Factors influencing genetic counseling attendance rate: a geographically based study

A study of factors influencing genetic counseling attendance rate has been conducted in the Bouches-du-Rh?ne area, in the south of France. In this area, a birth defects monitoring system (Eurocat n. 22) annually covers 23,000 births. All the genetic services are delivered by only one genetic center located in Marseilles, and the data collected are computerized. The comparison of these two data bases gives an opportunity to estimate the rate of genetic counseling attendance after the occurrence of an affected stillbirth or live birth. Among the parents of 358 infants born in 1983-84 in this area with a pathology requiring genetic counseling, 226 (63 per cent) attended the Genetic Center within the first year after birth. The rate of attendance is statistically higher (p less than 0.01) for the parents who had a stillbirth (78 per cent) than for those who had a live birth (57 per cent). It is also higher (p less than 0.01) for the Marseilles maternities group (68 per cent) than for the group outside Marseilles (50 per cent). The referral delays are also analyzed according to malformation etiology and to viability of the child by the eighth day of life. Besides evaluating a particular genetic center's effectiveness in diffusing information to the public concerned, this work shows that couples' request is strongly dependent on a psychological need.     

Gut repletion during diel vertical migration in the benthopelagic crustacean Eurydice truncata Norman, 1868 (Isopoda, Cirolanidae)

The sand-burrowing isopod Eurydice truncata migrates from thebenthos up to the neuston layer during the night. The gut contentsof vertical migrant animals sampled in nocturnal neuston haulsoff the Mediterranean coast of France were examined. The haulswere performed, on the one hand, from dusk to dawn, at a singlestation on the shelf and another on the slope, and, on the otherhand, in the middle of the night, at various stations from theinner shelf to the slope. In shelf waters, the percentage rateof filled guts increased quickly after dusk and had reachedalmost 100% after 3 h of darkness. Isopods feed on living neustonicanimals, preferably immobilized or passive living matter suchas insects trapped at the surface or fish spawn. During thenight, the gut contents gradually became more compact, and theremains of prey became less identifiable. The dry weight ofthe compacted gut contents of a single adult averages 0.50 mg,including 0.26 mg of organic carbon. At dawn, the downward migrationleads to this neustonic matter being vertically transferredfrom thesurface layer to within the sediment. A decrease inthe animal's level of gut fullness occurs from inshore to offshorewaters; this decrease in the feeding activity might generatea high rate of mortality in animals advected to slope water. Rsum. L'isopode fouisseur Eurydice truncata migre du benthosjusqu'en surface durant la nuit Les contenus stomacaux d'animauxprlevs dans le plancton de surface durant lanuit ont t examines.Les pches taient effectues du crepuscule l'aube, dans unemme station du plateau et de la pente continentale, en milieude nuit dans les diverses stations d'une radiale littoral-pentecontinentale. Sur le plateau, le taux d'estomac contenant dela nourriture augmente trs rapidement aprs le crepuscule,atteignant prs de 100% aprs trois heures d'obscurit. LesIsopodes se nourissent au dpens des animaux present dans l'hyponeustonet prefrentiellement sur la matire vivante immobilis ou passivecomme les insectes pigs en surface et les oeufs de poisson.Les contenus stomacaux, lches en debut de nuit, deviennentpar la suite de plus en plus compacts, les debris de proiesdevenant indistincts. Chezl'adulte le poids sec d'un contenustromacal en tat compact s'lve en fin de nuit a 0,50 mg,le carbone organique reprsentant 0,26 mg. A l'aube, la migrationdescendante conduit a un transfert de cette quantit de matireneustonique de la surface jusqu' l'intrieur du sediment. Letransfert pourrait atteindre en certaines zones, lorsque lespopulations de l'Isopode sont denses, plusieurs centaines dekg par km². Une diminution du taux de repletion stomacal estobservsupede la zone interne du plateau a la pente continentale;cette dcroissance de l'activit trophiqueest susceptible d'engendrerun taux de mortalit lev chez les animaux dplaces par lescourants superficiels de la zone neritique vers la zone bathyale.     

Rythme d'activité endogène chez un nébaliacé (Crustace phyllocaride)

In constant conditions and continuous darkness, the burrowing species Nebalia bipes (Fabricius) exhibits a clear circadian rhythm of emergence from the substratum and of swimming activity. The rhythm, in which activity occurs during the ‘expected night’, is obvious in both males and females and can remain overt for several weeks.The ‘free-running period’, although variable, is ≈ 24 h 20 min in a calm environment and at 18 °C. During the first day of the experiments, the swimming activity of freshly collected animals increases abruptly at dusk and then decreases gradually towards dawn. It has been possible to change the phase of the rhythm by subjecting the animals to a reversed LD schedule.The synchronization seems to result from the high photonegativity of Nebalia in normal daylight. The results of some experiments carried out with young juvenile animals suggests that the synchronization may possibly take place during the incubation period.     

