32 research outputs found

    Enterprise Risk Management, Corporate Governance And Systemic Risk: Some Research Perspectives

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    The general goal of Enterprise Risk Management (ERM) processes is to generate economic value through the coverage of firm business risk, on the one hand, and by exploiting the positive side of uncertainty conditions, on the other hand. The increasing attention attributed to ERM in the creation of economic value has led to even greater interactions between risk management mechanisms and the corporate governance system. In other words, in the last two decades, the relationships between corporate governance and ERM increased since the ERM processes have been considered more and more as critical drivers to combine strategic objectives with relative low volatility of company performance. The basic idea is that a good corporate governance system must deal about specific risks along with their interactions and, at the same time, the firm’s business risk as a whole. Moreover, an efficient and effective ERM system provides clear information about linkages between strategic opportunities and risk exposure and offers tools able to manage in an optimal way the negative side of business risk (or downside risk) as wellas its positive side (or upside risk). Accordingly, extant studies concerning the relationships between ERM and corporate governance have been focusing on a micro-level of analyses (i.e., the individual organization) and, specifically, on a firm’s benefits that stem from the adoption of proper ERM processes that are consistent with corporate governance goals and are able to sustain the increase of economic value while maintaining a bearable business risk over time. From our initial analyses, a gap in literature arises. We argue that the interdependence between ERM and corporate governance may be analyzed from a broader point of view as well (i.e., the firm and its task environment composed by its suppliers, customers, and partners). In particular, our research idea is to enlarge traditional studies about interrelations between corporate governance and ERM taking into account whether such interrelations could be a driver of risk transfer from the focal organization to other organizations that belong to its task environment. Moreover, this study aims to deepen the mechanisms by which the transfer of risk from a focal organization to its task environment may foster the emergence of systemic risk, i.e., a macro risk coming from domino and/or network effects. Therefore, our paper aims to find new research areas by combining micro and macro issues tied to corporate governance, ERM and systemic risk. The starting point of our work is the three following assumptions: 1) The compliance of a firm to ERM processes as well as to corporate governance rules implies the reduction as much as possible of firm business risk; 2) The reduction of the firm business risk leads to externalizing the firm business risk through risk-sharing mechanisms; 3) The risk-sharing may arise like a driver of systemic risk especially in those industries featured by strong network interrelations. Starting from the above assumptions, the paper goal is to open a new research area which combines four academic fields (ERM, corporate governance, corporate finance, and macro-finance). So far, our initial findings tell us that the following research questions arise: RQ1: What are the conditions under which the transfer of business risk towards organizations that belong to a firm task environment is likely to become a source of systemic risk in a specific industry? RQ2: How does the capital structure of a focal firm affect its propensity to transfer business risk not only to commercial but also to financial stakeholders included in firm task environment? RQ3: How does the transfer of business risk influence the capital cost of the focal firm as well as of the organizations that absorbed such risk

    Rat pial microvascular responses to melatonin during bilateral common carotid artery occlusion and reperfusion

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    The present study assessed the in vivo rat pial microvascular responses induced by melatonin during brain hypoperfusion and reperfusion (RE) injury. Pial microcirculation of male Wistar rats was visualized by fluorescence microscopy through a closed cranial window. Hypoperfusion was induced by bilateral common carotid artery occlusion (BCCAO, 30 min); thereafter, pial microcirculation was observed for 60 min. Arteriolar diameter, permeability increase, leukocyte adhesion to venular walls, perfused capillary length (PCL), and capillary red blood cell velocity (V(RBC) ) were investigated by computerized methods. Melatonin (0.5, 1, 2 mg/kg b.w.) was intravenously administered 10 min before BCCAO and at the beginning of RE. Pial arterioles were classified in five orders according to diameter, length, and branchings. In control group, BCCAO caused decrease in order 2 arteriole diameter (by 17.5 ± 3.0% of baseline) that was reduced by 11.8 ± 1.2% of baseline at the end of RE, accompanied by marked leakage and leukocyte adhesion. PCL and capillary V(RBC) decreased. At the end of BCCAO, melatonin highest dosage caused order 2 arteriole diameter reduction by 4.6 ± 2.0% of baseline. At RE, melatonin at the lower dosages caused different arteriolar responses. The highest dosage caused dilation in order 2 arteriole by 8.0 ± 1.5% of baseline, preventing leakage and leukocyte adhesion, while PCL and V(RBC) increased. Luzindole (4 mg/kg b.w.) prior to melatonin caused order 2 arteriole constriction by 12.0 ± 1.5% of baseline at RE, while leakage, leukocyte adhesion, PCL and V(RBC) were not affected. Prazosin (1 mg/kg b.w.) prior to melatonin did not significantly change melatonin's effects. In conclusion, melatonin caused different responses during hypoperfusion and RE, modulating pial arteriolar tone likely by MT1 and MT2 melatonin receptors while preventing blood-brain barrier changes through its free radical scavenging action

    Protective Effects of Quercetin on Rat Pial Microvascular Changes during Transient Bilateral Common Carotid Artery Occlusion and Reperfusion

