Gap junction distribution in the Drosophila wing disc mutants vg,l(2)gd,l(3)c43hs1, and l(2)gl4

The density of gap junctions in four Drosophila melanogaster mutants with abnormal wing disc development has been determined using quantitative electron microscopy and compared with the gap junction density in wild-type wing discs. No appreciable differences relative to wild-type controls were found in the cell death mutant vestigial or in the mildly hyperplastic mutant lethal giant disc which could not be accounted for in terms of altered lateral plasma membrane surface density or as an extension of the gap junction growth which normally occurs during the third larval stage of development in wild-type wing discs. However, both the severely hyperplastic mutant l₍₃₎c43^hs1 and the neoplastic mutant lethal giant larva have significant reductions in the gap junction surface density, the number of gap junctions, and the gap junction areal fraction of the lateral plasma membrane compared with wild-type controls. These differences cannot be attributed to altered lateral plasma membrane surface densities which are not significantly different from wild-type control wing discs. The reduced gap junction density in severely hyperplastic and neoplastic wing discs suggests that alterations in the number or distribution of gap junctions may be as disruptive to normal growth and development as their complete absence.     

Inhibition of Hill Reaction and Photophosphorylation by l,l,l-Trichloro-2,2-bis(p-chlorophenyl)ethane

The effect of DDT on DCIP and Fe(CN)₆^3– photoreductions,and cyclic and non-cyclic photo-phosphorylations, in some 30varieties of barley from widely different parts of the worldis reported. Whereas resistant barleys were not affected byDDT treatment, chloroplasts from treated susceptible barleysshowed parallel inhibitions of all the investigated aspectsof photosynthesis. However, in a few susceptible varieties inhibitionsof Fe(CN)₆^3– photoreduction or non-cyclic photophosphorylationwere not so pronounced. Possible reasons for these anomaliesare discussed; in particular earlier reports that DDT had noeffect on these latter photosynthetic activities may have beendue to the use of hypotonic media during chloroplast isolation.     

Activity of l,3-β-D-Glucanases in soil

Air-dried soil did not exhibit any measurable 1,3-β-D-glueanase activity. The enzyme activity was observed after a previous wetting of the soil or after supplementing it with glucose or caseine hydrolyzate. The addition of 1,3-β-D-glucan resulted in a significant increase of the enzyme activity in the variant with water and casein hydrolyzate but not in the variant treated with glucose.     

Validity of the Force-Velocity Relation for Muscle Contraction in the Length Region, l ≤ l0

Considerable attention has been directed to the characteristic force-velocity relation discovered by A. V. Hill in the study of muscle kinematics. Models of contractile process were tested on the basis of their compatibility with the Hill equation. However, almost all the isotonic data have been restricted to one length, l₀, the maximum length with almost no resting tension; the velocities measured are those initial values when the load begins to move. The force-velocity curve extrapolates to zero velocity for isometric tension, but only for the tension at that one length. Very few efforts have been made to study the profiles of the curves throughout the range of lengths over which shortening takes place. In examining the length region, l ≤ l₀, for an isotonically contracting muscle, not only is the force-velocity relation valid for the initial reference length, l₀, but also for any other length. The analysis in this report indicates that the constants a/P₀ and b/l₀ remain fixed throughout the length change of afterloaded isotonic shortening in the Rana pipiens sartorius muscles.     

Génétique de l’infertilité chez l’homme, nouvelles approches

15% of couples worldwide present with reproduction difficulties related to infertility. To date, very few genetic causes have been associated with male or female infertility. The identification of single-gene mutations causing male infertility is not a field of intense research at the present time, although they are probably responsible for a large number of so-called idiopathic cases of infertility. Murine models were created several years ago by gene knock-out by genetic recombination: more than 200 genes have been shown to be responsible for isolated syndromic infertility. This is the case for genes controlling meiosis. The course of meiosis and the genes associated with this process have been largely characterized in yeasts. Mammalian homologues were recently cloned and knocked out in mice, demonstrating their essential roles during meiosis and gametogenesis. The gonadal phenotype of these mutant animals is similar to that of certain patients with unexplained infertility. The search for possible mutations in meiosis genes, genes that have been highly preserved during evolution, is currently underway. These murine models are very useful to study and dissect the various steps of normal and pathological gametogenesis in mammals. This progress should lead, in the near future, to more precise diagnosis and therefore informed genetic counselling in these infertile couples.     

Mating in the mosquito, Anopheles gambiae s.l.

ABSTRACT. Swarming behaviour in the Anopheles gambiae complex was observed in the field, in the Gambia, West Africa, and in the laboratory. Naturally occurring swarms of A.melas were seen in a clearing at the edge of mangrove swamps close to their breeding sites. Males could be induced to swarm over artificial 'markers' within this 'arena' but not outside it. Females were observed entering the swarm and mating. In the laboratory, in an artificial 'dusk', male A.gambiae s.str. swarmed over a black marker on the floor of their 1.2-m cube cage. In contrast to the males, females made only short flights over the marker, performing brief turning movements at its edge. It is proposed that swarming brings about the aggregation necessary before short-range attraction can take place, and that, in nature, anopheline mosquitoes orientate visually first to an arena and then to a marker within the arena. Female behaviour can be interpreted as a process of scanning possible swarm sites until mating is achieved.     

