Electron Beam Welding In-Process Control and Monitoring

This work presents the results of an investigation of processes in the melting zone during Electron Beam Welding(EBW) through analysis of the secondary current in the plasma.The studies show that the spectrum of the secondary emission signal during steel welding has a pronounced periodic component at a frequency of around 15–25 kHz. The signal contains quasi-periodic sharp peaks (impulses). These impulses have stochastically varying amplitude and follow each other inseries, at random intervals between series. The impulses have a considerable current (up to 0.5 A). It was established that during electron-beam welding with the focal spot scanning these impulses follow each other almost periodically. It was shown that the probability of occurrence of these high-frequency perturbation increases with the concentration of energy in the interaction zone. The paper also presents hypotheses for the mechanism of the formation of the high-frequency oscillations in the secondary current signal in the plasma.

Frugivoria por aves em Nectandra megapotamica (Lauraceae) em uma área de Floresta Estacional Decidual no Rio Grande do Sul, Brasil

A importância dos frutos de Lauraceae tem sido relatada na dieta de muitas aves, principalmente das famílias Ramphastidae, Cotingidae e Trogonidae. Os objetivos deste estudo foram determinar quais espécies de aves consomem os frutos de Nectandra megapotamica (Spreng.) Mez (Lauraceae) numa área de Floresta Estacional Decidual e, com base na análise de alguns dos componentes qualitativos e quantitativos da dispersão, inferir quais aves podem atuar como dispersores de suas sementes. O estudo foi desenvolvido no Campo de Instrução de Santa Maria (CISM) (29º43'S, 53º42'W), município de Santa Maria, Rio Grande do Sul. Num total de 70 h de observação focal, foram registradas 726 visitas de 21 espécies de aves. As aves consideradas como potencialmente dispersoras de N. megapotamica foram Turdus albicollis Vieillot, 1818, T. rufiventris Vieillot, 1818, Pitangus sulphuratus (Linnaeus, 1766) e T. amaurochalinus Cabanis, 1850 entre as residentes, e Tyrannus savanna Vieillot, 1808 e Myiodynastes maculatus (Müller, 1766) entre as migratórias. As aves com dieta generalista pareceram favorecer a dispersão de N. megapotamica, pois consumiram os frutos inteiros, realizaram visitas curtas (menos de 3 minutos) e apresentaram maior freqüência de visitação que, por sua vez, está relacionada a uma maior remoção dos frutos. Nectandra megapotamica possui características que a incluem no sistema de dispersão generalista, exceto pelo alto valor nutritivo dos seus frutos.

Corythaica cyathicollis (Costa, 1864), aspectos sistemáticos, biológicos e econômicos (Hemiptera, Tingidae)

The present work deals with the systematic, biological and economic problems related to Corythaica cyathicollis (Costa, 1864) (Hemip., Tingidae). In the first part are presented the generic characteristics of Corythaica and is discussed the status of the specific name. The validity of C. cyathicollis, as stated by DRAKE and his collaborators, was denied by MONTE in his last works, he considered the species as C. passiflorae. Even in the modern literature no agreement has been achieved and three names are still used (cyathicollis, passiflorae and planaris) to designate the same insect. In order to resolve definitively this problem, a Neotype is designed to fill the place of the missing type of C. cyathicollis. Also in the first parte is discussed the taxonomic value of both male and female genitalia. The whole male copulator apparatus is studied and are illustrated the genital capsules of 8 species of this genus. Special mention is made of the shape of the basal plates and the proportions of the segmental membrana. The female genitalia is studied based upon the work of FELDMAN & BAILEY (1952). In the second part the biological cycle of C. cyathicollis is carefully studied. Descriptions of the egg are done and the ways of oviposition. The number of eggs laid by the female was observed to be about 350, during a period of more than 45 days. The eclosion of the neanide I is illustrated in some of its phases and the 5 larval instars are described and illustrated. Ending this part are included the lists of parasites and predators observed as well as the plant hosts. The actual geographical distribution is presented, based chiefly on HURD (1945). The economic problems concerning this species are reported in the third part of the work, and the ways of control are discussed. An experiment was carried out involving 4 insecticides: Malathion and Parathion, commonly used against this "lace bug"; Toxaphene and Dimethoate (American Cyanamid 12.880), the last one is an insecticide recently introduced in Brazil and was not previously used for these purposes, but gave the best results and it is quite able to control these insects even on crops showing highly developed infestations.

