Homozygous alpha-thalassemia has the beneficial effect in sickle cell anemia of reducing the hemolytic severity while changing several other hematological parameters. We examined in detail the cellular basis of some of these hematologic alterations. We find that the broad distribution in erythrocyte density and the large proportion of dense cells associated with sickle cell anemia are both redu...

Background: Sickle cell anemia is relatively common in Khuzestan province located in Southwest Iran. The characteristics of sickle cell disease in Iran are apparently different from other regions some of these characteristics might be related to β-chain haplotypes. The purpose of this study was to determine the frequency of β-chain haplotypes in 50 patients with homozygous sickle cell anemia in...

Dispersal has long been recognized as a mechanism that shapes many observed ecological and evolutionary processes. Thus, understanding the factors that promote its evolution remains a major goal in evolutionary ecology. Landscape connectivity may mediate the trade-off between the forces in favour of dispersal propensity (e.g. kin-competition, local extinction probability) and those against it (...

In the fIrst of two experiments, suppression of the visible persistence of a temporally leading stimulus by a trailing stimulus was studied as ajoint function of stimulus onset asynchrony (SOA) and of spatial proximity between the two stimuli. In agreement with earlier work, temporal integration between the two successive stimuli was progressively impaired as SOA was increased. In addition, deg...

Although people often assume that multiple motives for doing something will be more powerful and effective than a single motive, research suggests that different types of motives for the same action sometimes compete. More specifically, research suggests that instrumental motives, which are extrinsic to the activities at hand, can weaken internal motives, which are intrinsic to the activities a...

background: there are many parameters that modulate the severity of sickle cell anemia. fetal hemoglobin (hb f) is one of these major variables. however, its effect is clinically inconsistent. we conducted a descriptive study to assess the influence of hb f on clinical events and hematological variables in patients with sickle cell anemia. methods: 151 patients with sickle cell anemia with a st...

T HE NATURE of the transition from hemoglobin F synthesis to hemoglobin A synthesis in the fetus and newborn remains unknown. Although it is evident from the elution method developed by Kleihauer, Braun and Betke13 that hemoglobin F and hemoglobin A may coexist in single erythrocytes,24 quantitative data regarding the amounts of these hemoglobins in individual cells are lacking. An attempt to q...