Coopetition of software firms in Open source software ecosystems

Software firms participate in an ecosystem as a part of their innovation strategy to extend value creation beyond the firms boundary. Participation in an open and independent environment also implies the competition among firms with similar business models and targeted markets. Hence, firms need to consider potential opportunities and challenges upfront. This study explores how software firms interact with others in OSS ecosystems from a coopetition perspective. We performed a quantitative and qualitative analysis of three OSS projects. Finding shows that software firms emphasize the co-creation of common value and partly react to the potential competitiveness on OSS ecosystems. Six themes about coopetition were identified, including spanning gatekeepers, securing communication, open-core sourcing and filtering shared code. Our work contributes to software engineering research with a rich description of coopetition in OSS ecosystems. Moreover, we also come up with several implications for software firms in pursing a harmony participation in OSS ecosystems.Comment: This is the author's version of the work. Copyright owner's version can be accessed at https://link.springer.com/chapter/10.1007/978-3-319-69191-6_10, Coopetition of software firms in Open source software ecosystems, 8th ICSOB 2017, Essen, Germany (2017

Schiff Base Complexes of Copper(II)

The crystal structures of four Schiff base molecules are presented, one of which is a re-appraisal of a previously reported structure. Crystals of N,N\u27-1,2-phenylene-bis(salicylideneiminato)copper(II) have been grown from both chloroform and pyridine. The structure from chloroform shows two crystallographically distinct squareplanar molecules per asymmetric unit in an orthorhombic cell, a = 20.159(2), b = 14.918(1), c = 13.329(1) Å; space group Pna21. Two different stereochemistries are observed when pyridine is the solvent. One has square planar geometry and the other square pyramidal with a pyridine molecule bound in the fifth co-ordination site. The space group is P1 with a = 8.748(4), b = 14.499(4), c = 18.725(5) Å, α = 109.93(3), β = 91.99(2), γ = 101.64(3)°. Bis(N-phenyl pyridoxylideneiminato)copper(II) crystallises in a monoclinic cell, space group P21/c, a = 5.7037(6), b = 20.394(1), c = 10.6321(6) Å, β = 101.443(6)° with the trans square planar co-ordination geometry. In the re-appraised structure of aqua(5-phosphopyridoxylidene-DLphenylalanineato) copper(II) the complex is square pyramidal with two oxygen and one nitrogen donor from the ligand. The fourth site is occupied by a water molecule and the fifth, apical donor is a phosphate oxygen from an adjacent molecule. The space group is triclinic P1 with a = 8.697(2), b = 13.039(3), c = 12.418(3) Å, α = 110.49(2), β = 108.61(2), γ = 63.65(10)°

Towards identifying malnutrition among infants under 6 months: a mixed methods study of South-Sudanese refugees in Ethiopia

Objectives: To determine (i) whether distinct groups of infants under 6 months old (U6M) were identifiable as malnourished based on anthropometric measures and if so to determine the probability of admittance to GOAL Ethiopia’s Management of At Risk Mothers and Infants (MAMI) programme based on group membership; (ii) whether there were discrepancies in admission using recognised anthropometric criteria, compared with group membership and (iii) the barriers and potential solutions to identifying malnutrition within U6M. Design: Mixed-methods approaches were used, whereby data collected by GOAL Ethiopia underwent: factor mixture modelling, χ 2 analysis and logistic regression analysis. Qualitative analysis was performed through coding of key informant interviews. Setting: Data were collected in two refugee camps in Ethiopia. Key informant interviews were conducted remotely with international MAMI programmers and nutrition experts. Participants: Participants were 3444 South-Sudanese U6M and eleven key informants experienced in MAMI programming. Results: Well-nourished and malnourished groups were identified, with notable discrepancies between group membership and MAMI programme admittance. Despite weight for age z-scores (WAZ) emerging as the most discriminant measure to identify malnutrition, admittance was most strongly associated with mid-upper arm circumference (MUAC). Misconceptions surrounding malnutrition, a dearth of evidence and issues with the current identification protocol emerged as barriers to identifying malnutrition among U6M. Conclusions: Our model suggests that WAZ is the most discriminating anthropometric measure for malnutrition in this population. However, the challenges of using WAZ should be weighed up against the more scalable, but potentially overly sensitive and less accurate use of MUAC among U6M

Precise, high-throughput production of multicellular spheroids with a bespoke 3D bioprinter