Miocitólise e fibrose do miocárdio na doença de Chagas

A fibrose do miocárdio foi, primitivamente, atribuída á cicatrização de infartos e á miocardite intersticial. Em data relativamente recente maior atenção veio despertar a miocitólise como outra causa capaz de produzi-la (SCHLESINGER & REINER, MAGARINOS TORRES). Descrevemos, neste trabalho, a miocitólise difusa do miocárdio como diversa da miocitólise focal, estudada por SCHLESINGER & REINER. Na cardiopatia crônica chagásica, a fibrose do miocárdio é aparentemente, o resultado da miocitólise difusa em menor escala associada á da miocaedite específica. Embora não patognomônica da doença de Chagas, a miocitólise difusa, em sua fase crõnica (figs. 3 a 11), por vêzes distinguida, devidamente, da miocardite intersticial, é constante e, não raro, extensa na cardiopatia crônica chagásica, fato a ser levado em conta quando tentado o seu diagnóstico microscópico. A raridade, porém com que é surpreendida a sua fase aguda (figs. 13 e 14) indica que ela se processa de maneira lenta, atingindo, apenas, raras fibras musculares, em cada momento concreto, circunstãncia essa que, de certo modo, virá dificultar o seu estudo pelo microscópio electrônico. A lesão de C. Magarinos torres (figs. 15, 16 e 17) não parece relacionada com a miocitólise, embora reconheça, provàvelmente, uma patogenia semelhante: anemia local condicionando perturbações no metabolismo das células musculares cardíacas. A destruição de células musculares, discreta em cada campo microscópico, porém difundida, exige evidentemente menos afluxo de sangue arterial, nas zonas em que a miocitólise é mais acentuada, fato que não poderia explicar o colapso das finas ramificações arteriais ocasionalmente encontrado (figs. 18, 20 e 22). A conservação de capilares sanguíneos do primitivo estroma do miocárdio distingue a fibrose resultante da miocitólise difusa (figs. 8, 9, 11 e 12) da que produz a miocardite intersticial crõnica. A acentuada congestão dos capilares (fig. 12) atesta o intenso grau de insuficiência cardíaca congestiva presente nos pacientes com cardiopatia crõnica chagásica autopsiados, assim como a existência de um círculo vicioso: congestão crônica, anóxia, perturbações do metabolismo nas células musculares, miocitólise. Os fatos aqui referidos reforçam a hipótese segundo a qual a forma cardíaca da doença de Chagas estaria sempre condicionada a lesões vasculares do coração além da miocardite específica ìntimamente associada.

The Sanctified ‘Adultress’ and Her Circumstantial Clause: Bathsheba’s Bath and Self-Consecration in 2 Samuel 11

Bathsheba's actions in 2 Sam. 11.2-4 identify crucial aspects of her character. Past commentators interpret these words in connection with menstrual purification, stressing the certain paternity of David's adulterine child. This article demonstrates that the participles rōheset and mitqaddesšet and the noun mittum'ātāh do not denote menstrual cleansing. Bathsheba's washing is an innocent bath. She is the only individual human to self-sanctify, placing her in the company of the Israelite deity. The syntax of the verse necessitates that her action of self-sanctifying occurs simultaneously as David lies with her. The three focal terms highlight the important legitimacy of Bathsheba before the Israelite deity, her identity as a non-Israelite, her role as queen mother of the Solomonic line, and her full participation in the narrative.

