Conservadorismo cont��bil nas companhias abertas e fechadas brasileiras

Objetiva-se neste artigo identificar a exist��ncia de diferen��as significativas entre companhias abertas e fechadas brasileiras no n��vel de conservadorismo de suas demonstra����es cont��beis. A pesquisa, do tipo explorat��ria e descritiva, baseia-se em amostra composta por 1.384 empresas-ano, sendo 770 observa����es referentes a companhias fechadas e 614 a companhias abertas, no per��odo de 2000 a 2004. Utilizou-se o modelo de Ball e Shivakumar (2005) que permite analisar o n��vel de conservadorismo por meio da revers��o dos resultados cont��beis. Os resultados obtidos evidenciam que as companhias fechadas apresentam menor probabilidade de reconhecimento oportuno das perdas e, por isso, possuem menor n��vel de conservadorismo nas demonstra����es cont��beis em rela����o ��s companhias abertas.

Onde investir nos BRICS? Uma an��lise sob o prisma da organiza����o industrial

O presente estudo tem como objetivo identificar os setores mais atrativos para investimento do Brasil, R��ssia, ��ndia e China (BRICs) conforme a rela����o risco-retorno e gera����o de valor, tendo como base de estudos a teoria de Organiza����o Industrial (OI). Para isso, este trabalho analisou 2.770 empresas nos BRICs entre 1995 e 2008. Assim, foram investigados e comparados ��ndices de desempenho como retorno sobre ativo (ROA), retorno sobre a����es (ROE), ��ndice pre��o-lucro, valor de mercado sobre valor cont��bil e Q de Tobin das empresas. Os resultados obtidos refor��am os de Fama e French (1992), Mohanram (2005) e Goldszmidt, Brito e Vasconcelos (2007), por��m divergem do World Bank (2008) quanto �� China. Constatou-se que os setores mais atrativos na perspectiva de risco-retorno sobre o patrim��nio l��quido seriam ��leo & g��s na R��ssia e minera����o no Brasil, ��ndia e China, enquanto aqueles com menor atratividade seriam os setores t��xtil, motores, m��quinas & ferramentas e telecomunica����es no Brasil.

Preval��ncia de asma e sintomas asm��ticos em escolares de 13 e 14 anos de idade

OBJETIVO: Antes do uso do question��rio padronizado ISAAC (International Study of Asthma and Allergies in Childhood) em inqu��ritos epidemiol��gicos, pouco se conhecia sobre a ocorr��ncia comparativa de asma no mundo, dados os diferentes m��todos empregados. No Brasil, outros estudos utilizaram o question��rio ISAAC em regi��es urbanas. Realizou-se estudo utilizando esse question��rio nas zonas urbana e rural com o objetivo de estimar a preval��ncia de asma em escolares. M��TODOS: Estudo transversal com o question��rio escrito ISAAC, acrescido de perguntas sobre exposi����es de interesse, auto-aplicado em 3.770 escolares de 13 e 14 anos de idade do munic��pio de Montes Claros (MG) selecionados por sorteio. RESULTADOS: A preval��ncia de "sibilos no ��ltimo ano" foi 15,8%, e de "asma ou bronquite alguma vez na vida" 23,8%, sem diferen��a significativa entre sexos. Houve diferen��a estat��stica (p<0,05) entre sexos (feminino e masculino, respectivamente) em "sibilos alguma vez na vida" (37,8% e 33,6%), "sono alterado devido �� crise de sibilos" (13,7% e 9,5%) e "tosse seca noturna sem infec����o respirat��ria" (36,6% e 28,7%). Houve associa����o nociva entre "sibilos no ��ltimo ano", "contato com animais dom��sticos" (OR=1,27; IC 95%: 1,03-1,56) e "hist��ria familiar de asma" (OR=1,79; IC 95%: 1,50-2,14), e associa����o protetora entre "sibilos no ��ltimo ano" e "localiza����o rural da escola" (OR=0,63; IC 95%: 0,44-0,91), mas n��o houve associa����o com sexo, idade, dom��nio escolar e tabagismo passivo. CONCLUS��ES: A preval��ncia de asma na amostra estudada foi elevada, com alguns sintomas predominantes no sexo feminino. A ocorr��ncia de "sibilos no ��ltimo ano" mostrou-se associada �� hist��ria familiar, contato com animais dom��sticos e localiza����o urbana das escolas.

