A Review on the Characterization of Signals and Systems by Power Law Distributions

Power laws, also known as Pareto-like laws or Zipf-like laws, are commonly used to explain a variety of real world distinct phenomena, often described merely by the produced signals. In this paper, we study twelve cases, namely worldwide technological accidents, the annual revenue of America׳s largest private companies, the number of inhabitants in America׳s largest cities, the magnitude of earthquakes with minimum moment magnitude equal to 4, the total burned area in forest fires occurred in Portugal, the net worth of the richer people in America, the frequency of occurrence of words in the novel Ulysses, by James Joyce, the total number of deaths in worldwide terrorist attacks, the number of linking root domains of the top internet domains, the number of linking root domains of the top internet pages, the total number of human victims of tornadoes occurred in the U.S., and the number of inhabitants in the 60 most populated countries. The results demonstrate the emergence of statistical characteristics, very close to a power law behavior. Furthermore, the parametric characterization reveals complex relationships present at higher level of description.

The Self-Inflicted Burns - Typology and its Prognostic Relevance in a 14-Year Review of Self-Inflicted Burns in a Tertiary Referral Centre

Self-inflicted burns (SIB) are responsible for 2-6% of admissions to Burn Units in Europe and North America, and for as many as 25% of admissions in developing nations. Recently, a promising new tool was proposed to stratify SIB patients in the following subgroups: "typical", "delirious", and "reactive". However, as far as the authors know, the clinical usefulness of this instrument has not yet been validated by others. We retrospectively reviewed the clinical records of 56 patients admitted to our Burn Unit with the diagnosis of SIB injury in the past 14 years. The following parameters were evaluated: demographic features; psychiatric illness; substance abuse; mechanism of injury; burn depth, total body surface area (TBSA) involved, Abbreviated Burn Severity Index (ABSI); length of hospital stay, and mortality. All patients were followed up by a psychologist and a psychiatrist, and were classified according to the SIB-Typology Tool, into three classes: "typical", "delirious" and "reactive". There was a slight predominance of the "typical" type (44.6%), followed by the "delirious" type (30.4%), and, finally the "reactive" type (25.0%). Mortality was significantly higher in the "typical" subgroup. In conclusion, the SIB-Typology Tool appears to be a valuable instrument in the clinical management of SIB patients.

A Review of Operational Matrices and Spectral Techniques for Fractional Calculus

Recently, operational matrices were adapted for solving several kinds of fractional differential equations (FDEs). The use of numerical techniques in conjunction with operational matrices of some orthogonal polynomials, for the solution of FDEs on finite and infinite intervals, produced highly accurate solutions for such equations. This article discusses spectral techniques based on operational matrices of fractional derivatives and integrals for solving several kinds of linear and nonlinear FDEs. More precisely, we present the operational matrices of fractional derivatives and integrals, for several polynomials on bounded domains, such as the Legendre, Chebyshev, Jacobi and Bernstein polynomials, and we use them with different spectral techniques for solving the aforementioned equations on bounded domains. The operational matrices of fractional derivatives and integrals are also presented for orthogonal Laguerre and modified generalized Laguerre polynomials, and their use with numerical techniques for solving FDEs on a semi-infinite interval is discussed. Several examples are presented to illustrate the numerical and theoretical properties of various spectral techniques for solving FDEs on finite and semi-infinite intervals.

Oligodendroglioma in a patient with AIDS: case report and review of the literature

In the last years, new techniques of neuroimages and histopathological methods have been added to the management of cerebral mass lesions in patients with AIDS. Stereotactic biopsy is necessary when after 14 days of empirical treatment for Toxoplasma gondii encephalitis there is no clinical or neuroradiologic improvement. We report a woman with AIDS who developed a single focal brain lesion on the right frontal lobe. She presented a long history of headache and seizures. After two weeks of empirical treatment for toxoplasma encephalitis without response, a magnetic resonance image with spectroscopy was performed and showed a tumoral pattern with a choline peak, diminished of N-acetyl-aspartate and presence of lactate. A stereotactic biopsy was performed. Histopathological diagnosis was a diffuse oligodendroglioma type A. A microsurgical resection of the tumor was carried out and antiretroviral treatment was started. To date she is in good clinical condition, with undetectable plasma viral load and CD4 T cell count > 200 cell/uL.

Fractional State Space Analysis of Economy Systems

This paper examines modern economic growth according to the multidimensional scaling (MDS) method and state space portrait (SSP) analysis. Electing GDP per capita as the main indicator for economic growth and prosperity, the long-run perspective from 1870 to 2010 identifies the main similarities among 34 world partners’ modern economic growth and exemplifies the historical waving mechanics of the largest world economy, the USA. MDS reveals two main clusters among the European countries and their old offshore territories, and SSP identifies the Great Depression as a mild challenge to the American global performance, when compared to the Second World War and the 2008 crisis.

