Bud dormancy in apple trees after thermal fluctuations

The objective of this work was to evaluate the effect of heat waves on the evolution of bud dormancy, in apple trees with contrasting chilling requirements. Twigs of 'Castel Gala' and 'Royal Gala' were collected in orchards in Papanduva, state of Santa Catarina, Brazil, and were exposed to constant (3°C) or alternating (3 and 15°C for 12/12 hours) temperature, combined with zero, one or two days a week at 25°C. Two additional treatments were evaluated: constant temperature (3°C), with a heat wave of seven days at 25°C, in the beginning or in the middle of the experimental period. Periodically, part of the twigs was transferred to 25°C for daily budburst evaluation of apical and lateral buds. Endodormancy (dormancy induced by cold) was overcome with less than 330 chilling hours (CH) of constant cold in 'Castel Gala' and less than 618 CH in 'Royal Gala'. A daily 15°C-temperature cycle did not affect the endodormancy process. Heat waves during endodormancy resulted in an increased CH to achieve bud requirements. The negative effect of high temperature depended on the lasting of this condition. Chilling was partly cancelled during dormancy when the heat wave lasted 36 continuous hours or more. Therefore, budburst prediction models need adjustments, mainly for regions with mild and irregular winters, such as those of Southern Brazil.

Root abundance of maize in conventionally-tilled and zero-tilled soils of Argentina

Maize root growth is negatively affected by compacted layers in the surface (e.g. agricultural traffic) and subsoil layers (e.g. claypans). Both kinds of soil mechanical impedances often coexist in maize fields, but the combined effects on root growth have seldom been studied. Soil physical properties and maize root abundance were determined in three different soils of the Rolling Pampa of Argentina, in conventionally-tilled (CT) and zero-tilled (ZT) fields cultivated with maize. In the soil with a light Bt horizon (loamy Typic Argiudoll, Chivilcoy site), induced plough pans were detected in CT plots at a depth of 0-0.12 m through significant increases in bulk density (1.15 to 1.27 Mg m-3) and cone (tip angle of 60 º) penetrometer resistance (7.18 to 9.37 MPa in summer from ZT to CT, respectively). This caused a reduction in maize root abundance of 40-80 % in CT compared to ZT plots below the induced pans. Two of the studied soils had hard-structured Bt horizons (clay pans), but in only one of them (silty clay loam Abruptic Argiudoll, Villa Lía site) the expected penetrometer resistance increases (up to 9 MPa) were observed with depth. In the other clay pan soil (silty clay loam Vertic Argiudoll, Pérez Millán site), penetrometer resistance did not increase with depth but reached 14.5 MPa at 0.075 and 0.2 m depth in CT and ZT plots, respectively. However, maize root abundance was stratified in the first 0.2 m at the Villa Lía and Pérez Millán sites. There, the hard Bt horizons did not represent an absolute but a relative mechanical impedance to maize roots, by the observed root clumping through desiccation cracks.

Oxygen consumption of Litopenaeus vannamei juveniles in heterotrophic medium with zero water exchange

This work aimed at determining the dissolved oxygen consumption rate of Litopenaeus vannamei juveniles maintained in a microbial biofloc raceway system at high density with no aeration. Three 4 L bottles were filled for each treatment, sealed hermetically, and placed in an enclosed greenhouse raceway system. Four shrimp (13.2±1.42 g) were assigned to two sets of the bottles, which underwent the following treatments: light conditions with no shrimp; dark conditions with no shrimp; light conditions with shrimp; and dark conditions with shrimp. Dissolved oxygen content was measured every 10 min for 30 min. A quadratic behavior was observed in dissolved oxygen concentration over time. Significant differences for oxigen consumption were observed only at 10 and 20 min between shrimp maintained in the dark and those under light conditions. At 10 min, a higher value was observed in shrimp maintained under light, and at 20 min, in the dark. Significant differences between 10 and 20 min and between 10 and 30 min were observed when oxygen consumption was analyzed over time in the presence of light. Under dark conditions there were significant differences only between 20 and 30 min. Lethal oxygen concentration (0.65 mg L-1) would be reached in less than one hour either under light or dark conditions with no aeration.

