DOES OWNERSHIP STRUCTURE AFFECT FIRM’S PERFORMANCE? EMPIRICAL EVIDENCE FROM PAKISTAN

In Pakistan, the ownership of majority of the firms is characterized by the concentration of different groups such as family members, associated firms, institutional investors and insiders. The present study aims to investigate whether different ownership structure including family ownership, associated ownership, institutional ownership, concentrated ownership, managerial ownership, block holding, and foreign ownership contribute to the financial performance of nonfinancial firms listed at the Pakistan Stock Exchange (PSX). Findings suggest that a firm’s performance increases significantly in the presenceof associated ownership, concentrated ownership, institutionalownership and block holding. This indicates that these ownershipstructures add value and help in reducing agency problems. On the other hand, family and managerial ownership have a negative relationship with firm performance. These findings are consistent with the hypothesis of minority shareholder expropriation which states that when family ownership and managers’ involvement is higher in a firm, they exploit the funds of minor shareholders. Similarly, foreign ownership also does not add value

Genetic Diversity of Greenbugs, Schizaphis Graminum (Rondani), in Sexual Reproduction and Virulence to Host Plants

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Mixed Graviton and Scalar Bispectra in the EFT of Inflation: Soft Limits and Boostless Bootstrap

Boostless Bootstrap techniques have been applied by many in the literature to compute pure scalar and graviton correlators. In this paper, we focus primarily on mixed graviton and scalar correlators. We start by developing an EFT of Inflation (EFToI) with some general assumptions, clarifying various subtleties related to power counting. We verify explicitly the soft limits for mixed correlators, showing how they are satisfied for higher derivative operators beyond the Maldacena action. We clarify some confusion in the literature related to the soft limits for operators that modify the power spectra of gravitons or scalars. We then proceed to apply the boostless bootstrap rules to operators that do not modify the power spectra. Towards the end, we give a prescription that gives correlators for $\alpha$ vacua directly once we have the correlator for the Bunch-Davies vacuum. This enables us to bypass complicated in-in calculations for $\alpha$ vacua.Comment: 29 pages, 3 figures, References added, typos correcte

N-Screen Aware Multicriteria Hybrid Recommender System Using Weight Based Subspace Clustering

This paper presents a recommender system for N-screen services in which users have multiple devices with different capabilities. In N-screen services, a user can use various devices in different locations and time and can change a device while the service is running. N-screen aware recommendation seeks to improve the user experience with recommended content by considering the user N-screen device attributes such as screen resolution, media codec, remaining battery time, and access network and the user temporal usage pattern information that are not considered in existing recommender systems. For N-screen aware recommendation support, this work introduces a user device profile collaboration agent, manager, and N-screen control server to acquire and manage the user N-screen devices profile. Furthermore, a multicriteria hybrid framework is suggested that incorporates the N-screen devices information with user preferences and demographics. In addition, we propose an individual feature and subspace weight based clustering (IFSWC) to assign different weights to each subspace and each feature within a subspace in the hybrid framework. The proposed system improves the accuracy, precision, scalability, sparsity, and cold start issues. The simulation results demonstrate the effectiveness and prove the aforementioned statements

Amplitude's positivity vs. subluminality: Causality and Unitary Constraints on dimension 6 & 8 Gluonic operators in the SMEFT

We derive the causality and unitary constraints on dimension 6 and dimension 8 Gluon field strength operators in the Standard Model Effective Field Theory (SMEFT). In the first part of the paper, we use the 'amplitude analysis' i.e. dispersion relation for $2\rightarrow2$ scattering in the forward limit, to put bounds on the Wilson coefficients. We show that the dimension 6 operators can exist only in the presence of certain dimension 8 operators. It is interesting that the square of the dimension 6 Wilson coefficients can be constrained in this case even at the tree level. In the second part of this work, we successfully rederive all these bounds using the classical causality argument that demands that the speed of fluctuations about any non-trivial background should not exceed the speed of light. We also point out some subtleties in the superluminality analysis regarding whether the low-frequency phase velocity can always be used as the relevant quantity for Causality violation: as an example, we show that, due to these subtleties, if a small pion mass is added in the chiral Lagrangian, it is unclear if any strict positivity bound can be derived on the dimension 8 Wilson coefficient. Finally, we mention an interesting non-relativistic example where the subluminality requirement produces a stronger bound than the 'amplitude analysis'.Comment: 28 page

QoS and QoE Aware N-Screen Multicast Service

The paper focuses on ensuring the quality-of-service (QoS) and quality-of-experience (QoE) requirements of users having heterogeneous devices in a multicast session. QoS parameters such as bit rate, delays, and packet losses are good indicators for optimizing network services but fall short in characterizing user perception (QoE). In N-Screen service, the users have different devices with heterogeneous attributes like screen size, resolution, and access network interface, and the users have different QoE on N-Screen devices with the same QoS parameters. We formulate the objective function of the N-Screen multicast grouping to ensure the minimum user’s QoE with smaller bandwidth requirement. We propose a dynamic user reassignment scheme to maintain and satisfy the QoE by adapting the user’s membership to the varying network conditions. The proposed schemes combine the available bandwidth and multimedia visual quality to ensure the QoS and QoE. In the network architecture, we introduce the functions of the QoS and QoE aware multicast group management and the estimation schemes for the QoS and QoE parameters. The simulation results show that the proposed multicast service ensures the network QoS and guarantees the QoE of users in the varying network conditions

