4,869 research outputs found
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A comparison of methods for determining ploidy in white sturgeon (Acipenser transmontanus)
Release of sturgeon with abnormal ploidy into the wild may result in reduced fitness due to lowered fertility in the F2 and subsequent generations. Further, there is evidence that ploidy affects reproductive development and caviar yield. Therefore, the ability to accurately characterize the ploidy of white sturgeon (Acipenser transmontanus)is essential for both commercial and conservation aquaculture. This study compares nuclear volume and whole erythrocyte long-axis lengths obtained using Coulter counter and blood smears, respectively, from captive white sturgeon from populations originating in California and Idaho. We examine which method provides the most accurate, time efficient and cost-effective characterization of ploidy in this species. Results from Coulter counter and blood smears were compared to results from flow cytometry, the gold standard for genome size analysis. Previous work suggests that blood smears can distinguish between 8N (diploid)and 12N (triploid)sturgeon, but further analysis is required to see if this method can also be used to identify 10N fish and to provide robust evidence of its utility in 8N and 12N fish across populations. In this study, we demonstrated that the Coulter counter had 100% agreement with flow cytometry in ploidy assignment, while blood smears vary in their accuracy based on population. Blood smears showed a high degree of overlap in erythrocyte long-axis length between 8N and 10N individuals as well as some overlap between 10N and 12N individuals in the California fish, and a high degree of overlap between 8N and 12N individuals in the Idaho fish. Although blood smears are time-intensive and vary in their ploidy assignment accuracy, they are a low-cost technique and as such may have some utility for caviar farms attempting to identify 12N individuals in a small number of broodstock. By comparing the accuracy, efficiency and cost of these three methods, sturgeon farmers and conservation hatcheries will be able to choose the best method for their needs in determining the ploidy of their fish. We determined that Coulter counter is equally accurate to flow cytometry and is also the most time efficient method for ploidy determination in white sturgeon
Biomolecular imaging and electronic damage using X-ray free-electron lasers
Proposals to determine biomolecular structures from diffraction experiments
using femtosecond X-ray free-electron laser (XFEL) pulses involve a conflict
between the incident brightness required to achieve diffraction-limited atomic
resolution and the electronic and structural damage induced by the
illumination. Here we show that previous estimates of the conditions under
which biomolecular structures may be obtained in this manner are unduly
restrictive, because they are based on a coherent diffraction model that is not
appropriate to the proposed interaction conditions. A more detailed imaging
model derived from optical coherence theory and quantum electrodynamics is
shown to be far more tolerant of electronic damage. The nuclear density is
employed as the principal descriptor of molecular structure. The foundations of
the approach may also be used to characterize electrodynamical processes by
performing scattering experiments on complex molecules of known structure.Comment: 16 pages, 2 figure
Synovial cell metabolism and chronic inflammation in rheumatoid arthritis
Metabolomic studies of body fluids show that immune-mediated inflammatory diseases such as rheumatoid arthritis (RA) are associated with metabolic disruption. This is likely to reflect the increased bioenergetic and biosynthetic demands of sustained inflammation and changes to nutrient and oxygen availability in damaged tissue. The synovial membrane lining layer is the principle site of inflammation in RA. Here the resident cells are the fibroblast-like synoviocytes (FLS) and the synovial tissue macrophages (STM), which are transformed toward overproduction of enzymes which degrade cartilage and bone, and cytokines which promote immune cell infiltration. Recent studies have shown metabolic changes in both FLS and macrophages from RA patients and these may be therapeutically targetable. However, as the origins and subset specific functions of synoviocytes are poorly understood and the signaling modules which control metabolic deviation in RA synovial cells are yet to be explored, significant additional research is needed to translate these findings toward clinical application. Furthermore, in many inflamed tissues, different cell types can forge metabolic collaborations through solute carriers (SLC) in their membranes, to meet a high demand for energy or biomolecules. Such relationships are likely to exist in the synovium and are yet to be explored. Finally, it is not yet known whether metabolic change is a consequence of disease or if primary changes to cellular metabolism might underlie or contribute to early stage disease pathogenesis. This article collates what is known about metabolism in synovial tissue cells and highlights future research directions in this area
Formidable females and the power trajectories of socially integrated male vervet monkeys
Sexual conflict theory expects females to avoid nonoptimal mating attempts by males. Although female vervet monkeys, Chlorocebus pygerythrus, can resist direct mating attempts, higher-ranking males still have more mating opportunities than lower-ranking ones. We presume that rank-related access reflects maleemale competition that may conflict with female reproductive objectives. We extend an earlier report of codominance in this species to show that powerful females can undermine the restrictions imposed through maleemale competition by improving the dominance rank of preferred male associates. We found that the dominance hierarchies of the sexes were comprehensively interdigitated and that males who had more female spatial associates, and who groomed with well-connected females, were more likely improve their Elo-ratings, which we use as an index of male power. The effects of partner number and integration, which predicted the probability of the initiation of aggression by lower-ranking males, suggest that association with females offered the prospect of protected threat if this likelihood increased. Although female rank and aggression were not directly consequential for males, we argue that female power and influence are intertwined and that both stem from the strength of female reproductive control
Enhanced flight performance by genetic manipulation of wing shape in Drosophila
