Castration Reduces the Effect of Serotonin-1A Receptor Stimulation on Prepulse Inhibition in Rats.

This study examined the interaction between hormones and serotonin-1A (5-HT1A) receptor modulation of prepulse inhibition (PPI) of the acoustic startle response. Male and female rats were gonadectomized; some castrated rats received testosterone- or estrogen-filled implants. Rats were randomly injected with saline or 0.02 or 0.50 mg/kg 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), a selective 5-HT1A receptor agonist. All rats showed a dose-dependent disruption of PPI in response to 8-OH-DPAT. In untreated castrated rats, this disruption was significantly reduced (33% compared with 78% in sham-operated rats). Testosterone treatment reversed this reduction, but estrogen was less effective. Ovariectomized and sham-operated rats showed similar PPI in response to 8-OH-DPAT. These data suggest that the effect of 8-OH-DPAT on PPI in male rats depends on circulating hormone levels, particularly testosterone. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Beyond imprisonment of meaning: Technology facilitating redefining

Defining is a natural and necessary response to an ambiguous world, but causes fixation of categories and perspectives. On the basis of two earlier studies of project groups, we came to argue that redefining, and hence constructing various ways in which one perceives and understands something, enables groups to overcome imprisonment in meaning, establishing continuous development and flexibility. In this article, we first build a rationale for facilitating a process of redefining, to be taken into account when designing technology. Departing from this rationale, we discuss features of groupware technology that permit change by being flexible, and evoke redefining by engaging the user more actively. In so doing, we argue to think along new lines in the design of communication and collaboration technology. This paper proposes a specific perspective on technology, facilitating groups to engage in a productive, creative fashion of exploiting meaning potential.     

In situ wear studies of surface micromachined interfaces subject to controlled loading

Friction and wear are major limiting factors for the development and commercial implementation of devices fabricated by surface micromachining techniques. These tribological properties are studied using a polycrystalline silicon nanotractor device, which provides abundant, quantitative information about friction and wear at an actual microelectromechanical system (MEMS) interface. This in situ approach to measuring tribological properties of MEMS, combined with high-resolution atomic force microscope (AFM) images of wear tracks, provides insight into the effects of different MEMS surface processing on wear. In particular, monolayer coatings have a significant positive effect, while surface texturing does not strongly affect performance.     

Mangrove forests as a nature-based solution for coastal flood protection: Biophysical and ecological considerations

Nature-based coastal protection is increasingly recognised as a potentially sustainable and cost-effective solution to reduce coastal flood risk. It uses coastal ecosystems such as mangrove forests to create resilient designs for coastal flood protection. However, to use mangroves effectively as a nature-based measure for flood risk reduction, we must understand the biophysical processes that govern risk reduction capacity through mangrove ecosystem size and structure. In this perspective, we evaluate the current state of knowledge on local physical drivers and ecological processes that determine mangrove functioning as part of a nature-based flood defence. We show that the forest properties that comprise coastal flood protection are well-known, but models cannot yet pinpoint how spatial heterogeneity of the forest structure affects the capacity for wave or surge attenuation. Overall, there is relatively good understanding of the ecological processes that drive forest structure and size, but there is a lack of knowledge on how daily bed-level dynamics link to long-term biogeomorphic forest dynamics, and on the role of combined stressors influencing forest retreat. Integrating simulation models of forest structure under changing physical (e.g. due to sea-level change) and ecological drivers with hydrodynamic attenuation models will allow for better projections of long-term natural coastal protection.     

Structuring and financing international BOO/BOT desalination projects

There has been a recent increase in desalination projects in an effort to meet the growing demand for clean water. Desalination plants, like other large public service infrastructure, are capital intensive with long asset lives. This makes them prime vehicles to introduce private sector investment both equity and debt. Key to attracting the private sector, particularly International investors, is a well-developed commercial framework for the project following principles widely seen and understood by private investors. Desalination plants can easily fit into well-tested structures, which optimize the risk profile for each stakeholder, e.g. the consumer, the public sector authority, the equity investor/developer, the lenders; and reward each of them appropriately. This paper seeks to introduce a typical project financing structure and compare desalination to other infrastructure projects, which are also competing in the International arena for private investment. Given the success of recent private sector investment in desalination, and the growing demand for clean drinking water, it could be expected that this industry should continue to attract its fair share of the International investor community.     

