Epidemics of Liquidity Shortages in Interbank Markets

Financial contagion from liquidity shocks has being recently ascribed as a prominent driver of systemic risk in interbank lending markets. Building on standard compartment models used in epidemics, in this work we develop an EDB (Exposed-Distressed-Bankrupted) model for the dynamics of liquidity shocks reverberation between banks, and validate it on electronic market for interbank deposits data. We show that the interbank network was highly susceptible to liquidity contagion at the beginning of the 2007/2008 global financial crisis, and that the subsequent micro-prudential and liquidity hoarding policies adopted by banks increased the network resilience to systemic risk---yet with the undesired side effect of drying out liquidity from the market. We finally show that the individual riskiness of a bank is better captured by its network centrality than by its participation to the market, along with the currently debated concept of "too interconnected to fail"

Human brain evolution and the "Neuroevolutionary Time-depth Principle:" Implications for the Reclassification of fear-circuitry-related traits in DSM-V and for studying resilience to warzone-related posttraumatic stress disorder.

The DSM-III, DSM-IV, DSM-IV-TR and ICD-10 have judiciously minimized discussion of etiologies to distance clinical psychiatry from Freudian psychoanalysis. With this goal mostly achieved, discussion of etiological factors should be reintroduced into the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V). A research agenda for the DSM-V advocated the "development of a pathophysiologically based classification system". The author critically reviews the neuroevolutionary literature on stress-induced and fear circuitry disorders and related amygdala-driven, species-atypical fear behaviors of clinical severity in adult humans. Over 30 empirically testable/falsifiable predictions are presented. It is noted that in DSM-IV-TR and ICD-10, the classification of stress and fear circuitry disorders is neither mode-of-acquisition-based nor brain-evolution-based. For example, snake phobia (innate) and dog phobia (overconsolidational) are clustered together. Similarly, research on blood-injection-injury-type-specific phobia clusters two fears different in their innateness: 1) an arguably ontogenetic memory-trace-overconsolidation-based fear (hospital phobia) and 2) a hardwired (innate) fear of the sight of one's blood or a sharp object penetrating one's skin. Genetic architecture-charting of fear-circuitry-related traits has been challenging. Various, non-phenotype-based architectures can serve as targets for research. In this article, the author will propose one such alternative genetic architecture. This article was inspired by the following: A) Nesse's "Smoke-Detector Principle", B) the increasing suspicion that the "smooth" rather than "lumpy" distribution of complex psychiatric phenotypes (including fear-circuitry disorders) may in some cases be accounted for by oligogenic (and not necessarily polygenic) transmission, and C) insights from the initial sequence of the chimpanzee genome and comparison with the human genome by the Chimpanzee Sequencing and Analysis Consortium published in late 2005. Neuroevolutionary insights relevant to fear circuitry symptoms that primarily emerge overconsolidationally (especially Combat related Posttraumatic Stress Disorder) are presented. Also introduced is a human-evolution-based principle for clustering innate fear traits. The "Neuroevolutionary Time-depth Principle" of innate fears proposed in this article may be useful in the development of a neuroevolution-based taxonomic re-clustering of stress-triggered and fear-circuitry disorders in DSM-V. Four broad clusters of evolved fear circuits are proposed based on their time-depths: 1) Mesozoic (mammalian-wide) circuits hardwired by wild-type alleles driven to fixation by Mesozoic selective sweeps; 2) Cenozoic (simian-wide) circuits relevant to many specific phobias; 3) mid Paleolithic and upper Paleolithic (Homo sapiens-specific) circuits (arguably resulting mostly from mate-choice-driven stabilizing selection); 4) Neolithic circuits (arguably mostly related to stabilizing selection driven by gene-culture co-evolution). More importantly, the author presents evolutionary perspectives on warzone-related PTSD, Combat-Stress Reaction, Combat-related Stress, Operational-Stress, and other deployment-stress-induced symptoms. The Neuroevolutionary Time-depth Principle presented in this article may help explain the dissimilar stress-resilience levels following different types of acute threat to survival of oneself or one's progency (aka DSM-III and DSM-V PTSD Criterion-A events). PTSD rates following exposure to lethal inter-group violence (combat, warzone exposure or intentionally caused disasters such as terrorism) are usually 5-10 times higher than rates following large-scale natural disasters such as forest fires, floods, hurricanes, volcanic eruptions, and earthquakes. The author predicts that both intentionally-caused large-scale bioevent-disasters, as well as natural bioevents such as SARS and avian flu pandemics will be an exception and are likely to be followed by PTSD rates approaching those that follow warzone exposure. During bioevents, Amygdala-driven and locus-coeruleus-driven epidemic pseudosomatic symptoms may be an order of magnitude more common than infection-caused cytokine-driven symptoms. Implications for the red cross and FEMA are discussed. It is also argued that hospital phobia as well as dog phobia, bird phobia and bat phobia require re-taxonomization in DSM-V in a new "overconsolidational disorders" category anchored around PTSD. The overconsolidational spectrum category may be conceptualized as straddling the fear circuitry spectrum disorders and the affective spectrum disorders categories, and may be a category for which Pitman's secondary prevention propranolol regimen may be specifically indicated as a "morning after pill" intervention. Predictions are presented regarding obsessive-compulsive disorder (OCD) (e.g., female-pattern hoarding vs. male-pattern hoarding) and "culture-bound" acute anxiety symptoms (taijin-kyofusho, koro, shuk yang, shook yong, suo yang, rok-joo, jinjinia-bemar, karoshi, gwarosa, Voodoo death). Also discussed are insights relevant to pseudoneurological symptoms and to the forthcoming Dissociative-Conversive disorders category in DSM-V, including what the author terms fright-triggered acute pseudo-localized symptoms (i.e., pseudoparalysis, pseudocerebellar imbalance, psychogenic blindness, pseudoseizures, and epidemic sociogenic illness). Speculations based on studies of the human abnormal-spindle-like, microcephaly-associated (ASPM) gene, the microcephaly primary autosomal recessive (MCPH) gene, and the forkhead box p2 (FOXP2) gene are made and incorporated into what is termed "The pre-FOXP2 Hypothesis of Blood-Injection-Injury Phobia." Finally, the author argues for a non-reductionistic fusion of "distal (evolutionary) neurobiology" with clinical "proximal neurobiology," utilizing neurological heuristics. It is noted that the value of re-clustering fear traits based on behavioral ethology, human-phylogenomics-derived endophenotypes and on ontogenomics (gene-environment interactions) can be confirmed or disconfirmed using epidemiological or twin studies and psychiatric genomics

