2,033 research outputs found

    Business Model Adaptation: Evidence of Lean Experimentation in Digital Startups

    Get PDF
    Digital startups frequently adapt their business model, but in doing so they face resource scarcity and need to “make-do” in validating and implementing their design changes at a practical level. We thus argue that digital startups employ a Lean Experimental approach when adapting their BM to contextual conditions. By means of an exploratory multiple-case study on Digital startups, this research investigates the factors driving the deployment of an experimental approach and proposing some factors that may drive differences in its application. Results suggest that most startups dealing with BM adaptation engage in experimentation practices that can be identified with the Lean Startup Approaches (LSAs), although with different extents of application. In this sense, startups move from scarce resource availability in resembling selected elements of the framework, whereas those with higher resource availability seem to be more prone to adopting LSAs in a structured and customized way at the organizational level

    Analysis of genetic distance between Peruvian Alpaca (Vicugna Pacos) showing two distinct fleece phenotypes, Suri and Huacaya, by means of microsatellite markers

    Get PDF
    Two coat phenotypes exist in Alpaca, Huacaya and Suri. The two coats show different fleece structure, textile characteristics and prices on the market. Although present scientific knowledge suggests a simple genetic model of inheritance, there is a tendency to manage and consider the two phenotypes as two different breeds. A 13 microsatellite panel was used in this study to assess genetic distance between Suri and Huacaya alpacas in a sample of non-related animals from two phenotypically pure flocks at the Illpa-Puno experimental station in Quimsachata, Peru. The animals are part of a germplasm established approximately 20 years ago and have been bred separately according to their coat type since then. Genetic variability parameters were also calculated. The data were statistically analyzed using the software Genalex 6.3, Phylip 3.69 and Fstat 2.9.3.2. The sample was tested for Hardy-Weinberg equilibrium (HWE) and after strict Bonferroni correction only one locus (LCA37) showed deviation from equilibrium (P<0.05). Linkage disequilibrium (LD) was also tested and 9 loci associations showed significant disequilibrium. Observed heterozygosis (Ho= 0.766; SE=0.044), expected heterozygosis (He=0.769; SE=0.033), number of alleles (Na=9.667, SE=0.772) and Fixation index (F=0.004; SE=0.036) are comparable to data from previous studies. Measures of genetic distance were 0.06 for Nei's and 0.03 for Cavalli-Sforza's. The analysis of molecular variance reported no existing variance between populations. Considering the origin of the animals, their post domestication evolution and the reproductive practices in place, the results do not show genetic differentiation between the two populations for the studied loci

    Analysis of genetic distance between Peruvian Alpaca (Vicugna Pacos) showing two distinct fleece phenotypes, Suri and Huacaya, by means of microsatellite markers

    Get PDF
    Two coat phenotypes exist in Alpaca, Huacaya and Suri. The two coats show different fleece structure, textile characteristics and prices on the market. Although present scientific knowledge suggests a simple genetic model of inheritance, there is a tendency to manage and consider the two phenotypes as two different breeds. A 13 microsatellite panel was used in this study to assess genetic distance between Suri and Huacaya alpacas in a sample of non-related animals from two phenotypically pure flocks at the Illpa-Puno experimental station in Quimsachata, Peru. The animals are part of a germplasm established approximately 20 years ago and have been bred separately according to their coat type since then. Genetic variability parameters were also calculated. The data were statistically analyzed using the software Genalex 6.3, Phylip 3.69 and Fstat 2.9.3.2. The sample was tested for Hardy-Weinberg equilibrium (HWE) and after strict Bonferroni correction only one locus (LCA37) showed deviation from equilibrium (P<0.05). Linkage disequilibrium (LD) was also tested and 9 loci associations showed significant disequilibrium. Observed heterozygosis (Ho= 0.766; SE=0.044), expected heterozygosis (He=0.769; SE=0.033), number of alleles (Na=9.667, SE=0.772) and Fixation index (F=0.004; SE=0.036) are comparable to data from previous studies. Measures of genetic distance were 0.06 for Nei’s and 0.03 for Cavalli-Sforza’s. The analysis of molecular variance reported no existing variance between populations. Considering the origin of the animals, their post domestication evolution and the reproductive practices in place, the results do not show genetic differentiation between the two populations for the studied loci

