What are Firms? Evolution from Birth to Public Companies

We study how firm characteristics evolve from early business plan to initial public offering to public company for 49 venture capital financed companies. The average time elapsed is almost 6 years. We describe the financial performance, business idea, point(s) of differentiation, non-human capital assets, growth strategy, customers, competitors, alliances, top management, ownership structure, and the board of directors. Our analysis focuses on the nature and stability of those flrIn attributes. Firm business lines remain remarkably stable from business plan through public company. Within those business lines, non-human capital aspects of the businesses appear more stable than human capital aspects. In the cross-section, firms with more alienable assets have substantially more human capital turnover.Theory of the firm; Entrepreneurship; Venture capital; Firm life cycle

An Optimal Number-Dependent Preventive Maintenance Strategy for Offshore Wind Turbine Blades Considering Logistics

In offshore wind turbines, the blades are among the most critical and expensive components that suffer from different types of damage due to the harsh maritime environment and high load. The blade damages can be categorized into two types: the minor damage, which only causes a loss in wind capture without resulting in any turbine stoppage, and the major (catastrophic) damage, which stops the wind turbine and can only be corrected by replacement. In this paper, we propose an optimal number-dependent preventive maintenance (NDPM) strategy, in which a maintenance team is transported with an ordinary or expedited lead time to the offshore platform at the occurrence of the Nth minor damage or the first major damage, whichever comes first. The long-run expected cost of the maintenance strategy is derived, and the necessary conditions for an optimal solution are obtained. Finally, the proposed model is tested on real data collected from an offshore wind farm database. Also, a sensitivity analysis is conducted in order to evaluate the effect of changes in the model parameters on the optimal solution

Polyamines: total daily intake in adolescents compared to the intake estimated from the Swedish Nutrition Recommendations Objectified (SNO)

Background: Dietary polyamines have been shown to give a significant contribution to the body pool of polyamines. Knowing the levels of polyamines (putrescine, spermidine, and spermine) in different foods and the contribution of daily food choice to polyamine intake is of interest, due to the association of these bioactive amines to health and disease. Objective: To estimate polyamine intake and food contribution to this intake in adolescents compared to a diet fulfilling the Swedish Nutrition Recommendations. Design: A cross-sectional study of dietary intake in adolescents and an ‘ideal diet’ (Swedish nutrition recommendations objectified [SNO]) list of foods was used to compute polyamine intake using a database of polyamine contents of foods. For polyamine intake estimation, 7-day weighed food records collected from 93 adolescents were entered into dietetic software (Dietist XP) including data on polyamine contents of foods. The content of polyamines in foods recommended according to SNO was entered in the same way. Results: The adolescents’ mean daily polyamine intake was 316±170 µmol/day, while the calculated contribution according to SNO was considerably higher with an average polyamine intake of 541 µmol/day. In both adolescent's intake and SNO, fruits contributed to almost half of the total polyamine intake. The reason why the intake among the adolescents was lower than the one calculated from SNO was mainly due to the low vegetable consumption in the adolescents group. Conclusions: The average daily total polyamine intake was similar to that previously reported in Europe. With an ‘ideal’ diet according to Swedish nutrition recommendations, the intake of this bioactive non-nutrient would be higher than that reported by our adolescents and also higher than that previously reported from Europe

Material valorisation of amorphous polylactide. Influence of thermo-mechanical degradation on the morphology, segmental dynamics, thermal and mechanical performance

This paper reports the effects of multiple mechanical recycling on the structure and properties of amorphous polylactide (PLA). The influence of the thermo-mechanical degradation induced by means of five successive injection cycles was initially addressed in terms of macroscopic mechanical properties and surface modification. A deeper inspection on the structure and morphology of PLA was associated to the thermal properties and viscoelastic behaviour. Although FT-IR analysis did not show significant changes in functional groups, a remarkable reduction in molar mass was found by viscometry. PLA remained amorphous throughout the reprocessing cycles, but the occurrence of a cold-crystallization during DSC and DMTA measurements, which enthalpy increased with each reprocessing step, suggested chain scission due to thermo-mechanical degradation. The effect of chain shortening on the glass-rubber relaxation studied by DMTA showed an increase in free volume affecting the segmental dynamics of PLA, particularly after the application of the second reprocessing step, in connection to the overall loss of performance showed by the remaining properties

Decoupling the Spread of Grasslands from the Evolution of Grazer-type Herbivores in South America

