437 research outputs found
Validating a Noninvasive Technique for Monitoring Embryo Movement In Ovo
Avian embryos are a commonly used model system for developmental studies, but monitoring of physiological parameters such as heart rate (HR) and movement in ovo poses a challenge to researchers. These are also increasingly common research objectives for ecological and embryo behavior studies in oviparous species. We therefore explored the validity of a new digital egg-monitoring system for the noninvasive monitoring of these parameters. We tested the relationship between frequency-of-movement values gathered by digital monitoring and those gathered by the current standard method, which is comparatively invasive and requires egg windowing, and demonstrated that the digital monitoring method effectively distinguishes individual movements but cannot reliably monitor HR in actively motile embryos. We therefore provide recommendations for the appropriate use of this technique for avian physiologists. We also applied the digital monitoring method to reveal how frequency of movement varies throughout prenatal ontogeny in the chicken and showed that commonly used protocols in developmental studies can themselves alter motility; egg windowing and application of light modulate frequency of movement. Recent work has revealed the importance of embryo motility in regulating gene expression and cellular activity during developmental processes. Together with our data, this highlights the value of noninvasive monitoring methods and the importance of controlling for altered embryo motility/behavior in developmental studies
Stable sulforaphane protects against gait anomalies and modifies bone microarchitecture in the spontaneous STR/Ort model of osteoarthritis
Osteoarthritis (OA), affecting joints and bone, causes physical gait disability with huge socio-economic burden; treatment remains palliative. Roles for antioxidants in protecting against such chronic disorders have been examined previously. Sulforaphane is a naturally occurring antioxidant. Herein, we explore whether SFX-01®, a stable synthetic form of sulforaphane, modifies gait, bone architecture and slows/reverses articular cartilage destruction in a spontaneous OA model in STR/Ort mice. Sixteen mice (n = 8/group) were orally treated for 3 months with either 100 mg/kg SFX-01® or vehicle. Gait was recorded, tibiae were microCT scanned and analysed. OA lesion severity was graded histologically. The effect of SFX-01® on bone turnover markers in vivo was complemented by in vitro bone formation and resorption assays. Analysis revealed development of OA-related gait asymmetry in vehicle-treated STR/Ort mice, which did not emerge in SFX-01®-treated mice. We found significant improvements in trabecular and cortical bone. Despite these marked improvements, we found that histologically-graded OA severity in articular cartilage was unmodified in treated mice. These changes are also reflected in anabolic and anti-catabolic actions of SFX-01® treatment as reflected by alteration in serum markers as well as changes in primary osteoblast and osteoclast-like cells in vitro. We report that SFX-01® improves bone microarchitecture in vivo, produces corresponding changes in bone cell behaviour in vitro and leads to greater symmetry in gait, without marked effects on cartilage lesion severity in STR/Ort osteoarthritic mice. Our findings support both osteotrophic roles and novel beneficial gait effects for SFX-01® in this model of spontaneous OA
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Gratitude, resignation and the desire for dignity: lived experience of food charity recipients and their recommendations for improvement, Perth, Western Australia
ObjectiveThe present study explored recipients’ perceptions of food charity and their suggested improvements in inner-city Perth, Western Australia.DesignIn-depth interviews were conducted with charitable food service (CFS) recipients. Transcripts were thematically analysed using a phenomenological approach.SettingInterviews were conducted at two CFS in inner-city Perth.SubjectsFourteen adults.ResultsThe recipients’ journeys to a reliance on CFS were varied and multifactorial, with poverty, medical issues and homelessness common. The length of time recipients had relied on food charity ranged from 8 months to over 40 years. Most were ‘grateful yet resigned’, appreciative of any food and resigned to the poor quality, monotony and their unmet individual preferences. They wanted healthier food, more variety and better quality. Accessing services was described as a ‘full-time job’ fraught with unreliable information and transport difficulties. They called for improved information and assistance with transport. ‘Eroded dignity’ resulted from being fed without any choice and queuing for food in public places, often in a volatile environment. ‘Food memories and inclusion’ reflected a desire for commensality. Recipients suggested services offer choice and promote independence, focusing on their needs both physical and social.ConclusionsAlthough grateful, long-term CFS recipients described what constitutes a voluntary failure. Their service improvement recommendations can help meet their nutritional and social needs. A successful CFS provides a food service that prioritises nutritious, good-quality food and individual need, while promoting dignity and social inclusion, challenging in the current Australian context
