In situ liquid-liquid extraction as a sample preparation method for matrix-assisted laser desorption/ionization MS analysis of polypeptide mixtures

A novel liquid-liquid extraction (LLE) procedure was investigated for preparation of peptide and protein samples for matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). LLE using ethyl acetate as the water-immiscible organic solvent enabled segregation of hydrophobic and hydrophilic polypeptides in mixtures, thereby reducing the complexity of mass spectra obtained by MALDI MS. The LLE technique was optimized for rapid and sensitive in situ (on-target) sample preparation for MALDI MS analysis of proteins and peptides at low-picomole and subpicomole levels. Addition of MALDI matrix to the organic solvent enhanced the efficiency of the LLE-MALDI MS method for analysis of hydrophobic peptides and proteins. LLE-MALDI MS enabled the detection of the hydrophobic membrane protein bacteriorhodopsin as a component in a simple protein mixture. Peptide mixtures containing phosphorylated, glycosylated, or acylated peptides were successfully separated and analyzed by the in situ LLE-MALDI MS technique and demonstrate the potential of this method for enhanced separation and structural analysis of posttranslationally modified peptides in proteomics research.     

A method for diagnosing multiple diseases in MUNIN

A new method for diagnosing multiple diseases in large medical decision support systems based on causal probabilistic networks is proposed. The method is based on characteristics of the diagnostic process that we believe to be present in many diagnostic tasks, both inside and outside medicine. The diagnosis must often be made under uncertainty, choosing between diagnoses that each have small prior probabilities, but not so small that the possibility of two or more simultaneous diseases can be ignored. Often a symptom can be caused by several diseases and the presence of several diseases tend to aggravate the symptoms. For diagnostic problems that share these characteristic, we have proposed a method that operates in a number of phases: in the first phase only single diseases are considered and this helps to focus the attention on a smaller number of plausible diseases. In the second phase, pairs of diseases are considered, which make it possible to narrow down the field of plausible diagnoses further. In the following phases, larger subsets of diseases are considered. The method was applied to the diagnosis of neuromuscular disorders, using previous experience with the so-called MUNIN system as a starting point. The results showed that the method gave large reductions in computation time without compromising the computational accuracy in any substantial way. It is concluded that the method enables practical inference in large medical expert systems based on causal probabilistic networks.     

Technological change as a trade-off between social construction and technological paradigms

The theory of social construction of technology (SCOT) and the theory of technological paradigms (TTP) are normally regarded as competing or even incompatible perspectives on technological change. In this paper, we show how and when the perspectives are complementary by comparing how the theories conceptualise technology development, understand stakeholders, and determine driving forces for technological change. When stakeholders have different relations to the innovation process, and when the outcome of the innovation process is open, we argue that the two theories could be complementary tools for analysing the process. When using SCOT and TTP as complementary analytical tools, it becomes easier to understand and design innovation processes in which different stakeholders are attached to roles where they are able to contribute in the most productive ways.     

From Artefacts to Infrastructures

In their initial articulation of the direction of the CSCW field, scholars advanced an open-ended agenda. This continuing commitment to open-ness to different contexts and approaches is not, however, reflected in the contents of the major CSCW outlets. The field appears to privilege particular forms of cooperative work. We find many examples of what could be described as ‘localist studies’, restricted to particular settings and timeframes. This focus on the ‘here and now’ is particularly problematic when one considers the kinds of large-scale, integrated and interconnected workplace information technologies—or what we are calling Information Infrastructures—increasingly found within and across organisations today. CSCW appears unable (or unwilling) to grapple with these technologies—which were at the outset envisaged as falling within the scope of the field. Our paper hopes to facilitate greater CSCW attention to Information Infrastructures through offering a re-conceptualisation of the role and nature of ‘design’. Design within an Information Infrastructures perspective needs to accommodate non-local constraints. We discuss two such forms of constraint: standardisation (how local fitting entails unfitting at other sites) and embeddedness (the entanglement of one technology with other apparently unrelated ones). We illustrate these themes through introducing case material drawn on from a number of previous studies.     