    Subcutaneous interferon β-1a in pediatric patients with multiple sclerosis: Regional differences in clinical features, disease management, and treatment outcomes in an international retrospective study

    Get PDF
    AbstractBackgroundTo further understand management of pediatric patients with multiple sclerosis (MS), we examined disease features, clinical practice patterns, and response to treatment in the United States (US) and seven other countries ('rest of World'; ROW).MethodsAnonymized data, recorded as part of routine clinical practice, were obtained from medical records (1997–2009) of study participants (who received subcutaneous interferon β-1a before age 18years) from the US and ROW. Samples were stratified by age (preadolescents [<12years] and adolescents [12–17years]).ResultsUS adolescents had a higher mean body mass index versus ROW adolescents (BMI; 27.2 versus 22.5kg/m2), started disease-modifying therapy (DMT) earlier after the first relapse, were more likely to have received a DMT before initiating subcutaneous interferon β-1a, had a higher relapse rate, and were more likely to switch from subcutaneous interferon β-1a to another DMT before the end of the observation period.ConclusionsThis retrospective analysis of a multinational sample of pediatric MS patients who received subcutaneous interferon β-1a found that those from the US had higher BMI, relapsed more frequently, and were managed differently, compared with ROW patients. Future prospective studies are needed to confirm these observations and ascertain their clinical significance

    Heterogeneity of Signal Transducer and Activator of Transcription Binding Sites in the Long-Terminal Repeats of Distinct HIV-1 Subtypes

    Get PDF
    HIV-1 can be subdivided into distinct subtypes; the consequences of such a genomic variability remain largely speculative. The long terminal repeats (LTR) control HIV transcription and reflect the major differences of distinct viral subtypes. Three regions in the HIV-1 subtype B LTR are close matches to the Signal Transducer and Activator of Transcription (STAT) consensus sequence. Here, we show heterogeneity in these putative STAT binding sites among HIV-1 LTR subtypes A through G. Transfection of constitutively activated STAT5 lead to transcriptional activation of HIV-1 expression in 293T cells transfected with a reporter assay driven by HIV-1 LTR subtype B. Constitutively activated STAT5 transactivated the LTR of various subtypes in U937 cells with different potency. These findings support and expand the potential relevance of STAT5 activation in HIV infection and may bear relevance for a differential regulation of latency and expression of different subtypes of HIV-1

    Subcutaneous Interferon Beta-1a inPediatric Multiple Sclerosis: A Retrospective Study

    Get PDF
    To expand current knowledge, we examined the safety and tolerability of subcutaneous interferon b-1a in patients with pediatriconset multiple sclerosis. Records from 307 patients who had received at least 1 injection of subcutaneous interferon b-1a for demyelinating events when aged younger than 18 years were reviewed. Overall, 168 (54.7%) patients had at least 1 prespecified medical event related to or under close monitoring with subcutaneous interferon b-1a or specific to pediatric patients, 184 (59.9%) had nonserious medical events related to treatment or of unknown causality, and 12 (3.9%) had serious medical events irrespective of causality. The most common laboratory abnormalities were increased alanine (74/195; 37.9%) and aspartate aminotransferase levels (59/194; 30.4%). Annualized relapse rates were 1.79 before treatment and 0.47 during treatment. In conclusion, adult doses of subcutaneous interferon b-1a (44 and 22 mg, 3 times weekly) were well tolerated in pediatric patients and were associated with reduced relapse rates