All Optical Implementation of Multi-Spin Entanglement in a Semiconductor Quantum Well
We use ultrafast optical pulses and coherent techniques to create spin
entangled states of non-interacting electrons bound to donors (at least three)
and at least two Mn2+ ions in a CdTe quantum well. Our method, relying on the
exchange interaction between localized excitons and paramagnetic impurities,
can in principle be applied to entangle a large number of spins.Comment: 17 pages, 3 figure
Making Big Data Useful for Health Care: A Summary of the Inaugural MIT Critical Data Conference
With growing concerns that big data will only augment the problem of unreliable research, the Laboratory of Computational Physiology at the Massachusetts Institute of Technology organized the Critical Data Conference in January 2014. Thought leaders from academia, government, and industry across disciplines--including clinical medicine, computer science, public health, informatics, biomedical research, health technology, statistics, and epidemiology--gathered and discussed the pitfalls and challenges of big data in health care. The key message from the conference is that the value of large amounts of data hinges on the ability of researchers to share data, methodologies, and findings in an open setting. If empirical value is to be from the analysis of retrospective data, groups must continuously work together on similar problems to create more effective peer review. This will lead to improvement in methodology and quality, with each iteration of analysis resulting in more reliability
Mammalian Synthetic Biology:Time for Big MACs
The enabling technologies of synthetic biology are opening up new opportunities for engineering and enhancement of mammalian cells. This will stimulate diverse applications in many life science sectors such as regenerative medicine, development of biosensing cell lines, therapeutic protein production, and generation of new synthetic genetic regulatory circuits. Harnessing the full potential of these new engineering-based approaches requires the design and assembly of large DNA constructs-potentially up to chromosome scale-and the effective delivery of these large DNA payloads to the host cell. Random integration of large transgenes, encoding therapeutic proteins or genetic circuits into host chromosomes, has several drawbacks such as risks of insertional mutagenesis, lack of control over transgene copy-number and position-specific effects; these can compromise the intended functioning of genetic circuits. The development of a system orthogonal to the endogenous genome is therefore beneficial. Mammalian artificial chromosomes (MACs) are functional, add-on chromosomal elements, which behave as normal chromosomes-being replicating and portioned to daughter cells at each cell division. They are deployed as useful gene expression vectors as they remain independent from the host genome. MACs are maintained as a single-copy and can accommodate multiple gene expression cassettes of, in theory, unlimited DNA size (MACs up to 10 megabases have been constructed). MACs therefore enabled control over ectopic gene expression and represent an excellent platform to rapidly prototype and characterize novel synthetic gene circuits without recourse to engineering the host genome. This review describes the obstacles synthetic biologists face when working with mammalian systems and how the development of improved MACs can overcome these-particularly given the spectacular advances in DNA synthesis and assembly that are fuelling this research area.</p
Coherent ultrafast torsional motion and isomerization of a biomimetic dipolar photoswitch
Femtosecond fluorescence up-conversion, UV-Vis and IR transient absorption spectroscopy are used to study the photo-isomerization dynamics of a new type of zwitterionic photoswitch based on a N-alkylated indanylidene pyrroline Schiff base framework (ZW-NAIP). The system is biomimetic, as it mimics the photophysics of retinal, in coupling excited state charge translocation and isomerization. While the fluorescence lifetime is 140 fs, excited state absorption persists over 230 fs in the form of a vibrational wavepacket according to twisting of the isomerizing double bond. After a short "dark'' time window in the UV-visible spectra, which we associate with the passage through a conical intersection (CI), the wavepacket appears on the ground state potential energy surface, as evidenced by the transient mid-IR data. This allows for a precise timing of the photoreaction all the way from the initial Franck-Condon region, through the CI and into both ground state isomers, until incoherent vibrational relaxation dominates the dynamics. The photo-reaction dynamics remarkably follow those observed for retinal in rhodopsin, with the additional benefit that in ZW-NAIP the conformational change reverses the zwitterion dipole moment direction. Last, the pronounced low-frequency coherences make these molecules ideal systems for investigating wavepacket dynamics in the vicinity of a CI and for coherent control experiments
Associations between infant fungal and bacterial dysbiosis and childhood atopic wheeze in a nonindustrialized setting.
