Seabird eggs as bioindicators of chemical contamination in Chile

Seabird eggs were used as bioindicators of chemical contamination in Chile. Brown-hooded Gull (Larus maculipennis), Kelp Gull (Larus dominicanus), Trudeau's Tern (Sterna trudeaui), Neotropic Cormorant (Phalacrocorax brasilianus), and Pink-footed Shearwater (Puffinus creatopus) eggs were sampled at different breeding sites during the 1990s. Mercury and organochlorines (PCBs, DDT, HCB, HCH, and PCP) were quantified to reveal the interspecific differences, spatial and temporal trends in contamination levels. Trudeau's Tern displayed the highest levels of mercury (486 ng g(-1) wet weight). The highest sumDDT concentrations were measured in Brown-hooded Gulls (726 ng g(-1)). PCB levels were similar among the species (102-236 ng g(-1)), but the composition of the PCB mixture was different in Pink-footed Shearwaters. With the exception of the Brown-hooded Gull, all species studied presented similar and low levels of organochlorines (sumOHa). Residues of PCB and related compounds were not detected in any of the seabird eggs analyzed in Chile. Geographical variation was low, although levels of industrial chemicals were slightly higher in eggs from Concepción Bay, and agricultural chemicals in eggs from Valdivia. Also interannual variation was low, but some evidence was found of decreasing levels in gull eggs throughout the time of the study. The causes of the low levels and small variability in space and time of environmental chemicals in Chilean seabirds are discussed. We propose the use of seabirds in future monitoring of the development of chemical contamination in Chile.     

Population dynamics of weeds in no-tillage and conventional crop systems

Population dynamics of weeds in successive maize and bean crops were evaluated in two soil management systems (conventional and no-tillage), for two maize applications (grain and silage), and in four consecutive growing seasons. Every year, conventional tillage consisted in plowing and harrowing before sowing. In no-tillage, chemical weed desiccation was made with the mixture glyphosate + 2.4-D. To control weeds, the mixture fluazifop-p-butil + fomesafen was applied on the bean crop in all the planting seasons, and the herbicides nicosulfuron + atrazine on maize after crop emergence (1998--1999, 1999--2000, 2001--2002) and atrazine + metolachlor before emergence (2000--2001). Purple nutsedge (Cyperus rotundus) was the most important species under conventional soil tillage; while in no-tillage the dicotyledonous weed species (Amaranthus deflexus, Bidens pilosa, Euphorbia heterophylla, Galinsoga parviflora Ipomoea grandifolia) were the most relevant. Regardless of the maize use, the C. rotundus population and tuber bank, with prevailingly dormant tubers, was considerably reduced in no-tillage compared with the conventional system.     

Prenatal diagnosis of congenital human cytomegalovirus infection

Fifteen fetuses at risk of congenital human cytomegalovirus (HCMV) infection underwent prenatal diagnosis at 16–30 weeks' gestation by a combination of amniocentesis and fetal blood sampling. HCMV was isolated from the amniotic fluid in six patients, but HCMV-specific IgM was detected in only three of them. Two of the nine neonates, who were delivered following a negative prenatal diagnosis, had congenital HCMV infection diagnosed by virus isolation in the urine. The interval from infection to prenatal testing was 3 and 4 weeks in the two false-negative cases and ⩾ 7 weeks in the true-positive cases. Although timely testing for HCMV infection allows the option of termination of pregnancy, it may be flawed by false-negative results.     

Normal fetal growth in women with antiphospholipid syndrome treated with high-dose intravenous immunoglobulin (IVIG)

Antiphospholid antibodies are associated with fetal distress and fetal death. Although different therapeutic regimens have been used, the incidence of fetal growth retardation varies between 30 and 60 per cent of reported cases. We report the evolution of fetal growth in patients with antiphospholipid antibody syndrome treated with high-dose intravenous immunoglobulins (IVIG). Fourteen patients with a history of recurrent spontaneous abortion and immunological diagnosis of antiphospholipid syndrome were followed longitudinally. Intravenous immunoglobulin at a dose of 0.5 g/kg body weight for two consecutive days was started from the fifth week of pregnancy and repeated every 4 weeks until the 33rd week of gestation. Fetal biometry was evaluated longitudinally from the appearance of the gestational sac at 4 weekly intervals. In the period between 26 and 34 weeks, the frequency of evaluation was increased to every 14 days. Data obtained were compared with a control group of 70 fetuses with uneventful pregnancies matched for gestational age. Neonatal weight is shown in relation to the centiles for the normal population. One patient out of 14 (7.1 per cent) developed gestational hypertension and abruptio placentae. No other pregnancy complications were seen. No proteinuria was found. The mean maternal age was 31.2±3.8 years. Median birth weight was 3433 g±287. The median centile of the birth weight was 65.3±18.6. Mean gestational age at delivery was 1.3 weeks. No fetal or neonatal growth retardation was seen. No significant differences were found in the biometrical parameters investigated in the various gestational ages vs. the control group (Student's t-test not significant); a significant increase in head circumference (P< 0.001) and abdominal circumference (P< 0.05) was found at 36–37 weeks gestational age in the IVIG-treated fetuses. The presence of antiphospholipid antibodies is considered detrimental for pregnancy outcome because of their negative effects on placental vascular perfusion and fetal transfer of metabolites. The use of IVIG seems to avoid or inhibit the reduced availability of nutrients for the fetal anabolic functions, as the expected reduction in fetal growth was not seen in our series.     