Preval��ncia de parasitoses intestinais entre os usu��rios do centro de sa��de do Distrito de Sousas, Campinas, SP (1986-1990)

A preval��ncia das parasitoses intestinais foi levantada nos usu��rios do Centro de Sa��de do Distrito de Sousas, Campinas, SP entre 1986 e 1990. Dentre 770 prontu��rios observados constatou-se 114 casos positivos (14,8%) para protozo��rios, helmintos ou comensais. Ascaris lumbricoides (48,2%) seguido de Giardia lamblia (30,7%), Trichuris trichiura (18,4%) e Enterobius vermicularis (9,6%) foram mais prevalentes na faixa et��ria dos pr��-escolares. Os adultos, em maior n��mero na amostra, apresentam-se pouco parasitados. Os demais parasitos e comensais, concorrem com preval��ncia proporcional aos inqu��ritos tradicionais realizados na popula����o brasileira, �� exce����o da aus��ncia de ten��deos e baixa preval��ncia de Aneylostomatidae. Sugere-se a realiza����o de exame protoparasitol��gico de rotina entre os pr��-escolares e a utiliza����o de dados dos postos de atendimento prim��rio nos inqu��ritos parasitol��gicos.

Phlebotomine sandflies (Diptera: Psychodidae) in S��o Vicente F��rrer, a sympatric area to cutaneous and visceral leishmaniasis in the state of Pernambuco, Brazil

INTRODUCTION: In the last decades, a considerable geographic expansion of the leishmaniases in all regions of Brazil has been observed. The present study was carried out to identify the composition of the phlebotomine sandfly fauna and verify the seasonal variation of the main species after environmental changes occurred in S��o Vicente F��rrer Municipality, State of Pernambuco, Brazil. METHODS: Captures were carried out during four consecutive nights of each month using Centers for Disease Control and Prevention light traps from September 2009 to September 2010. The correlation between the number of phlebotomine sandflies captured and climatic factors (temperature and rainfall) was evaluated. RESULTS: A total of 13,872 specimens belonging to 20 species were captured, of which, 6,247 (45%) were females, and 7,625 (55%) were males. Lutzomyia migonei was the most abundant species with 9,964 (71.8%) specimens, being predominant in the intradomicile and peridomicile areas with 108 (86.4%) and 9,746 (97%), respectively. In the forest remnants, Lutzomyia complexa 2,395 (65%) and Lutzomyia sordellii 770 (20.8%) predominated. The correlation analysis between the total number of sandflies captured and climatic factors did not show a significant influence on population density. CONCLUSIONS: The high abundance of Lutzomyia migonei and Lutzomyia complexa indicates the possibility of new cases of cutaneous leishmaniasis (CL).

Liver fibrosis progression in HIV/hepatitis C virus coinfected patients with normal aminotransferases levels

INTRODUCTION: Approximately 30% of hepatitis C virus (HCV) monoinfected patients present persistently normal alanine aminotransferase (ALT) levels. Most of these patients have a slow progression of liver fibrosis. Studies have demonstrated the rate of liver fibrosis progression in hepatitis C virus-human immunodeficiency virus (HCV-HIV) coinfected patients is faster than in patients infected only by HCV. Few studies have evaluated the histological features of chronic hepatitis C in HIV-infected patients with normal ALT levels. METHODS: HCV-HIV coinfected patients (HCV-RNA and anti-HIV positive) with known time of HCV infection (intravenous drugs users) were selected. Patients with hepatitis B surface antigen (HBsAg) positive or hepatitis C treatment before liver biopsy were excluded. Patients were considered to have a normal ALT levels if they had at least 3 normal determinations in the previous 6 months prior to liver biopsy. All patients were submitted to liver biopsy and METAVIR scale was used. RESULTS: Of 50 studied patients 40 (80%) were males. All patients were treated with antiretroviral therapy. The ALT levels were normal in 13 (26%) patients. HCV-HIV co-infected patients with normal ALT levels had presented means of the liver fibrosis stages (0.77��0.44 versus 1.86��1.38; p<0.001) periportal inflammatory activity (0.62��0.77 versus 2.24��1.35; p<0.001) and liver fibrosis progression rate (0.058��0.043 fibrosis unit/year versus 0.118��0.102 fibrosis unit/year) significantly lower as compared to those with elevated ALT. CONCLUSIONS: HCV-HIV coinfected patients with persistently normal ALTs showed slower progression of liver fibrosis. In these patients the development of liver cirrhosis is improbable.