Autobiographical memory in the euthymic phase of recurrent depression.

The authors investigated autobiographical memory specificity in subjects who formerly had depression. In 122 euthymic patients with at least two previous major depressive episodes, memory specificity was significantly impaired compared to matched control participants but not related to residual symptoms and illness characteristics, was not differentially affected by cognitive therapy, and was also not predictive of relapse/recurrence during the 2-year follow-up. However, memory specificity was associated with age, education, and immediate and delayed memory recall. The results suggest that memory specificity may reflect a global cognitive impairment that remains in patients who (formerly) had depression but does not constitute a trait marker for vulnerability for relapse/recurrence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Unified View of Sediment Transport by Currents and Waves. IV: Application of Morphodynamic Model

The TR2004 transport formulations for clay, silt, and sand as proposed in Parts 1 and 2 have been implemented in morphodynamic models to predict bed level changes. These models have been verified using various laboratory and field data cases concerning coastal flow in offshore and near-shore zones. Furthermore, the model has been applied to two complicated sediment environments concerning the flow around a spurdike in a river and the tidal flow of cohesive sediments in the Yangtze Estuary in China. Overall, it is concluded that the morphodynamic models using default settings performs reasonably well. The applied scaling factors of the sediment transport model are in the generally accepted range of 0.5–2.     

The Dutch Renal Artery Stenosis Intervention Cooperative (DRASTIC) Study: rationale, design and inclusion data

RATIONALE: Renal artery stenosis may lead to renovascular hypertension, risking multiple organ damage including damage to the contralateral kidney. Progression of stenosis may impair the function of the affected kidney. It is important to identify individuals with this disease among hypertensive patients. The first aim of the Dutch Renal Artery Stenosis Intervention Cooperative (DRASTIC) study is to assess the prevalence of renal artery stenosis in patients with well-defined forms of drug-resistant hypertension, and to determine the predictive value of clinical characteristics and diagnostic tests in these pre-selected patients. With regard to treatment, the effect of renal angioplasty on hypertension is disappointing in atherosclerotic stenosis and technical failure frequently occurs. Therefore, the second aim is to compare the effects of balloon angioplasty and antihypertensive medication on blood pressure in patients with atherosclerotic renal artery stenosis. DESIGN HYPERTENSIVE: patients receiving standard antihypertensive medication in whom diastolic blood pressure remained > or =95 mmHg during three consecutive visits to the outpatient clinic underwent full diagnostic work-up, including renal arteriography. The prevalence of renal artery stenosis in this well-defined patient group was then established, and the predictive value of the various diagnostic tests was assessed. Patients with an atherosclerotic renal artery stenosis of > or =50% were then randomly assigned to balloon angioplasty or to treatment with antihypertensive drugs. After 1 year of intensive follow-up of blood pressure and renal function, re-arteriography was performed. CONCLUSION: In total, 1205 patients have been included in the study, about 500 have received diagnostic work-up, and it is expected that 100 patients will be randomly assigned for renal angioplasty or medical treatment.     

Designing a licence plate for memorability

Good memorability of licence plates is important in those cases where licence plates are viewed for a brief period of time and the information is essential for police investigations. The purpose of the current study was to design a new Dutch licence plate that could be remembered well. A memory experiment was conducted, in which 16 different character arrangements were presented for both 450 and 550 ms to 48 participants with ages varying between 20 and 57 years. Participants had to rehearse the stimuli for 6 s, after which they had to be written down. Based on literature on short-term memory for serial order, character arrangements differed on three dimensions: 1) number of alternations between letters and digits; 2) letter to digit ratio; and 3) equality of group size. Results showed that number of alternations between characters of different categories affected memory performance the most. Letter to digit ratio and equality of group size affected memory performance to a lesser, but still significant, extent. A significant interaction between the latter two factors indicates that equal groups only lead to fewer memory errors when more than three letters are used. With three or fewer letters, group size is not a significant factor any more. Based on these results, a new licence plate for Dutch vehicles was recommended, which was subsequently adopted.