Quantifying the added value of BiPV as a shading solution in atria

Building integration of photovoltaics (PV) has long been acknowledged as a key application for PV in developed countries. The avoided use of comparably priced alternatives such as polished or cut stone in commercial facades enables PV to be applied often at little or no additional cost. The use of semi-transparent PV modules within commercial atria represents an interesting application in this respect as they can be used to replace traditional shading solutions which often have a high maintenance burden. However, compared to standard double glazing, an element incorporating either mono or poly crystalline PV cells in a glass-glass construction comes at a cost premium. To justify such an application there must be significant added value in the PV solution. This paper critically appraises a semi-transparent PV atrium which links two administration buildings at the University of Southampton, enclosing the main campus reception desk. Choosing PV laminates for the atrium roof has multiple benefits for the building users and the wider University, such as electricity generation, solar shading, environmental and technology statements, enhanced comfort and prestigious office workspace. This paper compares alternative shading solutions for the atrium and discusses user perception of the building and the atrium’s impact on their personal workspace. It is shown that PV in commercial atria does not always have to be considered as a ‘luxury’ option. With appropriate consideration of added value factors its selection can be justified in terms of both cost and carbon footprint.     

Mutational analysis demonstrates that ClC-4 and ClC-5 directly mediate plasma membrane currents

ClC-4 and ClC-5, together with ClC-3, form a distinct branch of the CLC chloride channel family. Although ClC-5 was shown to be mainly expressed in endocytotic vesicles, expression of ClC-5 in Xenopus oocytes elicited chloride currents. We now show that ClC-4 also gives rise to strongly outwardly rectifying anion currents when expressed in oocytes. They closely resemble ClC-5 currents with which they share a NO3- > Cl- > Br- > I- conductance sequence that differs from that reported for the highly homologous ClC-3. Both ClC-4 and ClC-5 currents are reduced by lowering extracellular pH. We could measure similar currents after expressing either channel in HEK293 cells. To demonstrate that these currents are directly mediated by the channel proteins, we introduced several point mutations that change channel characteristics. In ClC-5, several point mutations alter the kinetics of activation but leave macroscopic rectification and ion selectivity unchanged. A mutation (N565K) equivalent to a mutation reported to have profound effects on ClC-3 does not have similar effects on ClC-5. Moreover, a mutation at the end of D2 (S168T in ClC-5) changes ion selectivity, and a mutation at the end of D3 (E211A in ClC-5 and E224A in ClC-4) changes voltage dependence and ion selectivity. This shows that ClC-4 and ClC-5 can directly mediate plasma membrane currents.     

The ubiquitin-like proteins SMT3 and SUMO-1 are conjugated by the UBC9 E2 enzyme

The ubiquitin-like protein SMT3 from Saccharomyces cerevisiae and SUMO-1, its mammalian homolog, can be covalently attached to other proteins posttranslationally. Conjugation of ubiquitin requires the activities of ubiquitin-activating (E1) and -conjugating (E2) enzymes and proceeds via thioester-linked enzyme-ubiquitin intermediates. Herein we show that UBC9, one of the 13 different E2 enzymes from yeast, is required for SMT3 conjugation in vivo. Moreover, recombinant yeast and mammalian UBC9 enzymes were found to form thioester complexes with SMT3 and SUMO-1, respectively. This suggests that UBC9 functions as an E2 in a SMT3/SUMO-1 conjugation pathway analogous to ubiquitin-conjugating enzymes. The role of yeast UBC9 in cell cycle progression may thus be mediated through its SMT3 conjugation activity.     

Unique structure and function of chloride transporting CLC proteins

CLC proteins are a large structurally defined family of Cl/sup -/ ion channels and H/sup +//Cl/sup -/ antiporters with nine distinct genes in mammals. The membrane-embedded part of CLC proteins bears no obvious similarity to any other class of membrane proteins, while the cytoplasmic C-terminus of most eukaryotic and some prokaryotic CLCs contains two regions with homology to cystathionine beta synthase (CBS) domains that are found in other proteins as well. Different members serve a broad range of physiological roles, including stabilization of the membrane potential, transepithelial ion transport, and vesicular acidification. Their physiological importance is underscored by the causative involvement in at least four different human genetic diseases. From functional studies of the Torpedo homologue ClC-0, a homodimeric architecture with two physically separate ion conduction pathways was anticipated and fully confirmed by solving the crystal structure of prokaryotic CLC homologues. The structure revealed a complex fold of 18 /spl alpha/-helices per subunit with at least two Cl/sup -/ ions bound in the center of each protopore. A critical glutamic acid residue was identified whose side-chain seems to occupy a third Cl/sup o/n binding site in the closed state and that moves away to allow Cl/sup i/nding. While the overall architecture and pore structure is certainly conserved from bacteria to humans, the bacterial proteins that were crystallized are actually not Cl/sup -/ ion channels, but coupled H/sup +//Cl/sup $/antiporters. These recent breakthroughs will allow us to study in further detail the structure, function, and the physiological and pathophysiological role of CLC proteins.     

