A single server Markovian queuing system with limited buffer and reverse balking

The phenomena are balking can be said to have been observed when a customer who has arrived into queuing system decides not to join it. Reverse balking is a particular type of balking wherein the probability that a customer will balk goes down as the system size goes up and vice versa. Such behavior can be observed in investment firms (insurance company, Mutual Fund Company, banks etc.). As the number of customers in the firm goes up, it creates trust among potential investors. Fewer customers would like to balk as the number of customers goes up. In this paper, we develop an M/M/1/k queuing system with reverse balking. The steady-state probabilities of the model are obtained and closed forms of expression of a number of performance measures are derived

The Hurewicz map in motivic homotopy theory

For an \A^1-connected pointed simplicial sheaf \sX over a perfect field $k$, we prove that the Hurewicz map \pi_1^{\A^1}(\sX) \to H_1^{\A^1}(\sX) is surjective. We also observe that the Hurewicz map for $\P^1_k$ is the abelianisation map. In the course of proving this result, we also show that for any morphism $\phi$ of strongly \A^1-invariant sheaves of groups, the image and kernel of $\phi$ are also strongly \A^1-invariant.Comment: 9 page

The Nisnevich motive of an algebraic stack

We construct the motive of an algebraic stack in the Nisnevich topology. For stacks which are Nisnevich locally quotient stacks, we give a presentation of the motive in terms of simplicial schemes. We also show that the motivic cohomology agrees with the Chow groups of Edidin-Graham-Totaro with integer coefficients

Phytosome: a novel dosage form for herbal drug delivery

Phytosome is a complex of a natural active ingredient and phospholipids. The term ‘Phyto’ means plant while ‘some’ means cell like structure. It is claimed that phytosome increases absorption of "conventional herbal extracts" or isolated active principles both orally as well as topically. In this era phytosome gain popularity as a potential drug delivery device due to excessive demand and utility of herbs or herb based medicines. This advance technology offers amenities like improved absorption, enhanced delivery & increased bioavailability of herbal extracts. These drug-phospholipid complexes can be fabricated in the form of solution, suspension, emulsion, syrup, lotion, gel, cream, aqueous micro dispersions. Standardized plant extracts, mainly polar phytoconstituents like flavonoids, terpenoids, tannins, xanthones shall be introduced in form of phytosome

Minimizing Weighted lp-Norm of Flow-Time in the Rejection Model

We consider the online scheduling problem to minimize the weighted ell_p-norm of flow-time of jobs. We study this problem under the rejection model introduced by Choudhury et al. (SODA 2015) - here the online algorithm is allowed to not serve an eps-fraction of the requests. We consider the restricted assignments setting where each job can go to a specified subset of machines. Our main result is an immediate dispatch non-migratory 1/eps^{O(1)}-competitive algorithm for this problem when one is allowed to reject at most eps-fraction of the total weight of jobs arriving. This is in contrast with the speed augmentation model under which no online algorithm for this problem can achieve a competitive ratio independent of p

Engagement Patterns of Peer-to-Peer Interactions on Mental Health Platforms

Mental illness is a global health problem, but access to mental healthcare resources remain poor worldwide. Online peer-to-peer support platforms attempt to alleviate this fundamental gap by enabling those who struggle with mental illness to provide and receive social support from their peers. However, successful social support requires users to engage with each other and failures may have serious consequences for users in need. Our understanding of engagement patterns on mental health platforms is limited but critical to inform the role, limitations, and design of these platforms. Here, we present a large-scale analysis of engagement patterns of 35 million posts on two popular online mental health platforms, TalkLife and Reddit. Leveraging communication models in human-computer interaction and communication theory, we operationalize a set of four engagement indicators based on attention and interaction. We then propose a generative model to jointly model these indicators of engagement, the output of which is synthesized into a novel set of eleven distinct, interpretable patterns. We demonstrate that this framework of engagement patterns enables informative evaluations and analysis of online support platforms. Specifically, we find that mutual back-and-forth interactions are associated with significantly higher user retention rates on TalkLife. Such back-and-forth interactions, in turn, are associated with early response times and the sentiment of posts.Comment: Accepted to ICWSM 202

Rejecting Jobs to Minimize Load and Maximum Flow-time

Online algorithms are usually analyzed using the notion of competitive ratio which compares the solution obtained by the algorithm to that obtained by an online adversary for the worst possible input sequence. Often this measure turns out to be too pessimistic, and one popular approach especially for scheduling problems has been that of "resource augmentation" which was first proposed by Kalyanasundaram and Pruhs. Although resource augmentation has been very successful in dealing with a variety of objective functions, there are problems for which even a (arbitrary) constant speedup cannot lead to a constant competitive algorithm. In this paper we propose a "rejection model" which requires no resource augmentation but which permits the online algorithm to not serve an epsilon-fraction of the requests. The problems considered in this paper are in the restricted assignment setting where each job can be assigned only to a subset of machines. For the load balancing problem where the objective is to minimize the maximum load on any machine, we give O(\log^2 1/\eps)-competitive algorithm which rejects at most an \eps-fraction of the jobs. For the problem of minimizing the maximum weighted flow-time, we give an O(1/\eps^4)-competitive algorithm which can reject at most an \eps-fraction of the jobs by weight. We also extend this result to a more general setting where the weights of a job for measuring its weighted flow-time and its contribution towards total allowed rejection weight are different. This is useful, for instance, when we consider the objective of minimizing the maximum stretch. We obtain an O(1/\eps^6)-competitive algorithm in this case. Our algorithms are immediate dispatch, though they may not be immediate reject. All these problems have very strong lower bounds in the speed augmentation model

Chloroquine encapsulated in malaria-infected erythrocyte-specific antibody-bearing liposomes effectively controls chloroquine-resistant Plasmodium berghei infections in mice

The suitability of liposomes as drug carriers in the treatment of drug-resistant rodent malaria was examined after covalently attaching F(ab')2 fragments of a mouse monoclonal antibody (MAb), MAb F10, raised against the host cell membranes isolated from the Plasmodium berghei-infected mouse erythrocytes, to the liposome surface. The antibody-bearing liposomes thus formed specifically recognized the P. berghei-infected mouse erythrocytes under both in vitro and in vivo conditions. No such specific binding of the liposomes with the infected cells was observed when MAb F10 was replaced by another mouse monoclonal antibody, MAb D2. Upon loading with the antimalarial drug chloroquine, the MAb F10-bearing liposomes effectively controlled not only the chloroquine-susceptible but also the chloroquine-resistant P. berghei infections in mice. The chloroquine delivered in these liposomes intravenously at a dosage of 5 mg/kg of body weight per day on days 4 and 6 postinfection completely cured the animals (75 to 90%) of chloroquine-resistant P. berghei infections. These results indicate that selective homing of chloroquine to malaria-infected erythrocytes may help to cure the chloroquine-resistant malarial infections with low doses of chloroquine