in conditioning the constituency-building strategies implemented by different players. Microprocessor technology is specifically characterised as an architectural, codified-knowledge component with indirect network externalities and weak appropriability regime. Finally, the paper also highlights the potential risks of both fragmentation and complete proprietary control of technology in technological processes involving strongly competitive situations.