72 research outputs found
Photoionization of ultracold and Bose-Einstein condensed Rb atoms
Photoionization of a cold atomic sample offers intriguing possibilities to
observe collective effects at extremely low temperatures. Irradiation of a
rubidium condensate and of cold rubidium atoms within a magneto-optical trap
with laser pulses ionizing through 1-photon and 2-photon absorption processes
has been performed. Losses and modifications in the density profile of the
remaining trapped cold cloud or the remaining condensate sample have been
examined as function of the ionizing laser parameters. Ionization
cross-sections were measured for atoms in a MOT, while in magnetic traps losses
larger than those expected for ionization process were measured.Comment: 9 pages, 7 figure
A Novel High-Affinity Sucrose Transporter Is Required for Virulence of the Plant Pathogen Ustilago maydis
A novel, high-affinity sucrose transporter identified in the plasma membrane of the plant pathogen Ustilago maydis is essential for fungal virulence and successful infection of maize
Transcriptional and genomic parallels between the monoxenous parasite Herpetomonas muscarum and Leishmania
Trypanosomatid parasites are causative agents of important human and animal diseases such as sleeping sickness and leishmaniasis. Most trypanosomatids are transmitted to their mammalian hosts by insects, often belonging to Diptera (or true flies). These are called dixenous trypanosomatids since they infect two different hosts, in contrast to those that infect just insects (monoxenous). However, it is still unclear whether dixenous and monoxenous trypanosomatids interact similarly with their insect host, as fly-monoxenous trypanosomatid interaction systems are rarely reported and under-studiedâdespite being common in nature. Here we present the genome of monoxenous trypanosomatid Herpetomonas muscarum and discuss its transcriptome during in vitro culture and during infection of its natural insect host Drosophila melanogaster. The H. muscarum genome is broadly syntenic with that of human parasite Leishmania major. We also found strong similarities between the H. muscarum transcriptome during fruit fly infection, and those of Leishmania during sand fly infections. Overall this suggests Drosophila-Herpetomonas is a suitable model for less accessible insect-trypanosomatid host-parasite systems such as sand fly-Leishmania
Cross-section for collisions of ultracold
In a magneto-optical trap (MOT) we are able to simultaneously trap and cool
7Li and Na.
We investigated the loading behavior of the cloud of Li atoms in presence of
the overlapped cloud of cold Na atoms, and, by blocking the weak repumping
beam for Na, compared it with the loading curve for Li atoms only.
Out of these loading curves we calculated the collision cross-section of Na
on Li to be 10-11 cm3/s
Photoionization cross-sections of the first excited states of sodium and lithium in a magneto-optical trap
A two element magneto-optical trap (MOT) for Na and 7Li or 6Li is used to
cool and trap each of them separately.
A fraction of the cold atoms is maintained in the first 2P3/2 excited
state by the cooling laser.
These excited state atoms are ionized by laser light in the near-UV region,
giving rise to a smaller number of trapped atoms and to different loading
parameters.
Photoionization cross-sections were derived out of these data.
They are in reasonable agreement with data previously obtained using thermal
samples and with theoretical predictions
Arimondo -Photoionization cross-sections of the first excited states of Sodium and Lithium in a magneto-optical trap
A two element magneto-optical trap (MOT) for Na and Li-7 or Li-6 is used to cool and trap each of them separately. A fraction of the cold atoms is maintained in the first P-2(3/2) excited state by the cooling laser. These excited state atoms are ionized by laser light in the near-UV region, giving rise to a smaller number of trapped atoms and to different loading parameters. Photoionization cross-sections were derived out of these data. They are in reasonable agreement with data previously obtained using thermal samples and with theoretical predictions
Photoionization cross-sections of the first excited states of sodium and lithium in a magneto-optical trap
A two element magneto-optical trap (MOT) for Na and Li-7 or Li-6 is used to cool and trap each of them separately. A fraction of the cold atoms is maintained in the first P-2(3/2) excited state by the cooling laser. These excited state atoms are ionized by laser light in the near-UV region, giving rise to a smaller number of trapped atoms and to different loading parameters. Photoionization cross-sections were derived out of these data. They are in reasonable agreement with data previously obtained using thermal samples and with theoretical predictions
Photoionization cross-sections of the first excited states of sodium and lithium in a magneto-optical trap
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