Assessment of schistosomiasis in the semi-arid Northeast region of Brazil: the S��o Francisco River large-scale water transposition project

Abstract: INTRODUCTION Risk of schistosomiasis expansion to semi-arid northeastern Brazil under the influence of the Integration Project of the S��o Francisco River (IPSFR) was assessed. METHODS: Stool examinations of schoolchildren, epidemiological investigation, and survey of the local host snail Biomphalaria straminea were performed in five IPSFR municipalities. RESULTS Six of 4,770 examined schoolchildren were egg-positive for Schistosoma mansoni. Biomphalaria straminea was widespread, but not naturally infected with S. mansoni. Snails experimentally exposed to two laboratory S. mansoni strains yielded infection indices of 1-4.5%. CONCLUSIONS: There is evidence of active schistosomiasis transmission in the area; thus, intensive surveillance actions are required.

Vegetational changes during the last millennium inferred from a palynological record from the Bananal Island, Tocantins, Brazil

The Bananal Island is regarded the largest fluvial island in the world, bounded by Araguaia and Java&#233;s rivers, being located in southwest of Tocantins. The objectives of this work were to provide information about the vegetational changes that occurred at the Bananal Island, in order to contribute to the understanding the dynamics of past and current savanna and areas of ecotones with forests. Thus, a sedimentary core collected from a small lake at the Bananal Island plain was submitted to pollen and radiocarbon dating analyses. The results showed that the last millennium was dominated by forest reflecting a wet climate. At the beginning of the record (920-770 yr cal BP) the wet climate and high rainfall produced flooding during long rainy seasons that maintained the Java&#233;s River connected to the studied lake, and hence, this environment was marked by the presence of a homogenous forest rich in Moraceae/Urticaceae, due to flooded soils occurrence. During the following period (770-304 yr cal BP) the reduced rainfall and shortening of the rainy seasons isolated the lake from the Java&#233;s River for long periods, which caused a diversification of the forest and gave rise to the appearance of the components of floodplain forest and marsh vegetation adapted to waterlogged soils. Since 304 years cal BP to the present day this environment remained dominated by this diverse forest and the lacustrine conditions were also similar to previous phase, with a slight increase of moisture in the last 84 years that caused the increase of Piranhea.

Estudo multic��ntrico do implante de stent intracoron��rio no Rio de Janeiro

OBJETIVO: Avaliar retrospectivamente, implante de stent (IS) em paciente com doen��a arterial coron��ria (DAC), realizado em 7 hospitais do Rio de Janeiro. M��TODOS: De junho/94 a dezembro/96, foram realizados 2.220 procedimentos, e desses, analisados 783 IS em 660 (29,7%) pacientes, atrav��s da coronariografia sem subtra����o digital. Os diversos tipos de stent, mais freq��entemente, usados foram: Palmaz-Schatz (40,9%), Gianturco-Roubin (29,1%) e NIR (22,0%). As indica����es para o IS foram: les��o de novo, 67,9%; les��o reesten��tica, 16,0%; les��o com resultado sub��timo da angioplastia transluminal coron��ria (ATC), 8,2%; oclus��o aguda ou prov��vel p��s-ATC, 4,9%; oclus��o cr��nica, 3,0%. Todos os stents foram implantados com alta press��o, sem controle pelo ultra-som intracoron��rio. A preven����o da trombose subaguda, na maioria dos pacientes (87,8%), foi feita com o uso de ticlopidina e ��cido acetil-salic��lico. RESULTADOS: Evolu����o imediata: a) sucesso no IS em 770 les��es: 98,0% em 646 (97,9%) pacientes; b) sucesso cl��nico em 634 (96,0%) casos; c) complica����es maiores: infarto agudo do mioc��rdio (IAM) - 1,1%; cirurgia de revasculariza����o mioc��rdica (CRM) - 1,4% e ��bito - 0,8%; d) complica����es vasculares com corre����o cir��rgica e/ou sangramento - 3,0%. Evolu����o tardia: a) dos 399 (60,4%) pacientes acompanhados clinicamente, a coronariografia de 121 (30,3%) mostrou retorno da les��o no IS em 79 (19,8%) casos; b) freq����ncia de outros eventos: IAM - 1,5%; CRM - 2,3%; ��bito -1,0% e outra ATC ou procedimento similar - 12,5%. CONCLUS��O: O estudo multic��ntrico mostrou que o IS na DAC pode ser realizado com seguran��a, alto ��ndice de sucesso imediato, poucas complica����es e baixa taxa de eventos card��acos na evolu����o tardia.

