1,679 research outputs found
Duplicated female receptacle organs for traumatic insemination in the tropical bed bug Cimex hemipterus: adaptive variation or malformation?
During mating, male bed bugs (Cimicidae) pierce the female abdomen to inject sperm using their needle-like genitalia. Females evolved specialized paragenital organs (the spermalege and associated structures) to receive traumatically injected ejaculates. In Leptocimex duplicatus, the spermalege is duplicated, but the evolutionary significance of this is unclear. In Cimex hemipterus and C. lectularius, in which females normally develop a single spermalege on the right side of the abdomen, similar duplication sometimes occurs. Using these aberrant morphs (D-females) of C. hemipterus, we tested the hypothesis that both of the duplicated spermaleges are functionally competent. Scars on female abdominal exoskeletons indicated frequent misdirected piercing by male genitalia. However, the piercing sites showed a highly biased distribution towards the right side of the female body. A mating experiment showed that when the normal insemination site (the right-side spermalege) was artificially covered, females remained unfertilized. This was true even when females also had a spermalege on the left side (D-females). This result was attributed to handedness in male mating behavior. Irrespective of the observed disuse of the left-side spermalege by males for insemination, histological examination failed to detect any differences between the right-side and left-side spermaleges. Moreover, an artificial insemination experiment confirmed that spermatozoa injected into the left-side spermalege show apparently normal migration behavior to the female reproductive organs, indicating an evolutionary potential for functionally-competent duplicated spermaleges. We discuss possible mechanisms for the evolutionary maintenance of D-females and propose a plausible route to the functionally-competent duplicated spermaleges observed in L. duplicatus
Mitochondrial Nutrition as a Strategy for Neuroprotection in Parkinson's Disease—Research Focus in the Department of Alternative Medicine and Experimental Therapeutics at Hokuriku University
Changes of lymphocyte subsets in leukemia patients who received allogenic bone marrow transplantation.
Proportional changes of lymphocyte subsets in the peripheral blood were monitored by two-color flow-cytometry in seven leukemia patients who had received allogenic bone marrow transplantation (BMT). Lymphocyte counts, and proportions of T and B-cells returned to normal ranges between the 2nd and 12th months after BMT. Activated T-cells prominently increased after BMT, and the values gradually returned toward normal. As to lymphocyte subsets, the proportions of CD 4+ cells had remained low, while those of CD 8+ cells high for a whole observation period after BMT. The changes of CD 4+ cells were caused by the decrease of suppressor-inducer T-cells (CD 4+ Leu 8+). High proportion of CD 8+ cells was mainly associated with increased suppressor T-cells (CD 8+ CD 11+). Among natural killer (NK) cells, highly active NK cells (CD 16+ CD 57-) markedly increased shortly after BMT, and gradually returned to normal. CD 16 -CD 57+ NK cells increased beyond normal ranges after the 2nd month. The incidence or degree of acute and chronic graft-versus-host diseases (GVHD) did not correlate with the changes of any lymphocyte subsets. The present results suggest that the increase of activated T-cells shortly after BMT reflects lymphocyte reconstitution. The prolonged immune deficiency after BMT might be related to either deficient expression of homing receptor (Leu 8 antigen) on CD 4+ cells or increased suppressor T-cells (CD 8+ CD 11+). In addition, the early increase of NK cells after BMT may compensate for the immune deficiency in BMT patients.</p
Replica theory for disorder-free spin-lattice glass transition on a tree-like simplex network
A class of pyrochlore oxides, MoO ( Ho, Y, Dy, Tb) with
magnetic ions on corner-sharing tetrahedra is known to exhibit spin-glass
transitions without appreciable amount of quenched disorder. Recently a
disorder-free theoretical model for such a system has been proposed which takes
into account not only spins but also lattice distortions as dynamical variables
[K. Mitsumoto, C. Hotta and H. Yoshino, Phys. Rev. Lett. 124, 087201 (2020)].
In the present paper we develop and analyze an exactly solvable disorder-free
mean-field model which is a higher-dimensional counterpart of the model. We
find the system exhibit complex free-energy landscape accompanying replica
symmetry breaking through the spin-lattice coupling.Comment: 16 pages, 6 figure
Elastic heterogeneity governs asymmetric adsorption-desorption in a soft porous crystal
Molecular adsorption in soft porous materials is crucial to control
liquid-liquid phase separation in polymer networks and biological cells,
refrigeration cycles of nanosponges, and energy storage in supercapacitors. The
deformation process of host porous matrices, coupled with the adsorption of
guest molecules, plays an essential role in developing stimuli-responsive
materials. In particular, metal-organic frameworks (MOFs) exhibit promising
stimuli-responsiveness and molecular adsorption selectivity, that enable
various applications based on MOFs. The adsorption of guest molecules in MOFs
changes the crystalline structure and elastic moduli of the host matrices.
Thus, the substances become elastically heterogeneous when adsorbed/desorbed
sites coexist. However, the role of elastic heterogeneity in the
adsorption-desorption transition has been overlooked. Here we show the
asymmetric role of elastic heterogeneity in the adsorption-desorption
transition. We construct a minimal model incorporating adsorption-induced
lattice expansion and an increase in the elastic moduli, and discover that the
transition is hindered entropically during the adsorption process and
energetically during the desorption process, leading to the strong hysteretic
nature of the transition. Furthermore, the adsorbed/desorbed sites exhibit
spatially heterogeneous domain formation due to elastic heterogeneity, implying
that the domain morphology and interfacial area between the adsorbed/desorbed
sites can be controlled by elastic heterogeneity. Our results provide a
theoretical guideline for designing soft porous crystals with tunable
adsorption hysteresis and the dispersion and domain morphology of adsorbates
using elastic heterogeneity.Comment: 15 pages, 12 figure
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