Bone marrow adipose tissue (BMAT) is hypothesized to serve as an expandable/contractible fat depot which functions, in part, to minimize energy requirements for sustaining optimal hematopoiesis. We ...investigated whether BMAT is required for immune reconstitution following injury. Male wild type (WBB6F1, WT) and BMAT-deficient WBB6F1/J-
/J (
) mice were lethally irradiated. Irradiation was followed by adoptive transfer of 1000 purified WT hematopoietic stem cells (HSCs). The extent of immune reconstitution in blood, bone marrow, and lymph nodes in the irradiated mice was determined using HSCs from green fluorescent protein (GFP)-expressing mice. We also evaluated skeletal response to treatment. Detection of GFP-positive B and T cells in peripheral blood at 4 and 9 weeks following adoptive transfer and in bone marrow and lymph nodes following necropsy revealed excellent immune reconstitution in both WT and BMAT-deficient mice. Adipocytes were numerous in the distal femur of WT mice but absent or rare in
mice. Bone parameters, including length, mass, density, bone volume, microarchitecture, and turnover balance, exhibited few differences between WT and BMAT-deficient mice. The minimal differences suggest that BMAT is not required for reconstitution of the immune system following lethal radiation and is not a major contributor to the skeletal phenotypes of kit signaling-deficient mice.
Management of grape powdery mildew (Erysiphe necator) and other polycyclic diseases often relies on calendar‐based pesticide application schedules that assume the presence of inoculum. An ...inexpensive, loop‐mediated isothermal amplification (LAMP) assay was designed to quickly detect airborne inoculum of E. necator to determine when to initiate a fungicide application programme. Field efficacy was tested in 2010 and 2011 in several commercial and research vineyards in the Willamette Valley of Oregon from pre‐bud break to véraison. In each vineyard, three impaction spore traps were placed adjacent to the trunk. One trap was maintained and used by the grower to conduct the LAMP assay (G‐LAMP) on‐site and the other two traps were used for laboratory‐conducted LAMP (L‐LAMP) and quantitative PCR assay (qPCR). Using the qPCR as a gold standard, L‐LAMP was comparable with qPCR in both years, and G‐LAMP was comparable to qPCR in 2011. Latent class analysis indicated that qPCR had a true positive proportion of 98% in 2010 and 89% in 2011 and true negative proportion of 96% in 2010 and 64% in 2011. An average of 3·3 fewer fungicide applications were used when they were initiated based on spore detection relative to the grower standard practice. There were no significant differences in berry or leaf incidence between plots with fungicides initiated at detection or grower standard practice plots, suggesting that growers using LAMP to initiate fungicide applications can use fewer fungicide applications to manage powdery mildew compared to standard practices.
Based on body weight, morbidly obese leptin-deficient ob/ob mice have less bone than expected, suggesting that leptin plays a role in the skeletal response to weight bearing. To evaluate this ...possibility, we compared the skeletal response of wild type (WT) and ob/ob mice to hindlimb unloading (HU). Mice were individually housed at 32 °C (thermoneutral) from 4 weeks of age (rapidly growing) to 16 weeks of age (approaching skeletal maturity). Mice were then randomized into one of 4 groups (n = 10/group): (1) WT control, (2) WT HU, (3) ob/ob control, and (4) ob/ob HU and the results analyzed by 2-way ANOVA. ob/ob mice pair-fed to WT mice had normal cancellous bone volume fraction (BV/TV) in distal femur, lower femur length and total bone area, mineral content (BMC) and density (BMD), and higher cancellous bone volume fraction in lumbar vertebra (LV). HU resulted in lower BMC and BMD in total femur, and lower BV/TV in distal femur and LV in both genotypes. Cancellous bone loss in femur in both genotypes was associated with increases in osteoclast-lined bone perimeter. In summary, leptin deficiency did not attenuate HU-induced osteopenia in male mice, suggesting that leptin is not required for bone loss induced by unweighting.
