A spatial regression analysis of German community characteristics associated with voluntary non-remunerated blood donor rates.

BACKGROUND AND OBJECTIVES: Previous studies have shown substantial geographical variation in blood donation within developed countries. To understand this issue better, we identified community characteristics associated with blood donor rates in German municipalities in an ecological analysis. MATERIALS AND METHODS: We calculated an aggregated rate of voluntary blood donors from each of 1533 municipalities in south-west Germany in 2007 from a database of the German Red Cross Blood Service. A multiple linear regression model estimated the association between the municipality-specific donor rate and several community characteristics. Finally, a spatial lag regression model was used to control for spatial autocorrelation that occurs when neighbouring units are related to each other. RESULTS: The spatial lag regression model showed that a relatively larger population, a higher percentage of inhabitants older than 30 years, a higher percentage of non-German citizens and a higher percentage of unemployed persons were associated with lower municipality-specific donor rates. Conversely, a higher donor rate was correlated with higher voter turnout, a higher percentage of inhabitants between 18 and 24 years and more frequent mobile donation sites. CONCLUSIONS: Blood donation appears to be a highly clustered regional phenomenon, suggesting the need for regionally targeted recruiting efforts and careful consideration of the value of mobile donation sites. Our model further suggests that municipalities with a decreasing percentage of 18- to 24-year-olds and an increasing percentage of older inhabitants may experience substantial declines in future blood donations.

[Psychological consequences of twinship on the children and their parents]. / Impact psychologique de la gémellité sur les enfants et leurs parents.

This paper presents a synthesis about the psychological consequences of twinship based on a review of the literature and on our clinical experience. During pregnancy, delivery and the immediate post-partum, mothers experience physical and psychological difficulties linked with increased medical risks for themselves and for the children. The twins mortality is high before and after delivery. Grieving for one twin creates particular problems for parents. During first months after hospital discharge mothers encounter material and emotional stress. They are caused by overload of mothering tasks and the specificity of mother-twins relationship. The impossibility to establish a dyadic relationship with each child creates feelings of frustration and guilt. The risk of child abuse is increased in twins. The balanced psychoemotional development of twins requires parental attitudes enhancing their individualization as opposed to their "collectivization". The risk of prematurity is ten times increased in twins which increases the risks of developmental disabilities. Considering that the number of twin deliveries is rising in our country it is important to be aware of the problems experienced by the families and to improve the way material and psychological help is provided to them.

A primer on medical imaging--Part two.

This month FDA Consumer offers the second of two articles on the wide array of radiological techniques that physicians can use to help them 'see' inside the body. The first article, in last month's issue, covered techniques that use X-rays, though often in ways far different from the traditional X-ray machine. Part two covers non-X-ray techniques, some of which work without potentially hazardous ionizing radiation.

A single genetic unit specifies two transposition functions in the maize element activator.

The self-mobile maize transposable element Ac (Activator) displays two trans-acting genetic functions: it induces transposition of the element Ds (Dissociation) but, as its dosage is increased, it also inhibits transposition. Previous work has shown that the 4563 base pair (bp)-long Ac element contains three open reading frames (ORF's) and that a deletion in ORF 1 in wx-m9(Ds), a Ds derivative from Ac isolated at the wx (waxy) locus, results in loss of transposition. The Ds element in the bronze allele bz-m2(DI) is shown to have arisen from Ac by a 1312-bp deletion that is located almost entirely within ORF 2 and does not affect ORF 1. The Ds elements in wx-m9(Ds) and bzm2(DI), defective in ORF 1 and ORF 2, respectively, do not complement genetically to restore the transposition function of Ac; therefore, this function must be specified jointly by ORF's 1 and 2. Furthermore, since bz-m2(DI) does not contribute to Ac's inhibitory dosage effect, both Ac properties result from the expression of the same genetic functional unit.

Analysis of sh-m6233, a mutation induced by the transposable element Ds in the sucrose synthase gene of Zea mays.

The unstable allele sh-m6233 caused by insertion of the transposable element Ds into the sucrose synthase gene of maize, was cloned. The mutation is caused by the insertion of an 4 kb DNA segment, consisting of two identical Ds elements of 2000 bp length, of which one is inserted into the center of the other in inverted orientation. This structure is, at the level of restriction mapping and partial DNA sequencing, identical to the double Ds element found in a larger insert in the mutant allele sh-m5933. 8 bp of host DNA are duplicated upon insertion. In a revertant, a 6-bp duplication is retained.

Genomic clones of a wild-type allele and a transposable element-induced mutant allele of the sucrose synthase gene of Zea mays L.

In an attempt to isolate the transposable genetic element Ds from Zea mays L., we cloned DNA fragments hybridizing to a cDNA clone derived from the sucrose synthase gene in a lambda vector (lambda::Zm Sh). The fragments cloned from wild-type and from the Ds-induced mutant sh-m5933 (lambda::Zm sh-m5933) share a segment 6 kb long while a contiguous segment of 15 kb of lambda::Zm sh-m5933 (mutant-derived DNA) does not hybridize to the DNA segment cloned from the wild-type. Restriction maps are given, and the junction point between the two DNA segments in the mutant clone was determined. Hybridization of DNA fragments, present in the wild-type DNA of lambda::Zm Sh, but not in the mutant clone, lambda::Zm sh-m5933, to genomic DNA of sh-m5933 showed that no part of this DNA is deleted. It cannot be said whether the DNA found in the mutant, but not in the wild-type clone, has been brought there by Ds insertion or by another Ds-dependent DNA rearrangement. The mutant-derived DNA was hybridized to genomic DNA of various maize lines digested by several restriction endonucleases. Approximately 40 bands were detected. The mutant-derived DNA contains two pairs of inverted repeats several hundred nucleotide pairs long, one of which is located at the junction to wild-type-derived DNA.