Ferro zero: uma nova abordagem para o tratamento de águas contaminadas com compostos orgânicos poluentes

Anthropogenic pollution of groundwater and surface water has become a very serious environmental problem around the world. A wide range of toxic pollutants is recalcitrant to the conventional treatment methods, thus there is much interest in the development of more efficient remediation processes. Degradation of organic pollutants by zero-valent iron is one of the most promising approaches for water treatment, mainly because it is of low cost, easy to obtain and effective. After a general introduction to water pollution and current treatments, this work highlights the advances, applications and future trends of water remediation by zero-valent iron. Special attention is given to degradation of organochloride and nitroaromatic compounds, which are commonly found in textile and paper mill effluents.

Capacidad de enraizamiento de plantas matrices promisorias de Myrciaria dubia (Kunth) Mc Vaugh en cámaras de subirrigación¹

Camu camu es una fruta nativa de la Amazonía, que llama la atención por el alto contenido de vitamina C (6,116 mg/ 100 g de pulpa), está en proceso de domesticación, por lo cual se está investigando un método de propagación vegetativa que permita avanzar en el proceso de mejoramiento genético. El objetivo de este trabajo fue evaluar la capacidad rizogénica de plantas matrices promisorias de camu camu "Myrciaria dubia (Kunth) McVaugh" según el aumento del número de hojas, mediante la técnica de estacas herbáceas en cámaras de subirrigación. El ensayo fue conducido mediante un Diseño de Bloques Completamente al Azar (DBCA) con arreglo factorial 9Ax3B, con 3 repeticiones y 15 estacas por unidad experimental. El factor A, estuvo constituido por nueve plantas matrices y el factor B: pares de hojas con 3 niveles: 1; 2 y 3 pares. El enraizamiento fue evaluado después de 90 días. Se observó que existió interacción estadística significativa para las variables: porcentaje de enraizamiento, longitud y número de raíces. Para las variables porcentaje de callo y porcentaje de mortalidad se encontró efecto de la planta matriz y pares de hojas. Los resultados muestran que el porcentaje de enraizamiento estuvo influenciado por efectos intrínsecos adherentes a la variabilidad genotípica de las plantas matrices, presentando un alto grado de dispersión, que osciló entre 91,11 % y 0,00 %, mostrando una alta variabilidad y marcada influencia de la planta matriz sobre el proceso de rizogénesis, influyendo de manera altamente significativa en el enraizamiento. Con respecto al área foliar, estacas con 2 y 3 pares de hojas, independiente de la planta matriz, presentaron mayor capacidad de enraizamiento. Con base en estos resultados se concluye que el efecto de la variabilidad genotípica y el área foliar influyen de manera altamente significativa en el proceso de rizogénesis de estacas herbáceas de camu camu.

Comparison of different methods for the determination of total organic carbon and humic substances in Brazilian soils

ABSTRACTAiming to compare three different methods for the determination of organic carbon (OC) in the soil and fractions of humic substances, seventeen Brazilian soil samples of different classes and textures were evaluated. Amounts of OC in the soil samples and the humic fractions were measured by the dichromate-oxidation method, with and without external heating in a digestion block at 130 °C for 30 min; by the loss-on-ignition method at 450 °C during 5 h and at 600 °C during 6 h; and by the dry combustion method. Dry combustion was used as reference in order to measure the efficiency of the other methods. Soil OC measured by the dichromate-oxidation method with external heating had the highest efficiency and the best results comparing to the reference method. When external heating was not used, the mean recovery efficiency dropped to 71%. The amount of OC was overestimated by the loss-on-ignition methods. Regression equations obtained between total OC contents of the reference method and those of the other methods showed relatively good adjustment, but all intercepts were different from zero (p < 0.01), which suggests that more accuracy can be obtained using not one single correction factor, but considering also the intercept. The Walkley-Black method underestimated the OC contents of the humic fractions, which was associated with the partial oxidation of the humin fraction. Better results were obtained when external heating was used. For the organic matter fractions, the OC in the humic and fulvic acid fractions can be determined without external heating if the reference method is not available, but the humin fraction requires the external heating.

