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Cronbach's alpha as a reliability estimate for a set of items has been repeatedly criticised. Using McDonald's omega or the Greatest Lower Bound (GLB) has been suggested instead. A simulation study using a single scale was performed on data with n = 60, 80, 120, 200, 300, 500 and 900 cases utilizing 4, 8, 16 or 32 items. A total of 10% of each item had missing values vs. there were no missing data. Skewness of the items were 0, 1 and 2. Correlations were homogenous vs. heterogeneous. Standard deviations were homogenous vs. heterogeneous. Underlying constructs were homogenous vs. heterogenous. Conditions were combined in a block design, and 1000 replications for each one were calculated. As a result, alpha slightly underestimated reliability in some cases, omega minimally overestimated in large samples, the GLB overestimated strongly in small samples. Additionally, GLB estimates had less precision within the 1000 replications, i.e., standard deviations were almost double as large as for alpha and omega. Interestingly, the performances of alpha and omega were basically similar. However, various programs showed different results particularly in cases with missing data on the items. Out of the programs examined, the R package MBESS displayed best results.

Building upon our recent study [G. S. Bali et al., “Eur. Phys. J. C 78, 217 (2018)], we investigate the feasibility of calculating the pion distribution amplitude from suitably chosen Euclidean correlation functions at large momentum. We demonstrate in this work the advantage of analyzing several correlation functions simultaneously and extracting the pion distribution amplitude from a global fit. This approach also allows us to study higher-twist corrections, which are a major source of systematic error. Our result for the higher-twist parameter ${\ensuremath{\delta}}_{2}^{\ensuremath{\pi}}$ is in good agreement with estimates from QCD sum rules. Another novel element is the use of all-to-all propagators, calculated using stochastic estimators, which enables an additional volume average of the correlation functions, thereby reducing statistical errors.

Two-pore channels (TPCs) are endolysosomal cation channels. Two members exist in humans, TPC1 and TPC2. Functional roles associated with the ubiquitously expressed TPCs include VEGF-induced neoangiogenesis, LDL-cholesterol trafficking and degradation, physical endurance under fasting conditions, autophagy regulation, the acrosome reaction in sperm, cancer cell migration, and intracellular trafficking of pathogens such as Ebola virus or bacterial toxins (e.g., cholera toxin). In a genome-wide association study for variants associated with human pigmentation characteristics two coding variants of TPC2, rs35264875 (encoding M484L) and rs3829241 (encoding G734E), have been found to be associated with a shift from brown to blond hair color. In two recent follow-up studies a role for TPC2 in pigmentation has been further confirmed. However, these human polymorphic variants have not been functionally characterized until now. The development of endolysosomal patch-clamp techniques has made it possible to investigate directly ion channel activities and characteristics in isolated endolysosomal organelles. We applied this technique here to scrutinize channel characteristics of the polymorphic TPC2 variants in direct comparison with WT. We found that both polymorphisms lead to a gain of channel function by independent mechanisms. We next conducted a clinical study with more than 100 blond- and brown/black-haired individuals. We performed a genotype/phenotype analysis and subsequently isolated fibroblasts from WT and polymorphic variant carriers for endolysosomal patch-clamp experimentation to confirm key in vitro findings.

Polarized membrane morphogenesis is a fundamental activity of eukaryotic cells. This process is essential for the biology of cells and tissues, and its execution demands exquisite temporal coordination of functionally diverse membrane signaling reactions with high spatial resolution. Moreover, mechanisms must exist to establish and preserve such organization in the face of randomizing forces that would diffuse it. Here we identify the conserved AtSfh1 Sec14-nodulin protein as a novel effector of phosphoinositide signaling in the extreme polarized membrane growth program exhibited by growing Arabidopsis root hairs. The data are consistent with Sec14-nodulin proteins controlling the lateral organization of phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) landmarks for polarized membrane morphogenesis in plants. This patterning activity requires both the PtdIns(4,5)P2 binding and homo-oligomerization activities of the AtSfh1 nodulin domain and is an essential aspect of the polarity signaling program in root hairs. Finally, the data suggest a general principle for how the phosphoinositide signaling landscape is physically bit mapped so that eukaryotic cells are able to convert a membrane surface into a high-definition lipid-signaling screen.

