The action of the primitive Steenrod-Milnor operations on the modular invariants

We compute the action of the primitive Steenrod-Milnor operations on generators of algebras of invariants of subgroups of general linear group GL_n=GL(n,F_p) in the polynomial algebra with p an odd prime number.Comment: This is the version published by Geometry & Topology Monographs on 14 November 200

High-directivity acoustic antenna

Acoustic antenna with unique electronic steering control is used to identify and define aerodynamic noise sources in free field, particularly in wind tunnel which is quite reverberant. Provision is made for high directivity as well as improved discrimination against unwanted background noise such as reverberation or echoes

On a minimal set of generators for the polynomial algebra of five variables as a module over the Steenrod algebra

Denote by $P_k$ the graded polynomial algebra $\mathbb F_2[x_1,x_2,\ldots ,x_k]$ over the prime field of two elements, $\mathbb F_2$, with the degree of each $x_i$ being 1. We study the Peterson hit problem of determining a minimal set of generators for $P_k$ as a module over the mod-$2$ Steenrod algebra, $\mathcal{A}.$ In this paper, we explicitly determine a minimal set of $\mathcal{A}$-generators for $P_k$ in the case $k=5$ and the degree $4(2^d - 1)$ with $d$ an arbitrary positive integer.Comment: 21 pages, This is a revision of a preprint of Quy Nhon University, Viet Nam, 2013. A shorter version of this paper was accepted for publication in Acta Mathematica Vietnamica. arXiv admin note: text overlap with arXiv:1412.330

Cryptococcal infection of the ventriculoperitoneal shunt in an immunocompetent patient

Patient: Male, 52 Final Diagnosis: Cryptococcal ventriculoperitoneal shunt infection Symptoms: Confusion • fever • Lethargy Medication: Amphotericin B • Flucytosine Clinical Procedure: Ventriculoperitoneal shunt removal Specialty: Infectious disease OBJECTIVE: Rare disease BACKGROUND: Ventriculoperitoneal shunting is an effective treatment for hydrocephalus. Ventriculoperitoneal shunt (VPS) infection is a common complication. Cryptococcus neoformans as an implicated organism is rare. In this report, we describe a patient with cryptococcal VPS infection. CASE REPORT: A 52-year-old male with normal pressure hydrocephalus, status post implantation of VPS one year prior to the presentation; who was admitted with a fever, lethargy and confusion for three days. He was treated empirically with intravenous cefepime and vancomycin for VPS infection. The CSF analysis from both the lumbar puncture and the VPS was significant for a low white blood count, low glucose and high protein. Other work-up including India ink and cryptococcal antigen was unrevealing. He remained febrile despite antibiotic treatment for 5 days. The CSF from the shunt was sent for analysis again and it demonstrated similar results from the prior study, but the culture was now positive for Cryptococcus neoformans. The patient was started on oral flucytosine and intravenous liposomal amphotericin B. The VPS was removed and an externalized ventricular catheter was placed. The patient showed rapid resolution of the symptoms. CONCLUSIONS: To date, there was a total of nine reported cases of cryptococcal VPS infection upon review of the literature. Our presenting case and the literature review highlight the difficulties in making an accurate diagnosis of cryptococcal shunt infection. There were case reports of false negative cryptococcal antigen tests with culture proven cryptococcal meningitis. The CSF culture from the shunt remains a mainstay for identifying cryptococcal shunt infection. Cryptococcal shunt infections are rare and early diagnosis and treatment is essential for patient management which involves shunt replacement with concomitant administration of intravenous antifungal medication. High clinical suspicion is crucial and shunt culture preferably from the valve is recommended