The Role of Indirect Network Effects in Explaining Platform Dominance in the Video Game Industry (2002-2006): A Network Perspective

Going beyond the traditional operationalization of indirect network effects as the number of complements available, this study focuses on the network positions of platforms and complementors to explain platform dominance. We use data from the U.S. home video game industry between 2002 and 2006 to test our model. While the impact of degree of linkages with complementors is not significant, our findings support that platform dominance is positively influenced by a greater variety of links with complementors and lesser degree of overlap with other platforms. We find support for the impact of complementor dominance on platform dominance and that this impact decreases with platform age. Our results have important implications for research in indirect network effects and also important managerial implications. Platform providers need to focus on making their platforms more heterogeneous and providing the third party developers with toolkits that encourage them to develop titles exclusively for a platform

Reducing Heart Failure Readmission Rates Through Implementation of Heart Failure Diuretic

Background and significance: heart disease was the number one cause of death in the United States in 2021, with 696, 962 deaths (Leading Causes of Death, 2022). There are about 6.2 million individuals in the U.S. total with heart failure (Kilgore et al., 2017). About one-quarter of patients with heart failure are readmitted within thirty days of discharge, while one-quarter of hospital readmissions are preventable. Between 2010-2017, over seven million patients were admitted for heart failure in the United States. Eighteen percent had a readmission within thirty days and thirty-one percent had a readmission within ninety days (Khan et al., 2021). Within the Allegheny Health Network, about thirteen percent of patients were admitted with heart failure in 2021 (Kwansy, 2022). To reduce hospital readmissions in my health system, heart failure patients discharged with home health services received a home heart failure diuretic rescue kit (See Appendix A). The protocol for the kit called for the nurse to follow a specific stepwise protocol for administering diuretic therapy and potassium supplementation (See Appendix B). Purpose: The purpose of this project is to evaluate the effectiveness of the home heart failure intravenous diuretic kit to prevent the readmission of heart failure patients to the hospital within a thirty-day period. The goal is to establish if the kit helped reduce hospitalization to reduce economic burden and improve morbidity and mortality. Methods: The home heart failure kit and protocol were implemented on February 21, 2022. The data that was considered for evaluation includes ordering the kit through the electronic health record, distribution of the kit from the pharmacy to the patient, utilizing the kit and the heart failure protocol at home by the home health nurses, and the knowledge of heart failure symptoms by the patient

Fermented batter characteristics in relation with the sensory properties of idli

Idli is one of the very popular fermented breakfast foods in the Indian subcontinent, prepared from a cereal-legume mix of rice (Oryza sativa) and black gram dhal (Phaseolus mungo). It is a natural microflora fermentation dominated by lactic acid bacteria and yeasts. Reduction in fermentation time, quality standardization and enhancement of the idli batter is of great commercial importance for large scale idli production and this can be potentially achieved though better understanding of idli batter fermentation. The present study documents how the dynamics of microbial growth influence the batter characteristics and idli qualities like firmness, cohesiveness and springiness. The results show that the lactic acid bacteria (LAB) and yeast and mould (YM) counts influence the physico-chemical properties of idli batter and consequently the organoleptic qualities of prepared idli

Newly proposed classification of celiac artery variations based on embryology and correlation with computed tomography angiography

Purpose: We studied the prevalence of celiac trunk and its anatomical variations on diagnostic computed tomography angiography (CTA) studies and have proposed a new classification to define the celiac artery (CA) variations based on embryology. Material and methods: We retrospectively assessed the celiac trunk variations in 1113 patients who came to our department for diagnostic CTA for liver and renal donor workup. The patient data were acquired from the Picture Archiving and Communication System of our institutions. We analysed the celiac trunk’s origin and branching pattern, including the superior mesenteric artery (SMA) and inferior phrenic artery (IPA). Results: We evaluated the CTA studies of 1050 patients. A normal trifurcation pattern, the most common type, was observed in 39% of cases. Variation with CA + left IPA was the most common subtype. Other variations noted in the study and their incidences are listed in the table below. We attempted to propose a new classification based on embryology, which comprises 6 main types and their subtypes. We also analysed previous studies from the literature, including cadaveric, post-mortem, CTA, and digital subtraction angiography studies and compared them with the present study. Conclusions: Because variations of CA classifications reported to date do not encompass all CA branching pattern variants, we have proposed a new classification that incorporates most of the variants. We reiterate the clinical importance of anatomical variants of CA, IPA, and SMA in surgical and interventional radiology procedures

Sirtuin 6 inhibition protects against glucocorticoid-induced skeletal muscle atrophy by regulating IGF/PI3K/AKT signaling