Insect wing shapes are remarkably diverse and the combination of shape and kinematics determines both aerial capabilities and power requirements. However, the contribution of any specific morphological feature to performance is not known. Using targeted RNA interference to modify wing shape far beyond the natural variation found within the population of a single species, we show a direct effect on flight performance that can be explained by physical modelling of the novel wing geometry. Our data show that altering the expression of a single gene can significantly enhance aerial agility and that the Drosophila wing shape is not, therefore, optimized for certain flight performance characteristics that are known to be important. Our technique points in a new direction for experiments on the evolution of performance specialities in animals
Recommendations for the transition of patients with ADHD from child to adult healthcare services:a consensus statement from the UK adult ADHD network
The aim of this consensus statement was to discuss transition of patients with ADHD from child to adult healthcare services, and formulate recommendations to facilitate successful transition. An expert workshop was convened in June 2012 by the UK Adult ADHD Network (UKAAN), attended by a multidisciplinary team of mental health professionals, allied professionals and patients. It was concluded that transitions must be planned through joint meetings involving referring/receiving services, patients and their families. Negotiation may be required to balance parental desire for continued involvement in their child’s care, and the child’s growing autonomy. Clear transition protocols can maintain standards of care, detailing relevant timeframes, responsibilities of agencies and preparing contingencies. Transition should be viewed as a process not an event, and should normally occur by the age of 18, however flexibility is required to accommodate individual needs. Transition is often poorly experienced, and adherence to clear recommendations is necessary to ensure effective transition and prevent drop-out from services
Social feasibility assessments in conservation translocations
This is the final version. Available on open access from Cell Press via the DOI in this recordImproving the effectiveness of conservation translocations could contribute to reversing global biodiversity loss. Although evaluations of ecological factors affecting translocation outcomes are commonplace, consideration of human social factors remains rare, hindering improvements to this conservation practice. We analysed 550 translocation case studies to explore the inclusion of social factors in project feasibility assessments. Reviewed projects often failed to assess social feasibility, and assessments, where attempted, tended to be narrow in scope. Consequently, challenges such as proactively addressing conflict often remained unaddressed. Insufficient knowledge sharing and prioritisation of ecological feasibility, to the detriment of social feasibility, remain barriers to effective planning. Successful outcomes of translocations are linked to early assessment of social feasibility and to the establishment of long-term commitments between people, places, and partners.Vincent Wildlife TrustDurrell Wildlife Conservation TrustUniversity of Exete
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Formidable females redux: male social integration into female networks and the value of dynamic multilayer networks
The development of multilayer network techniques is a boon for researchers who wish to understand how different interaction layers might influence each other, and how these in turn might influence group dynamics. Here, we investigate how integration between male and female grooming and aggression interaction networks influences male power trajectories in vervet monkeys Chlorocebus pygerythrus. Our previous analyses of this phenomenon used a monolayer approach, and our aim here is to extend these analyses using a dynamic multilayer approach. To do so, we constructed a temporal series of male and female interaction layers. We then used a multivariate multilevel autoregression model to compare cross-lagged associations between a male’s centrality in the female grooming layer and changes in male Elo ratings. Our results confirmed our original findings: changes in male centrality within the female grooming network were weakly but positively tied to changes in their Elo ratings. However, the multilayer network approach offered additional insights into this social process, identifying how changes in a male’s centrality cascade through the other network layers. This dynamic view indicates that the changes in Elo ratings are likely to be short-lived, but that male centrality within the female network had a much stronger impact throughout the multilayer network as a whole, especially on reducing intermale aggression (i.e., aggression directed by males toward other males). We suggest that multilayer social network approaches can take advantage of increased amounts of social data that are more commonly collected these days, using a variety of methods. Such data are inherently multilevel and multilayered, and thus offer the ability to quantify more precisely the dynamics of animal social behaviors
Onasemnogene abeparvovec preserves bulbar function in infants with presymptomatic spinal muscular atrophy: a post-hoc analysis of the SPR1NT trial
Bulbar function in spinal muscular atrophy has been defined as the ability to meet nutritional needs by mouth while maintaining airway protection and communicate verbally. The effects of disease-modifying treatment on bulbar function are not clear. A multidisciplinary team conducted post-hoc analyses of phase 3 SPR1NT trial data to evaluate bulbar function of infants at risk for spinal muscular atrophy who received one-time gene replacement therapy (onasemnogene abeparvovec) before symptom onset. Three endpoints represented adequate bulbar function in SPR1NT: (1) absence of physiologic swallowing impairment, (2) full oral nutrition, and (3) absence of adverse events indicating pulmonary instability. Communication was not assessed in SPR1NT. We descriptively assessed numbers/percentages of children who achieved each endpoint and all three collectively. SPR1NT included infants <6 postnatal weeks with two (n = 14) or three (n = 15) copies of the survival motor neuron 2 gene. At study end (18 [two-copy cohort] or 24 [three-copy cohort] months of age), 100% (29/29) of patients swallowed normally, achieved full oral nutrition, maintained pulmonary stability, and achieved the composite endpoint. When administered to infants before clinical symptom onset, onasemnogene abeparvovec allowed children at risk for spinal muscular atrophy to achieve milestones within published normal ranges of development and preserve bulbar function
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