Influence of microbial processes on the operation of a cold store in a shallow aquifer: impact on well injectivity and filter lifetime

In this study, the operation of a cold store, located in 30??0?m depth in the North German Basin, was investigated by direct counting of bacteria and genetic fingerprinting analysis. Quantification of microbes accounted for 1 to 10??0⁵ cells per ml fluid with minor differences in the microbial community composition between well and process fluids. The detected microorganisms belong to versatile phyla Proteobacteria and Flavobacteria. In addition to routine plant operation, a phase of plant malfunction caused by filter clogging was monitored. Increased abundance of sulfur-oxidizing bacteria indicated a change in the supply of electron acceptors, however, no changes in the availability of electron acceptors like nitrate or oxygen were detected. Sulfur- and iron-oxidizing bacteria played essential roles for the filter lifetimes at the topside facility and the injectivity of the wells due to the formation of biofilms and induced mineral precipitations. In particular, sulfur-oxidizing Thiothrix generated filamentous biofilms were involved in the filter clogging.     

HIV-1 gp160 decreases the K+ voltage-gated current from Jurkat E6.1 T cells by up-phosphorylation

HIV-1 gp120/gp160 is known to disturb the activity of p56lck, protein kinase C (PKC) and Ca2+ homeostasis in T lymphocytes. We found that gp160 decreases the Kv1.3 current of Jurkat E6.1 cells probably by increasing the PKC-dependent phosphorylation of Kv channel protein after 5 days. This decrease is dose-dependent. In contrast, gp160 did not decrease the Kv1.3 current of the JCaM1.6 cell line, a p56(lck)-defective Jurkat cell line. This shows that p56lck was at the beginning of the events which induced the Kv1.3 current decrease. As a consequence of this decrease, Jurkat E6.1 cells were depolarized and exhibited a volume increase.     

The environmental fate of arsenic in surface soil contaminated by historical herbicide application

Soils from many industrial sites are contaminated with arsenic because of the historical application of herbicide containing arsenic trioxide. The strong affinity of aqueous arsenic species for soil components has led to the retention of significant amounts of arsenic in surface soils decades after the original source application. Soil collected from a site which received a one-time surficial application of arsenical herbicide in the 1950s was investigated to understand the fate of arsenic under natural leaching conditions. Sequential chemical extraction of the contaminated soil revealed that the majority of the arsenic is in its secondary form. The synthetic acid rain leaching of arsenic from the weathered soil can be divided into two distinct stages. During the first stage, the leachate arsenic concentration underwent a rapid decline which suggests an equilibrium-controlled release event. The second leaching stage was marked by a slow, steady release of arsenic, a signature of a kinetically controlled process. A mathematical approach was employed to identify and describe the two distinct arsenic releasing processes (equilibrium desorption and kinetic desorption). This model considers both desorption processes simultaneously and produces leachate arsenic concentrations in good agreement with the measured data. According to the modeling results, 20% of the arsenic remaining in the soil resides in the herbicide source material after five decades of natural leaching; 25% exists on reversible adsorption sites and 55% is present on irreversible adsorption sites.     

Presence and Absence in ‘Abandoned’ Palestinian Villages

This essay deals with the way Palestinian villages, emptied during the 1948 war when their inhabitants fled or were expelled, were visually preserved in Israeli consciousness. The essay analyses a group of photographs in official Israeli archives that were taken by Israeli photographers between 1948 and 1951. These images, taken for Israeli national propaganda to describe the new Jewish immigrants who had been settled by the new Israeli state in these villages, show how they implement the Zionist world view. In contrast to these purposes, however, reading these institutional photography archives also makes it possible to learn about Palestinian identity before 1948 and gain insight into the Palestinian people, who are missing from these photographs. The essay shows how the manner of reading these archives makes possible the extraction of different layers of meanings.     

Highlights in Coupled Electrochemical Flow Cell-Mass Spectrometry,EC/MS

Probing electrochemical processes by mass spectrometry (EC/MS) is a developing field that benefits from the unmatched identification power of mass spectrometry and from the rapid transfer of electrochemical cell products to the mass spectrometer. Most of the current EC/MS efforts are directed towards the development of differential electrochemical mass spectrometry (DEMS) using the electro-ionization source for identification of volatile compounds, and towards the application of electrospray mass spectrometers for determination of semivolatile and nonvolatile products. The challenges in coupling mass spectrometry and electrochemistry are described, and different approaches to using the coupled system for diverse applications are reviewed, with emphasis on electrospray mass spectrometry. Reaction mechanism studies, diagnostic applications, and activity imaging of electrodes are demonstrated based on approaches that were devised in our laboratory.     

A high-performance VHDL-based virtual tester: a concept and a solution

Virtual test (VT) is a powerful technique to cut the time-to-market especially for SoC products. VT allows debugging mixed-signal test programs in a simulation environment if a fast and sufficiently accurate chip model can be made available several weeks before first silicon. VHDL behavioural models were found to cover both the needs of designers for sign-off simulation on chip level and of test engineers for VT. This paper presents a high-performance VT solution based on pure VHDL modelling of the hardware involved, a VHDL-based virtual tester concept and a snapshot test data extractor linking the test program to a simulator.     

Sudden death in a 4-month-old infant associated with anomalous origin of the left coronary artery

We describe the autopsy findings of a 4 months-old boy, who died suddenly after an episode of high airway infection of 3 days time. Autopsy examination showed cardiomegaly (80 g) with widening of the left cavities and thick and white endocardial surface, besides a severe thinning of the cardiac apex at the level of the left ventricle. Left coronary origin was in the pulmonary artery trunk. Histologically, the myocardium shows endomyocardial fibroelastosis and also multiple and extensive areas of old and recent infarcts in the left ventricle. The collateral coronary arteries, were increased in number, and branches showed a marked intimal oedema and a reduction of the luminal diameter.     

The effects of shoulder load and pinch force on electromyographic activity and blood flow in the forearm during a pinch task

The object of the current study was to determine whether static contraction of proximal musculature has an effect on the blood flow more distally in the upper extremity. Static contractions of muscles in the neck shoulder region at three levels (relaxed, shoulders elevated and shoulders elevated loaded with 4.95 kg each) were combined with intermittent pinch forces at 0, 10 and 25% of the maximum voluntary contraction (MVC). Blood flow to the forearm was measured with Doppler ultrasound. Myoelectric activity of the forearm and neck-shoulder muscles was recorded to check for the workload levels. Across all levels of shoulder load, blood flow increased significantly with increasing pinch force (21% at 10% MVC and by 44% at 25% MVC). Blood flow was significantly affected by shoulder load, with the lowest blood flow at the highest shoulder load. Interactions of pinch force and shoulder load were not significant. The myoelectric activity of forearm muscles increased with increasing pinch force. The activation of the trapezius muscle decreased with increasing pinch force and increased with increasing shoulder load. The precise mechanisms accounting for the influence of shoulder load remains unclear. The results of this study indicate that shoulder load might influence blood flow to the forearm.