Chronic activation of stress hormones such as glucocorticoids leads to skeletal muscle wasting in mammals. However, the molecular events that mediate glucocorticoid-induced muscle wasting are not well understood. Here, we show that SIRT6, a chromatin-associated deacetylase indirectly regulates glucocorticoid-induced muscle wasting by modulating IGF/PI3K/AKT signaling. Our results show that SIRT6 levels are increased during glucocorticoid-induced reduction of myotube size and during skeletal muscle atrophy in mice. Notably, overexpression of SIRT6 spontaneously decreases the size of primary myotubes in a cell-autonomous manner. On the other hand, SIRT6 depletion increases the diameter of myotubes and protects them against glucocorticoid-induced reduction in myotube size, which is associated with enhanced protein synthesis and repression of atrogenes. In line with this, we find that muscle-specific SIRT6 deficient mice are resistant to glucocorticoid-induced muscle wasting. Mechanistically, we find that SIRT6 deficiency hyperactivates IGF/PI3K/AKT signaling through c-Jun transcription factor-mediated increase in IGF2 expression. The increased activation, in turn, leads to nuclear exclusion and transcriptional repression of the FoxO transcription factor, a key activator of muscle atrophy. Further, we find that pharmacological inhibition of SIRT6 protects against glucocorticoid-induced muscle wasting in mice by regulating IGF/PI3K/AKT signaling implicating the role of SIRT6 in glucocorticoid-induced muscle atrophy.Fil: Mishra, Sneha. No especifíca;Fil: Cosentino, Claudia. Harvard Medical School; Estados UnidosFil: Tamta, Ankit Kumar. No especifíca;Fil: Khan, Danish. No especifíca;Fil: Srinivasan, Shalini. No especifíca;Fil: Ravi, Venkatraman. No especifíca;Fil: Abbotto, Elena. Università degli Studi di Genova; ItaliaFil: Arathi, Bangalore Prabhashankar. No especifíca;Fil: Kumar, Shweta. No especifíca;Fil: Jain, Aditi. No especifíca;Fil: Ramaian, Anand S.. No especifíca;Fil: Kizkekra, Shruti M.. No especifíca;Fil: Rajagopal, Raksha. No especifíca;Fil: Rao, Swathi. No especifíca;Fil: Krishna, Swati. No especifíca;Fil: Asirvatham Jeyaraj, Ninitha. Indian Institute of Technology; IndiaFil: Haggerty, Elizabeth R.. Harvard Medical School; Estados UnidosFil: Silberman, Dafne Magalí. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Kurland, Irwin J.. No especifíca;Fil: Veeranna, Ravindra P.. No especifíca;Fil: Jayavelu, Tamilselvan. No especifíca;Fil: Bruzzone, Santina. Università degli Studi di Genova; ItaliaFil: Mostoslavsky, Raul. Harvard Medical School; Estados UnidosFil: Sundaresan, Nagalingam R.. No especifíca

Between-strand disulfides: Forbidden disulfides linking adjacent ß-Strands

Between-strand disulfides (BSDs) connect cysteine (Cys) residues across adjacent strands of β-sheets. There are four BSD types which can be found in regular β-structure: CSDs, which link residues immediately opposite each other in the β-structure (residues i and j); ETDs, which connect Cys out of register by one residue (i and j ± 1); BDDs, which join Cys at positions i and j ± 2; and BFDs, which link residues i and j ± 3. Formation of these disulfides was initially predicted to be forbidden, producing too much local strain in the protein fold. However, BSDs do exist in nature. Significantly, their high levels of strain allow them to be involved in redox processes under physiological conditions. Here we characterise BSD motifs found in the Protein Data Bank (PDB), discussing important intrinsic factors, such as the disulfide conformation and torsional strain, and extrinsic factors, such as the influence of the β-sheet environment on the disulfide and vice versa. We also discuss the biological importance of BSDs, including the prevalence of non-homologous examples in the PDB, the conservation of BSD motifs amongst related proteins (BSD clusters) and experimental evidence for BSD redox activity. For clusters of homologous BSDs we present detailed data of the disulfide properties and the variations of these properties amongst the “redundant” structures. Identification of disulfides with the potential to be involved in biological redox processes via the analysis of these data will provide important insights into the function and mechanism of BSD-containing proteins. Characterisation of thiol-based redox signalling pathways will lead to significant breakthroughs in understanding the molecular basis of oxidative stress and associated pathways, such as ageing and neurodegenerative diseases

