| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Rodriguez-Sanchez, J. L., et al.
(författare)
-
Constraining the level density using fission of lead projectiles
- 2015
-
Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 92:4
-
Tidskriftsartikel (refereegranskat)abstract
- The nuclear level density is one of the main ingredients for the statistical description of the fission process. In this work, we propose to constrain the description of this parameter by using fission reactions induced by protons and light ions on Pb208 at high kinetic energies. The experiment was performed at GSI (Darmstadt), where the combined use of the inverse kinematics technique with an efficient detection setup allowed us to measure the atomic number of the two fission fragments in coincidence. This measurement permitted us to obtain with high precision the partial fission cross sections and the width of the charge distribution as a function of the atomic number of the fissioning system. These data and others previously measured, covering a large range in fissility, are compared to state-of-the-art calculations. The results reveal that total and partial fission cross sections cannot unambiguously constrain the level density at ground-state and saddle-point deformations and additional observables, such as the width of the charge distribution of the final fission fragments, are required.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Schwabl, P, et al.
(författare)
-
Meiotic sex in Chagas disease parasite Trypanosoma cruzi
- 2019
-
Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 10:1, s. 3972-
-
Tidskriftsartikel (refereegranskat)abstract
- Genetic exchange enables parasites to rapidly transform disease phenotypes and exploit new host populations. Trypanosoma cruzi, the parasitic agent of Chagas disease and a public health concern throughout Latin America, has for decades been presumed to exchange genetic material rarely and without classic meiotic sex. We present compelling evidence from 45 genomes sequenced from southern Ecuador that T. cruzi in fact maintains truly sexual, panmictic groups that can occur alongside others that remain highly clonal after past hybridization events. These groups with divergent reproductive strategies appear genetically isolated despite possible co-occurrence in vectors and hosts. We propose biological explanations for the fine-scale disconnectivity we observe and discuss the epidemiological consequences of flexible reproductive modes. Our study reinvigorates the hunt for the site of genetic exchange in the T. cruzi life cycle, provides tools to define the genetic determinants of parasite virulence, and reforms longstanding theory on clonality in trypanosomatid parasites.
|
|
| 8. |
|
|
| 9. |
- Akkoyunlu, Mustafa, et al.
(författare)
-
Biological activity of serum antibodies to a nonacylated form of lipoprotein D of Haemophilus influenzae
- 1996
-
Ingår i: Infection and Immunity. - 1098-5522. ; 64:11, s. 4586-4592
-
Tidskriftsartikel (refereegranskat)abstract
- Protein D, a surface-exposed 42-kDa membrane lipoprotein, is well conserved among both type b and nontypeable Haemophilus influenzae strains, and it is considered a vaccine against H. influenzae infections. Here, we report the large-scale purification of a nonacylated form of protein D (PDm) from the periplasmic space of Escherichia coli overexpressing PDm. Screening of human sera for levels of antibodies to PDm demonstrated that the immunoglobulin G (IgG) antibody level is above background levels in infants less than 6 months of age. Following a drop to background values in the age group 6 months to 1 year, IgG antibody levels start to increase, together with IgA antibody levels, after 1 year of age. The first appearance of serum IgM antibodies is in 6-month- to 1-year-old infants whose IgG antibody levels have dropped to the postnatal background level. Affinity-purified antibodies from humans and from PDm-immunized rats detected epitopes of protein D which are normally exposed on the bacterial surface. Affinity-isolated human anti-PDm antibodies eluted in acidic buffer were not bactericidal against H. influenzae. Loss of bactericidal activity may occur in this buffer, as was demonstrated in pooled human sera with high bactericidal activity after incubation in the same buffer. Hyperimmunization of rats with PDm induced high levels of serum IgG and IgA antibodies against PDm and significant bactericidal activity against homologous and heterologous H. influenzae strains.
|
|
| 10. |
|
|
