Abnormal amniotic fluid levels of CA 125 in second-trimester Down syndrome pregnancies

The aim of this study was to evaluate the concentration of CA 125 in second trimester amniotic fluid from Down syndrome pregnancies. CA 125 was measured in stored amniotic fluid samples from pregnancies of 14–19 weeks' gestation with and without Down syndrome fetuses. CA 125 levels were expressed in multiples of the median (MOM) for normal pregnancies of the same gestational age. Twenty-one pregnancies with Down syndrome fetuses and 63 unaffected controls matched for maternal age, gestational age, and duration of storage were studied. The median MOM values of the affected pregnancies were significantly higher than those of the controls (1·41 MOM versus 0·99 MOM). These findings show that there is an increased concentration of CA 125 in second-trimester amniotic fluid from Down syndrome pregnancies.     

Modelling of the acid-base properties of natural and synthetic adsorbent materials used for heavy metal removal from aqueous solutions

In this paper a comparison about kinetic behaviour, acid-base properties and copper removal capacities was carried out between two different adsorbent materials used for heavy metal removal from aqueous solutions: an aminodiacetic chelating resin as commercial product (Lewatit TP207) and a lyophilised bacterial biomass of Sphaerotilus natans. The acid-base properties of a S. natans cell suspension were well described by simplified mechanistic models without electrostatic corrections considering two kinds of weakly acidic active sites. In particular the introduction of two-peak distribution function for the proton affinity constants allows a better representation of the experimental data reproducing the site heterogeneity. A priori knowledge about resin functional groups (aminodiacetic groups) is the base for preliminary simulations of titration curve assuming a Donnan gel structure for the resin phase considered as a concentrated aqueous solution of aminodiacetic acid (ADA). Departures from experimental and simulated data can be interpreted by considering the heterogeneity of the functional groups and the effect of ionic concentration in the resin phase. Two-site continuous model describes adequately the experimental data. Moreover the values of apparent protonation constants (as adjustable parameters found by non-linear regression) are very near to the apparent constants evaluated by a Donnan model assuming the intrinsic constants in resin phase equal to the equilibrium constants in aqueous solution of ADA and considering the amphoteric nature of active sites for the evaluation of counter-ion concentration in the resin phase. Copper removal outlined the strong affinity of the active groups of the resin for this ion in solution compared to the S. natans biomass according to the complexation constants between aminodiacetic and mono-carboxylic groups and copper ions.     

Fungal biodegradation of naphthalene: microcosms studies

The present work is aimed to ascertain naphthalene biodegradation capability of P. chrysosporium and T. harzianum in soil microcosms. Considering the high naphthalene volatility, a suitable soil microcosm was set-up and used. Several degradation tests were conducted with different C/N ratio media for the two fungi in order to enquire the best range of working conditions. The kinetic studies were conducted at a maximal naphthalene concentration of 600 mg kg(-1). During experimental time course naphthalene concentration, CO2 evolution as well as phytotoxicity tests were performed as monitoring parameters. The results shown in the current paper, put in evidence that T. harzianum, differently than in liquid culture, is not able to biodegrade naphthalene directly in soil microcosm, while P. chrysosporium in the same conditions biodegrades the PAH till about 600 mg kg(-1). As concern the founded kinetics for P. chrysosporium, a saturation shape in presence of N-limited medium (high C/N ratio) was evaluated while a growing form more than linear in no-N limited medium (normal C/N ratio) was determined.     

Shell acquisition by hermit crabs: which tactic is more efficient?

Gastropod shells are limited resources for most hermit crab species, acting as primary factors in various aspects of their biology. To investigate the efficacy of different behavioral tactics adopted for their acquisition (locomotion, attendance at shell-supplying sites, interactions with conspecifics in aggregation) we conducted observations and experiments at a salt marsh in New England (USA). Locomotion, fast and meandering, significantly increased the chances of encountering empty shells and conspecifics. However, shell exchanges were rare. Simulated gastropod predation sites quickly attracted a larger number of hermit crabs than the other shell-supplying sites tested (live and dead conspecifics, live snails) and induced the rapid occupancy of all the empty shells offered, usually by the first crabs arriving at the site. Aggregations seemed not to function as shell exchange markets, as previously suggested for several other species. In the short run, exploitation seems to be more efficient for the acquisition of new shells by Pagurus longicarpus. In the long run, it is the density of nondestructive gastropod predators that regulates the availability of new shells of good quality in the pool available to this hermit crab species.     

The systematic position of some boring sponges (Demospongiae,Hadromerida) studied by molecular analysis

A phylogenetic analysis of some bioeroding sponges of the family Clionaidae (Order Hadromerida) was performed to resolve some taxonomic problems both at the specific and the supraspecific level using the D2 and D3 regions of 28S rDNA. Species belonging to the genera Cliona, Cliothosa, Spheciospongia (fam. Clionaidae) and Diplastrella (fam. Spirastrellidae) from the Mediterranean Sea and Celebes Sea (Indonesia) were analysed. In the phylogenetic tree, the species clustered on two main branches, one comprising Cliona celata, C. rhodensis, C. utricularis, and Cliothosa hancocki, and the other made up of C. viridis, C. nigricans, C. schmidti, C. jullieni, Spheciospongia solida and S. vagabunda. Above the species level, data do not support the separation of the genus Cliothosa from Cliona, while they do support the inclusion of some massive boring species, previously assigned to the genus Spirastrella, in the family Clionaidae. At the species level, data demonstrated the genetic identity of taxa C. viridis and C. nigricans, in spite of their considerable morphological differences. In contrast, the yellow species commonly attributed to C. celata are probably to be considered as a complex of sibling species with a number of distinct taxa present in the Mediterranean. Data also showed the identity of the Mediterranean and Pacific populations of C. schmidti, suggesting the status of a Tethyan relict for this species.     