Impacts of altimeter corrections on local linear sea level trends around Taiwan

Multi-mission altimeter measurements from TOPEX, Jason-1, and Jason-2 satellite altimetry over the 1993–2009 time span are used to characterize the local linear sea level trend (LSLT) around Taiwan. The results show that the long-term changes of default geophysical and range corrections, i.e. the inverted barometer correction, wet tropospheric correction, and sea state bias correction, have significant impacts on the determination of local LSLT. The trend of default corrections contribute more than 1.4 mm year^?1 along the coastline of China mainland and 2.1 mm year^?1 to local LSLT in the Taiwan Strait. The default-corrected altimetric data exhibit highest and lowest local LSLTs in the southeast and northwest of Taiwan, respectively. The regional LSLTs of 3.8 mm year^?1 and 4.6 mm year^?1 are estimated from the default-corrected and uncorrected altimetric data in the study area, respectively.     

Progress report from Denmark

Space heating is seen in Denmark as the area where there is greatest potential for saving in energy use; why and how is explained in this article from the Danish Building Research Institute. It summarises the new building code regulations for insulation, heating and ventilation as well as more recent rules for existing buildings. Further action planned for the future is also outlined and examples are given of the many R & D activities in the country.     

Perceived Air Quality,Sick Building Syndrome (SBS) Symptoms and Productivity in an Office with Two Different Pollution Loads

Abstract Perceived air quality, Sick Building Syndrome (SBS) symptoms and productivity were studied in an existing office in which the air pollution level could be modified by introducing or removing a pollution source. This reversible intervention allowed the space to be classified as either non-low-polluting or low-polluting, as specified in the new European design criteria for the indoor environment CEN CR 1752 (1998). The pollution source was a 20-year-old used carpet which was introduced on a rack behind a screen so that it was invisible to the occupants. Five groups of six female subjects each were exposed to the conditions in the office twice, once with the pollution source present and once with the pollution source absent, each exposure being 265 min in the afternoon, one group at a time. They assessed the perceived air quality and SBS symptoms while performing simulated office work. The subject-rated acceptability of the perceived air quality in the office corresponded to 22% dissatisfied when the pollution source was present, and to 15% dissatisfied when the pollution source was absent. In the former condition there was a significantly increased prevalence of headaches (P= 0.04) and significantly lower levels of reported effort (P=0.02) during the text typing and calculation tasks, both of which required a sustained level of concentration. In the text typing task, subjects worked significantly more slowly when the pollution source was present in the office (P=0.003), typing 6.5% less text than when the pollution source was absent from the office. Reducing the pollution load on indoor air proved to be an effective means of improving the comfort, health and productivity of building occupants.     

An investigation of governance frameworks for public projects in Norway and the UK

This paper describes four case studies which formed a key part of an investigation into public investment project governance frameworks in Norway and the UK. The studies looked at how the embedded governance principles worked out in practice, how they affected PM, and how consistent their effects were with their aims. Conclusion is made about the actual effects of the frameworks, and various areas for improvement or further study are highlighted.     

Partition noise in semiconductor lasers under CW and pulsed operation

A numerical model which simulates the mode partition noise in semiconductor lasers under CW as well as pulsed operation is presented. The noise levels in the individual modes under CW operation are in agreement with those predicted by an analytic small-signal model. Under simulated pulse modulation with pulse repetition frequencies of 633 MHz and 2.2 GHz, the probability density functions for the relative photon numbers in the individual modes are found. The data allow for an evaluation of the mode partition parameterk. For the central modes,kfactors are in the range of 0.31-0.42, depending on bias level and modulation frequency. Weaker side modes carrying less than 5 percent of the total output havekfactors smaller than 0.16.