Cardiovers��o el��trica e les��o mioc��rdica: avalia����o pelos novos marcadores de inj��ria card��aca

OBJETIVO: Avaliar, atrav��s da evolu����o dos novos marcadores bioqu��micos de inj��ria card��aca, se a cardiovers��o el��trica (CVE) causa les��o mioc��rdica. M��TODOS: Foram avaliados 76 pacientes (P) submetidos a CVE eletiva de fibrila����o atrial ou flutter atrial. Medidas de creatinafosfoquinase (CPK), CKMB-atividade e dosagem de CKMB-massa (M), mioglobina e troponina I card��aca (cTnI) foram determinadas antes e ap��s 6 e 24 horas da CVE. RESULTADOS: A CVE resultou um sucesso em 58 P (76,3%). A carga cumulativa (CC) foi de at�� 350 joules (J) em 36 P, de 500 a 650 J em 20 P e de 900 a 960 J em 20 P, com energia m��dia aplicada de 493 J (�� 309). A cTnI permaneceu dentro da normalidade nos 76 P. Com o aumento da CC, ocorreu eleva����o de CPK (> valor de p = 0,007), CKMB-atividade (> valor de p = 0,002), CKMB-M (> valor de p = 0,03) e mioglobina (> valor de p = 0,015). Correla����o positiva foi observada entre a CC e picos de CPK (r = 0,660; p < 0,001), CKMB-atividade (r = 0,429; p < 0,0001), CKMB-M (r = 0,265; p = 0,02) e mioglobina (r = 0,684; p < 0,0001). Correla����o tamb��m positiva ocorreu entre o n��mero de choques e picos de CPK (r = 0,770; p < 0,001), CKMB-atividade (r = 0,642; p < 0,0001), CKMB-M (r = 0,430; p < 0,0001) e mioglobina (r = 0,745; p < 0,0001). CONCLUS��O: A CVE n��o causa les��o mioc��rdica detect��vel pela dosagem da cTnI. Eleva����es de CPK, CKMB-atividade, CKMB-M e mioglobina s��o decorrentes de les��o do m��sculo esquel��tico, estando correlacionadas positivamente com a CC aplicada ou com o n��mero de choques.

Cost-Effectiveness of High, Moderate and Low-Dose Statins in the Prevention of Vascular Events in the Brazilian Public Health System

Background:Statins have proven efficacy in the reduction of cardiovascular events, but the financial impact of its widespread use can be substantial.Objective:To conduct a cost-effectiveness analysis of three statin dosing schemes in the Brazilian Unified National Health System (SUS) perspective.Methods:We developed a Markov model to evaluate the incremental cost-effectiveness ratios (ICERs) of low, intermediate and high intensity dose regimens in secondary and four primary scenarios (5%, 10%, 15% and 20% ten-year risk) of prevention of cardiovascular events. Regimens with expected low-density lipoprotein cholesterol reduction below 30% (e.g. simvastatin 10mg) were considered as low dose; between 30-40%, (atorvastatin 10mg, simvastatin 40mg), intermediate dose; and above 40% (atorvastatin 20-80mg, rosuvastatin 20mg), high-dose statins. Effectiveness data were obtained from a systematic review with 136,000 patients. National data were used to estimate utilities and costs (expressed as International Dollars - Int$). A willingness-to-pay (WTP) threshold equal to the Brazilian gross domestic product per capita (circa Int$11,770) was applied.Results:Low dose was dominated by extension in the primary prevention scenarios. In the five scenarios, the ICER of intermediate dose was below Int$10,000 per QALY. The ICER of the high versus intermediate dose comparison was above Int$27,000 per QALY in all scenarios. In the cost-effectiveness acceptability curves, intermediate dose had a probability above 50% of being cost-effective with ICERs between Int$ 9,000-20,000 per QALY in all scenarios.Conclusions:Considering a reasonable WTP threshold, intermediate dose statin therapy is economically attractive, and should be a priority intervention in prevention of cardiovascular events in Brazil.

