Preimplantation genetic diagnosis for single gene disorders: experience with five single gene disorders

We report our experience of 14 preimplantation genetic diagnosis (PGD) cycles in eight couples carrying five different single gene disorders, during the last 18 months. Diagnoses were performed for myotonic dystrophy (DM), cystic fibrosis (CF) [ΔF508 and exon 4 (621+1 G>T)], fragile X and CF simultaneously, and two disorders for which PGD had not been previously attempted, namely neurofibromatosis type 2 (NF2) and Crouzon syndrome. Diagnoses for single gene disorders were carried out on ideally two blastomeres biopsied from Day 3 embryos. A highly polymorphic marker was included in each diagnosis to control against contamination. For the dominant disorders, where possible, linked polymorphisms provided an additional means of determining the genotype of the embryo hence reducing the risk of misdiagnosis due to allele dropout (ADO). Multiplex fluorescent polymerase chain reaction (F-PCR) was used in all cases, followed by fragment analysis and/or single-stranded conformation polymorphism (SSCP) for genotyping. Embryo transfer was performed in 13 cycles resulting in one biochemical pregnancy for CF, three normal deliveries (a twin and a singleton) and one early miscarriage for DM and a singleton for Crouzon syndrome. In each case the untransferred embryos were used to confirm the diagnoses performed on the biopsied cells. The results were concordant in all cases. The inclusion of a polymorphic marker allowed the detection of extraneous DNA contamination in two cells from one case. Knowing the genotype of the contaminating DNA allowed its origin to be traced. All five pregnancies were obtained from embryos in which two blastomeres were biopsied for the diagnosis. Our data demonstrate the successful strategy of using multiplex PCR to simultaneously amplify the mutation site and a polymorphic locus, fluorescent PCR technology to achieve greater sensitivity, and two-cell biopsy to increase the efficiency and success of diagnoses. Copyright © 2002 John Wiley & Sons, Ltd.     

Near-surface monitoring for the ZERT shallow CO2 injection project

As part of a collaborative effort operated by the Zero Emission Research and Technology Center (ZERT), a series of two shallow releases of CO₂ was performed at a test site in Bozeman, MT. The purpose of the experiment was to simulate possible leakage scenarios from a carbon capture and storage operation in order to further develop and verify monitoring technologies used to characterize and quantify the release of CO₂. The project included collaboration with several research groups and organizations. Presented here are the results of soil–gas monitoring conducted by researchers from the National Energy Technology Laboratory, including CO₂ flux measurement, soil–gas analysis, perfluorocarbon tracer monitoring, and soil resistivity measurements. Together, these methods proved to be effective in detecting and characterizing leakage in the near-surface.     

Cuticular hydrocarbons correlate with fertility, not dominance, in a paper wasp, Polistes dominulus

Cuticular hydrocarbons (CHCs) are information-rich signals in social insects that coordinate behaviors within nests. However, in some taxa, the precise information conveyed by CHCs is poorly understood. In particular, there is a debate over whether CHCs convey information about their bearer's dominance or fertility. Distinguishing between dominance and fertility signaling is difficult because fertility and rank are frequently correlated within social insect colonies. This study disentangles those relationships by examining CHCs of Polistes dominulus paper wasps during the early nest-founding stage before dominance and fertility become correlated. First, we confirm that dominance and fertility are not associated in early spring foundresses. Then we show that CHCs are more strongly associated with fertility than dominance. There was no relationship between cuticular hydrocarbon profiles and a wasp’s ability to dominate rivals through aggression, suggesting that CHCs are unlikely to provide information about dominance. However, there was a significant correlation between ovarian development and the CHC profile, suggesting that CHCs could convey valuable information about their bearer's fertility. Furthermore, our data provide a potential mechanism for chemical signaling of fecundity, as there is a relationship between endogenous juvenile hormone titer (a gonadotropin), degree of ovarian development, and the CHC profile. Hormonal regulation of CHC profile expression offers a physiological mechanism to coordinate behavior, physical state, and signal expression.     

Body Mass Index (BMI) as a first-line screening criterion for detection of excessive daytime sleepiness among professional drivers

