Identifying Unknown Enzyme–Substrate Pairs from the Cellular Milieu with Native Mass Spectrometry

The enzyme–substrate complex is inherently transient, rendering its detection difficult. In our framework designed for bisubstrate systems—isotope‐labeled, activity‐based identification and tracking (IsoLAIT)—the common substrate, such as S‐adenosyl‐l ‐methionine (AdoMet) for methyltransferases, is replaced by an analogue (e.g., S‐adenosyl‐l ‐vinthionine) that, as a probe, creates a tightly bound [enzyme ? substrate ? probe] complex upon catalysis by thiopurine‐S‐methyltransferase (TPMT, EC 2.1.1.67). This persistent complex is then identified by native mass spectrometry from the cellular milieu without separation. Furthermore, the probe's isotope pattern flags even unknown substrates and enzymes. IsoLAIT is broadly applicable for other enzyme systems, particularly those catalyzing group transfer and with multiple substrates, such as glycosyltransferases and kinases.     

Novel filtration mode for fouling limitation in membrane bioreactors

A novel filtration mode is presented to reduce fouling propensity in membrane bioreactors (MBR). During this mode, an elevated high instantaneous flux (60Lm(-2)h(-1)) is initially applied for a short time (120s), followed by a longer filtration (290s) at lower flux (10.3Lm(-2)h(-1)) and a backwash in each filtration cycle. The mixed mode is expected to limit irreversible fouling as the reversible fouling created during the initial stage appears to protect the membrane. Hydraulic performance and the components of foulants were analyzed and compared with conventional continuous and backwash modes. It was found that the mixed mode featured lower trans-membrane pressure (TMP) after 24h of filtration when compared to other modes. The mixed mode was effective in preventing soluble microbial products (SMP) attaching directly onto the membrane surface, keeping the cake layer weakly compressed, and reducing the mixed liquor suspended solids (MLSS) accumulation on the membrane. This strategy reduced the resistances of both the cake layer and the gel layer. A factorial experimental design was carried out for eight runs with different conditions to identify the major operational parameters affecting the hydraulic performances. The results showed that the value of the flux in the initial high-flux period had the most effect on the performance of the mixed mode: high initial flux (60Lm(-2)h(-1)) led to improved performance.     

A Newly Designed and Constructed Instrument for Coupled Infrared Extinction and Size Distribution Measurements of Aerosols

Although atmospheric particles are often non-spherical, Mie theory is commonly used to acquire aerosol optical depth, composition, and transport information from satellite retrievals. In the infrared (IR) region, the radiative effects of aerosols, usually modeled with Mie theory, are subtracted from satellite spectral data to determine key atmospheric and oceanic properties. To gain a better understanding of the infrared radiative effects of aerosols and the methods used to model them, an instrument has been designed to simultaneously measure infrared extinction spectra and particle size distributions obtained from a scanning mobility particle sizer (SMPS) and an aerodynamic particle sizer (APS). Infrared extinction spectra are simulated with Mie theory using the measured particle size distributions and available literature optical constants. As a result, the errors associated with using Mie theory to model the infrared extinction of mineral dust aerosol can be quantitatively examined. Initial results for this instrument are presented here. For ammonium sulfate, the Mie theory simulation is in good agreement with our measured extinction spectrum. This is in accordance with the nearly spherical shape of ammonium sulfate particles. However, for illite, an abundant clay mineral, there is poor agreement between the experimental spectrum and the Mie simulation. This result is attributed to particle shape effects.     

A state of art review on the performance of transpired solar collector

Utilisation of solar radiation to heat air for various purposes, e.g. ventilation, pre heat, process air heat and their applications has attracted more and more interests. Wide range of applications adapted for different climates and in different building types ranging from houses to large industrial buildings. Recently in many European countries, USA and Canada this concept developed rapidly. Transpired solar collectors (TSCs) have proven reliable for various applications, e.g. heating spaces, providing warm ventilation air, supplying domestic hot water in summer, etc.Present paper consists of introduction to various types of TSCs, working principle, research literature for performance and modelling. Further various models have also been discussed and compared. The literature has shown that the most critical factors affecting TSC efficiency are wind velocity, flow rate, porosity, absorptivity and porosity.     