Diel vertical migration and endogenous swimming rhythm in Asterope mariae (Baird) and Philomedes interpuncta (Baird) (Crustacea Ostracoda Cypridinidae)

Among the benthic ostracods Asterope mariae and Philomedes interpuncta, the adult males emerge at dusk from the benthos and swim straight up to the surface, where they soon concentrate in the neustonic realm. The migration starts when the irradiance is almost 1 W cm^-2 and the maximal density occurs at the surface when the light has reached 0.005 W cm^-2, before it is completely dark. The migration ends <1 h later and very few animals are observed in the water column later in the night. Upward migration does not result from a positive phototaxis to dim light, but rather from a strong negative geotaxis and an increase in kinesis or swimming activity which occur at around 1 W cm^-2. This activity is induced both by the end of the diurnal period of photoinhibition and by an endogenous circadian rhythm. This rhythm could be clearly observed in both species from the recordings made during up to 2 weeks in constant darkness. The length of the period was roughly 24 h (24 h 3 min in Asterope, 23 h 10 min i Philomedes). The timing of the activity phase in total darkness varied depending on the post-capture history of the experimental animals, especially on the time of onset of the experiment. The adaptive advantage of this rapid diel vertical migration may be a question of feeding, but this may also increase the nocturnal dispersal of the reproductive males, and thus promote the reproduction of the species.      

Inshore and offshore diel migrations in European benthopelagic mysids, genera Gastrosaccus, Anchialina and Haplostylus (Crustacea, Mysidacea)

The nocturnal migratory activity of the six most abundant Gastrosaccinaeliving off the European coast, namely Gastrosaccus sanctus,Gastrosaccus spinifrr, Anchialina agilis, Haplostylus lobatus,Haplostylus lobatus var. armata and Haplostylus norrnani. wasstudied. Both Gastrosaccus perform horizontal and vertical migrationsnear sandy beaches. These migrations involve the whole population,which exhibits a superficial or hyponeustonic distribution inthe water column. Anchialina and Haplostylus perform verticalmigrations from inshore to slope waters. The timing of pelagicphases, as well as the distribution in the water column, dependon age. sex, depth and clarity. Male A.agilis and H.lobatusshow intense migratory activity leading to a hyponeustonic distributionin mid-shelf and slope waters a few hours after dusk. Femalesand juveniles show continuous pelagic phases and a uniform distributionfrom dusk to dawn. Haplosiylus lobatus var. armata and H.normanipopulations exhibit the same behaviour, consisting of overnightmigrations and a uniform to deep nocturnal distnbution. In shallowwaters, male Anchialina and Haplostylus no longer exhibit hyponeustonicbehaviour and their nocturnal distribution becomes more andmore deep as clarity increases. Above the slope, animals thatmigrate from the continental shelf during the night sometimesadopt permanent pelagic behaviour above more than 200 or 300m in depth. but upward nocturnal migration persists and leadsto superficial stratification, albeit delayed. Slow morningdescents to the bottom can occur even further from the 500 misobath.     

Le contrôle de l'émergence et des nages nocturnes chez les péracarides des plages de méditerranée. Eurydice affinis Hansen (Isopoda), Gastrosaccus mediterraneus Bacescu, Gastrosaccus spinifer (goës) (Mysidacea)

Along the Mediterranean sandy shores, Eurydice affinis Hansen, Gastrosaccus mediterraneus Bacescu and Gastrosaccus spinifer (Goës) are present during the day in the sand of the beaches, either near the limit of the wave wash or in the superficial fringe of the infralittoral. In the evening there is a general emergence and the animals rejoin the planktonic populations of the open sea.All the three species when kept in aktographs under constant conditions and continuous darkness exhibit a circadian rhythm of emergence and swimming activity of nocturnal frequency. The rhythm is clear and in the two Gastrosaccinae persists for ten days at least; it has been observed over about fifty days in G. spinifer. In E. affinis, the rhythm is only on some occasions clear; one frequently observes a permanent burying in the sediment, in which case the swimming rhythm can be brought to light by a mechanical disturbance or the withdrawal of the sediment.A study of the changes in the photokinetic reactions in a horizontal beam of white light, with intensities varying from 4000 to 10^?6 lux, allow the synchronization of the rhythms to be ascribed to a slight photonegative tendency of the animals at intensities > 1000 lux and a photopositive tendency, often marked, at lower intensities. The variations in the intensity of the reactions in the three species allows an explanation of the autonomous rhythms.A comparison between the photokinetic reactions of these species and those of the infralittoral Peracarida, which migrate in the nocturnal plankton, shows great differences with respect to light intensity. In the latter, the phototaxis is strongly negative and frequently accompanied by a strong photo-inhibition while in the former the phototaxis is still often positive and the kinesis is high. The photopositive reaction allows the animals to rejoin their daytime habitat soon after dawn when the swimming activity decreases.