Murine (endemic) typhus in Brazil: case report and review

Murine typhus has been increasingly recognized worldwide and is becoming a relevant differential diagnosis in febrile conditions. In Brazil, murine typhus has never received much attention. We present a recently diagnosed case and a literature review that suggests that the disease could be more prevalent in Southeastern Brazil than acknowledged until now.

Traumatic Clivus Epidural Hematoma: Case Report and Review of the Literature

BACKGROUND: Traumatic clival epidural hematoma is an extremely rare reported entity. CASE DESCRIPTION: We describe the case of a 26-year-old woman involved in a car accident who presented with a Glasgow Coma Scale score of 13, bilateral abducens palsy, bilateral numbness on the mandibular territory of the trigeminal nerve, and left hypoglossal palsy. Radiological examinations revealed a clival epidural hematoma. The patient was managed conservatively, with clinical improvement of her neurological condition. This is the first traumatic clival epidural hematoma reported in an adult. From a review of the literature, we found only 8 cases. CONCLUSION: The pathophysiology of these hematomas is still a subject of debate; occipitoatlantoaxial ligamentous instability may play a role in it. In one third of the cases, bilateral cranial nerve palsies were associated. Apparently, they have a benign outcome.

Hepatitis C in patients co-infected with human immunodeficiency virus. A review and experience of a Brazilian ambulatory

Hepatitis C virus (HCV) and human immunodeficiency virus (HIV) share the same transmission mechanisms. The prevalence of HCV in the HIV-infected population varies from region to region, throughout the world, depending on different exposure factors to both viruses. Co-infection with HIV accelerates the progression of the disease caused by HCV, appears to worsen the progression of the HIV infection and increases HCV transmission. Therefore, clinical management and treatment of HCV is a priority in medical facilities that receive HIV-infected patients. Clinical management of these patients involves specific diagnostic procedures and appropriately trained medical staff. The indication of treatment should meet specific clinical and laboratory criteria. There are a number of drugs currently available to treat hepatitis C in co-infected patients.

Oral cysticercosis: case report and review of the literature

Cysticercosis is a condition that occurs when man is infested by the larvae of Taenia solium, acting as an intermediate host instead of definitive. Oral cysticercosis is a rare event, and it represents a difficulty in clinical diagnosis. A case of oral cysticercosis in a 23-year-old white female who presented a painless swelling in the dorsal portion of the tongue is reported. An excisional biopsy was performed and histopathological examination revealed a cystic cavity containing the tapeworm.

Neuroschistosomiasis due to Schistosoma mansoni: a review of pathogenesis, clinical syndromes and diagnostic approaches

Neuroschistosomiasis (NS) is the second most common form of presentation of infection by the trematode, Schistosoma mansoni. Granulomatous inflammatory reaction occurs as a result of schistosome eggs being transmitted to spinal cord or brain via the vascular system, or by inadvertent adult worm migration to these organs. The two main clinical syndromes are spinal cord neuroschistosomiasis (acute or subacute myelopathy) and localized cerebral or cerebellar neuroschistosomiasis (focal CNS impairment, seizures, increased intracranial pressure). Presumptive diagnosis of NS requires confirming the presence of S. mansoni infection by stool microscopy or rectal biopsy for trematode eggs, and serologic testing of blood and spinal fluid. The localized lesions are identified by signs and symptoms, and confirmed by imaging techniques (contrast myelography, CT and MRI). Algorithms are presented to allow a stepwise approach to diagnosis.

Pulmonary thromboembolism in AIDS patient with chronic venous insufficiency, pulmonary tuberculosis and breast cancer: a case report and pathophysiology review

Recent literature reports thrombotic episodes occurring in patients with HIV infection associated with other abnormalities including neoplasms and infections predisposing to a hypercoagulable state. We report a 47-year-old woman who developed pulmonary thromboembolism in association with HIV infection, pulmonary tuberculosis and breast cancer. She was treated with rifampin, isoniazid, pyrazinamide; heparin, phenprocoumon, zidovudine, lamivudine and efavirenz. Acid fast bacilli were visualized in a sputum smear and three months after, Mycobacterium tuberculosis was isolated from lymph node biopsy during a episode of immune reconstitution. The isolated mycobacteria showed sensitivity to all first-line drugs. HIV infection, breast cancer and pulmonary tuberculosis have several mechanisms that induce hypercoagulable state and can lead to thromboembolic complications. Pulmonary thromboembolism in this patient was a diagnostic challenge because of all the other severe diseases that she experienced at the same time.