Can pretraining experiences explain individual differences in learning?

This study examined the effects of having experienced negative events related to the purpose of a training program on learning and retention. Participants were 32 private pilots who participated in an assertiveness-training study. The purpose of the training was to prevent aviation accidents caused by human error. Structured telephone interviews were conducted to determine whether participants had previously experienced 3 types of negative events related to the purpose of training. Results indicated a linear relationship between these negative events and assertive performance in a behavioral exercise 1 week after training. The same negative events, however, were not significantly related to the performance of untrained participants in the same behavioral exercise. It is suggested that previous experiences influenced posttraining performance by increasing motivation to learn. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

ClC-1 chloride channel mutations in myotonia congenita: variable penetrance of mutations shifting the voltage dependence

Mutations in the ClC-1 muscle chloride channel cause either recessive or dominant myotonia congenita. Using a systematic screening procedure, we have now identified four novel missense mutations in dominant (V286A, F307S) and recessive myotonia (V236L, G285E), and have analysed the effect of these and other recently described mutations (A313T, I556N) on channel properties in the Xenopus oocyte expression system. Mutations V286A, F307S and A313T displayed a 'classical' dominant phenotype: their voltage dependence was shifted towards positive potentials and displayed a dominant-negative effect by significantly imparting a voltage shift on mutant-wild-type heteromeric channels as found in heterozygous patients. In contrast, the recessive mutation V236L also shifted the voltage dependence to positive values, but co-expression with wild-type ClC-1 gave almost wild-type currents. I556N, a mutation found in patients with benign dominant myotonia, drastically shifts the voltage dependence, but only a slight shift is seen when co-expressed with wild-type ClC-1. Thus, the voltage dependence of mutant heteromeric channels is not always intermediate between those of the constituent homomeric channel subunits, a conclusion further supported by mixing different ClC-1 mutants. These complex interactions correlate clinically with various inheritance patterns, ranging from autosomal dominant with various degrees of penetrance to autosomal recessive.     

Investigation of Heavy Metal Release during Thermal Waste Treatment on a Forward‐Acting Grate by Means of Radiotracers

This paper deals with the determination of location, time and quantity of the release of heavy metals in a pilot‐scale grate system by means of short‐lived radioactive isotopes during the incineration of municipal waste. The isotopes ^69mZn (half life: 13.8 hours) and ⁶⁴Cu (half life: 12.7 hours) were used to represent heavy metals which can be released relatively well and more difficultly, respectively. Due to the implementation of isotopes which emit gamma rays, all measured values could be acquired without direct contact and without the need to take samples. The location of release was determined by means of NaI(Tl)‐scintillation detectors positioned alongside the outer walls of the grate. The time and the quantity of the release were measured with a detector located in a special absorption vessel for the purification of a partial flow of the exhaust gases.     

Establishing orally self-administered cocaine as a reinforcer in rats using home-cage pre-exposure

1. Rats were force-exposed to a cocaine + saccharin solution in their home cage water bottles for five days. They were then given 5 h home-cage access to both cocaine and cocaine-free solutions for 40 days. 2. The subjects consumed large doses of the cocaine solution despite the ad libitum availability of water. 3. The animals were then trained on a task consisting of operant bar pressing rewarded on an intermittent schedule with a liquid cocaine reinforcer. 4. All subjects performed the operant task and consumed doses of cocaine solution which are preferred over water in other paradigms. 5. Levels of responding were significantly reduced in three of four subjects when vehicle was substituted for liquid cocaine as the reward. 6. This demonstrates that orally self-administered cocaine can be used as a reinforcer in rats.     

Novel muscle chloride channel (CLCN1) mutations in myotonia congenita with various modes of inheritance including incomplete dominance and penetrance

Autosomal-dominant and -recessive myotonia congenita are caused by mutations in the skeletal muscle voltage-gated chloride channel gene (CLCN1). We searched for mutations in this gene in 20 unrelated families with myotonia congenita. We identified 11 different mutations in 10 families. Two of five new mutations (Ala313Thr and Ile556Asn) were both autosomal recessive and dominant with either reduced penetrance or incomplete dominance. Mutations in the CLCN1 gene do not therefore necessarily behave in a classic Mendelian manner.     

Schnellmethode zur halbquantitativen Polyethylen-Bestimmung in Landtierfetten

Rapid Method for Semi-Quantitative Polyethylene Determination in Terrestrial Animal Fats A raw material control and selection with respect to polyethylene contents is necessary from safety and economic point of view. The available methods of quantitative determination are very time consuming. The reliability of the up to now developed quick tests is not always sufficient. A method is presented which gives a reliable and distinct estimation of the polyethylene content in terrestrial animal fats. The polyethylene, contained in the sample is dissolved. After separation of the disturbing solid particles by rapid filtration polyethylene is flocculated. The judgement is carried through by use of a standard with sufficient repeatability and reproducibility. The procedure can be modified if necessary with respect to as well the polymer types which are to determine as the limit of detection.