Biased orientation games

We study biased {\em orientation games}, in which the board is the complete graph $K_n$, and Maker and Breaker take turns in directing previously undirected edges of $K_n$. At the end of the game, the obtained graph is a tournament. Maker wins if the tournament has some property $\mathcal P$ and Breaker wins otherwise. We provide bounds on the bias that is required for a Maker's win and for a Breaker's win in three different games. In the first game Maker wins if the obtained tournament has a cycle. The second game is Hamiltonicity, where Maker wins if the obtained tournament contains a Hamilton cycle. Finally, we consider the $H$-creation game, where Maker wins if the obtained tournament has a copy of some fixed graph $H$

Lenalidomide reduces microglial activation and behavioral deficits in a transgenic model of Parkinson's disease.

BackgroundParkinson's disease (PD) is one of the most common causes of dementia and motor deficits in the elderly. PD is characterized by the abnormal accumulation of the synaptic protein alpha-synuclein (α-syn) and degeneration of dopaminergic neurons in substantia nigra, which leads to neurodegeneration and neuroinflammation. Currently, there are no disease modifying alternatives for PD; however, targeting neuroinflammation might be a viable option for reducing motor deficits and neurodegeneration. Lenalidomide is a thalidomide derivative designed for reduced toxicity and increased immunomodulatory properties. Lenalidomide has shown protective effects in an animal model of amyotrophic lateral sclerosis, and its mechanism of action involves modulation of cytokine production and inhibition of NF-κB signaling.MethodsIn order to assess the effect of lenalidomide in an animal model of PD, mThy1-α-syn transgenic mice were treated with lenalidomide or the parent molecule thalidomide at 100 mg/kg for 4 weeks.ResultsLenalidomide reduced motor behavioral deficits and ameliorated dopaminergic fiber loss in the striatum. This protective action was accompanied by a reduction in microgliosis both in striatum and hippocampus. Central expression of pro-inflammatory cytokines was diminished in lenalidomide-treated transgenic animals, together with reduction in NF-κB activation.ConclusionThese results support the therapeutic potential of lenalidomide for reducing maladaptive neuroinflammation in PD and related neuropathologies

Unpacking the political legitimacy of parliament in an emerging democracy: the case of Malawi, 1994 to 2011

Thesis submitted in fulfilment of the requirements for the Degree of Doctor of Philosophy in Political Science Graduate School for Humanities and Social Sciences University of the WitwatersrandPolitical legitimacy manifests differently in different state institutions, and comprehending its dynamics is a prerequisite to understanding power, authority, capacity, consolidation, and sustainability of any political regime. Supported by evidence from a case study of the Malawian parliament from 1994 to 2011, my original contribution to knowledge is that political legitimacy of representative institutions in emerging democracies has three minimum dimensions, namely: public perception of the acceptability and fairness of formal procedures guiding a representative institution; public emotional attachment to the institution; and public perception of performance effectiveness of the institution. I label these dimensions as juridical; symbolic; and instrumental legitimacy respectively. I therefore posit that, deficiency in any or some of the three legitimacy dimensions has the potential to compel those represented, who may be self-confessed democrats, to demand institutional reforms that ironically may go against the very tenets of multi-party democracy. The Malawi parliament case shows that legitimacy deficiency of parliament seems to be facilitated by public dissatisfaction with their local socioeconomic status, in the context of a dysfunctional local government, and coupled with the public perception of parliament as a responsible institution given its status in the perceived representation hierarchy that places it above the local government. This situation is aggravated given the fact that Malawi parliament, rightly so, is neither institutionally nor financially supported to directly address local development issues; and that, erroneously, the parliament is neither institutionally nor financially supported to effectively carry out its representation function despite representation carrying the status of a meta-function. The lack of political will for public consultations and lack of intra-party democracy in political parties represented in parliament has also tremendously eroded the influence of political parties hence further undermining the legitimacy of the whole multi-party regime. Using principles of external validity in case study research therefore, the Malawian case study provides analytical insights that can be extrapolated to understand political legitimacy of representative institutions in other emerging democracies that have similar context to that of Malawi

High-frequency oscillatory ventilation in pediatric acute hypoxemic respiratory failure: disease-specific morbidity survival analysis.