    A novel de novo dominant mutation in ISCU associated with mitochondrial myopathy

    Get PDF
    BACKGROUND: Hereditary myopathy with lactic acidosis and myopathy with deficiency of succinate dehydrogenase and aconitase are variants of a recessive disorder characterised by childhood-onset early fatigue, dyspnoea and palpitations on trivial exercise. The disease is non-progressive, but life-threatening episodes of widespread weakness, metabolic acidosis and rhabdomyolysis may occur. So far, this disease has been molecularly defined only in Swedish patients, all homozygous for a deep intronic splicing affecting mutation in ISCU encoding a scaffold protein for the assembly of iron-sulfur (Fe-S) clusters. A single Scandinavian family was identified with a different mutation, a missense change in compound heterozygosity with the common intronic mutation. The aim of the study was to identify the genetic defect in our proband. METHODS: A next-generation sequencing (NGS) approach was carried out on an Italian male who presented in childhood with ptosis, severe muscle weakness and exercise intolerance. His disease was slowly progressive, with partial recovery between episodes. Patient's specimens and yeast models were investigated. RESULTS: Histochemical and biochemical analyses on muscle biopsy showed multiple defects affecting mitochondrial respiratory chain complexes. We identified a single heterozygous mutation p.Gly96Val in ISCU, which was absent in DNA from his parents indicating a possible de novo dominant effect in the patient. Patient fibroblasts showed normal levels of ISCU protein and a few variably affected Fe-S cluster-dependent enzymes. Yeast studies confirmed both pathogenicity and dominance of the identified missense mutation. CONCLUSION: We describe the first heterozygous dominant mutation in ISCU which results in a phenotype reminiscent of the recessive disease previously reported.This work was supported by the TelethonItaly [GrantGGP15041]; the Pierfranco and Luisa Mariani Foundation; the MRC7QQR [201572020] grant; the ERC advanced grant [FP77322424]; the NRJ Foundation7Institut de France; the E7Rare project GENOMIT. RL acknowledges generous financial support from Deutsche Forschungsgemeinschaft [SFB 987 and SPP 1927] and the LOEWE program of state Hessen

    Angiogenic and anti-inflammatory properties of micro-fragmented fat tissue and its derived mesenchymal stromal cells.

    Get PDF
    BACKGROUND: Adipose-derived mesenchymal stromal cells (Ad-MSCs) are a promising tool for advanced cell-based therapies. They are routinely obtained enzymatically from fat lipoaspirate (LP) as SVF, and may undergo prolonged ex vivo expansion, with significant senescence and decline in multipotency. Besides, these techniques have complex regulatory issues, thus incurring in the compelling requirements of GMP guidelines. Hence, availability of a minimally manipulated, autologous adipose tissue would have remarkable biomedical and clinical relevance. For this reason, a new device, named Lipogems® (LG), has been developed. This ready-to-use adipose tissue cell derivate has been shown to have in vivo efficacy upon transplantation for ischemic and inflammatory diseases. To broaden our knowledge, we here investigated the angiogenic and anti-inflammatory properties of LG and its derived MSC (LG-MSCs) population. METHODS: Human LG samples and their LG-MSCs were analyzed by immunohistochemistry for pericyte, endothelial and mesenchymal stromal cell marker expression. Angiogenesis was investigated testing the conditioned media (CM) of LG (LG-CM) and LG-MSCs (LG-MSCs-CM) on cultured endothelial cells (HUVECs), evaluating proliferation, cord formation, and the expression of the adhesion molecules (AM) VCAM-1 and ICAM-1. The macrophage cell line U937 was used to evaluate the anti-inflammatory properties, such as migration, adhesion on HUVECs, and release of RANTES and MCP-1. RESULTS: Our results indicate that LG contained a very high number of mesenchymal cells expressing NG2 and CD146 (both pericyte markers) together with an abundant microvascular endothelial cell (mEC) population. Substantially, both LG-CM and LG-MSC-CM increased cord formation, inhibited endothelial ICAM-1 and VCAM-1 expression following TNFα stimulation, and slightly improved HUVEC proliferation. The addition of LG-CM and LG-MSC-CM strongly inhibited U937 migration upon stimulation with the chemokine MCP-1, reduced their adhesion on HUVECs and significantly suppressed the release of RANTES and MCP-1. CONCLUSIONS: Our data indicate that LG micro-fragmented adipose tissue retains either per se, or in its embedded MSCs content, the capacity to induce vascular stabilization and to inhibit several macrophage functions involved in inflammation
    corecore