462 research outputs found
Spot Exchange Rate Volatility, Uncertain Policies and Export Investment Decision of Firms: A Mean-Variance Decision Approach
This paper studies characteristics of optimal investment decisions of risk-averse firms who engage in exports under two types of risks: endogenous and background risks. While endogenous risk arises from the fluctuations in spot exchange rate and affects directly the profit of an exporting firm, background risk arises from uncertain changes in firm- and industry- specific domestic and foreign policies. We propose a mean-variance decision-theoretic model to trace out impact of perturbations in the distributions of these uncertainties on the optimal investment strategy. A testable empirical model is derived and applied to a panel of 840 exporting Indian manufacturing firms for the period 1995-2015. Our results suggest that Indian manufacturing exporters depict decreasing absolute risk aversion and that firms’ risk preferences are prone to variance vulnerability
A Case of Hemophagocytic Syndrome due to Tuberculosis: Uncommon Manifestation of a Common Disease
Hemophagocytic syndrome, also known as hemophagocytic lymphohistiocytosis (HLH), is the manifestation of immune dysregulation. It is associated with ineffective but exaggerated immune response and infiltration of active lymphocytes and histiocytes in various organs. This devastating clinical condition has myriad of clinical and biochemical manifestations such as fever, splenomegaly, pancytopenia, hypertrygliceridemia, and hyperferritinemia. It can be either primary or secondary. Primary HLH usually presents in childhood. Secondary HLH occurs due to infection mostly viruses but other aetiologies are also important as early detection and treatment may improve survival. Hemophagocytosis due to tuberculosis is uncommon. Only handful of cases have been reported mostly in immunocompromised patients. We report a case of hemophagocytic syndrome associated with disseminated tuberculosis in an immunocompetent women highlighting early diagnosis and treatment is a demanding need in this devastating disease
Distorted wurtzite unit cells: Determination of lattice parameters of non-polar a-plane AlGaN and estimation of solid phase Al content
Unlike c-plane nitrides, ``non-polar" nitrides grown in e.g. the a-plane or
m-plane orientation encounter anisotropic in-plane strain due to the anisotropy
in the lattice and thermal mismatch with the substrate or buffer layer. Such
anisotropic strain results in a distortion of the wurtzite unit cell and
creates difficulty in accurate determination of lattice parameters and solid
phase group-III content (x_solid) in ternary alloys. In this paper we show that
the lattice distortion is orthorhombic, and outline a relatively simple
procedure for measurement of lattice parameters of non-polar group III-nitrides
epilayers from high resolution x-ray diffraction measurements. We derive an
approximate expression for x_solid taking into account the anisotropic strain.
We illustrate this using data for a-plane AlGaN, where we measure the lattice
parameters and estimate the solid phase Al content, and also show that this
method is applicable for m-plane structures as well
Unbounded Predicate Inner Product Functional Encryption from Pairings
Predicate inner product functional encryption (P-IPFE) is essentially attribute-based IPFE (AB-IPFE) which additionally hides attributes associated to ciphertexts. In a P-IPFE, a message x is encrypted under an attribute w and a secret key is generated for a pair (y, v) such that recovery of ⟨ x, y⟩ requires the vectors w, v to satisfy a linear relation. We call a P-IPFE unbounded if it can encrypt unbounded length attributes and message vectors. ∙ zero predicate IPFE. We construct the first unbounded zero predicate IPFE (UZP-IPFE) which recovers ⟨ x, y⟩ if ⟨ w, v⟩ = 0 . This construction is inspired by the unbounded IPFE of Tomida and Takashima (ASIACRYPT 2018) and the unbounded zero inner product encryption of Okamoto and Takashima (ASIACRYPT 2012). The UZP-IPFE stands secure against general attackers capable of decrypting the challenge ciphertext. Concretely, it provides full attribute-hiding security in the indistinguishability-based semi-adaptive model under the standard symmetric external Diffie–Hellman assumption. ∙ non-zero predicate IPFE. We present the first unbounded non-zero predicate IPFE (UNP-IPFE) that successfully recovers ⟨ x, y⟩ if ⟨ w, v⟩ ≠ 0 . We generically transform an unbounded quadratic FE (UQFE) scheme to weak attribute-hiding UNP-IPFE in both public and secret key setting. Interestingly, our secret key simulation secure UNP-IPFE has succinct secret keys and is constructed from a novel succinct UQFE that we build in the random oracle model. We leave the problem of constructing a succinct public key UNP-IPFE or UQFE in the standard model as an important open problem
Fructose-1, 6-bisphosphatase in human fetal brain and liver during development
Activity of fructose-1,6-bisphosphatase (EC 3.1.3.11), one of the key gluconeogenic enzymes, was measured in human fetal brain and liver during development. Fructose-1,6-bisphosphatase was distributed throughout the different regions of the brain. In contrast to the partially purified enzyme from the brain, the liver enzyme was dependent on Mg2+ for maximal activity, EDTA, citrate, oleate and linoleate were stimulatory, whereas 5'-AMP inhibited the activity of the liver enzyme
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