Fabricació de Lents Zonals de Fresnel per aplicació als raigs X tous

Estudi elaborat a partir d’una estada al Paul Scherrer Institut del Maig a l’Octubre del 2006 amb l’ajuda i supervisió dels Dr. Konstantins Jefimovs i Dr. Christian David. Focalitzar raigs X tous és una necessitat essencial per al microanàlisis, la microscopia, i fer imatges en moltes Instal·lacions de Radiació Sincrotró. Les Lents Zonals de Fresnel (FZP, de la denominació anglesa “Fresnel Zone Plates”) han demostrat donar uns punts focals amb una resolució espacial destacada i una baixa il·luminació de fons. Tanmateix, la fabricació de FZP és complexa i no totalment reproduïble. A més a més, el temps de vida de les FZP és força curt, ja que estant situades sobre membranes de nitrur de silici molt fines i altament absorbents. Per tant, hem fet esforços per implementar FZP de silici, que s’espera que siguin més resistents. L’element està fet d’una oblia de cristall de silici poc absorbent, i no presenta cap interfase entre materials. Així doncs, aquestes lents són especialment adequades per a aguantar les extremes càrregues de radiació de les fonts de raigs X més brillants. Particularment, això és molt important per a les aplicacions a les pròximes generacions de fonts de raigs X, com els Làsers d’Electrons Lliures (FEL, de la denominació anglesa “Free Electron Laser”). El silici també garanteix que no hi hagi cap banda d’absorció en el rang d’energies de la finestra de l’aigua (200-520 eV), fent aquestes lents ideals per a fer imatges de mostres biològiques. En aquest informe, hi ha una descripció detallada de tots els passos involucrats en la fabricació de les Lents Zonals de Fresnel de silici. En resum, les estructures de FZP es modelen sobre una resina utilitzant litografia per feix d’electrons i llavors el patró es transmet al silici mitjançant un gravat d’ions reactius (RIE, de la denominació anglesa ‘Reactive Ion Etching’) utilitzant una fina (20 nm) màscara de Crintermitja. Les membranes de silici es poden aprimar després de la fabricació de les estructures per a garantir una transmissió suficient fins i tot a baixes energies. Aquest informe també inclou l’anàlisi i la discussió d’alguns experiments preliminars per avaluar el rendiment de les Si FZPs fets a la línia de llum PolLux del Swiss Ligth Source amb l’ajuda dels Dr. Jörg Raabe i Dr. George Tzvetkov.

Panencefalite subaguda esclerosante: estudo comparativo entre as lesões humanas e as experimentais determinadas por agente encefalitogênico de origem humana

Neste trabalho estudamos as alterações histopatológicas encontradas no sistema nervoso central de dois pacientes com "panencefalite subaguda esclerosante" comparando-as com as modificações estruturais determinadas no sistema nervoso central de sete macacos rhesus nos quais este material foi inoculado. Os animais apresentaram sinais de comprometimento neurológico, traduzido por caquexia e paralisia do trem posterior, após um longo período de incubação, em torno de 18 meses. Dois animais morreram antes de qualquer manifestação neurológica, de infecção pulmonar intercorrente acidental. Nas passagens sucessivas houve um encurtamento do periódo de incubação para cerca de 40 dias. As alterações histopatológicas encontradas, consistiram, nos casos humanos, em leptomeningite focal, focos de neuronofagia, granulomas corticais e nos núcleos basais, grande perda da população neuronal com ocasional estado esponjoso do córtice cerebral, infiltrados perivasculares, e gliose da substância branca, sem perda de mielina. No material experimental foram observadas estas mesmas modificações, se bem que de caráter muito menos intenso. Tanto no material humano como no experimental a mielina estava praticamente normal. Sugere-se que o quadro anátomo-clínico chamado "panencefalite subaguda esclerosante (SSPE) possa ser determinado, não apenas pelo vírus do sarampo, mas também por outros vírus, especialmente os do grupo papova, já encontrado por outros autores, em casos de "panencefalite subaguda esclerosante".

A patologia da doença de Chagas experimental no cão

Cães jovens infectados pelo Trypanosoma cruzi desenvolveram a fase aguda da infecção e foram estudados durante o 7º até o 50º dia por métodos morfológicos, parasitológicos, imunológicos e eletrocardiográficos. ocorreu intensa miocardite que se iniciava nos átrios e se propagava aos ventrículos e, quando plenamente desenvolvida, predominava no átrio direito, na metade direita do septo interventricular e na parede livre do ventrículodireito. As alterações eletrocardiográficas foram progressivas e revelavam o progressivo e predominante comprometimento atrial, mas a interferência com a propagação do estímulo (bloqueio) só apareceu nas fases terminais, coincidente com a presença de inflamação e necrose ao longo do tecido de condução. Quinze cães foram submetidos a tratamento específico e em alguns destes as modificações anátomo-patológicas e eletrocardiográficas representaram uma reversão progressiva das lesões observadas antes. Dez animais evoluíram para a fase crônica indeterminada da infecção, três deles após tratamento, e foram acompanhados por períodos de oito meses a três anos, sem que nenhum desenvolvesse sinais de insuficiência cardíaca congestiva. As alterações eletrocardiográficas observadas nestes casos foram inespecíficas e algumas arritmias apareceram transitoriamente. No sistema excito-condutor foram encontradas lesões focais de fibrose, esclero-atrofia e infiltração adiposa, as quais foram interpretadas como seqüelas deixadas pela fase aguda. A miocardite encontrada foi focal e discreta. Foi examinado para complementação o material de um caso de forma crônica cardíaca no cão, o qual exibiu miocardite difusa com fibrose focal e intersticial e sinais de atividade do processo inflamatório, além de bloqueio de ramo direito e hemibloqueio anterior esquerdo. Assim, o modelo canino da doença de Chagas reproduz todas as fases da cardiopatia, tal como aparece no homem, sendo que as formas crõnicas sintomáticas são de reprodução experimental imprevisível. O presente trabalho objetivou caracterizar os aspectos da patologia da doença de Chagas no cão, tentar as suas correlações eletrocardiográficas, os seus aspectos evolutivos, com a finalidade de fornecer elementos para estudos futuros com o referido modelo experimental.