Imunidade relativa à poliomielite em crianças de zero a dez anos, após o "Quarto Dia Nacional de Vacinação Contra a Poliomielite" com a vacinação oral trivalente, tipo Sabin, em área da Região da Grande São Paulo, SP (Brasil), 1982

Efetuou-se um levantamento soro-epidemiológico, abrangendo 898 crianças, para a verificação da imunidade aos poliovírus 1, 2 e 3 por meio da determinação dos títulos de anticorpos neutralizantes. De 522 crianças, ou seja, de 58,1% da população estudada, foi possível a obtenção de informações referentes à situação vacinal a partir de anotações existentes nas próprias Cadernetas de Vacinação. Neste último sub-grupo foi estudado o estado imunitário em relação ao número de doses de vacina oral tipo Sabin recebidas. Os resultados mostraram alta proporção de imunes para os três tipos de poliovírus entre as crianças estudadas, porém também revelaram a existência de lacuna imunitária nos menores de um ano, especialmente no primeiro semestre de vida. Não foram observadas diferenças importantes na proporção de imunes segundo o sorotipo considerado. Salientou-se a necessidade de um alerta constante e permanente em relação à ocorrência de possíveis surtos epidêmicos em segmentos mais vulneráveis da população, particularmente entre crianças menores de 1 ano.

Studies on some species of Culex (Melanoconion), with the description of a new one from Southern Brazil (Diptera: Culicidae)

Redescription of Culex (Melanoconion) oedipus Root and of Cx. (Mel.) plectoporpe Root, as well as the description of a new one, named Cx. (Mel.) rabelloi, are made. The material was collected in S.Paulo State, Southern Brazil. The descriptions include adults, pupal and larval stages, illustrating the morphological aspects and with pictures of breeding places. Some data about known distribution and bionomics are presented, remarking that all the three species seem to be closely associated with artificial manmade enviroments.

Diagnóstico nutricional de crianças de zero a cinco anos atendidas pela rede municipal de saúde em área urbana da região sul do Brasil, 1988

Como um dos requisitos para a operacionalização do Sistema de Vigilância Alimentar e Nutricional (SISVAN) no município de Curitiba, PR, Brasil, foi realizado um levantamento epidemiológico retrospectivo com dados de 1988, que buscou através do exame antropométrico conhecer a prevalência e as formas de desnutrição calórico-protéico de crianças menores de cinco anos atendidas pela Rede Municipal de Saúde de Curitiba. Numa amostra de 4.213 crianças encontrou-se pela Classificação de Gòmez 28,1% de desnutridos, sendo que 3,6% destes situam-se no grau II e III. A Classificação de Seoane e Latham modificada por Batista Filho revelou que 19,7% das crianças apresentam alguma forma de desnutrição. O perfil antropométrico revelou maior concentração de crianças no primeiro decil a partir do sexto mês de vida, sendo esta mais acentuada no grupo etário de 12 a 24 meses para os índices: peso/idade e altura/idade.

Anticorpos neutralizantes contra poliovírus em soros de recém-nascidos antes e após imunização em massa da população brasileira de zero a cinco anos de idade. São Paulo, Brasil (1980)

Foram colhidas amostras de sangue de 178 recém-nascidos (RN) em berçários de hospital localizado no Município de São Paulo. Noventa crianças foram puncionadas antes do primeiro "Dia Nacional de Vacinação Contra a Poliomielite" e as outras 88, após o segundo "Dia Nacional de Vacinação Contra a Poliomielite", realizados em 1980. Nessas campanhas foram imunizadas as crianças com idade de zero a cinco anos, em todo o Brasil. No presente trabalho pesquisou-se os títulos de anticorpos neutralizantes contra poliovírus nos dois grupos de recém-nascidos. Após a imunização em massa verificou-se que a taxa de recém-nascidos triplo suscetíveis decresceu de 8,9% para 4,5%, enquanto que o aumento observado do triplo imunes foi de 38,9% para 52,3%; essas diferenças mostraram-se estatisticamente significantes ao nível de 5,0%. A proporção de recém-nascidos, com títulos de anticorpos neutralizantes contra poliovírus iguais ou maiores do que 8, aumentou após as campanhas de imunização, quando passaram de 68,9% para 81,8%, de 73,3% para 83,0% e de 57,8% para 70,5%, respectivamente, para os sorotipos 1, 2 e 3. Essas diferenças mostraram se estatisticamente significantes, ao nível de 5,0%, em relação aos poliovírus 1 e 3.