WHILE LABOUR HOARDING MAY BE OVER, INSIDERS’ CONTROL IS NOT. DETERMINANTS OF EMPLOYMENT GROWTH IN POLISH LARGE FIRMS, 1996-2001.

This paper examines the determinants of employment changes using a panel of Polish large firms during the period 1996-2001. We investigate the impact of wages, output growth, investment, firm size and sectors upon employment, focusing on the asymmetry hypothesis. We find that investment plays an important role in enhancing employment growth. We also notice that employment dynamics is not affected by alternative wages and therefore appears consistent with the ‘right to manage’ model. Furthermore, unlike the early transition period, we can confirm that employment adjusts to positive sales growth, not just to decline as found in studies on earlier periods (K?ll?, 1998). This reflects that labour hoarding can no longer be a factor, which decreased employment elasticity in times of positive demand shocks. Interestingly, large state companies appear to cut employment in response to output growth, when one controls for investment. A result, which may be consistent with the insiders (employee) control model.http://deepblue.lib.umich.edu/bitstream/2027.42/39979/3/wp593.pd

WHILE LABOUR HOARDING MAY BE OVER, INSIDERS’ CONTROL IS NOT. DETERMINANTS OF EMPLOYMENT GROWTH IN POLISH LARGE FIRMS, 1996-2001.

This paper examines the determinants of employment changes using a panel of Polish large firms during the period 1996-2001. We investigate the impact of wages, output growth, investment, firm size and sectors upon employment, focusing on the asymmetry hypothesis. We find that investment plays an important role in enhancing employment growth. We also notice that employment dynamics is not affected by alternative wages and therefore appears consistent with the ‘right to manage’ model. Furthermore, unlike the early transition period, we can confirm that employment adjusts to positive sales growth, not just to decline as found in studies on earlier periods (K?ll?, 1998). This reflects that labour hoarding can no longer be a factor, which decreased employment elasticity in times of positive demand shocks. Interestingly, large state companies appear to cut employment in response to output growth, when one controls for investment. A result, which may be consistent with the insiders (employee) control model.EMPLOYMENT, TRANSITION, ASSYMETRY, PRIVATISATION, INSIDERS

Balancing operating revenues and occupied refurbishment costs 2: a Space Syntax approach to locating hoardings