A bump on a bump? Emerging intuitions concerning the relative difficulty of the sciences.

In 4 studies, the authors examined how intuitions about the relative difficulties of the sciences develop. In Study 1, familiar everyday phenomena in physics, chemistry, biology, psychology, and economics were pretested in adults, so as to be equally difficult to explain. When participants in kindergarten, Grades 2, 4, 6, and 8, and college were asked to rate the difficulty of understanding these phenomena, children revealed a strong bias to see natural science phenomena as more difficult than those in psychology. The perceived relative difficulty of economics dropped dramatically in late childhood. In Study 2, children saw neuroscience phenomena as much more difficult than cognitive psychology phenomena, which were seen as more difficult than social psychology phenomena, even though all phenomena were again equated for difficulty in adults. In Study 3, we explored the basis for these results in intuitions about common knowledge and firsthand experience. Study 4 showed that the intuitions about the differences between the disciplines were based on intuitions about difficulty of understanding and not on the basis of more general intuitions about the feasibility or truth of the phenomena in question. Taken together, in the studies, the authors find an early emerging basis for judgments that some sciences are intrinsically more difficult than others, a bias that may persevere in adults in subtler forms in such settings as the courtroom. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Identification and prediction of distress trajectories in the first year after a breast cancer diagnosis.

Objective: In this article, we aim to (a) identify distinct trajectories of psychological distress in the first year after a breast cancer diagnosis in women treated with adjuvant therapy and (b) explore possible predictors of these trajectories, that is, demographic, medical, and personal characteristics. Method: The 171 patients were assessed after diagnosis, after surgery, after adjuvant treatment, in the reentry phase, and in the (short-term) survivorship phase (2 and 6 months after the end of treatment, respectively). Main Outcome Measure: Psychological distress was assessed with the 12-item General Health Questionnaire. Results: There were four trajectories of distress: a group that experienced no distress (36.3%), a group that experienced distress only in the active treatment phase (33.3%), a group that experienced distress in the reentry and survivorship phase (15.2%), and a group that experienced chronic distress (15.2%). Personality and physical complaints resulting from adjuvant treatment could distinguish the distress trajectories. Mastery was the only unique predictor. Conclusion: Most patients were not distressed in response to breast cancer or only temporarily so. Yet, a minority of patients became or remained distressed after the end of treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Long-term outcome from childhood traumatic brain injury: Intellectual ability, personality, and quality of life.

Objective: Only a handful of studies have attempted to explore very long-term outcomes from childhood traumatic brain injury (TBI). These studies have generally failed to fully consider the impact of injury severity or employ measures sensitive to the survivor's day-to-day function. This study examined outcomes in adulthood, with a focus on functional abilities including education, employment, and quality of life (QOL), and employed predictors including injury severity, age at injury, socioeconomic factors, intelligence, and personality. Method: The study was retrospective and cross-sectional and included 50 adult survivors of child TBI (31 males), aged 19–30 years at evaluation (M = 24.2, SD = 3.6), with injury on average 13.3 years prior to evaluation. Participants were divided according to injury severity—mild (n = 20), moderate (n = 12), and severe (n = 18)—completed an intellectual evaluation and questionnaires regarding educational and employment status, personality, and quality of life. Results: Intellectual and personality measures indicated good outcomes, with mean scores for all groups in the average range and few severity-based findings. In contrast, those with more severe TBI were more likely to have educational and employment problems. QOL was significantly reduced in the context of severe insult, with lower IQ and personality factors most predictive of outcome in this domain. Mild and moderate TBI were generally more benign. Conclusions: Findings suggest that, while TBI is a lifelong problem, its impact is most dramatic in the domain of QOL, where a complex interaction occurs between injury factors, cognition, and personality. (PsycINFO Database Record (c) 2011 APA, all rights reserved)