Natural female mating rate maximizes hatchling size in a marine invertebrate.

1. Males and females often differ in their optimal mating rates, resulting potentially in conflicts over remating. In species with separate sexes, females typically have a lower optimal mating rate than males, and can regulate contacts with males accordingly. The realized mating rate may therefore be closer to the female's optimum. In simultaneous hermaphrodites, however, it has been suggested that the intraindividual optimization between 'male' and 'female' interests generates more 'male'-driven mating rates. 2. In order to assess the consequences of variation in mating rate on 'female' reproductive output, we exposed the simultaneously hermaphroditic sea slug Chelidonura sandrana to four mating rate regimes and recorded the effects on a variety of fitness components. 3. In focal 'females', we found (i) a slight but significant linear decrease in fecundity with mating rate, whereas (ii) maternal investment in egg capsule volume peaked at an intermediate mating rate. 4. Combining the observed fecundity cost with the apparent benefits of larger offspring size suggests that total female fitness is maximized at an intermediate mating rate. With the latter being close to the natural mating rate of C. sandrana in the field, our findings challenge the assumption of 'male'-driven mating systems in simultaneous hermaphrodites. 5. Our study provides experimental evidence for various mathematical models in which female fitness is maximized at intermediate mating rates.

Functional cine magnetic resonance imaging in women after abdominal sacrocolpopexy.

OBJECTIVE: To evaluate whether functional cine magnetic resonance imaging (MRI) is a reliable method for verifying postoperative anatomy and function in women after abdominal sacrocolpopexy. METHODS: We did postoperative functional cine MRI in 25 women who had sacrocolpopexies. Visibility of grafts and vaginal and sacral fixation points were assessed and correlated with intraoperative results. Ranges of vaginal movement were calculated and compared with results of postoperative gynecologic examinations. RESULTS: Functional cine MRI achieved full view of vaginas in all cases. The mean vaginal axis was 142 degrees. Grafts were entirely visible in 13 women, partly visible in nine, and not visible in three. Functional cine MRI defined exactly the sacral fixation points in 22 women. Compared with intraoperative results, functional cine MRI showed a higher level of fixation in nine of 11 women. Functional cine MRI defined exact vaginal fixations point in 15 of 25 women. According to the pubococcygeal reference line, the postoperative range of movement of the vaginal apex was 1.8 cm. Recurrent vaginal vault prolapses in three women were detected equally by functional cine MRIs and gynecologic examinations. In those cases, no parts of patches were seen on the images. CONCLUSION: Functional cine MRI provided reliable abdominal sacrocolpopexy follow-up data. It might help with individual surgical planning and augment understanding of benefits and flaws of various surgical approaches to repair of vaginal vault prolapse.

The used tire trade: a mechanism for the worldwide dispersal of container breeding mosquitoes.

Modern transportation methods have facilitated an extensive trade in used tires at the national and international level. The history and reasons for this trade are described. Comprehensive data on United States imports and United States, Japanese, and Korean exports of used tires for the period 1978-85 reveal an unprecedented potential for the worldwide dispersal of important vector mosquitoes such as Aedes albopictus and Ae. aegypti. Other articles of commerce with similar potential may await recognition.

Susceptibility status of Aedes albopictus to three topically applied adulticides.

The baseline susceptibility of Aedes albopictus (Sabah strain) to malathion was determined. Both laboratory-colonized and field-collected Ae. albopictus at Harris County, TX are resistant to malathion but susceptible to Scourge. The acute toxicity of bendiocarb to Ae. albopictus is confounded by its rapid knockdown and delayed recovery syndrome of poisoning.

[Functional MRI of the pelvic floor: its normal anatomy and pathological findings]. / Funktionelle MRT des Beckenbodens: normale Anatomie und pathologische Befunde.

PURPOSE: Functional MRI of the pelvic floor allows mapping and definition of different forms of pelvic floor dysfunction. METHODS: We performed functional MRT of the pelvic floor in 39 healthy nulliparas and 324 patients. The diagnosis of a pathological organ descent was made if certain landmarks of the pelvic floor compartments descended below the pubococcygeal reference-line (PC-line). RESULTS: If there was no organ descent below the PC-line on straining and if the pelvic floor muscles hardly changed position, a normal finding was diagnosed. 70% of organ prolapses came in the combined form. The generally gradual development of an organ descent led to a change of the main finding in 21.6%. The masking of a cystocele (48.6%) or of an enterocele (34.3%) by a rectocele was most frequent in these cases. DISCUSSION: The use of functional MRI of the pelvic floor appears to be especially useful in young patients, in cases of divergent clinical and sonographic or radiological findings and if the presence of a predominant hernial sac with or without enterocele/rectocele is supposed.

Breeding structure of a colonising species: Aedes albopictus (Skuse) in the United States.