By placing hoardings in publicly accessible areas while carrying out phased occupied refurbishments, a contractor is temporarily redesigning that area. This reconfiguration affects the normal pedestrian flows through such areas. A technique for the analysis of such flows has been developed under a general area of research called Space Syntax. This demonstrates the extent to which visual barriers both constrain and promote pedestrian movement. The main analytical techniques used are Axial analysis and Visibility Graph Analysis which are based upon lines or areas of visibility. Empirical evidence is presented in observations carried out at London Victoria Station before and during a small refurbishment project involving the temporary closure of a single entrance. This evidence is in line with previous Space Syntax studies. The relationship between changes in the station configuration and visitor numbers to retail outlets suggests the need to place hoardings in such a way that both movement and browsing areas remain spatially separated but visually connected. This is also suggested by previous Space Syntax studies and is incorporated into a brief set of general guidelines for clients and contractors to assist the minimisation of disruption to pedestrian movement in publicly accessible areas

Towards an Improved Hoarding Procedure in a Mobile Environment

Frequent disconnection has been a critical issue in wireless network communication therefore causing excessive delay in data delivery. In this paper, we formulated a management mechanism based on computational optimization to achieve efficient and fast computation in order to reduce inherent delay during the hoarding process. The simulated result obtained is evaluated based on hoard size and delivery time. Keywords: Hoarding Procedure, Mobile computing Environment and Computational Optimization

Behavioral flexibility vs. rules of thumb: how do grey squirrels deal with conflicting risks?

In order to test how flexibly animals are able to behave when making trade-offs that involve assessing constantly changing risks, we examined whether wild Eastern grey squirrels showed flexibility of behavioral responses in the face of variation in two conflicting risks, cache pilferage and predation. We established that cache pilferage risk decreased with distance from cover, and was thus negatively correlated with long-term predation risk. We then measured changes in foraging and food caching behavior in the face of changes in the risk of predation and food theft over a short time-scale. We found that, overall, squirrels move further away from the safety of cover when they cache, compared to when they forage, as predicted by pilferage risk. However, there was no effect of immediate pilferage or predation risk (i.e. the presence of potential predators or pilferers) on the distance from cover at which they cached, and only a slight increase in forage distance when predation risk increased. These results suggest that ‘rules of thumb’ based on static cues may be more cost-effective for assessing risk than closely tracking changes over time in the way suggested by a number of models of risk assessment

Effects of bee density and sublethal imidacloprid exposure on cluster temperatures of caged honey bees

International audienceAbstractSurvivorship, syrup consumption, and cluster temperatures of honey bees were kept in hoarding cages with different numbers of bees. Cages with either 50, 100, 150, or 200 bees each were monitored over 4–6 weeks in incubators with 12h/12h 30° C/15° C temperature cycles to induce clustering. Survivorship and syrup consumption rates per bee were not different among the bee density groups, but cluster temperatures were. Cluster temperatures ranged from 0.45°C above incubator temperature in the 50 bee cages to 4.05° C in the 200 bee cages over the 1st 7 days, with each additional bee adding on average 0.02° C to cluster temperature. In another set of experiments, cages were established with about 200 bees each, and imidacloprid added to the syrup at 0, 5, 20, and 100 ppb. Imidacloprid in the syrup did not affect bee survivorship but it did reduce syrup consumption per bee, with bees fed 100 ppb imidacloprid syrup consuming on average 631 mg per bee over 28 days while average consumption among the other groups ranged from 853 to 914 mg. Cluster temperature was affected by imidacloprid treatment: bees fed 5 ppb imidacloprid syrup had higher cluster temperatures over the 1st 10 days, 4.17° C above incubator temperature, than either bees fed 100 ppb syrup or control (2.35 and 3.19° C, respectively)

Review of Some Transaction Models used in Mobile Databases

Mobile computing is presently experiencing a period of unprecedented growth with the convergence of communication and computing capabilities of mobile phones and personal digital assistant. However, mobile computing presents many inherent problems that lead to poor network connectivity. To overcome poor connectivity and reduce cost, mobile clients are forced to operate in disconnected and partially connected modes. One of the main goals of mobile data access is to reach the ubiquity inherent to the mobile systems: to access information regardless of time and place. Due to mobile systems restrictions such as, for instance, limited memory and narrow bandwidth, it is only natural that researchers expend efforts to soothe such issues. This work approaches the issues regarding the cache management in mobile databases, with emphasis in techniques to reduce cache faults while the mobile device is either connected, or with a narrow bandwidth, or disconnected at all. Thus, it is expected improve data availability while a disconnection. Here in the paper, we try to describe various mobile transaction models, focusing on versatile data sharing mechanisms in volatile mobile environments