Dreissenid mussels from the Great Lakes contain elevated thiaminase activity

We examined thiaminase activity in dreissenid mussels collected at different depths and seasons, and from various locations in Lakes Michigan, Ontario, and Huron. Here we present evidence that two dreissenid mussel species (Dreissena bugensis and D. polymorpha) contain thiaminase activity that is 5–100 fold greater than observed in Great Lakes fishes. Thiaminase activity in zebra mussels ranged from 10,600 to 47,900 pmol g^− 1·min^− 1 and activities in quagga mussels ranged from 19,500 to 223,800 pmol g^− 1·min^− 1. Activity in the mussels was greatest in spring, less in summer, and least in fall. Additionally, we observed greater thiaminase activity in dreissenid mussels collected at shallow depths compared to mussels collected at deeper depths. Dreissenids constitute a significant and previously unknown pool of thiaminase in the Great Lakes food web compared to other known sources of this thiamine (vitamin B₁)-degrading enzyme. Thiaminase in forage fish of the Great Lakes has been causally linked to thiamine deficiency in salmonines. We currently do not know whether linkages exist between thiaminase activities observed in dreissenids and the thiaminase activities in higher trophic levels of the Great Lakes food web. However, the extreme thiaminase activities observed in dreissenids from the Great Lakes may represent a serious unanticipated negative effect of these exotic species on Great Lakes ecosystems.     

Thiamine concentrations in lake whitefish eggs from the upper Great Lakes are related to maternal diet

Thiamine deficiency is responsible for reproductive impairment in several species of salmonines in the Great lakes, and is thought to be caused by the consumption of prey containing thiaminase, a thiamine-degrading enzyme. Because thiaminase levels are extremely high in dreissenid mussels, fish that prey on them may be susceptible to thiamine deficiency. We determined thiamine concentrations in lake whitefish Coregonus clupeaformis eggs from the upper Laurentian Great Lakes to assess the potential for thiamine deficiency and to determine if thiamine concentrations in lake whitefish eggs were related to maternal diet. Mean thiamine concentrations in lake whitefish eggs were highest in Lake Huron, intermediate in Lake Superior, and lowest in Lake Michigan. Some fish had thiamine concentrations below putative thresholds for lethal and sublethal effects in salmonines, suggesting that some larval lake whitefish may currently be at risk of at least sublethal effects of low thiamine concentrations, although thiamine thresholds are unknown for lake whitefish. Egg thiamine concentrations in lake whitefish eggs were statistically significantly related to isotopic carbon signatures, suggesting that egg thiamine levels were related to maternal diet, but low egg thiamine concentrations did not appear to be associated with a diet of dreissenids. Egg thiamine concentrations were not statistically significantly related to multifunction oxidase induction, suggesting that lower egg thiamine concentrations in lake whitefish were not related to contaminant exposure.     

Effect of hot-air drying on flavour compounds of bell peppers (Capsicum annuum)

The influence of hot-air drying on the composition of both volatile and non-volatile flavour compounds of different Dutch bell pepper cultivars was investigated. Contents of glucose, fructose, ascorbic, citric, and oxalic acid decreased significantly after drying, while the levels of sucrose, malic, fumaric, and cis-aconitic acid increased. Glucose, fructose and ascorbic acid probably participate in Maillard reactions during heating. Different effects of drying could be distinguished on the composition of volatile compounds. The majority of these compounds evaporated during drying. Some compounds were partly retained in the dried bell peppers, whereas others disappeared completely. Gas chromatography-sniffing port analysis revealed that compounds with mainly “fresh” odour notes like lettuce/grassy/green bell pepper ((Z-2-3-hexenal), fruity/almond ((E)-2-hexenal), fruity (octanal), lettuce/green bell pepper ((Z)-3-hexenol), and grassy/green bell pepper ((Z)-2-hexenal) decreased or disappeared after drying. Another group of compounds increased or were formed during drying, like 4-octen-3-one, (E)-2-heptenal, (E)-2-octenal, (E,Z)- and (E,E)-2,4-heptadienal, decanal, and (E)-2-nonenal; most are known as autoxidation products of unsatu-rated fatty acids. The increased levels of 2-methylpropionic and 2- and 3-methylbutyric acid, 2-metlhylpropanal, and 2- and 3-methylbutanal seemed to be due to Strecker degradation. Gas chromatography-sniffing port analysis showed that the latter three compounds had distinct cacao, sweaty, and spicy odour characteristics.     

Effect of vegetated-banks on local scour around a wing-wall abutment with circular edges

Failure of bridges due to local scour in the vicinity of bridge abutments is a common occurrence. In this study, experiments under two different channel conditions were conducted to assess the impacts of vegetation on channel banks on local scour around a wing-wall abutment with circular edges. Some experiments were conducted in channel with vegetation on channel banks, and other experiments in channel without vegetation on channel bank. The flow velocity and Reynolds stress distributions in scour holes around a wing-wall abutment with circular edges were compared under these 2 different channel conditions. Results reveal that the vegetated-banks can reduce the time for achieving the equilibrium condition from 17 h to 9 h. Also, vegetated-bank channels can result in a significant decrease in the maximum scour depth from 0.084 m（for bare channel bank） to 0.00032 m. Additionally, around the abutment, vegetated-banks play a significant role in diminishing the Reynolds stress（RS） near the bed and removing negative values in RS distribution by weakening unfavorable pressure gradient and down-flow in the upstream of abutment.     