Heteronanoparticles represent a new class of nanomaterials exhibiting multifunctional and collective properties, which could find applications in medical imaging and therapy, catalysis, photovoltaics, and electronics. This present work demonstrates the intrinsic heteroepitaxial linkage in heterodimer nanoparticles to enable interaction of the individual components across their interface. It revealed distinct differences between Au@MnO and Au@Fe3O4 regarding the synthetic procedure and growth kinetics, as well as the properties to be altered by the variation of the electronic structure of the metal oxides. The chemically related metal oxides differ concerning their band gap; while MnO is a Mott-Hubbard insulator with a large band gap, Fe3O4 is a semimetal with thermally activated conductivity. The fluorescence dynamics indicate a prolonged relaxation time (>2 ns) for electrons of the conduction band of the Au nanoparticles after interfacing to Fe3O4. Here, the semiconductor is not depleted and forms an ohmic contact to the Au domain. In contrast, the fluorescence dynamics and ESCA of Au@MnO affirmed the weak interaction with the electrons of the Au domain, where the junction behaves as a Schottky barrier.

The leptonic decay of charged pions is investigated in the presence of background magnetic fields. In this situation, Lorentz symmetry is broken, and new fundamental decay constants need to be introduced, associated with the decay via the vector part of the electroweak current. We calculate the magnetic field dependence of both the usual and a new decay constant nonperturbatively on the lattice. We employ both Wilson and staggered quarks and extrapolate the results to the continuum limit. With this nonperturbative input, we calculate the tree level electroweak amplitude for the full decay rate in strong magnetic fields. We find that the muonic decay of the charged pion is enhanced drastically by the magnetic field. We comment on possible astrophysical implications.

Recent developments show that the standardization of cloud service descriptions and exchange leads the way for the rise of cloud federations. In these federations CSPs (cloud service providers) can use resources of other CSPs in the case of a lack of local resources or they can add remote services to their catalogue. Cloud federations again demand for cloud brokers which offer the resources and services of different CSPs transparently to the users. Research of cloud federations in the real world is very complex and expensive as distributed hard- and software scenarios are needed. Therefore we present FederatedCloudSim, a very flexible cloud simulation framework that can be used to simulate many federated cloud scenarios while respecting SLAs (service level agreements). In this paper we also present first simulation results and explain different simulation scenarios.

In organisms from all kingdoms of life, ammonia and its conjugated ion ammonium are transported across membranes by proteins of the AMT/Rh family. Efficient and successful growth often depends on sufficient ammonium nutrition. The proteins mediating this transport, the so called Ammonium Transporter (AMT) or Rhesus like (Rh) proteins, share a very similar trimeric overall structure and a high sequence similarity even throughout the kingdoms. Even though structural components of the transport mechanism, like an external substrate recruitment site, an essential twin histidine pore motif, a phenylalanine gate and the hydrophobic pore are strongly conserved and have been analyzed in detail by molecular dynamic simulations and mutational studies, the substrate(s), which pass the central pores of the AMT/Rh subunits, NH4(+), NH3 + H(+), NH4(+) + H(+) or NH3, are still a matter of debate for most proteins, including the best characterized AmtB protein from Escherichia coli. The lack of a robust expression system for functional analysis has hampered proof of structural and mutational studies, although the NH3 transport function for Rh-like proteins is rarely disputed. In plant transporters belonging to the subfamily AMT1, transport is associated with electrical currents, while some plant transporters, notably of the AMT2 type, were suggested to transport NH3 across the membrane, without associated ionic currents. Here we summarize data in favor of each substrate for the distinct AMT/Rh classes, discuss mutants and how they differ in structure and functionality. A common mechanism with deprotonation and subsequent NH3 transport through the central subunit pore is suggested.

Collective I/O is a parallel I/O technique designed to deliver high performance data access to scientific applications running on high-end computing clusters. In collective I/O, write performance is highly dependent upon the storage system response time and limited by the slowest writer. The storage system response time in conjunction with the need for global synchronisation, required during every round of data exchange and write, severely impacts collective I/O performance. Future Exascale systems will have an increasing number of processor cores, while the number of storage servers will remain relatively small. Therefore, the storage system concurrency level will further increase, worsening the global synchronisation problem. Nowadays high performance computing nodes also have access to locally attached solid state drives, effectively providing an additional tier in the storage hierarchy. Unfortunately, this tier is not always fully integrated. In this paper we propose a set of MPI-IO hints extensions that enable users to take advantage of fast, locally attached storage devices to boost collective I/O performance by increasing parallelism and reducing global synchronisation impact in the ROMIO implementation. We demonstrate that by using local storage resources, collective write performance can be greatly improved compared to the case in which only the global parallel file system is used, but can also decrease if the ratio between aggregators and compute nodes is too small.