SIMS: A Hybrid Method for Rapid Conformational Analysis

Proteins are at the root of many biological functions, often performing complex tasks as the result of large changes in their structure. Describing the exact details of these conformational changes, however, remains a central challenge for computational biology due the enormous computational requirements of the problem. This has engendered the development of a rich variety of useful methods designed to answer specific questions at different levels of spatial, temporal, and energetic resolution. These methods fall largely into two classes: physically accurate, but computationally demanding methods and fast, approximate methods. We introduce here a new hybrid modeling tool, the Structured Intuitive Move Selector (SIMS), designed to bridge the divide between these two classes, while allowing the benefits of both to be seamlessly integrated into a single framework. This is achieved by applying a modern motion planning algorithm, borrowed from the field of robotics, in tandem with a well-established protein modeling library. SIMS can combine precise energy calculations with approximate or specialized conformational sampling routines to produce rapid, yet accurate, analysis of the large-scale conformational variability of protein systems. Several key advancements are shown, including the abstract use of generically defined moves (conformational sampling methods) and an expansive probabilistic conformational exploration. We present three example problems that SIMS is applied to and demonstrate a rapid solution for each. These include the automatic determination of ﾑﾑactiveﾒﾒ residues for the hinge-based system Cyanovirin-N, exploring conformational changes involving long-range coordinated motion between non-sequential residues in Ribose- Binding Protein, and the rapid discovery of a transient conformational state of Maltose-Binding Protein, previously only determined by Molecular Dynamics. For all cases we provide energetic validations using well-established energy fields, demonstrating this framework as a fast and accurate tool for the analysis of a wide range of protein flexibility problems

When guanxi meets structural holes : exploring the guanxi networks of Chinese entrepreneurs on digital platforms

In this exploratory study, we investigate how Chinese entrepreneurs on digital platforms interact and leverage guanxi (a system of relationships and social network) to buffer the negative impacts of structural holes on knowledge orchestration. We develop our research model and formulate ten hypotheses by drawing on the literature. We adopt a mixed-methods research approach in which we use quantitative surveys to test the hypotheses, and qualitative interviews to explain why certain relationships are stronger in one stage of entrepreneurial development than the other. The study contributes to the literature on digital entrepreneurship in two ways. First, this study offers an initial understanding of the dynamics of guanxi networks for knowledge mobilisation and knowledge coordination across start-up and growth stages of Chinese entrepreneurs on digital platforms. Second, by drawing on the relevant literature, our findings extend the current understanding of knowledge orchestration of digital entrepreneurs and contribute to the literatures of structural holes theory and guanxi

Fluorescent amino acids as versatile building blocks for chemical biology

Fluorophores have transformed the way we study biological systems, enabling non-invasive studies in cells and intact organisms, which increase our understanding of complex processes at the molecular level. Fluorescent amino acids have become an essential chemical tool because they can be used to construct fluorescent macromolecules, such as peptides and proteins, without disrupting their native biomolecular properties. Fluorescent and fluorogenic amino acids with unique photophysical properties have been designed for tracking protein–protein interactions in situ or imaging nanoscopic events in real time with high spatial resolution. In this Review, we discuss advances in the design and synthesis of fluorescent amino acids and how they have contributed to the field of chemical biology in the past 10 years. Important areas of research that we review include novel methodologies to synthesize building blocks with tunable spectral properties, their integration into peptide and protein scaffolds using site-specific genetic encoding and bioorthogonal approaches, and their application to design novel artificial proteins, as well as to investigate biological processes in cells by means of optical imaging. [Figure not available: see fulltext.]

SARS-CoV-2 B.1.617.2 Delta variant replication and immune evasion

Abstract: The B.1.617.2 (Delta) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first identified in the state of Maharashtra in late 2020 and spread throughout India, outcompeting pre-existing lineages including B.1.617.1 (Kappa) and B.1.1.7 (Alpha)1. In vitro, B.1.617.2 is sixfold less sensitive to serum neutralizing antibodies from recovered individuals, and eightfold less sensitive to vaccine-elicited antibodies, compared with wild-type Wuhan-1 bearing D614G. Serum neutralizing titres against B.1.617.2 were lower in ChAdOx1 vaccinees than in BNT162b2 vaccinees. B.1.617.2 spike pseudotyped viruses exhibited compromised sensitivity to monoclonal antibodies to the receptor-binding domain and the amino-terminal domain. B.1.617.2 demonstrated higher replication efficiency than B.1.1.7 in both airway organoid and human airway epithelial systems, associated with B.1.617.2 spike being in a predominantly cleaved state compared with B.1.1.7 spike. The B.1.617.2 spike protein was able to mediate highly efficient syncytium formation that was less sensitive to inhibition by neutralizing antibody, compared with that of wild-type spike. We also observed that B.1.617.2 had higher replication and spike-mediated entry than B.1.617.1, potentially explaining the B.1.617.2 dominance. In an analysis of more than 130 SARS-CoV-2-infected health care workers across three centres in India during a period of mixed lineage circulation, we observed reduced ChAdOx1 vaccine effectiveness against B.1.617.2 relative to non-B.1.617.2, with the caveat of possible residual confounding. Compromised vaccine efficacy against the highly fit and immune-evasive B.1.617.2 Delta variant warrants continued infection control measures in the post-vaccination era