Estudos experimentais s��bre a origem do milho

1) It may seem rather strange that, in spite of the efforts of a considerable number of scientists, the problem of the origin of indian corn or maize still has remained an open question. There are no fossil remains or archaeological relics except those which are quite identical with types still existing. (Fig. 1). The main difficulty in finding the wild ancestor- which may still exist - results from the fact that it has been somewhat difficult to decide what it should be like and also where to look for it. 2) There is no need to discuss the literature since an excellent review has recently been published by MANGELSDORF and REEVES (1939). It may be sufficient to state that there are basically two hypotheses, that of ST. HILAIRE (1829) who considered Brazilian pod corn as the nearest relative of wild corn still existing, and that of ASCHERSON (1875) who considered Euchlaena from Central America as the wild ancestor of corn. Later hypotheses represent or variants of these two hypotheses or of other concepts, howewer generally with neither disproving their predecessors nor showing why the new hypotheses were better than the older ones. Since nearly all possible combinations of ideas have thus been put forward, it har- dly seems possible to find something theoretically new, while it is essential first to produce new facts. 3) The studies about the origin of maize received a new impulse from MANGELSDORF and REEVES'S experimental work on both Zea-Tripsacum and Zea-Euchlaena hybrids. Independently I started experiments in 1937 with the hope that new results might be obtained when using South American material. Having lost priority in some respects I decided to withold publication untill now, when I can put forward more concise ideas about the origin of maize, based on a new experimental reconstruction of the "wild type". 4) The two main aspects of MANGELSDORF and REEVES hypothesis are discussed. We agree with the authors that ST. HILAIRE's theory is probably correct in so far as the tunicata gene is a wild type relic gene, but cannot accept the reconstruction of wild corn as a homozygous pod corn with a hermaphroditic tassel. As shown experimentally (Fig. 2-3) these tassels have their central spike transformed into a terminal, many rowed ear with a flexible rachis, while possessing at the same time the lateral ear. Thus no explanation is given of the origin of the corn ear, which is the main feature of cultivated corn (BRIEGER, 1943). The second part of the hypothesis referring to the origin of Euchlaena from corn, inverting thus ASCHERSON's theory, cannot be accepted for several reasons, stated in some detail. The data at hand justify only the conclusion that both genera, Euchlaena and Zea, are related, and there is as little proof for considering the former as ancestor of the latter as there is for the new inverse theory. 5) The analysis of indigenous corn, which will be published in detail by BRIEGER and CUTLER, showed several very primitive characters, but no type was found which was in all characters sufficiently primitive. A genetical analysis of Paulista Pod Corn showed that it contains the same gene as other tunicates, in the IV chromosome, the segregation being complicated by a new gametophyte factor Ga3. The full results of this analysis shall be published elsewhere. (BRIEGER). Selection experiments with Paulista Pod Corn showed that no approximation to a wild ancestor may be obtained when limiting the studies to pure corn. Thus it seemed necessary to substitute "domesticated" by "wild type" modifiers, and the only means for achieving this substitution are hybridizations with Euchlaena. These hybrids have now been analysed init fourth generation, including backcrosses, and, again, the full data will be published elsewhere, by BRIEGER and ADDISON. In one present publication three forms obtained will be described only, which represent an approximation to wild type corn. 6) Before entering howewer into detail, some arguments against ST. HILAIRE's theory must be mentioned. The premendelian argument, referring to the instability of this character, is explained by the fact that all fertile pod corn plants are heterozygous for the dominant Tu factor. But the sterility of the homozygous TuTu, which phenotypically cannot be identified, is still unexplained. The most important argument against the acceptance of the Tunicata faetor as wild type relic gene was removed recently by CUTLER (not yet published) who showed that this type has been preserved for centuries by the Bolivian indians as a mystical "medicine". 7) The main botanical requirements for transforming the corn ear into a wild type structure are stated, and alternative solutions given. One series of these characters are found in Tripsacum and Euchlaena : 2 rows on opposite sides of the rachis, protection of the grains by scales, fragility of the rachis. There remains the other alternative : 4 rows, possibly forming double rows of female and male spikelets, protection of kernels by their glumes, separation of grains at their base from the cob which is thin and flexible. 