1,207 research outputs found
First metatarsophalangeal joint range of motion is associated with lower limb kinematics in individuals with first metatarsophalangeal joint osteoarthritis.
BACKGROUND: Osteoarthritis of the first metatarsophalangeal joint (1st MTP joint OA) is a common and disabling condition that results in pain and limited joint range of motion. There is inconsistent evidence regarding the relationship between clinical measurement of 1st MTP joint maximum dorsiflexion and dynamic function of the joint during level walking. Therefore, the aim of this study was to examine the association between passive non-weightbearing (NWB) 1st MTP joint maximum dorsiflexion and sagittal plane kinematics in individuals with radiographically confirmed 1st MTP joint OA. METHODS: Forty-eight individuals with radiographically confirmed 1st MTP joint OA (24 males and 24 females; mean age 57.8âyears, standard deviation 10.5) underwent clinical measurement of passive NWB 1st MTP joint maximum dorsiflexion and gait analysis during level walking using a 10-camera infrared Vicon motion analysis system. Sagittal plane kinematics of the 1st MTP, ankle, knee, and hip joints were calculated. Associations between passive NWB 1st MTP joint maximum dorsiflexion and kinematic variables were explored using Pearson's r correlation coefficients. RESULTS: Passive NWB 1st MTP joint maximum dorsiflexion was significantly associated with maximum 1st MTPJ dorsiflexion (râ=Â 0.486, pâ<â0.001), ankle joint maximum plantarflexion (râ=Â 0.383, pâ=Â 0.007), and ankle joint excursion (râ=Â 0.399, pâ=Â 0.005) during gait. There were no significant associations between passive NWB 1st MTP joint maximum dorsiflexion and sagittal plane kinematics of the knee or hip joints. CONCLUSIONS: These findings suggest that clinical measurement of 1st MTP joint maximum dorsiflexion provides useful insights into the dynamic function of the foot and ankle during the propulsive phase of gait in this population
Ultrafast optical control of entanglement between two quantum dot spins
The interaction between two quantum bits enables entanglement, the
two-particle correlations that are at the heart of quantum information science.
In semiconductor quantum dots much work has focused on demonstrating single
spin qubit control using optical techniques. However, optical control of
entanglement of two spin qubits remains a major challenge for scaling from a
single qubit to a full-fledged quantum information platform. Here, we combine
advances in vertically-stacked quantum dots with ultrafast laser techniques to
achieve optical control of the entangled state of two electron spins. Each
electron is in a separate InAs quantum dot, and the spins interact through
tunneling, where the tunneling rate determines how rapidly entangling
operations can be performed. The two-qubit gate speeds achieved here are over
an order of magnitude faster than in other systems. These results demonstrate
the viability and advantages of optically controlled quantum dot spins for
multi-qubit systems.Comment: 24 pages, 5 figure
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Choices: Future Trade-Offs and Plausible Pathways
Policy development and management of deltas in the Anthropocene involves the consideration of trade-offs and the balancing of positive and negative consequences for delta functions and the societies that rely on them. This assessment outlines policy-driven and spatial trade-offs that dominate the landscape of choice. It highlights examples of such trade-offs using plausible delta futures and the governance choices associated with them. The analysis is based on modelling broad-scale processes and individual adaptive actions. It highlights how policy choices to maximise economic growth can, for example, have unforeseen consequences such as diminished well-being for some populations. Hence the chapter concludes that trade-offs are a crucial governance challenge for future sustainability of deltas
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Contrasting response of hydrological cycle over land and ocean to a changing CO2 pathway
The hydrological cycle has a significant impact on human activities and ecosystems, so understanding its mechanisms with respect to a changing climate is essential. In particular, a more detailed understanding of hydrological cycle response to transient climate change is required for successful adaptation and mitigation policies. In this study, we exploit large ensemble model experiments using the Community Earth System Model version 1.2.2 (CESM1) in which CO2 concentrations increase steadily and then decrease along the same path. Our results show that precipitation changes in the CO2 increasing and decreasing phases are nearly symmetrical over land but asymmetric over oceans. After CO2 concentrations peak, the ocean continues to uptake heat from the atmosphere, which is a key process leading the hydrological cycleâs contrasting response over land and ocean. The symmetrical hydrological cycle response over land involves a complex interplay between rapid responses to CO2 and slower responses to ensuing warming. Therefore, the surface energy constraints lead to the contrasting hydrological response over land and ocean to CO2 forcing that needs to be verified and considered in climate change mitigation and adaption actions
Neuropathic pain associated with first metatarsophalangeal joint osteoarthritis: frequency and associated factors.
