Prepare for the Expected Worst: Algorithms for Reconfigurable Resources Under Uncertainty

In this paper we study how to optimally balance cheap inflexible resources with more expensive, reconfigurable resources despite uncertainty in the input problem. Specifically, we introduce the MinEMax model to study "build versus rent" problems. In our model different scenarios appear independently. Before knowing which scenarios appear, we may build rigid resources that cannot be changed for different scenarios. Once we know which scenarios appear, we are allowed to rent reconfigurable but expensive resources to use across scenarios. Although computing the objective in our model might seem to require enumerating exponentially-many possibilities, we show it is well estimated by a surrogate objective which is representable by a polynomial-size LP. In this surrogate objective we pay for each scenario only to the extent that it exceeds a certain threshold. Using this objective we design algorithms that approximately-optimally balance inflexible and reconfigurable resources for several NP-hard covering problems. For example, we study variants of minimum spanning and Steiner trees, minimum cuts, and facility location. Up to constants, our approximation guarantees match those of previously-studied algorithms for demand-robust and stochastic two-stage models. Lastly, we demonstrate that our problem is sufficiently general to smoothly interpolate between previous demand-robust and stochastic two-stage problems

Development of concurrent infection of notoedric mange in rabbits infected with Trypanosoma evansi

This report describes observations on the development of cutaneous lesions in rabbits experimentally infected with Trypanosoma evansi. Skinscrapings revealed the presence of different developmental stages of Notoedres cati var. cuniculi and the animals were successfully treated by combined anti-Trypanosoma (diminazene aceturate @ 3.5 mg.kg-1body weight) and acaricid treatments (doramectin @ 400mg.kg-1body weight). T. evansi infection probably made the rabbits more prone to infection of notoedric mange and doramectin proved to be effective, practical and well tolerated means of treatment

Dimension Reduction via Colour Refinement

Colour refinement is a basic algorithmic routine for graph isomorphism testing, appearing as a subroutine in almost all practical isomorphism solvers. It partitions the vertices of a graph into "colour classes" in such a way that all vertices in the same colour class have the same number of neighbours in every colour class. Tinhofer (Disc. App. Math., 1991), Ramana, Scheinerman, and Ullman (Disc. Math., 1994) and Godsil (Lin. Alg. and its App., 1997) established a tight correspondence between colour refinement and fractional isomorphisms of graphs, which are solutions to the LP relaxation of a natural ILP formulation of graph isomorphism. We introduce a version of colour refinement for matrices and extend existing quasilinear algorithms for computing the colour classes. Then we generalise the correspondence between colour refinement and fractional automorphisms and develop a theory of fractional automorphisms and isomorphisms of matrices. We apply our results to reduce the dimensions of systems of linear equations and linear programs. Specifically, we show that any given LP L can efficiently be transformed into a (potentially) smaller LP L' whose number of variables and constraints is the number of colour classes of the colour refinement algorithm, applied to a matrix associated with the LP. The transformation is such that we can easily (by a linear mapping) map both feasible and optimal solutions back and forth between the two LPs. We demonstrate empirically that colour refinement can indeed greatly reduce the cost of solving linear programs

Nonlinear dynamics of the interface of dielectric liquids in a strong electric field: Reduced equations of motion

The evolution of the interface between two ideal dielectric liquids in a strong vertical electric field is studied. It is found that a particular flow regime, for which the velocity potential and the electric field potential are linearly dependent functions, is possible if the ratio of the permittivities of liquids is inversely proportional to the ratio of their densities. The corresponding reduced equations for interface motion are derived. In the limit of small density ratio, these equations coincide with the well-known equations describing the Laplacian growth.Comment: 10 page

Macro/micro observational studies of fibres maintaining the biceps brachii tendon in the bicipital groove: application to surgery, pathology and kinesiology

Background: There is controversy over the nature of tissues covering the bicipital groove protecting the biceps brachii tendon from dislocation/subluxation causing shoulder pain. Recent researches on cadaveric dissection and histological studies have changed the old concept of the transverse humeral ligament covering the bicipital groove to tendinous fibres of the subscapularis or interdigitating fibres of the subscapularis and supraspinatus. The change has not been incorporated into standard text books of anatomy. Therefore, the aim of the study is to support the new or old concept. Materials and methods: Eighteen embalmed shoulders were dissected to determine the nature of the tissues over the bicipital groove. Tissues from 4 shoulders were processed and 16 histological slides were examined for fibre types. Theoretical analysis of ligament and tendon has also been carried out. Results: The dissection study revealed that the tissues over the bicipital groove were tendinous fibres of subscapularis/interdigitating fibres of the subscapularis and supraspinatus and fibrous expansions from the posterior lamina of the pectoralis major. This was supported by the histological slides which showed the signatures of collagen fibres with the characteristics of tendinous fibres. Conclusions: No separate anatomical entity such as the transverse humeral ligament was detected in this study. Thus present study supports the view that the tissues covering the bicipital groove were formed by tendinous rather than ligamentous fibres