OBJECTIVES: Obstructive sleep apnea (OSA) is the main predisposing factor of excessive daytime sleepiness (EDS), and, therefore, increases the risk of road crashes. However, it is difficult to rely on medical intake for OSA or fatigue since drivers' symptoms reports are not reliable. On the other hand, direct measurement of EDS among large numbers of drivers carries serious practical drawbacks. Obstructive sleep apnea, in turn, is strongly related to obesity, and elevated body mass index (BMI) is considered one of the major risk factors for OSA. Thus, it could be postulated that BMI may carry predictive value for EDS proneness. METHODS: The present study examined the interrelation between BMI, degree of OSA, as measured with Respiratory Distress Index (RDI), and the degree of EDS, as measured with the mean sleep onset latency in the Multiple Sleep Latency Test (MSLT) among obese (BMI = 32) professional drivers. The drivers went through polysomnography followed by the five sessions of MSLT in the next day. RESULTS: In accordance with prior studies, we have found strong correlation between BMI and the degree of OSA on the one hand, and between the degree of OSA and EDS on the other hand. OSA was detected among 77.7% of the drivers, 47.1% were sleepy, 19% had severe sleepiness [mean sleep latency [MSL < or = 5 min.], 28.1% had moderate sleepiness [MSL < or = 10 min.]. None of the drivers complained about any sleep problem, including snoring, and all reported that they do not experience excessive daytime sleepiness. Thus, there was no correlation between their subjective report and objective findings. CONCLUSIONS: Obese drivers with BMI above 32 are highly prone to be sleepy during the day. Their subjective reports of OSA or fatigue symptoms are not reliable. Therefore it is highly recommended to screen them easily by weight and height measure for further sleep study and decision about their driving abilities.     

Effects of mesh size on estimation of population densities of tropical euthecosomatous pteropods

Euthecosomatous pteropods were collected in successive oblique plankton tows with 1 m diameter nets equipped with No. 0, No. 6, and No. 20 nylon mesh. Comparisons of samples revealed that the same species were collected by all 3 nets, but the No. 0 and No. 6 nets failed to collect veligers and juveniles of Spiratella inflata and Creseis virgula conica. Collections with nets of larger mesh size may erroneously suggest seasonal variations in population densities due, not to actual changes in total density, but to changes in the size of individuals and changes in the relative numbers of the different life stages. A large diameter net equipped with No. 20 mesh is recommended for work that includes the smallest life stages of tropical pteropods.     

Calling energetics of a neotropical treefrog,Hyla microcephala

Summary We investigated the calling energetics of Hyla microcephala, a neotropical treefrog with an unusually complex vocal repertoire. Males respond to the calls of other individuals by adding secondary click notes to their calls, thereby increasing the total number of notes given per minute. Rates of oxygen consumption of males calling in metabolic chambers were 0.41–2.80 ml O₂/(g·h), corresponding to calling rates of 205–6330 notes/h. Note rate explained 95% of the variance in meta-bolic rate; the effect of variation in body size and temperature was small. Data from playback experiments with males in the field showed that note rate increased as as the number of notes in a stimulus call increased, and this resulted in substantial increases in the cost of calling. Average metabolic rates for males in the field were about 1.7 ml O₂/(g·h), for a net cost of calling of about 20 J/h for an average-size male. However, estimated metabolic rates varied by more than 300% and were strongly influenced by the proximity and calling activity of other males in the chorus. Male H. microcephala appear to conserve energy by reducing calling rates when only a few males are active and increasing calling efforts only when vocal competition among males is intense.     

Measuring environmental success

Process improvement, environmental results, and customer satisfaction all can—and need to—be measured in order to achieve total quality environmental management. This article details why and how to take such measures, with examples of leading company practices.     

Corporate environmental management study shows shift from compliance to strategy

The Abt study of forty-one mostly Fortune 200 nonservice firms forms a new picture of environmental management. We present data indicating that environmental management is becoming central to corporate strategy and is being managed as an arena of competition rather than as a compliance-driven function. We look at environmental management's new role through four lenses: its relationship to strategic planning; its evolving management structures that show environment increasingly integrated into the main functions of the business; innovation in corporate environmental investments reflecting new drivers beyond compliance; and new management systems and measures of firm-wide performance that demonstrate that environment is being seen increasingly as an arena of competitive concern. We argue that much of the change is driven by three realities. First, as customers integrate environmental values into their conceptions of product quality, they are buying more products with identifiably environmental attributes. This change translates environmental management, historically a cost center, into a potential source of sales revenue, a change which cannot be underestimated. Second, recent life-threatening damage to the global ecosystem and atmosphere reframes environmental management. This moves firms toward a systemic and global approach matched to the globalization of competitive and market concerns, and it places environmental management in the strategic sphere. And third, pollution prevention in its cross-fertilization with total quality management is driving firms to focus on managing environment as an integral part of product management, and is helping them to reassess environmental performance as a contributor to productivity and innovation.     

Signature whistles of free-ranging bottlenose dolphins Tursiops truncatus: stability and mother-offspring comparisons

Summary Mother-calf whistle exchanges were recorded from temporarily captured free-ranging bottlenose dolphins from 1975 to 1989. This is part of a long-term research project studying social structure and behavior of a community of approximately 100 dolphins in waters near Sarasota, Florida. Analysis of whistle exchanges from 12 mothercalf pairs shows that signature whistles can remain stable for periods up to at least 12 years. We looked for effects of vocal learning on the development of the signature whistle by comparing whistles of calves to those of their mothers. Eight female calves produced whistles distinct from those of their mothers, while four male calves produced whistles similar to those of their mothers. Male calves appeared to produce a greater proportion of whistles other than the signature whistle (termed variants). We hypothesize that these sex differences in whistle vocalizations may reflect differences in the roles males and females play in the social structure of the community.