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Supplying high voltage radio frequency (RF) is a critical part of ion trapping system due to impedance mismatching between RF source and the ion trap. A helical resonator has been constructed in order to deliver narrow bandwidth and high voltage RF to the ion trap for stable confinement of ions. The performances of the helical resonator have been studied for different capacitive load of the ion trap. Both the resonant frequency and quality factor of the resonator show strong dependence on external capacitive loads.

The rates and routes of lethal systemic spread in breast cancer are poorly understood owing to a lack of molecularly characterized patient cohorts with long-term, detailed follow-up data. Long-term follow-up is especially important for those with oestrogen-receptor (ER)-positive breast cancers, which can recur up to two decades after initial diagnosis1–6. It is therefore essential to identify patients who have a high risk of late relapse7–9. Here we present a statistical framework that models distinct disease stages (locoregional recurrence, distant recurrence, breast-cancer-related death and death from other causes) and competing risks of mortality from breast cancer, while yielding individual risk-of-recurrence predictions. We apply this model to 3,240 patients with breast cancer, including 1,980 for whom molecular data are available, and delineate spatiotemporal patterns of relapse across different categories of molecular information (namely immunohistochemical subtypes; PAM50 subtypes, which are based on gene-expression patterns10,11; and integrative or IntClust subtypes, which are based on patterns of genomic copy-number alterations and gene expression12,13). We identify four late-recurring integrative subtypes, comprising about one quarter (26%) of tumours that are both positive for ER and negative for human epidermal growth factor receptor 2, each with characteristic tumour-driving alterations in genomic copy number and a high risk of recurrence (mean 47–62%) up to 20 years after diagnosis. We also define a subgroup of triple-negative breast cancers in which cancer rarely recurs after five years, and a separate subgroup in which patients remain at risk. Use of the integrative subtypes improves the prediction of late, distant relapse beyond what is possible with clinical covariates (nodal status, tumour size, tumour grade and immunohistochemical subtype). These findings highlight opportunities for improved patient stratification and biomarker-driven clinical trials. A statistical framework for breast-cancer recurrence uses long-term follow-up data and a knowledge of molecular subcategories to model distinct disease stages and to predict the risk of relapse.

We are developing a frequency standard based on the ultra-narrow electric octupole transition of the ytterbium-ion (171Yb+), which is in the optical wavelength region. In this article, we describe optimized design of our end-cap type Paul trap which will be used for trapping single ions for precision frequency metrology. Selection of the materials for fabricating different parts of the trap assembly is also described. Customized design of the ultra-high vacuum chamber, which houses the ion trap, oven producing ytterbium atomic beam, compensation electrodes and high numerical aperture fluorescence collection lens together with four pairs of optical viewports is lastly described.

In this paper we have argued that the specific-factor model of trade is more suitable to the analysis of trade problems in the presence of unemployment than the traditional Heckscher-Ohlin, non-specific factor model used by Brecher and others. Among other things we have shown that protection granted to a land-using industry is unlikely to reduce unemployment, benefiting landlords at the expense of capitalists, while protection conferred to a non-land-using industry is likely to stimulate employment.

This paper examines the impact of the presence of a forward exchange market on the financial and operational decisions of a multinational firm. The study concentrates especially on the effects of increased uncertainly and increased risk aversion on the part of the multinational firm. It is shown that the presence of the forward market allows the firm to respond to changes in uncertainly and risk aversion by adjusting its transactions in the forward market while leaving its production and sales decisions unchanged. The forward market, thus, promotes stability with respect to the operational as opposed to the financial variables; and its also makes it possible to adopt decentralized decision making.© 1982 JIBS. Journal of International Business Studies (1982) 13, 59–70

The various paradoxes of social choice uncovered by Arrow [1], Sen [10] and others1 have led some writers to question the basic assumption of a binary social choice function underlying most of these paradoxes. Schwartz [8], for example, proves an important theorem which may be considered to be a generalization of the famous paradox of Arrow,2 and then lays the blame for this paradox on the assumption of a binary social choice function.3 He then proceeds to define a type of choice functions which, like binary choice functions, define the best elements in sets of more than two alternatives on the basis of binary comparisons, but which, as he claims, have an advantage over binary choice functions, in so far as they always ensure the existence of best elements for sets of more than two alternatives irrespective of the results of binary comparisons.4 The purpose of this paper is to show that even a considerable weakening of the assumption of a binary social choice function does not go very far towards solving some of the paradoxes under consideration, and that if replacing the requirement of a binary social choice function by a Schwartz type social choice function solves these paradoxes, it does so only by violating the universally acceptable value judgment that in choosing from a set of alternatives, society should never choose an alternative which is Pareto inoptimal in that set (i.e., the socially best alternatives in a set should always be Pareto optimal). This argument is substantiated with the help of an extended version of Sen's [10] paradox of a Paretian liberal, and thus a by-product of our analysis is a generalization of the theorem of Sen [10]. The argument itself, however, is more general and applies also to the impossibility result proved by Schwartz [8].