Atelosteogenesis type II: Sonographic and radiological correlation

Atelosteogenesis type II is a lethal chondrodysplasia characterized by severe micromelia, spinal abnormalities, talipes equinovarus, and abducted thumbs and toes. We present a case diagnosed at 21 weeks of gestation in which antenatal sonographic and post-mortem radiological findings were correlated. The patient had a recurrence of this disorder in a subsequent pregnancy which was terminated at 15 weeks, supporting previous reports of an autosomal recessive inheritance pattern. The feasibility of diagnosing the following morphological features by prenatal ultrasonography is demonstrated: coronal clefts of the vertebral bodies, metaphyseal and epiphyseal abnormalities, spinal deviations such as cervical kyphosis and a horizontal sacrum, additional ossification centres in the pelvis, and preaxial deviation of the thumbs and toes. The differential diagnosis of this disorder from other skeletal dysplasias with similar features is discussed.     

A new environmentally friendly process for the recovery of gold from electronic waste

A new method for the recovery of precious metals, in particular gold, from electronic waste is proposed. This work focused on the research of an easily renewable etching agent, in order to make an environmentally friendly process possible. Two well known hydrometallurgical etching agents, FeCl₃ and CuCl₂, were evaluated in terms of efficiency and kinetics, testing solutions with different concentration of etchant and hydrochloric acid. The recovery of spent etching solutions was evaluated: promising results were found in the case of CuCl₂, which can be completely restored by oxidation of the cuprous chloride formed during the etching using atmospheric oxygen.     

Within-clutch egg size asymmetry covaries with embryo sex in the yellow-legged gull Larus michahellis

Non-random sex allocation may occur whenever the expected reproductive value of sons and daughters differs, as is the case when the sexes differ in susceptibility to environmental conditions or maternal effects (e.g. egg size and hatch order). Under such circumstances, covariation between egg and clutch characteristics and egg sex may be expected, and this covariation should vary with maternal state or ecological conditions. In this 2-year study (2007–2008), we examined sex allocation in relation to egg and clutch traits in the yellow-legged gull Larus michahellis, a species where male chicks are larger and more susceptible to harsh rearing conditions than female ones. In 2008, eggs were more likely male early in the season in two- but not three-egg clutches, and large eggs were more likely males late in the season. No egg/clutch traits predicted egg sex in 2007. Within-clutch egg mass asymmetry (the difference in egg mass between the first- and last-laid eggs) predicted sex in both years. In 2007, clutches with smaller egg mass variation were more likely to contain males, while in 2008 this relationship held for the last-laid egg and was reversed for the preceding egg(s). Laying order and sex of the previous egg did not predict egg sex, providing no evidence of sex-specific oocyte clustering. Thus, the relationships between egg sex and egg/clutch traits differed among years, suggesting a phenotypically plastic response of females to extrinsic conditions, and involved within-clutch egg mass asymmetry, a trait likely reflecting variation in maternal quality and/or reproductive tactics, which has been largely neglected in previous studies of sex allocation.     

Heavy metals in albanian coastal sediments

Heavy metals (Fe, Mn, Cr, Ni, Cu, Cd, Pb, Sn) concentration has been determined on 39 coastal sediment samples collected in Albania. The relationship between the heavy metals content and the grain size has been considered. All metals, except Cu and Cd, resulted accumulated in the finest fraction, which constituted up to 95% of most of the considered sediments. A good correlation has been found for Ni, Cr, Fe, Zn, Cu in the entire area, indicating a common origin for these metals in the analyzed sediments. Concentration values fall in the range reported for Dinaric chain derived sediments, revealing, generally, a natural origin of the metal contents. Though in some selected areas such as the Drin and the Skumbin Bay, an antropogenic input of Cr, Fe, Ni and Cu can be observed, as the result of discharging of mines and smelter activities.