OBJECTIVE: To determine whether neuropathic pain is a feature of first metatarsophalangeal (MTP) joint osteoarthritis (OA). METHODS: Ninety-eight participants (mean age 57.4âyears, standard deviation 10.3) with symptomatic radiographic first MTP joint OA completed the painDETECT questionnaire (PDQ), which incorporates nine questions regarding the intensity and quality of pain. The likelihood of neuropathic pain was determined using established cut-points of the PDQ. Participants with unlikely neuropathic pain were then compared to those with possible/likely neuropathic pain in relation to age, sex, general health (Short Form [SF] 12), psychological wellbeing (Depression, Anxiety and Stress Scale), pain characteristics (self-efficacy, duration, and severity), foot health (Foot Health Status Questionnaire [FHSQ]), first MTP dorsiflexion range of motion and radiographic severity. Effect sizes (Cohen's d) were also calculated. RESULTS: Thirty (31%) participants had possible/likely neuropathic pain (possible n=19, [19.4%], likely n=11 [11.2%]). The most common neuropathic symptoms were sensitivity to pressure (56%), sudden pain attacks/electric shocks (36%) and burning (25%). Compared to those with unlikely neuropathic pain, those with possible/likely neuropathic pain were significantly older (d=0.59, p=0.010), had worse SF12 physical (d=1.10, p<0.001), pain self-efficacy (d=0.98, p<0.001), FHSQ pain (d=0.98, p<0.001) and FHSQ function (d=0.82, p<0.001) scores, and had higher pain severity at rest (d=1.01, p<0.001). CONCLUSION: A significant proportion of individuals with first MTP joint OA report symptoms suggestive of neuropathic pain, which may partly explain the suboptimal responses to commonly used treatments for this condition. Screening for neuropathic pain may assist in the selection of targeted interventions and improve clinical outcomes
Using zebrafish larval models to study brain injury, locomotor and neuroinflammatory outcomes following intracerebral haemorrhage.
Intracerebral haemorrhage (ICH) is a devastating condition with limited treatment options, and current understanding of pathophysiology is incomplete. Spontaneous cerebral bleeding is a characteristic of the human condition that has proven difficult to recapitulate in existing pre-clinical rodent models. Zebrafish larvae are frequently used as vertebrate disease models and are associated with several advantages, including high fecundity, optical translucency and non-protected status prior to 5 days post-fertilisation. Furthermore, other groups have shown that zebrafish larvae can exhibit spontaneous ICH. The aim of this study was to investigate whether such models can be utilised to study the pathological consequences of bleeding in the brain, in the context of pre-clinical ICH research. Here, we compared existing genetic (bubblehead) and chemically inducible (atorvastatin) zebrafish larval models of spontaneous ICH and studied the subsequent disease processes. Through live, non-invasive imaging of transgenic fluorescent reporter lines and behavioural assessment we quantified brain injury, locomotor function and neuroinflammation following ICH. We show that ICH in both zebrafish larval models is comparable in timing, frequency and location. ICH results in increased brain cell death and a persistent locomotor deficit. Additionally, in haemorrhaged larvae we observed a significant increase in macrophage recruitment to the site of injury. Live in vivo imaging allowed us to track active macrophage-based phagocytosis of dying brain cells 24 hours after haemorrhage. Morphological analyses and quantification indicated that an increase in overall macrophage activation occurs in the haemorrhaged brain. Our study shows that in zebrafish larvae, bleeding in the brain induces quantifiable phenotypic outcomes that mimic key features of human ICH. We hope that this methodology will enable the pre-clinical ICH community to adopt the zebrafish larval model as an alternative to rodents, supporting future high throughput drug screening and as a complementary approach to elucidating crucial mechanisms associated with ICH pathophysiology
Prioritization of fish communities with a view to conservation and restoration on a large scale European basin, the Loire (France)
The hierarchical organization of important sites for the conservation or the
restoration of fish communities is a great challenge for managers, especially because of
financial or time constraints. In this perspective, we developed a methodology, which is
easy to implement in different locations. Based on the fish assemblage characteristics of
the Loire basin (France), we created a synthetic conservation value index including the
rarity, the conservation status and the species origin. The relationship between this new
synthetic index and the Fish-Based Index allowed us to establish a classification protocol
of the sites along the Loire including fish assemblages to be restored or conserved. Sites
presenting disturbed fish assemblages, a low rarity index, few threatened species, and a
high proportion of non-native species were considered as important for the restoration of
fish biodiversity. These sites were found mainly in areas where the assemblages are
typical of the bream zone, e.g. with a higher number of eurytopic and limnophilic
species. On the contrary, important sites for conservation were defined as having an
important conservation potential (high RI, a lot of threatened species, and few nonnatives
fish species) and an undisturbed fish assemblage similar to the expected community
if habitats are undisturbed. Important sites for conservation were found in the
Loire basinâs medium reaches which host assemblages typical for the grayling and the
barbell zones, e.g. with a higher number of rheophilic species. The synthetic conservation value index could be adapted and completed with other criteria according to
management priorities and capacities
A prospective study of serum insulin-like growth factor-I (IGF-I), IGF-II, IGF-binding protein-3 and breast cancer risk.
The associations between serum concentrations of insulin-like growth factor-I (IGF-I), IGF-II and IGF-binding proteins (IGFBP)-3 and risk of breast cancer were investigated in a nested case-control study involving 117 cases (70 premenopausal and 47 postmenopausal at blood collection) and 350 matched controls within a cohort of women from the island of Guernsey, UK. Women using exogenous hormones at the time of blood collection were excluded. Premenopausal women in the top vs bottom third of serum IGF-I concentration had a nonsignificantly increased risk for breast cancer after adjustment for IGFBP-3 (odds ratio (OR) 1.71; 95% confidence interval (CI): 0.74-3.95; test for linear trend, P=0.21). Serum IGFBP-3 was associated with a reduction in risk in premenopausal women after adjustment for IGF-I (top third vs the bottom third: OR 0.49; 95% CI: 0.21-1.12, P for trend=0.07). Neither IGF-I nor IGFBP-3 was associated with risk in postmenopausal women and serum IGF-II concentration was not associated with risk in pre- or postmenopausal women. These data are compatible with the hypothesis that premenopausal women with a relatively high circulating concentration of IGF-I and low IGFBP-3 are at an increased risk of developing breast cancer
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