Investment styles of islamic equity funds

We investigate the dynamics of investment styles of Islamic equity funds (IEFs), mainly through portfolio holdings. We rely on an unbiased survivorship sample of 224 active portfolios domiciled in 22 countries from 2004 to 2018 to shed new light on style concentration. IEFs are overwhelmingly skewed initially to value stocks in Islamic countries and growth stocks in non-Islamic countries. We find a subsequent shift from these styles to a more blended approach. Investments in Islamic countries shift from mid-cap to large-cap stocks, while those in non-Islamic countries remain in extremely large-cap stocks. The propensity of style shift is larger in asset type than in asset size. The style drift analyses show that most IEFs drift in style, with a more aggressive drift in Islamic countries than in their non-Islamic counterparts. They are more likely to alter their portfolio exposure in the sight of adverse outcomes. Implications of our results for faith-based investors and regulators are identified in the study.fals

Sukuk and bond dynamics in relation to exchange rate

Purpose: This study aims to contribute by expanding the existing literature on Sukuk return and volatility and exploring the implications of the Sukuk-exchange rate interactions. Design/methodology/approach: This study examines the dynamic interactions of Sukuk with exchange rate in 15 countries, employing the Wavelet approach that considers both time and investment horizons. Findings: The results reveal significant evolving coherence of Sukuk return and volatility with the underlying exchange rate. The relationship is more potent than what this study witnesses in their counterpart bond market. For Sukuk returns, the coherence is negative, whereas it is positive for volatility. Notably, the coherence is strong in the medium to long term and intensifies during extreme economic episodes, especially during the COVID-19 pandemic. These findings are further validated by comparing firm-level matched data for Sukuk and conventional bond. Originality/value: To the best of the authors’ knowledge, this is the first study that reports the dynamic relationship of Sukuk return and volatility with the underlying exchange rate in 15 countries. Collectively, this study unites valuable insights for faith-based active Islamic investors and cross-border portfolio managers

Unique attributes of cyanobacterial metabolism revealed by improved genome-scale metabolic modeling and essential gene analysis

The model cyanobacterium, Synechococcus elongatus PCC 7942, is a genetically tractable obligate phototroph that is being developed for the bioproduction of high-value chemicals. Genome-scale models (GEMs) have been successfully used to assess and engineer cellular metabolism; however, GEMs of phototrophic metabolism have been limited by the lack of experimental datasets for model validation and the challenges of incorporating photon uptake. Here, we develop a GEM of metabolism in S. elongatus using random barcode transposon site sequencing (RB-TnSeq) essential gene and physiological data specific to photoautotrophic metabolism. The model explicitly describes photon absorption and accounts for shading, resulting in the characteristic linear growth curve of photoautotrophs. GEM predictions of gene essentiality were compared with data obtained from recent dense-transposon mutagenesis experiments. This dataset allowed major improvements to the accuracy of the model. Furthermore, discrepancies between GEM predictions and the in vivo dataset revealed biological characteristics, such as the importance of a truncated, linear TCA pathway, low flux toward amino acid synthesis from photorespiration, and knowledge gaps within nucleotide metabolism. Coupling of strong experimental support and photoautotrophic modeling methods thus resulted in a highly accurate model of S. elongatus metabolism that highlights previously unknown areas of S. elongatus biology

Soft Poly(dimethylsiloxane) Elastomers from Architecture-Driven Entanglement Free Design

We fabricate soft, solvent-free polydimethylsiloxane (PDMS) elastomers by crosslinking bottlebrush polymers rather than linear polymers. We design the chemistry to allow commercially available linear PDMS precursors to deterministically form bottlebrush polymers, which are simultaneously crosslinked, enabling a one-step synthesis. The bottlebrush architecture prevents the formation of entanglements, resulting in elastomers with precisely controllable elastic moduli from ~1 to ~100 kPa, below the intrinsic lower limit of traditional elastomers. Moreover, the solvent-free nature of the soft PDMS elastomers enables a negligible contact adhesion compared to commercially available silicone products of similar stiffness. The exceptional combination of softness and negligible adhesiveness may greatly broaden the applications of PDMS elastomers in both industry and research

Microporous metal-organic framework with potential for carbon dioxide capture at ambient conditions

Carbon dioxide capture and separation are important industrial processes that allow the use of carbon dioxide for the production of a range of chemical products and materials, and to minimize the effects of carbon dioxide emission. Porous metal-organic frameworks are promising materials to achieve such separations and to replace current technologies, which use aqueous solvents to chemically absorb carbon dioxide. Here we show that a metal-organic frameworks (UTSA-16) displays high uptake (160 cm3 cm−3) of CO2 at ambient conditions, making it a potentially useful adsorbent material for post-combustion carbon dioxide capture and biogas stream purification. This has been further confirmed by simulated breakthrough experiments. The high storage capacities and selectivities of UTSA-16 for carbon dioxide capture are attributed to the optimal pore cages and the strong binding sites to carbon dioxide, which have been demonstrated by neutron diffraction studies