Leachate/domestic wastewater aerobic co-treatment: A pilot-scale study using multivariate analysis

Multivariate analysis was used to identify the variables affecting the performance of pilot-scale activated sludge (AS) reactors treating old leachate from a landfill and from domestic wastewater. Raw leachate was pre-treated using air stripping to partially remove the total ammoniacal nitrogen (TAN). The control AS reactor (AS-0%) was loaded only with domestic wastewater, whereas the other reactor was loaded with mixtures containing leachate at volumetric ratios of 2 and 5%. The best removal efficiencies were obtained for a ratio of 2%, as follows: 70 ± 4% for total suspended solids (TSS), 70 ± 3% for soluble chemical oxygen demand (SCOD), 70 ± 4% for dissolved organic carbon (DOC), and 51 ± 9% for the leachate slowly biodegradable organic matter (SBOM). Fourier transform infrared (FTIR) spectroscopic analysis confirmed that most of the SBOM was removed by partial biodegradation rather than dilution or adsorption of organics in the sludge. Nitrification was approximately 80% in the AS-0% and AS-2% reactors. No significant accumulation of heavy metals was observed for any of the tested volumetric ratios. Principal component analysis (PCA) and partial least squares (PLS) indicated that the data dimension could be reduced and that TAN, SCOD, DOC and nitrification efficiency were the main variables that affected the performance of the AS reactors.

A global reference for caesarean section rates (C-Model): a multicountry cross-sectional study

Objective

To generate a global reference for caesarean section (CS) rates at health facilities.

Design

Cross‐sectional study.

Setting

Health facilities from 43 countries.

Population/Sample

Thirty eight thousand three hundred and twenty‐four women giving birth from 22 countries for model building and 10 045 875 women giving birth from 43 countries for model testing.

Methods

We hypothesised that mathematical models could determine the relationship between clinical‐obstetric characteristics and CS. These models generated probabilities of CS that could be compared with the observed CS rates. We devised a three‐step approach to generate the global benchmark of CS rates at health facilities: creation of a multi‐country reference population, building mathematical models, and testing these models.

Main outcome measures

Area under the ROC curves, diagnostic odds ratio, expected CS rate, observed CS rate.

Results

According to the different versions of the model, areas under the ROC curves suggested a good discriminatory capacity of C‐Model, with summary estimates ranging from 0.832 to 0.844. The C‐Model was able to generate expected CS rates adjusted for the case‐mix of the obstetric population. We have also prepared an e‐calculator to facilitate use of C‐Model (www.who.int/reproductivehealth/publications/maternal_perinatal_health/c-model/en/).

Conclusions

This article describes the development of a global reference for CS rates. Based on maternal characteristics, this tool was able to generate an individualised expected CS rate for health facilities or groups of health facilities. With C‐Model, obstetric teams, health system managers, health facilities, health insurance companies, and governments can produce a customised reference CS rate for assessing use (and overuse) of CS.

Tweetable abstract

The C‐Model provides a customized benchmark for caesarean section rates in health facilities and systems.

The C‐Model provides a customized benchmark for caesarean section rates in health facilities and systems.

Co-treatment of landfill leachate and domestic wastewater using a submerged aerobic biofilter

This study used a pilot-scale submerged aerobic biofilter (SAB) to evaluate the co-treatment of domestic wastewater and landfill leachate that was pre-treated by air stripping. The leachate tested volumetric ratios were 0, 2, and 5%. At a hydraulic retention time of 24 h, the SAB was best operated with a volumetric ratio of 2% and removed 98% of the biochemical oxygen demand (BOD), 80% of the chemical oxygen demand (COD) and dissolved organic carbon (DOC), and 90% of the total suspended solids (TSS). A proposed method, which we called the "equivalent in humic acid" (Eq.HA) approach, indicated that the hardly biodegradable organic matter in leachate was removed by partial degradation (71% of DOC Eq.HA removal). Adding leachate at a volumetric ratio of 5%, the concentration of the hardly biodegradable organic matter was decreased primarily as a result of dilution rather than biodegradation, which was confirmed by Fourier transform infrared (FTIR) spectroscopy. The total ammoniacal nitrogen (TAN) was mostly removed (90%) by nitrification, and the SAB performances at the volumetric ratios of 0 and 2% were equal. For the three tested volumetric ratios of leachate (0, 2, and 5%), the concentrations of heavy metals in the treated samples were below the local limits.