San Servolo, l’île des fous

A monastery was first constructed in San Servolo, an island situated between San Marco and the Lido, then a military hospital. Mad people from Venice were accommodated there from the Napoleonian period to the end of the 1970’s, when psychiatric hospitals were closed due to the “Basaglia law”. San Servolo hosts now an international university center and the Museum of Mental Hospital.     

A field study on the red-bellied tamarin,Saguinus l. labiatus,in Bolivia

A 5-month field study was conducted on red-bellied tamarins,Saguinus labiatus labiatus, in the Pando Department of northern Bolivia. Group sizes ranged from 5 to 10 animals, and each group associated with a group of saddle-backed tamarins,Saguinus fuscicollis weddelli. Members of three groups were trapped and marked and data were collected by radiolocation. The average range size used over 10 days was 19 ha. On average the groups entered about 29% of their range each day and had a mean daily path length of about 1487 m. The groups used a number of different sleeping sites within their ranges. They fed on a variety of different fruits and also on nectar from flowers, resin, and insects. Areas within the home range which were used significantly more than expected were generally those in which one or more of the following existed: a sleeping site, an intergroup encounter site, or a site where the group took shelter during an extended period of heavy rain.     

Detailed Studies on Trimethylselyl Triflate Mediated Glycosylation via a 3,5-O-(l,l,3,3-Tetraisopropyl-Disiloxane-l,3-diyl)-2-O-methylribofuranos-l-yl Trichloroacetimidate Intermediate

Abstract

The reaction of 3,5-O-(l,l,3,3-tetraisopropyldisiloxane-l,3-diyl)-2-O-methylribofuranos-1-yl trichloroacetimidate as the ribosyl donor with bis(trimethylsilyl)thymine was studied in detail. As the result, it was concluded that the main product is an α-glycoside derivative unlike the previous report. In connection with this glycosylation, several chemical properties of the byproduct obtained by the Chapman arrangement are described.     

Tn292l, a transposon encoding fosfomycin resistance.

The determinant of resistance to fosfomycin of the Serratia marcescens plasmid pOU900 was transposed into the plasmid ColE1 and into the plasmid RP4 in the absence of the RecA function of the host. In each case, the acquisition of fosfomycin resistance was correlated with the presence of a discrete piece of DNA, uniform in size and in restriction pattern, This new, 7.5-megadalton transposable element encoding resistance to fosfomycin has been called Tn2921. A preliminary map of the transposon is presented.     

Phylogeny of the bee subtribe Caenohalictina Michener (Hymenoptera,Apidae s.l., Halictinae s.l.)

Gonçalves, R. B. & Melo, G. A. R. (2009). Phylogeny of the bee subtribe Caenohalictina Michener (Hymenoptera, Apidae s.l., Halictinae s.l.). —Zoologica Scripta, 39, 187–197. Recently, Caenohalictina Michener, 1954 was formally proposed as a group within Halictini based on a phylogenetic analysis using DNA data. Morphological synapomorphies for the subtribe are not stabilized and the relationships among its attributed genera were not completely reconstructed. Also, there are different propositions for the scope and classification of the genera. This study investigates the monophyly of Caenohalictina based on morphological characters and presents a hypothesis for the relationships among its genera and subgenera. For this purpose, a matrix of 36 terminals and 96 characters was coded. The cladistic analysis using character equal weighting resulted in one most parsimonious tree with 189 steps. According to this hypothesis, the subtribe is monophyletic with five synapomorphies supporting it. The relationships among Caenohalictina taxa are: Habralictus(Caenohalictus (((Agapostemon s.s. + Notagapostemon) (Agapostemonoides (Rhinetula (Paragapostemon + Dinagapostemon)))) + ((Ruizanthedella (Ruizantheda + Oragapostemon)) + (Brasilagapostemon (Pseudagapostemon s.s. + Neagapostemon))))). The subgenus Habralictus s.s. is paraphyletic with respect to Habralictus (Zikaniella) crassipes, hence both subgenera are not recognized. Comments on alternative generic classifications and biogeographic patterns are presented.     

L’évaluation des nouvelles technologies en santé : un nouveau besoin,l’évaluation de l’adaptation à l’usage

In healthcare, technologies have a critical role in diagnostic, treatment and monitoring of the patients, either in hospitals settings or at home. But in order to be used in clinical routine, their assessment does not always comply with strict scientific criteria. In some situations, these technologies can also turn out useless, too costly or dangerous when integrated without precaution in the healthcare professional environment. In France, to address this issue, the Ministry of Health and the National Agency for Research in Medicine have installed new “Innovative Technologies” (IT) modules attached to existing Centres for Clinical Research (CRC). Eight CRC-IT (in short, CIT) have been accredited in different technological domains. They may support and secure the dissemination of promising IT applications in healthcare by assessing (i) the actual benefit for the patients, or medical service rendered, (ii) the potential drawbacks and (iii) the anticipated Return On Investment for the healthcare system. The procedures used to evaluate other healthcare innovations such as new drugs cannot be applied for the evaluation of innovative technologies. CIT also have to adapt their methodology to the type of device and domain. Besides the impact on the patient or public health, CIT are able to analyze the impact of innovative technologies on the quality of care and on their use by professionals.