BACKGROUND: Asthma is the most prevalent chronic disease of childhood. Recently, we identified a critical window early in the life of both mice and Canadian infants during which gut microbial changes (dysbiosis) affect asthma development. Given geographic differences in human gut microbiota worldwide, we studied the effects of gut microbial dysbiosis on atopic wheeze in a population living in a distinct developing world environment. OBJECTIVE: We sought to determine whether microbial alterations in early infancy are associated with the development of atopic wheeze in a nonindustrialized setting. METHODS: We conducted a case-control study nested within a birth cohort from rural Ecuador in which we identified 27 children with atopic wheeze and 70 healthy control subjects at 5 years of age. We analyzed bacterial and eukaryotic gut microbiota in stool samples collected at 3 months of age using 16S and 18S sequencing. Bacterial metagenomes were predicted from 16S rRNA data by using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States and categorized by function with Kyoto Encyclopedia of Genes and Genomes ontology. Concentrations of fecal short-chain fatty acids were determined by using gas chromatography. RESULTS: As previously observed in Canadian infants, microbial dysbiosis at 3 months of age was associated with later development of atopic wheeze. However, the dysbiosis in Ecuadorian babies involved different bacterial taxa, was more pronounced, and also involved several fungal taxa. Predicted metagenomic analysis emphasized significant dysbiosis-associated differences in genes involved in carbohydrate and taurine metabolism. Levels of the fecal short-chain fatty acids acetate and caproate were reduced and increased, respectively, in the 3-month stool samples of children who went on to have atopic wheeze. CONCLUSIONS: Our findings support the importance of fungal and bacterial microbiota during the first 100 days of life on the development of atopic wheeze and provide additional support for considering modulation of the gut microbiome as a primary asthma prevention strategy
An ultra-scale-down method to predict diafiltration performance during formulation of concentrated mAb solutions
Formulation of monoclonal antibody (mAb) solutions using membrane filtration processing is a critical unit operation in the preparation of antibody therapies. A key constraint in formulation process development, particularly in the early stages of development and when using high protein concentration solutions, is the availability of material for experimental studies. Ultra-scale down (USD) technologies use a combination of critical flow regime analysis, bioprocess modelling and experimentation at the milliliter scale to enable a more effective process development approach significantly reducing process material, cost and time requirements (Rayat et al, 2016). The ability to predict the performance of large-scale (LS) operations, e.g. flux profile characteristics and changes in protein structure, will help maximize the value of eventual high cost pilot-scale runs during process development. In this study a USD membrane device, comprising a sheared cell unit with a rotating disc and with an effective membrane area of 0.00021 m2 developed at University College London, is used to predict the performance of a LS cross-flow membrane cassette of area 0.11 m2. The USD set up was designed to mimic the LS in terms of processing volumes, membrane area and process times. Computational Fluid Dynamics (CFD) is implemented to characterize average shear rates as a function of suspension viscosities and disc speed of the USD membrane device. A series of trials at USD scale established the effect of average shear rate on flux and the rate of flux decline during a diafiltration operation reaching 7 diafiltration volumes. A series of LS runs were carried out at different cross flow rates covering a similar range of average shear rates as the USD trials. Good correlation was obtained between USD and LS performance using constant average shear rate over the membrane surface as the basis for scale translation between the two scales of operation. The predicted effect of change in shear rate on flux in USD matched that found in LS. This scale correlation on performance was additionally verified by studying the effect of type and concentration of mAb. The comparable process performance was achieved at USD with 520-fold reduction in effective membrane area, required process material and diafiltration buffer for the trial. Future studies will include membrane concentration operations and evaluating sensitivity to stress-related effects and the impact of operation at higher protein concentrations. Rayat, A.CME; Chatel, A; Hoare, M; Lye, G.J (2016). Ultra scale-down approaches to enhance the creation of bioprocesses at scale: impacts of process shear stress and early recovery stages. Current Opinion in Chemical Engineering 14:150-15
The importance of perceptual experience in the esthetic appreciation of the body.
Several studies suggest that sociocultural models conveying extreme thinness as the widespread ideal of beauty exert an important influence on the perceptual and emotional representation of body image. The psychological mechanisms underlying such environmental influences, however, are unclear. Here, we utilized a perceptual adaptation paradigm to investigate how perceptual experience modulates body esthetic appreciation. We found that the liking judgments of round bodies increased or decreased after brief exposure to round or thin bodies, respectively. No change occurred in the liking judgments of thin bodies. The results suggest that perceptual experience may shape our esthetic appreciation to favor more familiar round body figures. Importantly, individuals with more deficits in interoceptive awareness were less prone to increase their liking ratings of round bodies after exposure, suggesting a specific risk factor for the susceptibility to the influence of the extreme thin vs. round body ideals of beauty portrayed by the media
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