Aerobic co-treatment of landfill leachate and domestic wastewater - are slowly biodegradable organics removed or simply diluted?

This study investigated the co-treatment of landfill leachate/domestic wastewater in bench-scale activated sludge (AS) reactors to determine whether the slowly biodegradable organic matter (SBOM) was removed rather than diluted. The AS reactors were loaded with mixtures of raw leachate and leachate that was pretreated by air stripping. The tested volumetric ratios were 0%, 0.2%, 2% and 5%. For all of the tested conditions, the reactors performed better when pretreated leachate was used rather than raw leachate, and the best volumetric ratio was 2%. The following removals were obtained: 97% for the biochemical oxygen demand (BOD5,20), 79% for total suspended solids, 77% for dissolved organic carbon and 84% for soluble chemical oxygen demand. Most of the pretreated leachate SBOM (65%) was removed rather than diluted or adsorbed into the sludge, as confirmed by Fourier transform infrared (FTIR) spectroscopy analyses.

Seasonal patterns and influence of temperature on the daily activity of the diurnal neotropical rodent Necromys lasiurus

We investigated the relation between temperature and diel activity patterns of Necromys lasiurus (Lund, 1841) in 10 sites of open vegetation (grassland fields) in the Cerrado (savanna-like vegetation) of central Brazil. We used live traps equipped with timing devices during two trapping sessions: in the end of the dry season (session 1, October 2001) and in the wet season (session 2, January–February 2002). Necromys lasiurus is basically a diurnal rodent with more pronounced crepuscular and nocturnal activity in the dry season than in the wet season. Only in the wet season did we detect significant between-gender differences, with males being less active than females in the first hours after sunrise but more active between 0900 and 1200. There was no significant activity–temperature relation in the dry season, but in the wet season, both genders showed a positive relation between ambient temperature and activity. Individuals might be avoiding hot midday hours in the end of the dry season to minimize time exposure to a physiologically stressful condition caused by the joint action of high temperatures and extremely low relative humidity (<15%). In the rainy season, the high relative humidity (80%–90%) might allow the animals to show a positive relation between activity and ambient temperature.

A Randomised, Double-blind Comparison of Three Different Volumes of Hypobaric Intrathecal Bupivacaine for Orthopaedic Surgery

This study was designed to evaluate different doses of hypobaric 0.15% bupivacaine administered to achieve unilateral orthopaedic surgery under subarachnoid block.

Using a randomised, double-blinded protocol, 150 ASA I to II patients scheduled for elective unilateral orthopaedic surgery were allocated to received a subarachnoid block with hypobaric bupivacaine 0.15% 4.5 mg (3 ml) (Group 1), 6.0 mg (4 ml) (Group 2) or 7.5 mg (5 ml) (Group 3). Measurements included cardiovascular and haemodynamic stability, incidence of unilateral anaesthesia, time to recover from motor block, postoperative urinary retention, transitory neurological symptoms and postdural puncture headache.

There was a dose-dependent increase in the duration of the block, from 1:55±00:20 hours (4.5 mg) to 2:15±00:22 hours (6.0 mg) and 3:15±00:31 hours (7.5 mg). The sensory block in the operated limb was significantly higher than that in the non-operated limb at all times. The increasing dose resulted in an increase of the motor block score. Seventy percent of patients had unilateral block. It was concluded that the spinal anaesthesia in all groups was suitable for single limb orthopaedic surgery. The smallest dose (4.5 mg) of hypobaric 0.15% bupivacaine resulted in more unilateral blocks, with narrower distribution and shorter duration.