8) Three successive stages in the reconstruction of wild corn, obtained experimentally, are discussed and illustrated, all characterized by the presence of the Tu gene. a) The structure of the Fl hybrids has already been described in 1943. The main features of the Tunicata hybrids (Fig. -8), when compared with non-tunicate hybrids (Fig. 5-6), consist in the absence of scaly protections, the fragility of the rachis and finally the differentiation of the double rows into one male and one female spikelet. As has been pointed out, these characters represent new phenotypic effects of the tunicate factor which do not appear in the presence of pure maize modifiers. b) The next step was observed among the first backcross to teosinte (Fig. 9). As shown in the photography, Fig. 9D, the features are essencially those of the Fl plants, except that the rachis is more teosinte like, with longer internodes, irregular four-row-arrangement and a complete fragility on the nodes. c) In the next generation a completely new type appeared (Fig. 10) which resembles neither corn nor teosinte, mainly in consequence of one character: the rachis is thin and flexible and not fragile, while the grains have an abscission layer at the base, The medium sized, pointed, brownish and hard granis are protected by their well developed corneous glumes. This last form may not yet be the nearest approach to a wild grass, and I shall try in further experiments to introduce other changes such as an increase of fertile flowers per spikelet, the reduction of difference between terminal and lateral inflorescences, etc.. But the nature of the atavistic reversion is alveadwy such that it alters considerably our expectation when looking for a still existing wild ancestor of corn. 9) The next step in our deductions must now consist in an reversion of our question. We must now explain how we may obtain domesticated corn, starting from a hypothetical wild plant, similar to type c. Of the several changes which must have been necessary to attract the attention of the Indians, the following two seem to me the most important: the disappearance of all abscission layers and the reduction of the glumes. This may have been brought about by an accumulation of mutations. But it seems much more probable to assume that some crossing with a tripsacoid grass or even with Tripsacum australe may have been responsible. In such a cross, the two types of abscission layer would be counterbalanced as shown by the Flhybrids of corn, Tripsacum and Euchlaena. Furthermore in later generations a.tu-allele of Tripsacum may become homozygous and substitute the wild tunicate factor of corn. The hypothesis of a hybrid origin of cultivated corn is not completely new, but has been discussed already by HARSHBERGER and COLLINS. Our hypothesis differs from that of MANGELSDORF and REEVES who assume that crosses with Tripsacum are responsible only for some features of Central and North American corn. 10) The following arguments give indirects evidence in support of our hypothesis: a) Several characters have been observed in indigenous corn from the central region of South America, which may be interpreted as "tripsacoid". b) Equally "zeoid" characters seem to be present in Tripsacum australe of central South-America. c) A system of unbalanced factors, combined by the in-tergeneric cross, may be responsible for the sterility of the wild type tunicata factor when homozygous, a result of the action of modifiers, brought in from Tripsacum together with the tuallele. d) The hybrid theory may explain satisfactorily the presence of so many lethals and semilethals, responsible for the phenomenon of inbreeding in cultivated corn. It must be emphasized that corn does not possess any efficient mechanism to prevent crossing and which could explain the accumulation of these mutants during the evolutionary process. Teosinte which'has about the same mechanism of sexual reproduction has not accumulated such genes, nor self-sterile plants in spite of their pronounced preference for crossing. 11) The second most important step in domestication must have consisted in transforming a four rowed ear into an ear with many rows. The fusion theory, recently revived byLANGHAM is rejected. What happened evidently, just as in succulent pXants (Cactus) or in cones os Gymnosperms, is that there has been a change in phyllotaxy and a symmetry of longitudinal rows superimposed on the original spiral arrangement. 12) The geographical distribution of indigenous corn in South America has been discussed. So far, we may distinguish three zones. The most primitive corn appears in the central lowlands of what I call the Central Triangle of South America: east of the Andies, south of the Amazone-Basin, Northwest of a line formed by the rivers S��o Prancisco-Paran�� and including the Paraguay-Basin. The uniformity of the types found in this extremely large zone is astonishing (BRIEGER and CUTLER). To the west, there is the well known Andian region, characterized by a large number of extremely diverse types from small pop corn to large Cuszco, from soft starch to modified sweet corn, from large cylindrical ears to small round ears, etc.. The third region extends along the atlantic coast in the east, from the Caribean Sea to the Argentine, and is characterized by Cateto, an orange hard flint corn. The Andean types must have been obtained very early, and undoubtedly are the result of the intense Inca agriculture. The Cateto type may be obtained easily by crosses, for instance, of "S��o Paulo Pointed Pop" to some orange soft corn of the central region. The relation of these three South American zones to Central and North America are not discussed, and it seems essential first to study the intermediate region of Ecuador, Colombia and Venezuela. The geograprical distribution of chromosome knobs is rapidly discussed; but it seems that no conclusions can be drawn before a large number of Tripsacum species has been analysed.