This study investigated the effects of a 14-day spaceflight on bone mass, density and microarchitecture in weight bearing (femur and humerus) and non-weight bearing (2(nd) lumbar vertebra and ...calvarium) bones in the context of ovarian hormone insufficiency. 12-week-old Fisher 344 rats were ovariectomized 2 weeks before flight and randomized into one of three groups: 1) baseline (n = 6), 2) ground control (n = 12) or 3) spaceflight (n = 12). Additional ground-based ovary-intact rats provided age-matched reference values at baseline (n = 8) and landing (n = 10). Ovariectomy resulted in bone- and bone compartment-specific deficits in cancellous bone volume fraction. Spaceflight resulted in lower cortical bone accrual in the femur but had no effect on cortical bone in the humerus or calvarium. Cancellous bone volume fraction was lower in flight animals compared to ground control animals in lumbar vertebra and distal femur metaphysis and epiphysis; significant differences were not detected in the distal humerus. Bone loss (compared to baseline controls) in the femur metaphysis was associated with lower trabecular number, whereas trabecular thickness and number were lower in the epiphysis. In summary, the effect of spaceflight on bone microarchitecture in ovariectomized rats was bone-and bone compartment-specific but not strictly related to weight bearing.
Research on astronaut health and model organisms have revealed six features of spaceflight biology that guide our current understanding of fundamental molecular changes that occur during space ...travel. The features include oxidative stress, DNA damage, mitochondrial dysregulation, epigenetic changes (including gene regulation), telomere length alterations, and microbiome shifts. Here we review the known hazards of human spaceflight, how spaceflight affects living systems through these six fundamental features, and the associated health risks of space exploration. We also discuss the essential issues related to the health and safety of astronauts involved in future missions, especially planned long-duration and Martian missions.
An international group of spaceflight researchers detail how spaceflight affects human biology from the molecular to physiological level and identify key challenges for making space exploration compatible with human health.
Bone marrow adipose tissue (MAT) is negatively associated with bone mass. Since osteoblasts and adipocytes are derived from the same precursor cells, adipocyte differentiation may occur at the ...expense of osteoblast differentiation. We used MAT-deficient Kit
(MAT-) mice to determine if absence of MAT reduced bone loss in hindlimb-unloaded (HU) mice. Male MAT- and wild-type (WT) mice were randomly assigned to a baseline, control or HU group (n = 10 mice/group) within each genotype and HU groups unloaded for 2 weeks. Femurs were evaluated using micro-computed tomography, histomorphometry and targeted gene profiling. MAT- mice had a greater reduction in bone volume fraction after HU than did WT mice. HU MAT- mice had elevated cancellous bone formation and resorption compared to other treatment groups as well as a unique profile of differentially expressed genes. Adoptive transfer of WT bone marrow-derived hematopoietic stem cells reconstituted c-kit but not MAT in Kit
mice. The MAT- WT → Kit
mice lost cancellous bone following 2 weeks of HU. In summary, results from this study suggest that MAT deficiency was not protective, and was associated with exaggerated disuse-induced cancellous bone loss.
The possibility of improving the limit on the branching fraction of the lepton flavor violating decay
τ
±
→ µ
±
µ
±
µ
∓
at LHCb is discussed. It is shown that a simple, cut-based analysis is ...sufficient to improve the upper limit on this branching fraction within the lifetime of LHCb.
The possibility of improving the limit on the branching fraction of the lepton flavor violating decay {tau}{sup {+-}} {yields} Micro-Sign {sup {+-}} Micro-Sign {sup {+-}} Micro-Sign {sup ...Minus-Or-Plus-Sign} at LHCb is discussed. It is shown that a simple, cut-based analysis is sufficient to improve the upper limit on this branching fraction within the lifetime of LHCb.
The possibility of improving the limit on the branching fraction of the lepton flavor violating decay τ.sup.± → μ.sup.±μ.sup.±μ.sup.∓ at LHCb is discussed. It is shown that a simple, cut-based ...analysis is sufficient to improve the upper limit on this branching fraction within the lifetime of LHCb. DOI: 10.1134/S1063778812090074
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