Selective sensory spinal anaesthesia with hypobaric lidocaine for anorectal surgery

BACKGROUND

Lidocaine has been used for spinal anaesthesia since 1948, seemingly without causing concern until recently. This study aimed at evaluating the feasibility of performing anorectal surgery in outpatient settings with low hypobaric lidocaine doses.

METHODS

Three groups of 50 patients, physical status ASA I-II, undergoing anorectal surgical procedures in a prone jack-knife position, received 3 ml (18 mg), 4 ml (24 mg) or 5 ml (30 mg) of hypobaric 0.6% lidocaine. Sensory and motor blockade, time until first urination, ambulation, complications and the need for analgesics were evaluated. Patients were followed until the third post-operative day.

RESULTS

Adequate sensory block was obtained in all patients. Blockade was significantly lower in Group 1. The level at 15 min was L(1) with 3 ml, T(11) with 4 ml and T(10) with 5 ml. Only 24 patients presented a moderate motor block. There was no hypotension, nausea or vomiting, urine retention, transitory neurological symptom or post-dural puncture headache in any patients. There was one case of bradycardia with 4 ml and two cases with 5 ml.

CONCLUSIONS

Hypobaric lidocaine predominantly provided a sensory block after injection in the prone jack-knife position. The smallest dose (3 ml=18 mg) provides sufficient analgesia with a lesser dispersion and a shorter duration. The major advantages were haemodynamic stability and a high degree of patient satisfaction.

Caracterização das frações das substâncias húmicas de diferentes tamanhos moleculares

Neste trabalho realizou-se a extração das substâncias húmicas (SH) provenientes da turfa coletada às margens do rio Mogi-Guaçu, segundo metodologia descrita por Rosa et al., 2000. As SH foram fracionadas em um equipamento de ultrafiltração em três faixas de tamanhos moleculares 30 - 100 KDa, <30 KDa e >100 KDa. As frações foram caracterizadas por diferentes técnicas analíticas, infravermelho (IV), análise elementar, espectroscopia na região do ultravioleta/visível (UV/Vis) e ressonância paramagnética eletrônica (EPR). Verificou-se que as frações de menor tamanho molecular (30 - 100 KDa e <30 KDa) possuem um maior número de moléculas com oxigênio ligados, enquanto que a fração de maior tamanho molecular (>100 KDa) apresentou um maior número de moléculas aromáticas. Através dos resultados das análises elementares e de ressonância paramagnética eletrônica, constatou-se que a fração <30 KDa apresentou uma menor porcentagem de carbono, nitrogênio e hidrogênio e uma menor quantidade de radicais livres em relação as demais, indicando que esta fração possui um menor número de anéis aromáticos conjugados. Já nas análises por IV foram observadas bandas características das SH.

Palm harvesting affects seed predation of Euterpe edulis, a threatened palm of the Brazilian Atlantic Forest

The palm tree Euterpe edulis is endemic to the Atlantic Forest, where it constitutes an economically important forest product. The often unplanned and illegal harvesting of palm hearts has led to drastic reductions in the populations of E. edulis in many areas where this palm used to be the dominant understorey tree species. We investigated the effects of harvesting on seed and seedling predation of E. edulis. We tested the predictions of the dominance-predation hypothesis according to which predator satiation leads to an inverse relationship between the amount of predation and the dominance of a tree species. During two consecutive years, seeds were set experimentally on an unharvested (> 250 adult palms/ha) and a neighboring harvested site (few, if any, adult palms) located in the Atlantic Forest of SE Brazil. Seedling mortality was studied at both sites for a six-month period in each of two consecutive years. Seed predation caused by rodents was higher at the harvested site, while insects caused more damage to seeds placed at the unharvested site. The proportion of seeds preyed upon by rodents varied annually, while insect predation did not. Seedling mortality did not differ between harvested and unharvested sites. The dominance-predation hypothesis was confirmed for generalist rodent seed predators, but not for specialist insect predators. This result shows that density-dependent mortality, not only at the individual level but also at the population-level scale, is a function of the class of predators and their types of foraging behavior.