Glomerulonephritis in schistosomiasis with mesangial IgM deposits

Twenty one cases of hepatoesplenic schistosomiasis patients without clinical and laboratory evidence of renal disease, were studied by surgical biopsies using light microscopy and immunofluorescence. The cases were classified histologically as: normal pattern (6 cases); minimal changes (6 cases); and mesangial proliferative glomerulonephritis (9 cases). By the immunofluorescence microscopy using anti IgM, IgG, IgA and C3, the predominant finding in all biopsies, except the normal cases, was granular deposits of IgM in the mesangium along with C3. On the other hand, IgG was present in all cases including normal biopsies along the capillary walls. However IgG was also present in the mesangium only in cases with glomerular lesions. This finding may well be similar to that recently described as IgM mesangial nephropathy. According to our cases a mesangial proliferative glomerulonephritis, characterized by segmental cell proliferation and deposition of IgM in the mesangium, is probably the entity found in the early stages of mansonic schistosomiasis.

Chronic murine myocarditis due to Trypanosoma cruzi: an ultrastructural study and immunochemical characterization of cardiac interstitial matrix

In an attempt to define the mouse-model for chronic Chagas' disease, a serological, histopathological and ultrastructural study as well as immunotyping of myocardium collagenic matrix were performed on Swiss mice, chronically infected with Trypanosoma cruzi strains: 21 SF and mambaí (Type II); PMN and Bolivia (Type III), spontaneously surviving after 154 to 468 days of infection. Haemagglutination and indirect immunofluorescence tests showed high titres of specific antibodies. The ultrastructural study disclosed the cellular constitution of the inflammatory infiltrate showing the predominance of monocytes, macrophages with intense phagocytic activity, fibroblasts, myofibroblasts and abundant collagen matrix suggesting the association of the inflammatory process with fibrogenesis in chronic chagasic cardiomyopathy. Artertolar and blood capillary alterations together with dissociation of cardiac cells from the capillary wall by edema and inflammation were related to ultrastructural lesions of myocardial cells. Rupture of parasitized cardiac myocells contribute to intensify the inflammatory process in focal areas. Collagen immunotyping showed the predominance of Types III and IV collagen. Collagen degradation and phagocytosis were present suggesting a reversibility of the fibrous process. The mouse model seems to be valuable in the study of the pathogenetic mechanisms in Chagas cardiomyopathy, providing that T. cruzi strains of low virulence and high pathogenecity are used.

An episode mimicking a versive seizure in acute bilateral pontine stroke.

Pontine ischemia usually results in focal deficits such as hemiparesis, facial palsy, dysarthria, disorders of eye movements or vertigo. Although rarely described, involuntary abnormal movements and "convulsions" due to pontine lesions can also occur. Here we describe a 67-year-old woman with hypertension who presented with a tonic movement mimicking a versive seizure in the acute phase of bilateral pontine ischemia. Post-stroke movement disorders are well known. They are usually associated with supratentorial lesions and rarely occur in the acute phase, but "seizure-like" episodes can be seen in pontine ischemia. Awareness of this rare phenomenon is useful for the management of acute stroke patients.