Summary Quantum chemical workflows can be built up within the science gateway Molecular Simulation Grid. Complex workflows required by the end users are dissected into smaller workflows that can be combined freely to larger meta‐workflows. General quantum chemical workflows are described here as well as the real use case of a spectroscopic analysis resulting in an end‐user desired meta‐workflow. All workflow features are implemented via Web Services Parallel Grid Runtime and Developer Environment and submitted to UNICORE. The workflows are stored in the Molecular Simulation Grid repository and ported to the SHIWA repository. Copyright © 2014 John Wiley & Sons, Ltd.

A bstract We perform a systematic study of the correlation functions of two quark currents in a pion using lattice QCD. We obtain good signals for all but one of the relevant Wick contractions of quark fields. We investigate the quark mass dependence of our results and test the importance of correlations between the quark and the antiquark in the pion. Our lattice data are compared with predictions from chiral perturbation theory.

A bstract We perform a lattice study of double parton distributions in the pion, using the relationship between their Mellin moments and pion matrix elements of two local currents. A good statistical signal is obtained for almost all relevant Wick contractions. We investigate correlations in the spatial distribution of two partons in the pion, as well as correlations involving the parton polarisation. The patterns we observe depend significantly on the quark mass. We investigate the assumption that double parton distributions approximately factorise into a convolution of single parton distributions.

Modularity, professionality, portability, and integration are the key features of the TUebingen System for TExt Processing programs (TUSTEP), a professional toolbox for those academic fields where texts are the object of research. Its potential is illustrated by two examples: (i) typesetting a TEI-lite encoded text, using the TEI tags as formatting instructions; (ii) preparing a critical edition, starting from automatic collation, then semi-automatically selecting the 'substantial' variants from the collation results, transforming them into a critical apparatus, and publishing the edition both in print and electronically.

A bstract We evaluate nucleon four-point functions in the framework of lattice QCD in order to extract the first Mellin moment of double parton distributions (DPDs) in the unpolarized proton. In this first study, we employ an n f = 2+1 ensemble with pseudoscalar masses of m π = 355 MeV and m K = 441 MeV. The results are converted to the scale μ = 2 GeV. Our calculation includes all Wick contractions, and for almost all of them a good statistical signal is obtained. We analyze the dependence of the DPD Mellin moments on the quark flavor and the quark polarization. Furthermore, the validity of frequently used factorization assumptions is investigated.

Great efforts are made to store data in a secure, reliable, and authentic way in large storage systems. Specialized, system specific clients help to achieve these goals. Nevertheless, often standard tools for hashing, compressing, and encrypting data are arranged in transparent pipelines. We analyze the potential of Unix shell pipelines with several high-speed and high-compression algorithms that can be used to achieve data security, reduction, and authenticity. Furthermore, we compare the pipelines of standard tools against a house made pipeline implemented in C++ and show that there is great potential for performance improvement.

To easily analyse and visualize cell kill dynamics measured by survival fraction after single or combined treatments a MATLAB®-based application was developed. A statistical analysis with different options of visualisation of single and combined treatment effects can be performed in a few steps not requiring advanced knowledge of statistical programs.

Computer systems provide different heterogeneous resources (e.g., GPUs, DSPs and FPGAs) that accelerate applications and that can reduce the energy consumption by using them. Usually, these resources have an isolated memory and a require target specific code to be written. There exist tools that can automatically generate target specific codes for program parts, so-called kernels. The data objects required for a target kernel execution need to be moved to the target resource memory. It is the programmers' responsibility to serialize these data objects used in the kernel and to copy them to or from the resource's memory. Typically, the programmer writes his own serializing function or uses existing serialization libraries. Unfortunately, both approaches require code modifications, and the programmer needs knowledge of the used data structure format. There is a need for a tool that is able to automatically extract the original kernel data objects, serialize them, and migrate them to a target resource without requiring intervention from the programmer. In this paper, we present a tool collection ConSerner that automatically identifies, gathers, and serializes the context of a kernel and migrates it to a target resource's memory where a target specific kernel is executed with this data. This is all done transparently to the programmer. Complex data structures can be used without making a modification of the program code by a programmer necessary. Predefined data structures in external libraries (e.g., the STL's vector) can also be used as long as the source code of these libraries is available.