The evolution of high-crowned cheek teeth (hypsodonty) in herbivorous mammals during the late Cenozoic is classically regarded as an adaptive response to the near-global spread of grass-dominated habitats. Precocious hypsodonty in middle Eocene (~38 million years (Myr) ago) faunas from Patagonia, South America, is therefore thought to signal Earth’s first grasslands, 20 million years earlier than elsewhere. Here, using a high-resolution, 43–18 million-year record of plant silica (phytoliths) from Patagonia, we show that although open-habitat grasses existed in southern South America since the middle Eocene (~40 Myr ago), they were minor floral components in overall forested habitats between 40 and 18 Myr ago. Thus, distinctly different, continent-specific environmental conditions (arid grasslands versus ash-laden forests) triggered convergent cheek–tooth evolution in Cenozoic herbivores. Hypsodonty evolution is an important example where the present is an insufficient key to the past, and contextual information from fossils is vital for understanding processes of adaptation

Picropodophyllin causes mitotic arrest and catastrophe by depolymerizing microtubules via Insulin-like growth factor-1 receptor-independent mechanism

Picropodophyllin (PPP) is an anticancer drug undergoing clinical development in NSCLC. PPP has been shown to suppress IGF-1R signaling and to induce a G2/M cell cycle phase arrest but the exact mechanisms remain to be elucidated. The present study identified an IGF-1-independent mechanism of PPP leading to pro-metaphase arrest. The mitotic block was induced in human cancer cell lines and in an A549 xenograft mouse but did not occur in normal hepatocytes/mouse tissues. Cell cycle arrest by PPP occurred in vitro and in vivo accompanied by prominent CDK1 activation, and was IGF-1R-independent since it occurred also in IGF-1R-depleted and null cells. The tumor cells were not arrested in G2/M but in mitosis. Centrosome separation was prevented during mitotic entry, resulting in a monopolar mitotic spindle with subsequent prometaphase-arrest, independent of Plk1/Aurora A or Eg5, and leading to cell features of mitotic catastrophe. PPP also increased soluble tubulin and decreased spindle-associated tubulin within minutes, indicating that it interfered with microtubule dynamics. These results provide a novel IGF-1R-independent mechanism of antitumor effects of PPP

Polyamines in foods: development of a food database

Background: Knowing the levels of polyamines (putrescine, spermidine, and spermine) in different foods is of interest due to the association of these bioactive nutrients to health and diseases. There is a lack of relevant information on their contents in foods. Objective: To develop a food polyamine database from published data by which polyamine intake and food contribution to this intake can be estimated, and to determine the levels of polyamines in Swedish dairy products. Design: Extensive literature search and laboratory analysis of selected Swedish dairy products. Polyamine contents in foods were collected using an extensive literature search of databases. Polyamines in different types of Swedish dairy products (milk with different fat percentages, yogurt, cheeses, and sour milk) were determined using high performance liquid chromatography (HPLC) equipped with a UV detector. Results: Fruits and cheese were the highest sources of putrescine, while vegetables and meat products were found to be rich in spermidine and spermine, respectively. The content of polyamines in cheese varied considerably between studies. In analyzed Swedish dairy products, matured cheese had the highest total polyamine contents with values of 52.3, 1.2, and 2.6 mg/kg for putrescine, spermidine, and spermine, respectively. Low fat milk had higher putrescine and spermidine, 1.2 and 1.0 mg/kg, respectively, than the other types of milk. Conclusions: The database aids other researchers in their quest for information regarding polyamine intake from foods. Connecting the polyamine contents in food with the Swedish Food Database allows for estimation of polyamine contents per portion

Effect of the dissolution time into an acid hydrolytic solvent to taylor electrospun nanofibrous polycaprolactone scaffolds

The hydrolysis of the polycaprolactone (PCL) as a function of the dissolution time in a formic/ acetic acid mixture was considered as a method for tailoring the morphology of nanofibrous PCL scaffolds. Hence, the aim of this research was to establish a correlation between the dissolution time of the polymer in the acid solvent with the physicochemical properties of the electrospun nanofibrous scaffolds and their further service life behaviour. The physico-chemical properties of the scaffolds were assessed in terms of fibre morphology, molar mass and thermal behaviour. A reduction of the molar mass and the lamellar thickness as well as an increase of the crystallinity degree were observed as a function of dissolution time. Bead-free fibres were found after 24 and 48 h of dissolution time, with similar diameter distributions. The decrease of the fibre diameter distributions along with the apparition of beads was especially significant for scaffolds prepared after 72 h and 120 h of dissolution time in the acid mixture. The service life of the obtained devices was evaluated by means of in vitro validation under abiotic physiological conditions. All the scaffolds maintained the nanofibrous structure after 100 days of immersion in water and PBS. The molar mass was barely affected and the crystallinity degree and the lamellar thickness increased along immersion, preventing scaffolds from degradation. Scaffolds prepared after 24 h and 48 h kept their fibre diameters, whereas those prepared after 72 h and 120 h showed a significant reduction. This PCL tailoring procedure to obtain scaffolds that maintain the nanoscaled structure after such long in vitro evaluation will bring new opportunities in the design of longterm biomedical patches