Studies on male genitalia of sarcophagidae (Diptera) based on scanning electron microscope observations

Male genitalia of Oxyvinia exicisa (Lopes), Oxysarcodexia thomax (Walker), O. fluminensis Lopes, Sarcodexia lambens (Wiedemann), Peckia chrysostoma (Wiedemann) and Liopygia ruficornis (Fabricius) were studied based on scanning electron microscope photography. Some important details were evidentiated with this method.

Towards the Physical Map of the Trypanosoma cruzi Nuclear Genome: Construction of YAC and BAC Libraries of the Reference Clone T. cruzi CL-Brener

Strategies to construct the physical map of the Trypanosoma cruzi nuclear genome have to capitalize on three main advantages of the parasite genome, namely (a) its small size, (b) the fact that all chromosomes can be defined, and many of them can be isolated by pulse field gel electrophoresis, and (c) the fact that simple Southern blots of electrophoretic karyotypes can be used to map sequence tagged sites and expressed sequence tags to chromosomal bands. A major drawback to cope with is the complexity of T. cruzi genetics, that hinders the construction of a comprehensive genetic map. As a first step towards physical mapping, we report the construction and partial characterization of a T. cruzi CL-Brener genomic library in yeast artificial chromosomes (YACs) that consists of 2,770 individual YACs with a mean insert size of 365 kb encompassing around 10 genomic equivalents. Two libraries in bacterial artificial chromosomes (BACs) have been constructed, BACI and BACII. Both libraries represent about three genome equivalents. A third BAC library (BAC III) is being constructed. YACs and BACs are invaluable tools for physical mapping. More generally, they have to be considered as a common resource for research in Chagas disease

Ultrasound monitoring of structural urinary tract disease in Schistosoma haematobium infection

A major advance in our understanding of the natural history of Schistosoma haematobium-related morbidity has come through the introduction of the portable ultrasound machines for non-invasive examination of the kidneys and bladder. With the use of generators or battery packs to supply power in non-clinical field settings, and with the use of instant photography or miniaturized thermal printers to record permanent images, it is possible to examine scores of individuals in endemic communities every day. Broad-based ultrasound screening has allowed better definition of age-specific disease risks in urinary schistosomiasis. Results indicate that urinary tract abnormalities are common (18% overall prevalence) in S. haematobium transmission areas, with a 2-4% risk of either severe bladder abnormality or advanced ureteral obstruction. In longitudinal surveys, ultrasound studies have shown that praziquantel and metrifonate therapy are rapidly effective in reversing urinary tract abnormalities among children. The benefits of treating adults are less well known, but research in progress should help to define this issue. Similarly, the prognosis of specific ultrasound findings needs to be clarified, and the ease of sonographic examination will make such long-term follow-up studies feasible. In summary, the painless, quick, and reproducible ultrasound examination has become an essential tool in the study of urinary schistosomiasis.