Comparison among some well known control schemes with different tuning methods

AbstractThis paper presents a comparison between some well-known control schemes such as feedback, feedback plus feed-forward, cascade and cascade plus feed-forward for controlling a third-order process. The controller applied in various control schemes is a PID controller that has been tuned using Ziegler Nichols (ZN) and relay auto-tuning (RA) methods. The comparative analysis is based upon various performance measures such as rise time (tr), settling time (ts), maximum overshoot (Mp), steady-state error (ess), integral of absolute error (IAE), integral of square error (ISE), integral of time square error (ITSE), and integral of time absolute error (ITAE). Simulation results show that the RA method provides superior performance in case of feedback plus feed-forward and cascade control schemes. On the other hand, the ZN method proves to be better in case of cascade plus feed-forward control scheme

Micro-RNA-1 is decreased by hypoxia and contributes to the development of pulmonary vascular remodeling via regulation of sphingosine kinase 1

Sphingosine kinase 1 (SphK1) upregulation is associated with pathologic pulmonary vascular remodeling in pulmonary arterial hypertension (PAH), but the mechanisms controlling its expression are undefined. In this study, we sought to characterize the regulation of SphK1 expression by micro-RNAs (miRs). In silico analysis of the SphK1 3'-untranslated region identified several putative miR binding sites, with miR-1-3p (miR-1) being the most highly predicted target. Therefore we further investigated the role of miR-1 in modulating SphK1 expression and characterized its effects on the phenotype of pulmonary artery smooth muscle cells (PASMCs) and the development of experimental pulmonary hypertension in vivo. Our results demonstrate that miR-1 is downregulated by hypoxia in PASMCs and can directly inhibit SphK1 expression. Overexpression of miR-1 in human PASMCs inhibits basal and hypoxia-induced proliferation and migration. Human PASMCs isolated from PAH patients exhibit reduced miR-1 expression. We also demonstrate that miR-1 is downregulated in mouse lung tissues during experimental hypoxia-mediated pulmonary hypertension (HPH), consistent with upregulation of SphK1. Furthermore, administration of miR-1 mimics in vivo prevented the development of HPH in mice and attenuated induction of SphK1 in PASMCs. These data reveal the importance of miR-1 in regulating SphK1 expression during hypoxia in PASMCs. A pivotal role is played by miR-1 in pulmonary vascular remodeling, including PASMC proliferation and migration, and its overexpression protects from the development of HPH in vivo. These studies improve our understanding of the molecular mechanisms underlying the pathogenesis of pulmonary hypertension

An observational study to correlate arterial lactate level and peripheral perfusion index in context of tissue perfusion in sepsis

Background: In view of goal directed therapies, the predictive value of the course of peripheral perfusion parameters over time has not been studied. Moreover serial assessment of peripheral perfusion index (PI) can be more predictive for mortality when compared to a single assessment of peripheral perfusion. Successfully normalized PI (≥1.4) during treatment might be an indication to stop the resuscitation, whereas pursuing normalized PI (≥1.4) might not result in better outcomes compared with mild-to moderate PI impairment after a normalized arterial lactate level. Complementing arterial lactate assessment with PI during resuscitation can better identify the endpoint of resuscitation and patients at higher risk of adverse outcomes. By simple clinical assessment of peripheral perfusion immediately during and after resuscitation, clinicians will be able to discriminate patients at high risk for developing severe complications even in the rural setups. Methods: This prospective study was conducted on 100 patients admitted at Dr. Kiran C. Patel Medical College and Research Institute, over a period of 12months (Janury 2022 to December 2022). Patients of sepsis were selected on the basis of criteria for tissue hypoperfusion and classification of sepsis. Results: On statistical analysis, PI was found to have significant correlation with arterial lactate levels (P<0.001) in PI <1.4 sub-measurement and not in PI >1.4. SOFA score & metabolic parameters were also found to have statistical significance. Conclusions: We inferred that peripheral perfusion index monitoring could provide useful information to determine the possibility of hyperlactatemia in critically ill patients thus providing a noninvasive source of tissue-bed perfusion monitoring even in the absence of facilities and infrastructure to measure the lactate levels thereby providing a gross insight in the perfusion haemodynamics of the patients of sepsis even in the primary healthcare setups too