Molluscum contagiosum: serology and electron microscopy findings in twenty one patients

Twenty one cases of molluscum contagiosum virus disease were collected for electron microscopical and serological tests. Molluscum virus was detected in the crust, inside the vacuoles formed in the keratinocytes cells. The patients developed specific antibodies to the virus detected by complement fixation test.

Antibody response to heat-inactivated hepatitis B vaccine (CLB-3mg) in hemodialysis patients and occupational risk personnel: a one year follow-up

Immune response against hepatitis B vaccine (CLB 3mg) was evaluated in 59 hemodialysis patients and 20 occupational risk personnel. Seroconversion was induced in 52.5% and 70.0% respectively. Twelve months after the first dose, 37.5% of patients and 60.0% of occupational risk personnel had detectable anti-HBs level. Antibody level was expressed in sample ratio units (SRU). Considering only the responders, in the patients group 38.7% had a low anti-HBs response (2.1-9.9 SRU) 32.3% a medium response (10-99.9 SRU) and 29.0% a high response (>100 SRU) while in occupational risk personnel these values were 14.3%, 64.3% and 21.4% respectively. The authors suggest the use of HBV vaccines with more elevated HBsAg concentration or a reinforced immunization schedule to improve the anti-HBs response not only for patients but also for healthy persons.

High prevalence of hepatitis C infection among Brazilian hemodialysis patients in Rio de Janeiro: a one-year follow-up study

Nearly 400 hemodialysis patients treated at 5 different hemodialysis units in Rio de Janeiro were tested for one year for the presence of hepatitis C and B markers. During the same period, samples were also obtained from 35 continuous ambulatory peritoneal dialysis (CAPD) patients and from 242 health care workers. Depending on the hemodialysis unit studied, anti-HCV prevalence rates ranging from 47% to 82% (mean 65%) were detected. CAPD patients showed a lower prevalence of 17%. The prevalence of antibodies against hepatitis C virus (anti-HCV) among health care workers was 2.9%. We observed a hepatitis C attack rate of 11.5% per year in the anti-HCV-negative hemodialysis patient population. An average of 9.4% of the hemodialysis patients were chronic carriers of hepatitis B virus (HBV) (range 1.8% - 20.4%), while 48.9% showed markers of previous HBV infection. The HBV attack rate was 4.5% per year (range 0% - 6%). These results indicate an alarming high prevalence of anti-HCV among hemodialysis patients of this studied region.

Studies on human anti-rabies immunization in Brazil: II - Preliminary evaluation of the 2-1-1 schedule for human pre-exposure anti-rabies immunization, employing suckling mouse brain vaccine

This study reports preliminary results of virus neutralizing antibody (VNA) titers obtained on different days in the course of human anti-rabies immunization with the 2-1-1 schedule (one dose is given in the right arm and one dose in the left arm at day 0, and one dose is apllied on days 7 and 21), recommended by WHO for post-exposure treatment with cell culture vaccines. A variant schedule (double dose on day zero and another on day 14) was also tested, both employing suckling mouse brain vaccine. A complete seroconversion rate was obtained after only 3 vaccine doses, and almost all patients (11 of 12) presented titers higher than 1.0 IU/ml. Both neutralizing response and seroconversion rates were lower in the group receiving only 3 doses, regardless of the sample collecting day. Although our results are lower than those found with cell culture vaccines, the geometry mean of VNA is fully satisfactory, overcoming the lower limit recommended by WHO of 0.5 IU/ml. The 2-1-1 schedule could be an alternative one for pre exposure immunization, shorter than the classical 3+1 regimen (one dose on days 0, 2, 4 and 30) with only three visits to the doctor, instead of four.