Evaluation of adult and offspring thiamine deficiency in salmonine species from Lake Ontario

Thiamine Deficiency Complex (TDC) is an ongoing problem impacting salmonine health in various waterbodies, including Lake Ontario. The prevalence of TDC has been variable and explanations for differences are limited. In the current study, thiamine concentrations were measured in eggs, liver tissue, and muscle tissue sampled from brown trout (Salmo trutta), Chinook salmon (Oncorhynchus tshawytscha), coho salmon (O. kisutch), lake trout (Salvelinus namaycush), and steelhead trout (O. mykiss) that were collected from Lake Ontario and its surrounding tributaries. The occurrence of TDC was measured for each species based on TDC-induced offspring mortality rates under laboratory conditions. TDC-induced offspring mortality was observed for all species except brown trout. For affected species, egg free thiamine (Th) was consistently low compared to lake trout collected from Lake Superior that are considered thiamine replete. In addition, species with the lowest percentages of Th in their eggs were the most susceptible to TDC, suggesting that limited thiamine reserves in the form of Th may cause TDC-induced offspring mortality. Lastly, our results show that egg thiamine concentrations have yearly variation and increased for all species throughout the study. Reasons for such variation are undetermined; but, if egg thiamine concentrations continue to increase, the impacts of TDC on these salmonine species may lessen. Future monitoring is needed for determining if thiamine concentrations are increasing and the potential impacts that may have on the entire Lake Ontario fishery.     

The Examination for Professional Practice in Psychology (EPPP) in the era of evidence-based practice.

Professional psychology has increasingly moved toward evidence-based practice. However, instruments used to assess psychologists seeking licensure, such as the Examination for Professional Practice in Psychology (EPPP), have received relatively little empirical scrutiny. Therefore, the authors evaluated the available evidence in support of the EPPP’s validity and current use as a core component of professional licensure. Although the EPPP has in many ways been extensively evaluated, there is a paucity of criterion, predictive, and incremental validity evidence available. Further, several aspects of the content validation studies were examined, and the authors question whether the EPPP, as currently constructed, can meet its stated goals. Given that the EPPP is a high-stakes examination and given the authors’ best estimate (based on a sample of 16 states) that 35% of applicants fail the examination, it is recommended that the EPPP be more extensively evaluated. An outline of major decision points in this proposed evaluation process is provided, several suggestions for further research are proposed, and the field is encouraged to discuss these issues further. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optimal and heuristic solution methods for a multiprocessor machine scheduling problem

This paper deals with the scheduling of operations on a multiprocessor machine in the context of shoe manufacturing. Multiprocessor machines are composed of several parallel processors. Unlike parallel machines, the entire machine needs to be stopped whenever a single processor needs a setup. Our industrial partner, one of the major winter-shoe manufacturers in Canada, offers a relatively large variety of models. For each of these models, all the sizes proposed by this manufacturer must be produced in various quantities. Our objective is to schedule the production of the required sizes on the machine's different processors in order to minimize the global makespan, which includes both the production time and the set up time. We first present a mathematical formulation of the problem. Then, we introduce a decomposition procedure based on the mathematical model, and we demonstrate that this procedure is very efficient for small- and medium-size instances. We also propose two construction heuristics and two improvement heuristics for larger problems, and we report the results of our extensive computational experiments to demonstrate the quality of the proposed heuristics in terms of reducing production time and computational effort.     

Unique and common mechanisms of change across cognitive and dynamic psychotherapies.

The goal of this article was to examine theoretically important mechanisms of change in psychotherapy outcome across different types of treatment. Specifically, the role of gains in self-understanding, acquisition of compensatory skills, and improvements in views of the self were examined. A pooled study database collected at the University of Pennsylvania Center for Psychotherapy Research, which includes studies conducted from 1995 to 2002 evaluating the efficacy of cognitive and psychodynamic therapies for a variety of disorders, was used. Patient samples included major depressive disorder, generalized anxiety disorder, panic disorder, borderline personality disorder, and adolescent anxiety disorders. A common assessment battery of mechanism and outcome measures was given at treatment intake, termination, and 6-month follow-up for all 184 patients. Improvements in self-understanding, compensatory skills, and views of the self were all associated with symptom change across the diverse psychotherapies. Changes in self-understanding and compensatory skills across treatment were predictive of follow-up symptom course. Changes in self-understanding demonstrated specificity of change to dynamic psychotherapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A self-adaptive universal receiver

In this paper we describe a new Self-Adaptive Re-Configurable Terminal, based on blind recognition of the system in use. This new terminal is operates thanks to a new radio interface receiver concept comprising two functional phases. These two phases are mapped on a specific architecture previously presented in [1]. The first one is devoted to a Wide Band Analysis (Wba) of the received signal in order to find which standard is being used. The second one being the demodulation itself. In this paper we focus on thisWba. It includes an iterative process in order to find the right bandwidth which has to be compatible with the Signal Processing techniques we use. During the last step of the process, blind standard recognition is performed by means of Radial Basis Function Neural Networks, which allow making full use of the analogy between our problem and conventional pattern recognition problems. Extensive simulation with true data of signals received in our lab has been performed and confirms the interest and efficiency of this type of recognition.