Allelic and genotypic frequencies were monitored at seven enzymatic loci in newly established Aedes albopictus (Skuse) populations in the United States. Populations were sampled within the cities of New Orleans, Louisiana, Houston, Texas, three counties surrounding Houston, Memphis, Tennessee, Jacksonville, Florida, and Evansville and Indianapolis, Indiana. Unique alleles and relatively high levels of heterozygosity were detected in New Orleans, Houston, surrounding counties and Indianapolis suggesting relatively large and independent introductions in these cities. No unique alleles and low heterozygosities were detected in Memphis, Evansville and Jacksonville suggesting that a population bottleneck may have accompanied the founding of these populations. The bottleneck may have resulted from a small number of founding individuals or may have been generated through repeated control efforts. Genetic distance estimates indicated that Houston, New Orleans and Indianapolis were genetically similar. Evansville and Memphis were also found to be similar. Significant differentiation of allele frequencies existed among and within cities. Variance in allele frequencies among all samples was partitioned into the variance among cities and among locations within cities. Most of the variance was attributable to local differentiation. The most parsimonious explanation of this result is that much genetic drift accompanied the establishment of local populations in cities and that there has been little subsequent gene flow. Analysis of genotypic frequencies detected a slight but consistent excess of homozygotes suggesting inbreeding.

Temporal variation in genetic structure of a colonising species: Aedes albopictus in the United States.

The medically important mosquito, Aedes albopictus, has recently become established in several locations within the United States. A three-year survey of temporal variation in allele frequencies at ten enzymatic loci in 17 populations was undertaken to determine the extent and direction of change since the colonization event. Significant, but non-directional, changes were detected in allele frequencies at most of the loci in all populations. Some alleles detected at low frequencies in earlier samples were not found in subsequent samples. Variance of allele frequencies remained unchanged. In at least two locations, there was an increase in mean heterozygosity, perhaps because of gene flow. There was no significant change in the levels of genetic variation within and among populations. The results from this study indicate that the breeding structure of Ae. albopictus in the U.S. did not differ substantially from that in a native habitat, either soon after colonisation or after several generations in the new habitat. We suggest that a large founder population, gene flow and a rapid population expansion could explain the present breeding structure of Ae. albopictus.

Detection and mapping of intraabdominal adhesions by using functional cine MR imaging: preliminary results.

PURPOSE: To identify and map intraabdominal adhesions by using functional cine magnetic resonance (MR) Imaging. MATERIALS AND METHODS: Twenty-seven patients suspected of having intraabdominal adhesions were examined. Section-by-section dynamic depiction of induced visceral slide throughout the whole abdomen was achieved by using a transverse or sagittal true fast imaging with steady-state precession sequence. Location and type of diagnosed adhesions were documented by using the nine segments of the abdominal map. These criteria and intraoperative results were compared in 13 patients. RESULTS: MR images depicted a total of 42 intraabdominal adhesions; 21 (50%) were in the lower abdomen. The most common types of adhesions were located between the ventral abdominal wall and small-bowel loops (n = 10 [24%]) and between adjacent small-bowel loops (n = 9 [21%]). Comparison with the intraoperative results showed a sensitivity of 87.5% and a specificity of 92.5%. MR imaging was most accurate in depicting adhesions to the abdominal wall (15 [94%] of 16) and subperitoneal space (eight [100%] of eight). The presence of adhesions between bowel loops was overestimated. CONCLUSION: Detection of visceral slide at functional cine MR imaging is easy to perform and represents a well-tolerated and accurate procedure for use in the identification of intraabdominal adhesions in patients with chronic pain and equivocal clinical findings.

[Functional MRI of the pelvic floor. The methods and reference values]. / Funktionelle MRT des Beckenbodens. Methodik und Referenzwerte.

PURPOSE: Functional cine MRI of the pelvic floor is a yet another modality in addition to various radiological fluoroscopic techniques. This article describes our own method in view of the recent literature and provides morphometric reference values. MATERIAL AND METHOD: We examined 20 nulliparous women (range of age: 25-51 years) with normal findings in the gynecological and urodynamic examination. Functional cine MRI was performed on a 1.5 Tesla equipment after opacification of the vagina and rectum. We used a T2-weighted gradient-echo sequence (Ture-FISP) to determine the position of the reference organs at rest and during straining/defecation. Two different reference lines were used. In addition 29 morphometric and functional parameters were measured, all of them being observer independent. RESULTS: Functional cine MRI was able to show the extent and interaction of the pelvic floor organs in all cases with the reference organs always remaining above the pubococcygeal reference line. The depth of the rectocele was 2 cm. With the exception of the diameter of urogenital hiatus the different parts of the levator ani muscle could not be determined. DISCUSSION: Functional cine MRI using an appropriate organ opacification and slice positioning is an objective, unifying diagnostic approach of the pelvic floor. The reference data given can be of help to distinguish normal from abnormal findings.

[Filmless documentation and image distribution to referring physicians exemplified by a radiologic community practice]. / Filmlose Befundung und Bildverteilung an Zuweiser am Beispiel einer radiologischen Gemeinschaftspraxis.

In healthcare, cost effectiveness as well as the quality of examinations and procedures are subjected to quickly increasing expectations and demands: we like to demonstrate how the resulting challenges and problems can be met with implementation of modern information technology. Analysing the respective demands (pattern of quantities) and choosing the adequate technical solution/technical approach, we found filmless reading and the usage of digital image distribution to communicate with referring physicians to be cost effective as well as of higher quality. Special attention should be paid to the rigorous maintenance of data security and access. Today's information technology allows individual adjustment to the respective size and requirements of a radiological department or practice for filmless reading and digital image distribution. Working with the systems as a matter of routine and using all of the expanding technological possibilities, an important improvement of service and quality can be achieved. Amortisation will be obtained despite high investments, due to the subsequent savings in personal- and enterprise costs.