BackgroundMultiple ventilatory strategies for acute hypoxemic respiratory failure (AHRF) in children have been advocated, including high-frequency oscillatory ventilation (HFOV). Despite the frequent deployment of HFOV, randomized controlled trials remain elusive and currently there are no pediatric trials looking at its use. Our longitudinal study analyzed the predictive clinical outcome of HFOV in pediatric AHRF given disease-specific morbidity.MethodsA retrospective 8-year review on pediatric intensive care unit admissions with AHRF ventilated by HFOV was performed. Primary outcomes included survival, morbidity, length of stay (LOS), and factors associated with survival or mortality.ResultsA total of 102 patients underwent HFOV with a 66 % overall survival rate. Survivors had a greater LOS than nonsurvivors (p = 0.001). Mortality odds ratio (OR) for patients without bronchiolitis was 8.19 (CI = 1.02, 65.43), and without pneumonia it was 3.07 (CI = 1.12, 8.39). A lower oxygenation index (OI) after HFOV commencement and at subsequent time points analyzed predicted survival. After 24 h, mortality was associated with an OI > 35 [OR = 31.11 (CI = 3.25, 297.98)]. Sepsis-related mortality was associated with a higher baseline FiO(2) (0.88 vs. 0.65), higher OI (42 vs. 22), and augmented metabolic acidosis (pH of 7.25 vs. 7.32) evaluated 4 h on HFOV (p < 0.05).ConclusionHigh-frequency oscillatory ventilation may be safely utilized. It has a 66 % overall survival rate in pediatric AHRF of various etiologies. Patients with morbidity limited to the respiratory system and optimized oxygenation indices are most likely to survive on HFOV

The bi-conical vector model at 1/N1/N

We study finite $N$ aspects of the $O(m)\times O(N-m)$ vector model with quartic interactions in general $2\leq d \leq 6$ spacetime dimensions. This model has recently been shown to display the phenomenon of persistent symmetry breaking at a perturbative Wilson-Fisher-like fixed point in $d=4-\epsilon$ dimensions. The large rank limit of the bi-conical model displays a conformal manifold and a moduli space of vacua. We find a set of three double trace scalar operators that are respectively irrelevant, relevant and marginal deformations of the conformal manifold in general $d$. We calculate the anomalous dimensions of the single and multi-trace scalar operators to the first sub-leading order in the large rank expansion. The anomalous dimension of the marginal operator does not vanish in general, indicating that the conformal manifold is lifted at finite $N$. In the case of equal ranks we are able to derive explicitly the scaling dimensions of various operators as functions of only $d$.Comment: 35 pages, 47 figure

Neuroprotective effects of Cerebrolysin in triple repeat Tau transgenic model of Pick's disease and fronto-temporal tauopathies.

BackgroundTauopathies are a group of neurodegenerative disorders with accumulation of three-repeat (3R) or four-repeat (4R) Tau. While 3R tau is found in Pick's disease and Alzheimer's disease (AD), 4R tau is more abundant in corticobasal degeneration, progressive supranuclear palsy, and AD. We have previously shown that Cerebrolysin™ (CBL), a neuropeptide mixture with neurotrophic effects, ameliorates the pathology in amyloid precursor protein transgenic (tg) mouse model of AD and 4R tau, however it is unclear if CBL ameliorates the deficits and neuropathology in the mouse model of Pick's disease over expressing 3R tau.ResultsMice expressing 3R tau (L266V and G272V mutations) under the mThy-1 promoter were treated with CBL in two separate groups, the first was 3 months old (treated for 3 months, IP) and the second was 6 months old (treated for 3 months, IP) at the start of the treatment. We found that although the levels of total 3R tau were unchanged, CBL reduced the levels of hyper-phosphorylated tau in both groups of mice. This was accompanied by reduced neurodegenerative pathology in the neocortex and hippocampus in both groups and by improvements in the behavioral deficits in the nest-building test and water maze in the 3-6 month group.ConclusionTaken together these results support the notion that CBL may be beneficial in other taupathy models by reducing the levels of aberrantly phosphorylated tau