The conduction system of the heart in mice chronically infected with Trypanosoma cruzi: histopathological lesions and electrocardiographic correlations

Chronic focal and diffuse myiocarditis with interstitial fibrosis developed in Swiss outbred mice and in the inbred AKR and A/J strains of mice which were chronically infected with several Trypanosoma cruzi strains belonging to three biological types (Type I, II and III). High incidence of electrocardiographic changes with predominance of intraventricular conduction disturbances, 1st. and 2nd. degree AV block, arrhythmias, comparable with those found in human Chagas' disease, were also present. Morphological study of the conduction tissue of the heart revealed inflammatory and fibrotic changes. The presence of inflammation in the inter-atrial septum almost always coincided with the inflammatory involvement of the ventricular conduction system. Focal inflammation was associated with vacuolization and focal necrosis of the specific fibers. Most of the lesions were seen affecting the His bundel (76.3% of the cases), the right bundle branch (73.3%), AV node (43.9%) and left bundle branch (37.5%). Correlation between morphological changes in the conduction tissue and electrocardiographic alteration occured in 53.0 to 62.5% of the cases, according to the experimental groups.

A contribution to the study of acute schistosomiasis (an experimental trial)

In an attempt to establish an experimental model of acute schistosomiasis, sequential histological changes were investigated in the skin, lung, liver and spleen of mice infected with 30 or 100 cercariae of Schistosoma mansoni according to four sets of experiments: single infection, repeated infections, unisexual infection and infection in mice born from infected mothers. Animals were killed every other day from exposure up to 50 days after infection. Only mild, isolated, focal inflammatory changes were found before the appearance of mature eggs in the liver, even when repeated infections were made. Severe changes of reactive hepatitis and splenitis appeared suddenly when the first mature eggs were deposited, around the 37th to 42nd day after infection. The mature eggs induced lytic and coagulative necrosis of hepatocytes around them which was soon followed by dense infiltration of eosinophils. So, mature egg-induced lesions appeared as the major factors in the pathogenesis of acute schistosomiasis in mice. Mice born from infected mothers were apparently able to rapidly modulate the egg-lesions, forming early fibrotic granulomas. The murine model of acute schistosomiasis appeared adequate for the study of pathology and pathogenesis of acute schistosomiasis.

Long-term outcome after cognitive and behavioral regression in nonlesional epilepsy with continuous spike-waves during slow-wave sleep.

PURPOSE: To present the long-term follow-up of 10 adolescents and young adults with documented cognitive and behavioral regression as children due to nonlesional focal, mainly frontal, epilepsy with continuous spike-waves during slow wave sleep (CSWS). METHODS: Past medical and electroencephalography (EEG) data were reviewed and neuropsychological tests exploring main cognitive functions were administered. KEY FINDINGS: After a mean duration of follow-up of 15.6 years (range, 8-23 years), none of the 10 patients had recovered fully, but four regained borderline to normal intelligence and were almost independent. Patients with prolonged global intellectual regression had the worst outcome, whereas those with more specific and short-lived deficits recovered best. The marked behavioral disorders resolved in all but one patient. Executive functions were neither severely nor homogenously affected. Three patients with a frontal syndrome during the active phase (AP) disclosed only mild residual executive and social cognition deficits. The main cognitive gains occurred shortly after the AP, but qualitative improvements continued to occur. Long-term outcome correlated best with duration of CSWS. SIGNIFICANCE: Our findings emphasize that cognitive recovery after cessation of CSWS depends on the severity and duration of the initial regression. None of our patients had major executive and social cognition deficits with preserved intelligence, as reported in adults with early destructive lesions of the frontal lobes. Early recognition of epilepsy with CSWS and rapid introduction of effective therapy are crucial for a best possible outcome.

Comparison of pathologic changes in mammalian hosts infected with Schistosoma mansoni, S. japonicum and S. haematobium

The hepatic, intestinal and cardiopulmonary lesions produced by Schistosoma mansoni, S. haematobium and S. japonicum in man and experimental animals often bear striking similarities but usually have distinctive features as well. These are often related to parasitologic differences. Thus S. japonicum and S. haematobium lay their eggs in clusters which elicit the formation of large composite granulomas. The worms of these two species also tend to be sedentary, remaining in a single location for prolonged periods, thus producing large focal lesions in the intestines or urinary tract. Worm pairs of these two species also are gregarious and many worm pairs are often found in a single lesion. The size of circumoval granulomas, and the degree of fibrosis, are T cell dependent. The modulation of granuloma size is largely T cell dependent in mice infected with S. mansoni but is mostly regulated by serum factors in S. japonicum infected mice. In spite of these differences in egg laying and immunoregulation both S. mansoni and S. japonicum produce Symmers' fibrosis in the chimpanzee while S. haematobium does not, despite the presence of numerous eggs in the liver.