91 research outputs found
Parallel sparse interpolation using small primes
To interpolate a supersparse polynomial with integer coefficients, two
alternative approaches are the Prony-based "big prime" technique, which acts
over a single large finite field, or the more recently-proposed "small primes"
technique, which reduces the unknown sparse polynomial to many low-degree dense
polynomials. While the latter technique has not yet reached the same
theoretical efficiency as Prony-based methods, it has an obvious potential for
parallelization. We present a heuristic "small primes" interpolation algorithm
and report on a low-level C implementation using FLINT and MPI.Comment: Accepted to PASCO 201
Computing Matrix Canonical Forms of Ore Polynomials
We present algorithms to compute canonical forms of matrices of Ore polynomials while controlling intermediate expression swell. Given a square non-singular input matrix of Ore polynomials, we give an extension of the algorithm by Labhalla et al. 1992, to compute the Hermite form. We also give a new fraction-free algorithm to compute the Popov form, accompanied by an implementation and experimental results that compare it to the best known algorithms in the literature. Our algorithm is output-sensitive, with a cost that depends on the orthogonality defect of the input matrix: the sum of the row degrees in the input matrix minus the sum of the row degrees in the Popov form. We also use the recent advances in polynomial matrix computations, including fast inversion and rank profile computation, to describe an algorithm that computes the transformation matrix corresponding to the Popov form
Syndrome dâinterruption de la tige pituitaire Ă rĂ©vĂ©lation tardive
Le syndrome d'interruption de la tige pituitaire est une cause assez fréquente de déficit en hormone de croissance et d'hypopituitarisme souvent révélé pendant la période néonatale et l'enfance. Cette observation illustre les particularités d'une révélation tardive de ce syndrome. Il s'agit d'une patiente ùgée de 17ans hospitalisée pour aménorrhée primaire et impubérisme. Elle n'a pas d'antécédent d'incident néonatal. L'examen clinique révÚle un retard de croissance sévÚre. L'hypophysiogramme a montré un hypopituitarisme complet sans diabÚte insipide. L'imagerie par résonnance magnétique a montré une interruption de la tige pituitaire avec une post hypophyse ectopique. Une malformation rénale a été objectivée, ce qui est en faveur d'une origine congénitale malformative de ce syndrome. Une substitution hormonale a été administrée à cette patiente. Cette forme clinique tardive souligne la nécessité de diagnostic précoce d'impubérisme et/ou de retard de croissance révélant une pathologie à potentiel de gravité important.Pan African Medical Journal 2016; 2
Obstructive sleep apnea presenting as pseudopheochromocytoma
A 52-year-old female with a history of poorly controlled resistant hypertension was admitted to our hospital with severe hypertension. She had a history of fatigue and intermittent episodes of palpitations. Laboratory evaluation was significant for elevated 24-h urinary catecholamine levels (3,5 times the upper normal levels). This case was presenting with a clinical and biochemical picture indistinguishable from that of pheochromocytoma. However, neither computed tomography nor meta-iodo-benzyl-guanidine scintigraphy detected any catecholamine-producing tumor in or outside the adrenal glands. Our patient was screened with full polysomnography because of heavy snoring, daytime somnolence and obesity. It revealed severe obstructive sleep apnea syndrome. After three months of continuous positive airway pressure therapy, the patient experienced resolution of his presenting symptoms, improved blood pressure control and normalization of his urinary catecholamine levels. This case highlights sleep disordered breathing as a potentially reversible cause of pseudo-pheochromocytoma.Pan African Medical Journal 2016; 2
Reversible dilated cardiomyopathy caused by hypothyroidism
The association between lack of thyroid hormones and cardiac dysfunction has been well described. We report two new cases of patients with dilated cardiomyopathy (DCM), revealing a periphery hypothyroidism and for whom cardiac function significantly improved after L thyroxin substitutive treatment. Our cases highlight the necessity to perform thyroid function testing to investigate the etiology of non ischemic DCM
Kyste hydatique du massĂ©ter: a propos dâun cas
La localisation cervico faciale et particuliĂšrement musculaire massĂ©tĂ©rine est exceptionnelle mĂȘme en zone dâendĂ©mie. Le kyste hydatique au niveau de cette localisation pose un problĂšme de diagnostic et des difficultĂ©s thĂ©rapeutiques du fait de la prĂ©sence de filets nerveux du VII. Les auteurs rapportent un cas rare de localisation primaire dâun kyste hydatique au niveau du muscle massĂ©ter.Mots clĂšs : Kyste hydatique, face, massĂ©ter, imagerie, chirurgie
Myofibromatose infantile infratemporale
La myofibromatose infantile est une affection prolifĂ©rative mĂ©senchymateuse rare de l'enfance (1 / 400 000). Ce processus tumoral bĂ©nin peut intĂ©resser les tissus mous, les muscles, lâos et rarement les viscĂšres. elle peut se prĂ©senter sous une forme solitaire ou multicentrique. La localisation cervico-faciale intĂ©resse 30% des cas. dans la littĂ©rature la localisation infratemporale est trĂšs rare. Nous prĂ©sentons le cas d'un garçon de quatre ans qui sâest prĂ©sentĂ© avec une rĂ©cente limitation de lâouverture buccale. L'imagerie (Tdm et iRm) faisait Ă©voquer une tumeur maligne. Le diagnostic a Ă©tĂ© histologique. LâĂ©volution a Ă©tĂ© spectaculaire, basĂ©e sur des contrĂŽles cliniques et iRm, a Ă©tĂ© marquĂ©e par une rĂ©gression quasi totale des signes cliniques et des anomalies Ă lâimagerie Ă partir du troisiĂšme mois.Mots-clĂ©s : myofibromatose infantile, infratemporale
Carcinome parathyroidien
Parathyroid cancer is uncommon and its etiology is largely unknown. It is difficult to diagnose. The preoperative syndrome is unusually severe primary hyperparathyroidism. Intraoperatively, many characteristics of the tumor may be highly suggestive. Confirmation requires pathological analysis of the operative specimens and the diagnosis is strengthened in the presence of associated Shantz and Castelman criteria. Specific immunohistochemical techniques have been shown to be contributive. The diagnosis can be further supported by the clinical course of local recurrence or metastatic spread.Treatment of this tumor is primarly surgical. In some cases, postoperative radiotherapy may improve locoregional control of the tumor. The disease control can be monitored by regula assay of serum calcium and the parathormone. We report a case of parathyroid carcinoma, with special emphasis on the diagnostic modalities of this tumor, its treatmentand its prognosis.Keywords: Hypercalcemia, Primary Hyperparathyroidism, Parathyroid carcinoma, Surgery
Graves' Disease Associated with Cerebrovascular Disease and Antiphospholipid Antibody Syndrome
Thyroid disorders are commonly associated with coagulopathy. Patients with hyperthyroidism
have increased risk for developing thromboembolic accidents, which are favoured by a simultaneous presence of antiphospholipid antibodies syndrome. in this paper, we describe the case of a patient with Graves' disease, who developed strokes with antiphospholipid antibodies syndrome
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