Zusammenfassung: 210 Männer mit idiopathischer Oligozoospermie bzw. OAT-Syn-drom wurden 5 Monate lang mit 2times10 bzw. 2 times 20 mg Tamoxifen/die behandelt. Beglei-tende Untersuchungen haben ergeben, daß Körpergewicht, Blutdruck, Blutsenkung und zelluläres Blutbild einschließlich Thrombozyten keine signifikante Änderung erfahren. Die Überprüfung der Serummultianalyse zeigte — innerhalb des Normwertbereiches — signifikante Änderungen bei: Kreatinin, Albumin, Cholesterin, Phosphor, Natrium, Calcium, alkalischer Phosphatase, LAP und γ-GT. Die meisten Befundänderungen lassen sich mit ei-ner anabolen Stoffwechsellage bei steigendem Testosteronspiegel und einer Mehrbelastung der Leberfunktion erklären. Bei mehr als der Hälfte von 41 sonographisch untersuchten Patienten ließ sich eine Zunahme des Hodenvolumens feststellen. Therapeutic Results with Tamoxifen in Oligozoospermia I. Remarks on Mode of Action and Metabolism Based on Clinical Findings and Laboratory Investigations Summary: 210 males with idiopathic oligozoospermia or oligo-astheno-teratozoosper-mia were treated with tamoxifen (2 times 10 resp. 2 times 20 mg daily) over a period of five months. Investigations which were performed concomitantly revealed no significant changes in body weight, blood pressure, blood sedimentation rate, red and white blood count including the number of thrombocytes. In the multi-analysis of serum we found significant differences within the normal range concerning the following parameters: crea-tinine, albumin, cholesterol, phosphorus, sodium, calcium, alkaline phosphatase, LAP and γ-GT. Most of those changes in serum values could be explained by an anabolic metabolism due to an increased testosterone level and by additional stress of the liver function. On 41 of those patients an ultrasonography of the testes was performed; in more than 50% the testicular volume increased during therapy with tamoxifen.

Zusammenfassung: Während einer 5monatigen Tamoxifentherapie (2 times 10 bzw. 2 times 20 mg/die) kommt es zu einem signifikanten Anstieg von Testosteron, LH, FSH, Östradiol, freiem Testosteron und SHBG. Der Prolaktinspiegel fällt ab. Im Ejakulat sinken innerhalb des Normwertes der pH-Wert und die Fruktose. Die Spermatozoendichte steigt signifikant an; dabei bleibt unsicher, ob mit 2 times 20 mg/die bessere Ergebnisse erzielt werden. Mit unseren bisherigen Untersuchungsmethoden war eine Auswahl der Patienten, die auf die Behandlung gut ansprechen, nicht möglich. Tamoxifen scheint bei normo-, aber auch bei hypo- und hypergonadotropen Patienten wirksam zu sein. Summary: Therapeutic Results with Tamoxifen in Oligozoospermia II. Hormonal Analysis and Semen Parameters During a five months lasting treatment with tamoxifen (2 times10 resp. 2 times 20 mg daily) a significant increase of testosterone, LH, FSH, estradiol, free testosterone and SHBG was found. The prolactin levels diminished. In semen analysis the values of pH and fructose decreased within the normal range. The sperm density increased significantly, but we could not ascertain whether a dosage of 2 times 20 mg/die will provide better therapeutic results. Furthermore the hormonal and seminal investigations described in this paper did not allow to predict those patients who would be good responders on tamoxifen therapy. Tamoxifen seems to be effective in normo-, but also in hypo- and hypergonado-tropic patients.

BACKGROUND: The Item Response Theory (IRT) is becoming increasingly popular for item analysis. Theoretical considerations and simulation studies suggest that parameter estimates will become precise only by utilizing many items in large samples. METHOD: A simulation study focusing on a single scale was performed on data with (a) n = 40, 60, 80, 120, 200, 300, 500, and 900 cases utilizing (b) 4, 8, 16, or 32 items. The items were (c) symmetrically distributed vs. skew (skewness 0, 1, and 2). Item loadings were (d) homogeneous vs. heterogeneous. Item loadings were (e) low vs. high. Half of the items had (f) a correlated error or not. The number of answering categories (g) was four vs. five. A total of 10% of each item had missing values. The ability-estimates from the IRT model and the simple sum score served as criteria for evaluating the results. RESULTS: The ability-estimate from the IRT model outperformed the sum score when there were many items, skewed distributed items, and the item loadings were heterogeneous and high. The sum score outperformed the ability-estimate when there were few items, nonskewed items, and homogeneous and low item loadings. However, convergence rates were partly low in small samples. Correlated errors affected, both negatively, the ability-estimate and the sum score. CONCLUSION: With skew item distributions and heterogeneous item loadings, utilizing an IRT model is recommended. However, with few items, many cases are required, conversely, with few cases many items. With few items and few cases, the sum score performs better.