Amenorrhea Due to Defects in Steroid Biosynthesis

Amenorrhea as the first manifestation of a steroid biosynthetic defect is rather unusual. The common forms of congenital adrenal hyperplasia are classic examples of steroid biosynthetic defects. Yet in genotypic females, this disorder is usually evident from birth because of virilization. Effective treatment usually ensues and amenorrhea is only a problem when control is inadequate. However, there are individuals whose disorder will be manifest for the first time in the postnatal or adult period. In addition, multiple other steroid defects have now been clearly delineated. Many of these individuals will have amenorrhea, virilization, or sexual ambiguities as part of the clinical picture. The paper will describe some of the more clearly delineated steroidal biosynthetic defects. Also the clinical management of patients with postnatal onset of 21-hydroxylase deficiency form of congenital adrenal hyperplasia will be discussed

Vertical integration and firm boundaries : the evidence

Since Ronald H. Coase's (1937) seminal paper, a rich set of theories has been developed that deal with firm boundaries in vertical or input–output structures. In the last twenty-five years, empirical evidence that can shed light on those theories also has been accumulating. We review the findings of empirical studies that have addressed two main interrelated questions: First, what types of transactions are best brought within the firm and, second, what are the consequences of vertical integration decisions for economic outcomes such as prices, quantities, investment, and profits. Throughout, we highlight areas of potential cross-fertilization and promising areas for future work

Regulation and the Evolution of Corporate Boards: Monitoring, Advising or Window Dressing?

An earlier version of this paper was entitled “Deregulation and Board Composition: Evidence on the Value of the Revolving Door.”It is generally agreed that boards are endogenously determined institutions that serve both oversight and advisory roles in a firm. While the oversight role of boards has been extensively studied, relatively few studies have examined the advisory role of corporate boards. We examine the participation of political directors on the boards of natural gas companies between 1930 and 1998. We focus on the expansion of federal regulation of the natural gas industry in 1938 and 1954 and subsequent partial deregulation in 1986. Using data sets covering the periods from 1930 to 1990 and 1978 to 1998, we test whether regulation and deregulation altered the composition of companies' boards as the firms' environment changed. In particular, did regulation cause an increase and deregulation a decrease in the number of political directors on corporate boards? We find evidence that the number of political directors increases as firms shift from market to political competition. Specifically, the regulation of natural gas is associated with an increase in the number of political directors and deregulation is associated with a decrease in the number of political directors on boards

The theory of the firm and its critics: a stocktaking and assessment

Includes bibliographical references."Prepared for Jean-Michel Glachant and Eric Brousseau, eds. New Institutional Economics: A Textbook, Cambridge, Cambridge University Press.""This version: August 22, 2005."Since its emergence in the 1970s the modern economic or Coasian theory of the firm has been discussed and challenged by sociologists, heterodox economists, management scholars, and other critics. This chapter reviews and assesses these critiques, focusing on behavioral issues (bounded rationality and motivation), process (including path dependence and the selection argument), entrepreneurship, and the challenge from knowledge-based theories of the firm

First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far

Vertical integration for full outsourcing: growth and internationalization of a portuguese packaging firm

Based on a case study of a Portuguese packaging firm, this paper examines how vertical integration of the supplier serves as a vehicle for the full outsourcing of the client firms' needs in a solution that reduces transaction costs, favors specialization, and permits small and mediumsized firms to develop competencies that may be exploited in a wide array of projects. Vertical integration by the supplier (a governance decision) is a strategic response to changes in the sourcing model of the clients. Client-supplier relationships have inter-spatial and inter-temporal value that surpasses spot market exchanges

Neonicotinoids target distinct nicotinic acetylcholine receptors and neurons, leading to differential risks to bumblebees

This research was funded jointly by BBSRC, DEFRA, NERC, the Scottish Government and The Wellcome Trust, under the Insect Pollinators Initiative (UK) grant BB/1000313/1(CNC).There is growing concern over the risk to bee populations from neonicotinoid insecticides and the long-term consequences of reduced numbers of insect pollinators to essential ecosystem services and food security. Our knowledge of the risk of neonicotinoids to bees is based on studies of imidacloprid and thiamethoxam and these findings are extrapolated to clothianidin based on its higher potency at nicotinic acetylcholine receptors. This study addresses the specificity and consequences of all three neonicotinoids to determine their relative risk to bumblebees at field-relevant levels (2.5 ppb). We find compound-specific effects at all levels (individual cells, bees and whole colonies in semi-field conditions). Imidacloprid and clothianidin display distinct, overlapping, abilities to stimulate Kenyon cells, indicating the potential to differentially influence bumblebee behavior. Bee immobility was induced only by imidacloprid, and an increased vulnerability to clothianidin toxicity only occurred following chronic exposure to clothianidin or thiamethoxam. At the whole colony level, only thiamethoxam altered the sex ratio (more males present) and only clothianidin increased queen production. Finally, both imidacloprid and thiamethoxam caused deficits in colony strength, while no detrimental effects of clothianidin were observed. Given these findings, neonicotinoid risk needs to be considered independently for each compound and target species.Publisher PDFPeer reviewe

Internalisation Theory and outward direct investment by emerging market multinationals

The rise of multinational enterprises from emerging countries (EMNEs) poses an important test for theories of the multinational enterprise such as internalisation theory. It has been contended that new phenomena need new theory. This paper proposes that internalisation theory is appropriate to analyse EMNEs. This paper examines four approaches to EMNEs—international investment strategies, domestic market imperfections, international corporate networks and domestic institutions—and three case studies—Chinese outward FDI, Indian foreign acquisitions and investment in tax havens—to show the enduring relevance and predictive power of internalisation theory. This analysis encompasses many other approaches as special cases of internalisation theory. The use of internalisation theory to analyse EMNEs is to be commended, not only because of its theoretical inclusivity, but also because it has the ability to connect and to explain seemingly desperate phenomena

How can humans understand their automated cars? HMI principles, problems and solutions

As long as vehicles do not provide full automation, the design and function of the Human Machine Interface (HMI) is crucial for ensuring that the human “driver” and the vehicle-based automated systems collaborate in a safe manner. When the driver is decoupled from active control, the design of the HMI becomes even more critical. Without mutual understanding, the two agents (human and vehicle) will fail to accurately comprehend each other’s intentions and actions. This paper proposes a set of design principles for in-vehicle HMI and reviews some current HMI designs in the light of those principles. We argue that in many respects, the current designs fall short of best practice and have the potential to confuse the driver. This can lead to a mismatch between the operation of the automation in the light of the current external situation and the driver’s awareness of how well the automation is currently handling that situation. A model to illustrate how the various principles are interrelated is proposed. Finally, recommendations are made on how, building on each principle, HMI design solutions can be adopted to address these challenges