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    The aim of this study was to assess the in vivo effects of quercetin on pial microvascular responses during transient bilateral common carotid artery occlusion (BCCAO) and reperfusion. Rat pial microcirculation was visualized by fluorescence microscopy through a closed cranial window. Pial arterioles were classified in five orders of branchings. Capillaries were assigned order 0, the smallest arterioles order 1, and the largest ones order 5. In ischemic rats, 30 min BCCAO and 60 min reperfusion caused arteriolar diameter decrease (by 14.5 ± 3.3% of baseline in order 2), microvascular leakage [0.47 ± 0.04, normalized gray levels (NGL)], leukocyte adhesion in venules (9 ± 2/100 μm venular length, v.l./30 s), and reduction of capillary perfusion (by 40 ± 7% of baseline). Moreover, at the end of BCCAO and reperfusion there was a significant increase in reactive oxygen species (ROS) formation when compared with baseline. Quercetin highest dose determined dilation in all arteriolar orders (by 40 ± 4% of baseline in order 2) and prevented microvascular permeability (0.15 ± 0.02 NGL), leukocyte adhesion (3 ± 1/100 μm v.l./30 s) as well as ROS formation, while capillary perfusion was protected. Inhibition of endothelial nitric oxide synthase (NOS) prior to quercetin reduced arteriolar dilation (order 2 diameter increase by 10.3 ± 2.5% of baseline) and caused permeability increase (0.29 ± 0.03 NGL); inhibition of neuronal NOS or inducible NOS did not affect quercetin-induced effects. Inhibition of guanylyl cyclase prior to quercetin reversed the quercetin’s effects on pial arteriolar diameter and leakage. In conclusion, quercetin was able to protect pial microcirculation from ischemia–reperfusion damage inducing arteriolar dilation likely by nitric oxide release. Moreover, quercetin scavenger activity blunted ROS formation preserving the blood–brain barrier integrity

    Rat Pial Microvascular Responses to Transient Bilateral Common Carotid Artery Occlusion and Reperfusion: Quercetin’s Mechanism of Action

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    The aim of the present study was to assess quercetin’s mechanism of action in rat pial microvessels during transient bilateral common carotid artery occlusion (BCCAO) and reperfusion. Rat pial microcirculation was visualized using fluorescence microscopy through a closed cranial window. Pial arterioles were classified in five orders of branchings. In ischemic rats, 30 min BCCAO and 60 min reperfusion caused arteriolar diameter decrease, microvascular leakage, leukocyte adhesion in venules, and reduction of capillary perfusion. Quercetin highest dose determined dilation in all arteriolar orders, by 40 ± 4% of baseline in order 2 vessels, and prevented microvascular permeability [0.15 ± 0.02 normalized gray levels (NGL)], leukocyte adhesion, and capillary failure. Protein kinase C (PKC) inhibition exerted by chelerythrine prior to quercetin attenuated quercetin-induced effects: order 2 arterioles dilated by 19.0 ± 2.4% baseline, while there was an increase in permeability (0.40 ± 0.05 NGL) and leukocyte adhesion with a marked decrease in capillary perfusion. Tyrosine kinase (TK) inhibition by tyrphostin 47 prior to quercetin lessened smaller pial arterioles responses, dilating by 20.7 ± 2.5% of baseline, while leakage increased (0.39 ± 0.04 NGL) sustained by slight leukocyte adhesion and ameliorated capillary perfusion. Inhibition of endothelium nitric oxide synthase (eNOS) by NG-nitro-L-arginine-methyl ester (L-NAME) prior to PKC or TK reduced the quercetin’s effects on pial arteriolar diameter and leakage. eNOS inhibition by L-NAME reduced quercetin effects on pial arteriolar diameter and leakage. Finally, combined inhibition of PKC and TK prior to quercetin abolished quercetin-induced effects, decreasing eNOS expression, while blocking ATP-sensitive potassium (KATP) channels by glibenclamide suppressed arteriolar dilation. In conclusion, the protective effects of quercetin could be due to different mechanisms resulting in NO release throughout PKC and TK intracellular signaling pathway activation

    Long term remodeling of rat pial microcirculation after transient middle cerebral artery occlusion and reperfusion.

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    Objective: The aim of this study was to assess the in vivo structural and functional remodeling of pial arteriolar networks in the ischemic area of rats submitted to transient middle cerebral artery occlusion (MCAO) and different time intervals of reperfusion. Methods and results: Two closed cranial windows were implanted above the left and right parietal cortex to observe pial microcirculation by fluorescence microscopy. The geometric characteristics of pial arteriolar networks, permeability increase, leukocyte adhesion and capillary density were analyzed after 1 h or 1, 7, 14 or 28 days of reperfusion. MCAO and 1-hour reperfusion caused marked microvascular changes in pial networks. The necrotic core was devoid of vessels, while the penumbra area presented a few arterioles, capillaries and venules with severe neuronal damage. Penumbra microvascular permeability and leukocyte adhesion were pronounced. At 7 days of reperfusion, new pial arterioles were organized in anastomotic vessels, overlapping the ischemic core and in penetrating pial arterioles. Vascular remodeling caused different arteriolar rearrangement up to 28 days of reperfusion and animals gradually regained their motor and sensory functions. Conclusions: Transient MCAO-induced pial-network remodeling is characterized by arteriolar anastomotic arcades. Remodeling mechanisms appear to be accompanied by an increased expression of nitric oxide synthases
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