Meiofauna densities and gastrotrich community composition in a Mediterranean sea cave

During the past 5 decades, the large-sized biota inhabiting dark marine caves has attracted the attention of many marine biologists; in contrast, studies concerning the meiofaunal organisms of these peculiar biotopes remain scanty and mostly with a taxonomic aim. In this study, the nature and abundance of meiofaunal taxa living in a Mediterranean, semi-submerged sea cave was surveyed in relation to distance from the entrance and over two different seasonal periods. Particular attention was paid to the Gastrotricha taxocene. Research was carried out in a cave along the Ionian coast of Apulia (southern Italy), the “Grotta Piccola del Ciolo” which opens for approximately 120 m on the north-eastern side of a shallow fjord and has a bottom blanketed by fine to very fine sand, occasionally rich in detritus. Quantitative samples in four replicates were collected by SCUBA diving, in November 2000 and June 2001, coring the sediment with a hand-held piston corer in three light-free sites (stations 1–3) located at increasing distances from the entrance. At each site, two additional 500-ml sediment samples were collected for an in vivo study of the Gastrotricha. Faunistic analysis found a fairly high meiobenthic diversity, identifying representatives of more than 12 major groups, with total abundances ranging from 656 ind./10 cm² (10 cm²) in November to 1,069 ind./10 cm² in June. Station 1, the closest to the entrance invariably hosted the most abundant meiofaunal community (851 ind./10 cm² in November and 1932 ind./10 cm² in June), followed by station 2 or 3 depending on the season. While nematodes and harpacticoids appear as the most abundant taxa when the cave is considered as a whole, other taxa may prevail numerically in selected stations, e.g. priapulids, which are the second most abundant taxon at station 1 (30 ind./10 cm² in November and 83 ind./10 cm² in June). Although the density of total meiofauna and that of the single groups may not be very high, the cave is interesting by virtue of the peculiarity of the hosted fauna, e.g., species and genera new to science or new to the Mediterranean Sea. Regarding the Gastrotricha, we found 16 species, accounting for 1.3–2.6% of the total meiobenthos (density = 8.4 ind./10 cm² in November and 27.4 ind./10 cm² in June). Analysis of the gastrotrich community found, particularly in June, an assemblage of taxa quite different from those found in open habitats, even at the family level; differences that are probably due to the exploitation of different food resources by animals populating the two environments, i.e. algae in the open sea versus bacteria in the caves. Results indicate that for meiofauna, as happens for macrofauna, the marine caves may represent hotspots of biodiversity and endemism; the driving forces at the base of the trophic depletion hypothesis seem to be responsible for structuring the meiofauna community inside the cave.     

Fighting behavior in hermit crabs: the combined effect of resource-holding potential and resource value in Pagurus longicarpus

A study was conducted to determine whether asymmetries in both resource-holding potential (RHP) and resource value (RV) influence dominance and fighting behavior in the hermit crab Pagurus longicarpus. A total of 120 groups of three crabs were observed for 10 min in four experiments that tested all diverse combinations of equal/different RHP (i.e. ‘body size’) and equal/different RV (i.e. ‘shell size’ and ‘shell quality’). In a fifth experiment, dominant and subordinate individuals of the same size category (26 groups) were forced to enter shells of opposite quality than those previously occupied, and then the behavior of the reconstituted original groups was observed for additional 10 min. As expected, crabs in lower quality shells were more willing to initiate and to escalate fights. However, their attacks were directed to any crab of the group, independently of the defender's shell quality, and the fight duration did not vary with the different value of the resources at stake. This may indicate that P. longicarpus is unable to assess the quality of the shells available in its social environment but bases its tactical decisions during fights solely on its own resource. This suggestion was confirmed by the change in the fighting behavior of crabs whose shell quality was experimentally altered. This manipulation induced an overall increase in the intensity of aggression, drastic modification of crab behavior, and inversion of the hierarchy even though these crabs have had previous experiences of wins/losses and were familiar to the other members of the group. In this species, large crab size and/or the occupancy of adequate (and oversized) shells appeared to be the most likely determinant of contest resolution. Individuals seemed to retain a memory of the previously held resource and behaved accordingly.     

Nonylphenols in freshwaters of the hydrologic system of an Italian district: association with human activities and evaluation of human exposure

A sampling campaign for the determination of concentrations of nonylphenol isomers (NPs) in freshwaters and sediments of the hydrologic system of the Rieti district (central Italy) was conducted from 2002 to 2003. Eighteen sampling points, selected on the basis of the different human activities in the vicinity, were monitored; six series of water samples (from June 2002 to February 2003) and one of sediment samples (summer 2002) were analyzed by GC/MS.

There was a direct relationship between concentrations of NPs and the presence of urban or industrial activities near the sampling point. However, concentrations of NPs in water were in the range of <0.1–1.4 μg l⁻¹, and their presence limited to short distances from the sources of contamination. Accumulation factors in sediment samples ranged from 10² to 5 × 10³.