Probing the initial state of inflation: analytical structure of cosmological correlators

We study the analytic structure of in-in correlation functions in a deSitter background. The aim of this study is to probe the initial conditions for inflation through the features of correlation functions of the field fluctuations, and understand precisely how an in-in correlator responds to particles in the initial state. We emphasize that the choice of vacuua and the corresponding particle interpretation for these fluctuations is flexible, and we clarify the role of this choice at the level of calculations and their diagrammatic interpretation. We consider several possibilities aside from the standard Bunch Davies vacuum prescription for the initial state, and trace the change in pole structure as one begins adding excitations; starting from just a single particle, to highly excited states and special cases such as a coherent state. We illustrate - with the example of coherent states - the subtleties in concluding a Bunch Davies initial state from the absence of physical poles in the bispectrum, which is interesting in light of some recent literature. Initial states with a finite number of excitations are plagued with disconnected diagrams isolated in phase space, and we highlight their implications on the observation of these signals, and how the situation changes as one begins to excite more and more particles. We also comment about the implications of various initial conditions on the squeezed limit of the bispectrum. These new pole structures are a direct consequence of mixing of positive and negative frequency modes which is a characteristic of curved spacetimes; in particular, we see in detail how particles in an initial state replicate mode mixing structures. This study aims to clarify the missing details that link quantum and classical initial conditions, and sharpen our understanding of in-in correlators in inflation.Comment: 46 pages, typos corrected, sections have been slightly rearranged, no changes in the main result

Studies on Buddleja asiatica antibacterial, antifungal, antispasmodic and Ca++ antagonist activities

Crude extract of Buddleja asiatica Lour and its fractions, chloroform (F1), ethyl acetate (F2) and nbutanol (F3) were evaluated for antibacterial, antifungal, antispasmodic and Ca++ antagonist activities. The antibacterial activity was performed against 11 types of bacteria. The crude extract and fractions F2 and F3 exhibited significant activity, while F1 showed low activity in killing the Shigella flexenari, Sternostoma boydi and Escherichia coli. In the rest bacteria, the crude extract and all the fractions (F1 to F3) revealed minimum to nil inhibitory effect. The fungicidal activity of the crude extract and all the fractions (F1 to F3) was also performed against six different fungi. The crude extract and fractions F1 and F3 displayed significant activity, while fraction F2 showed moderate activity against Fusarium solani. In the case of Microsporum canis, the crude extract and fraction F3 showed high activity but in the other four fungi, the inhibition area exhibited optimum to nil activity in crude extract and all the fractions (F1 to F3). In isolated rabbit jejunum preparations, B. asiatica crude extract caused concentration-dependent (0.03 to 1.0 mg/ml) relaxation of spontaneous and high K+ (80 mM)-induced contractions. The results indicate the antibacterial, antifungal, antispasmodic and Ca++ antagonist potential of B. asiatica Lour

Antimicrobial and antioxidant activities of the plant Heliotropium strigosum

Heliotropium strigosum is an important medicinal plant and belongs to the Boraginaceae family. Traditionally, this plant is used as laxative and diuretic. The juice of the plant is used to treat gum boils, sore eyes and also as a cure for stings of nettles, insects and snake bites. The current study was carried out to evaluate the  medicinal properties of this plant. The plant was collected from Malakand, Pakistan. It was dried in shade and  crushed into powder. The shade dried plant powder was macerated for 15 days. A crude extract and ethyl  acetate, n-hexane, chloroform and aqueous fractions were obtained. The crude extract and fractions were  screened for antibacterial, antifungal and antioxidant properties. The plant showed excellent antimicrobial  activity. Chloroform and n-hexane fractions inhibited the growth of all four fungal strains that were used in the  antifungal assays. Crude extract showed antifungal activity against all fungal strains except Aspergillus flavus. The aqueous and ethyl acetate fractions had no antifungal activity. The plant exhibited excellent antibacterial activity against Pseudomonas aeruginosa and Staphylococcus epidermidis, moderate activity against  methicillin resistant Staphylococcus aureus (MRSA) and Bacillus subtillus but was inactive against   Escherichia coli and Klebsiella pneumonia. The plant showed excellent diphenyl picryl hydrazine (DPPH)  scavenging activity. Antioxidant activity was shown by ethyl acetate, n-hexane and aqueous fractions. Crude extract and chloroform fractions were lacking in DPPH scavenging activity.Key words: Heliotropium strigosum, antibacterial, antifungal, antioxidant