Type II single umbilical artery (persistent vitelline artery) in an otherwise normal fetus

A single umbilical artery resulting from absence of the umbilical arteries and persistence of the vitelline artery that arises directly from the abdominal aorta has been described only in malformed fetuses with sirenomelia or caudal regression. Such an aberrant artery was suggested to be the etiology of sirenomelia caused by a ‘steal’ mechanism of blood flow from the caudal end of the embryo. We present a case in which prenatal ultrasound showed a similar aberrant single artery arising from the abdominal aorta in an otherwise normal fetus with a normal course of pregnancy. This vessel, a continuation of the superior mesenteric artery (SMA), corresponds to a persistent vitelline artery assuming the function of the umbilical arteries. The etiology of such a finding and its possible consequences are discussed. Copyright © 2002 John Wiley & Sons, Ltd.     

Fetal akinesia/hypokinesia sequence: Prenatal diagnosis and intra-familial variability

Intrauterine fetal movement plays a key role in normal embryonic and fetal development (Moessinger, 1983). When movement is absent or decreased, abnormal development takes place which can be appreciated in newborns and/or fetuses with the fetal akinesia/ hypokinesia sequence. This sequence is caused by a number of heterogeneous entities which result in decreased fetal movements by the action of intrinsic or extrinsic factors. Prenatal diagnosis of the akinesia/hypokinesia sequence may be possible during the second trimester through the use of real-time ultrasonographic evaluation of fetal movement. We report a family with three consecutive affected pregnancies in which the prenatal presentation of this sequence varied. Based on the phenotypic findings of the three affected fetuses, we believe that although they superficially resemble those features found in the New–Laxova syndrome, they are probably affected with a distinctly different lethal form of akinesia/ hypokinesia transmitted in an autosomal recessive fashion.     

Differential sex- and age-related migration of Bluethroats Luscinia svecica at Eilat, Israel

This paper examines the phenology and biometrics of Bluethroats staging in the Eilat region. This is of special interest because of the extreme conditions with which this temperate zone breeding species has to contend because Eilat is a desert habitat and is the last green area before the crossing of the deserts in autumn or after it in spring. Data were collected during 20 spring and 18 autumn migration seasons in the years 1984–2003, and a total of 7,464 Bluethroat were recorded. The number of trapped birds was much higher in autumn than in spring. The majority of Bluethroats caught in both the autumn and spring migrations were juveniles. We found differences in sex ratio in the individual age classes only in the autumn wherein among both adults and juveniles, males were in greater numbers. We also found significant differences in the dates of ringed birds from different sex–age classes in the spring and in autumn migrations. In spring, males from both age classes were caught earlier than females. In autumn, adult birds arrived earlier than juveniles. We think that it is important to identify and conserve the high quality stopover habitats such as Eilat wherein not only Bluethroats have been shown to stopover but also several hundred other species.     

A New Conceptual Framework for Sustainable Development

A critical review of the multidisciplinary literature on sustainable development reveals a lack of a comprehensive theoretical framework for understanding sustainable development and its complexities. A critical review shows that the definitions of sustainable development are vague; there is a lack of operative definitions and disagreement over what should be sustained; the concept is unclear in terms of emotional commitment; and it “remains a confused topic”, “fraught with contradictions”. This article aims to theoretically synthesize the interdisciplinary literature on sustainable development, and then identify the results by broad categories. Therefore, this article uses conceptual analysis, which reviews multidisciplinary literature on sustainable development, which recognizes patterns and similarities within the literature, then it synthesizes the patterns to different categories and independent concepts, where each concept has distinctive meanings and represents close ideas on sustainability. The analytical process elaborates seven concepts that together assemble the theoretical framework of ‘sustainable development’ and each concept represents distinctive meanings of the theoretical framework.