Influência da taxa de dose na degradação do herbicida ácido diclorofenóxiacético (2,4-d) por meio da radiação gama do cobalto-60

Métodos convencionais de descontaminação ambiental, algumas vezes apenas transferem esses resíduos de um lugar para outro. Esse estudo tem como objetivo checar a influência de diferentes taxas de doses de radiação gama do cobalto-60 na degradação do herbicida 2,4-D, em água e metanol. Os resultados mostraram que o 2,4-D, em água, foi totalmente degradado em uma dose de 30 kGy, utilizando-se taxa de dose de 2,7 kGy h-1 e 20 kGy com uma taxa de dose de 5- 60 kGy h-1. Para o metanol, a total degradação do 2,4-D ocorreu com uma dose de 150 kGy e taxa de dose de 2,7 kGy h-1 e 100 kGy utilizando-se taxa de dose de 5- 60 kGy h-1. Assim conclui-se que a degradação do herbicida 2,4-D é dependente da dose e da taxa de dose de radiação.O valor radiolítico da degradação do 2,4-D foi calculado.

Molecular diagnosis and counseling in a family presenting compound heterozygosity for autosomal recessive limb-girdle muscular dystrophy

The present report concerns two patients, male and female siblings, manifesting a different degree of severity for the same autosomal recessive limb-girdle muscular dystrophy. The index case (male sib) carried the clinical diagnosis of Becker muscular dystrophy at the time when the sister, with a much milder presentation, first sought counseling and prenatal diagnosis for a pregnancy already in course. Molecular and immunocytochemical tests then available favoured the diagnosis of an autosomal recessive myopathy, but did not enable exclusion of a dystrophinopathy The couple was counseled accordingly, although prenatal diagnosis could not be offered. Both patients were later found to carry one gamma- and two alpha-sarcoglycan gene mutations, one of the latter being new This raised a counseling dilemma: depending on which combination was the disease-causing genotype, there would be a minimal or a significant 25% risk to offspring. We describe the studies carried out and emphasise the importance of differential diagnosis and extensive molecular characterisation in this group of disorders, so as to enable correct genetic counseling and prenatal diagnosis.

[Key aspects of sexual behavior and safer sex practice among men in the city of São Paulo]

Heterosexual relations currently constitute the predominant route of HIV transmission to women in Brazil. Few studies have approached male sexual behavior taking women into account. This study included 597 men ages 21 to 50 in São Paulo city and explored several aspects pertaining to safer sex, such as sexual partners, knowledge of sexually transmitted diseases (STDs)/AIDS, risk perception, and protective practices aimed at AIDS prevention. The results showed that, similar to other countries, the proportion of men who have sex with men is low (5%), that younger men adopt more protective behavior than older men regarding multiple partners and condom use, that knowledge of AIDS is widespread (but that there is still a lack of knowledge concerning STDs in general), and that although risk perception increases protective behavior, presumption of the partner's behavior influences this perception, placing men and women in a vulnerable situation.

Do women's attitudes towards abortion and contraceptive methods influence their option for sterilization?

This paper analyzes the attitudes of low-income women towards abortion and contraception. A survey was conducted in 1992 with a total of 3,149 childbearing-age women living on the outskirts of the Greater Metropolitan São Paulo Area. The study focuses on a sub-sample of 583 women. Attitudes of sterilized and non-sterilized women are compared. Women, especially those sterilized, found the most important attribute of a contraceptive method to be its effectiveness. Women currently taking the pill were less likely than those sterilized to agree that sterilization was the best method because of its effectiveness. Sterilized women were less likely than non-sterilized women to trust the pill. Sterilized women were more likely than non-sterilized to have reported adverse effects from the pill. Most women found abortion unacceptable except in the case of risk to the woman's life. Women using more effective methods showed stronger negative attitudes towards abortion. The tendency to be sterilized while still young was associated with more negative attitudes towards abortion. Family planning activities in basic health care services should include individual counseling for contraceptive use.