3D in vitro cancer models are important therapeutic and biological discovery tools, yet formation of multicellular spheroids in a throughput and highly controlled manner to achieve robust and statistically relevant data, remains challenging. Here, we developed an enabling technology consisting of a bespoke drop-on-demand 3D bioprinter capable of high-throughput printing of 96-well plates of spheroids. 3D-multicellular spheroids are embedded inside a tissue-like matrix with precise control over size and cell number. Application of 3D bioprinting for high-throughput drug screening was demonstrated with doxorubicin. Measurements showed that IC 50 values were sensitive to spheroid size, embedding and how spheroids conform to the embedding, revealing parameters shaping biological responses in these models. Our study demonstrates the potential of 3D bioprinting as a robust high-throughput platform to screen biological and therapeutic parameters. Significance Statement In vitro 3D cell cultures serve as more realistic models, compared to 2D cell culture, for understanding diverse biology and for drug discovery. Preparing 3D cell cultures with defined parameters is challenging, with significant failure rates when embedding 3D multicellular spheroids into extracellular mimics. Here, we report a new 3D bioprinter we developed in conjunction with bioinks to allow 3D-multicellular spheroids to be produced in a high-throughput manner. High-throughput production of embedded multicellular spheroids allowed entire drug-dose responses to be performed in 96-well plate format with statistically relevant numbers of data points. We have deconvoluted important parameters in drug responses including the impact of spheroid size and embedding in an extracellular matrix mimic on IC 50 values

Self-Doping of Gold Chains on Silicon: A New Structural Model for Si(111)5x2-Au

A new structural model for the Si(111)5x2-Au reconstruction is proposed and analyzed using first-principles calculations. The basic model consists of a "double honeycomb chain" decorated by Si adatoms. The 5x1 periodicity of the honeycomb chains is doubled by the presence of a half-occupied row of Si atoms that partially rebonds the chains. Additional adatoms supply electrons that dope the parent band structure and stabilize the period doubling; the optimal doping corresponds to one adatom per four 5x2 cells, in agreement with experiment. All the main features observed in scanning tunneling microscopy and photoemission are well reproduced.Comment: 4 pages, 4 figures, to appear in Phys. Rev. Lett. (preprint with high quality figures available at http://cst-www.nrl.navy.mil/~erwin/papers/ausi111

Appropriateness of strategy comparisons in cost-effectiveness analyses of infant pneumococcal vaccination: a systematic review

Objectives: Cost-effectiveness analysis (CEA) is the standard framework for informing the efficient allocation of scarce healthcare resources. The importance of considering all relevant intervention strategies and appropriate incremental comparisons have both long been recognized in CEA. Failure to apply methods correctly can lead to suboptimal policies. Our objective is to assess if CEAs of infant pneumococcal vaccination apply appropriate methods with respect to the completeness of strategies assessed and incremental comparisons between them. Methods: We conducted a systematic search of the PubMed, Scopus, Embase, and Web of Science databases and performed a comparative analysis of the retrieved pneumococcal vaccination CEAs. We checked the appropriateness of the incremental analyses by attempting to replicate the published incremental cost-effectiveness (CE) ratios from the reported costs and health effects. Results: Our search returned twenty-nine eligible articles. Most studies failed to recognize one or more intervention strategies (n = 21). Incremental comparisons were questionable in four CEAs and insufficient reporting of cost and health effect estimates was identified in three studies. Overall, we only found four studies that made appropriate comparisons between all strategies. Lastly, study findings appear to be strongly associated with manufacturer sponsorship. Conclusions: We found considerable scope for improvement regarding strategy comparison in the infant pneumococcal vaccination literature. To prevent overestimation of the CE of new vaccines, we urge greater adherence to existing guidelines recommending that all available strategies are evaluated to capture relevant comparators for CE evaluation. Closer adherence to existing guidelines will generate better evidence, leading to more effective vaccination policies

Highly ordered tailored three-dimensional hierarchical nano/microporous gold–carbon architectures

The preparation and characterization of three-dimensional hierarchical architectures, consisting of monolithic nanoporous gold or silver films formed on highly ordered 3D microporous carbon supports, are described. The formation of these nano/microporous structures involves the electrodeposition or sputtering of metal alloys onto the lithographically patterned multi-layered microporous carbon, followed by preferential chemical dealloying of the less noble component. The resulting hierarchical structure displays a highly developed 3D interconnected network of micropores with a nanoporous metal coating. Tailoring the nanoporosity of the metal films and the diameter of the large micropores has been accomplished by systematically changing the alloy compositions via control of the deposition potential, plating solution and coarsening time. SEM imaging illustrates the formation of unique biomimetic nanocoral- or nanocauliflower-like self-supporting structures, depending on the specific preparation conditions. The new 3D hierarchical nano/microporous architectures allow for enhanced mass transport and catalytic activity compared to common nanoporous films prepared on planar substrates. The functionality of this new carbon–gold hierarchical structure is illustrated for the greatly enhanced performance of enzymatic biofuel cells where a substantially higher power output is observed compared to the bare microporous carbon substrate