The provision of female sterilization in São Paulo, Brazil: a study among low income women

This paper examines some problems involved in the provision of female sterilization procedures in Brazil, mainly those concerned with the ways in which this operation is offered. Female sterilization provision is analysed by reference to the broader institutional context and from the client's perspectives. These themes are discussed in the light of some recent survey findings. A survey was carried out between March and July, 1992 in two selected poor areas of São Paulo Metropolitan Region. 3149 women were asked about contraceptive use including 407 sterilized women under 40 years old who were also interviewed about their adaptation to sterilization. Further information was also obtained through in-depth interviews with 15 sterilized women who regretted the operation. The findings highlight a complex network of interests and misunderstandings which shape the nature of choice of female sterilization by Brazilian low income women.

[Female sterilization among low income women in a metropolitan region of southeastern Brazil and factors related to its prevalence]

A survey carried out in the metropolitan region of S. Paulo between March and July, 1992, shows that of 3,149 low income women aged from 15 to 49, 21.8% had been sterilized. Of those women living in marital union 29.2% had been sterilized and 34.4% were on the pill. Four hundred and seven sterilized women under 40 years old who underwent sterilization at least one year before the interview were asked about their reproductive life, the previous use of contraception, the decision-making process regarding their sterilization, the access to the operation and their adaptation after the operation. The results show that access to sterilization is obtained by means of payment to the doctor even in the case of low income women. The lack of regulation of sterilization and the insufficient provision of family planning methods by the Women's Health Comprehensive Programme are probably encouraging young women to opt for sterilization. The provision of sterilization presents ethical problems. The study shows that the irreversibility of the procedure was not understood by almost 40% of the women sterilized. The acceptability of sterilization as a result of a complex social strategy involving various sectors of Brazilian society associated with the need for the control of fertility felt by women are discussed. The need to regulate and control the procedure is discussed. The regulation of sterilization would create fairer access to sterilization and could safeguard the ethical aspects of its choice.

Occurrence and prevalence of bot flies, Metacuterebra apicalis (Diptera: Cuterebridae), in rodents of cerrado from central Brazil

The occurrence and prevalence of Metacuterebra apicalis (Diptera: Cuterebridae) in natural populations of Oryzomys subflavus, Bolomys lasiurus, and Thalpomys cerradensis (Rodentia: Muridae) from August 1990 to July 1992 in the cerrado, a common savanna-like vegetation type of central Brazil, are reported. An increase in bot infection in the 3 rodent species between October 1991 and July 1992 without correlation to precipitation was detected. The prevalence was lower than in neotropical forest formations. Mean intensity was 1.3 bots (range 1-2) for T. cerradensis and 1 bot for B. lasiurus and O. subflavus. This is the first record of T. cerradensis as host of bot flies.

The phospholipase activities present in preheparin mouse plasma are inhibited by antiserum to hepatic lipase

1. Preheparin plasma from mice, but not rats or man, contains high levels of phospholipase A and lysophospholipase activities which are distinct from lecithin:cholesterol acyltransferase (LCAT). 2. Neither the phospholipase A nor the lysophospholipase activities in preheparin plasma are inhibited by incubation in the presence of protamine sulphate or high salt concentrations. 3. When mouse plasma is incubated in the presence of an antiserum specific for rat hepatic triacylglycerol lipase (HTGL), the phospholipase activities are abolished. 4. These observations suggest that the phospholipase activities are attributable to the action of HTGL, which, in the mouse appears to be a freely circulating enzyme, whereas for other species this enzyme only appears in the blood following administration of heparin.