305 research outputs found
Edible crabs “Go West”: migrations and incubation cycle of Cancer pagurus revealed by electronic tags
Crustaceans are key components of marine ecosystems which, like other exploited marine taxa, show seasonable patterns of distribution and activity, with consequences for their availability to capture by targeted fisheries. Despite concerns over the sustainability of crab fisheries worldwide, difficulties in observing crabs’ behaviour over their annual cycles, and the timings and durations of reproduction, remain poorly understood. From the release of 128 mature female edible crabs tagged with electronic data storage tags (DSTs), we demonstrate predominantly westward migration in the English Channel. Eastern Channel crabs migrated further than western Channel crabs, while crabs released outside the Channel showed little or no migration. Individual migrations were punctuated by a 7-month hiatus, when crabs remained stationary, coincident with the main period of crab spawning and egg incubation. Incubation commenced earlier in the west, from late October onwards, and brooding locations, determined using tidal geolocation, occurred throughout the species range. With an overall return rate of 34%, our results demonstrate that previous reluctance to tag crabs with relatively high-cost DSTs for fear of loss following moulting is unfounded, and that DSTs can generate precise information with regards life-history metrics that would be unachievable using other conventional means
Quantum simulation of the wavefunction to probe frustrated Heisenberg spin systems
Quantum simulators are controllable quantum systems that can reproduce the
dynamics of the system of interest, which are unfeasible for classical
computers. Recent developments in quantum technology enable the precise control
of individual quantum particles as required for studying complex quantum
systems. Particularly, quantum simulators capable of simulating frustrated
Heisenberg spin systems provide platforms for understanding exotic matter such
as high-temperature superconductors. Here we report the analog quantum
simulation of the ground-state wavefunction to probe arbitrary Heisenberg-type
interactions among four spin-1/2 particles . Depending on the interaction
strength, frustration within the system emerges such that the ground state
evolves from a localized to a resonating valence-bond state. This spin-1/2
tetramer is created using the polarization states of four photons. The
single-particle addressability and tunable measurement-induced interactions
provide us insights into entanglement dynamics among individual particles. We
directly extract ground-state energies and pair-wise quantum correlations to
observe the monogamy of entanglement
Recommended from our members
Dissecting the illegal ivory trade: an analysis of ivory seizures data
Reliable evidence of trends in the illegal ivory trade is important for informing decision making for elephants but it is difficult to obtain due to the covert nature of the trade. The Elephant Trade Information System, a global database of reported seizures of illegal ivory, holds the only extensive information on illicit trade available. However inherent biases in seizure data make it difficult to infer trends; countries differ in their ability to make and report seizures and these differences cannot be directly measured. We developed a new modelling framework to provide quantitative evidence on trends in the illegal ivory trade from seizures data. The framework used Bayesian hierarchical latent variable models to reduce bias in seizures data by identifying proxy variables that describe the variability in seizure and reporting rates between countries and over time. Models produced bias-adjusted smoothed estimates of relative trends in illegal ivory activity for raw and worked ivory in three weight classes. Activity is represented by two indicators describing the number of illegal ivory transactions--Transactions Index--and the total weight of illegal ivory transactions--Weights Index--at global, regional or national levels. Globally, activity was found to be rapidly increasing and at its highest level for 16 years, more than doubling from 2007 to 2011 and tripling from 1998 to 2011. Over 70% of the Transactions Index is from shipments of worked ivory weighing less than 10 kg and the rapid increase since 2007 is mainly due to increased consumption in China. Over 70% of the Weights Index is from shipments of raw ivory weighing at least 100 kg mainly moving from Central and East Africa to Southeast and East Asia. The results tie together recent findings on trends in poaching rates, declining populations and consumption and provide detailed evidence to inform international decision making on elephants
Effectiveness and Cost-effectiveness of Outpatient Physiotherapy After Knee Replacement for Osteoarthritis: Study Protocol for a Randomised Controlled Trial
Background: Primary total knee replacement is a common operation that is performed to provide pain relief and restore functional ability. Inpatient physiotherapy is routinely provided after surgery to enhance recovery prior to hospital discharge. However, international variation exists in the provision of outpatient physiotherapy after hospital discharge. While evidence indicates that outpatient physiotherapy can improve short-term function, the longer term benefits are unknown. The aim of this randomised controlled trial is to evaluate the long-term clinical effectiveness and cost-effectiveness of a 6-week group-based outpatient physiotherapy intervention following knee replacement.
Methods/design: Two hundred and fifty-six patients waiting for knee replacement because of osteoarthritis will be recruited from two orthopaedic centres. Participants randomised to the usual-care group (n = 128) will be given a booklet about exercise and referred for physiotherapy if deemed appropriate by the clinical care team. The intervention group (n = 128) will receive the same usual care and additionally be invited to attend a group-based outpatient physiotherapy class starting 6 weeks after surgery. The 1-hour class will be run on a weekly basis over
6 weeks and will involve task-orientated and individualised exercises.
The primary outcome will be the Lower Extremity Functional Scale at 12 months post-operative. Secondary outcomes include: quality of life, knee pain and function, depression, anxiety and satisfaction. Data collection will be by questionnaire prior to surgery and 3, 6 and 12 months after surgery and will include a resource-use questionnaire to enable a trial-based economic evaluation. Trial participation and satisfaction with the classes will be evaluated through structured telephone interviews. The primary statistical and economic analyses will be conducted on an intention-to-treat basis with and without imputation of missing data. The primary economic result will estimate the incremental cost per quality-adjusted life year gained from this intervention from a National Health Services (NHS) and personal social services perspective.
Discussion: This research aims to benefit patients and the NHS by providing evidence on the long-term effectiveness and cost-effectiveness of outpatient physiotherapy after knee replacement. If the intervention is found to be effective and cost-effective, implementation into clinical practice could lead to improvement in patients’ outcomes and improved health care resource efficiency
The inheritance of seed dormancy in Sinapis arvensis L
Selection for dormant and non-dormant seed in Sinapis arvensis was carried to the seventh and fourteenth generation, respectively. Crosses between the dormant and non-dormant lines clearly showed both a maternal and an embryonic component of seed dormancy. A model for the number of alleles controlling dormancy was constructed and tested. The maternal component of dormancy was shown to be controlled by a single locus with two alleles, the dormant allele being dominant to the non-dormant. No clear picture of the control of the embryonic component of dormancy was found
Current trends in the cardiovascular clinical trial arena (I)
The existence of effective therapies for most cardiovascular disease states, coupled with increased requirements that potential benefits of new drugs be evaluated on clinical rather than surrogate endpoints, makes it increasingly difficult to substantiate any incremental improvements in efficacy that these new drugs might offer. Compounding the problem is the highly controversial issue of comparing new agents with placebos rather than active pharmaceuticals in drug efficacy trials. Despite the recent consensus that placebos may be used ethically in well-defined, justifiable circumstances, the problem persists, in part because of increased scrutiny by ethics committees but also because of considerable lingering disagreement regarding the propriety and scientific value of placebo-controlled trials (and trials of antihypertensive drugs in particular). The disagreement also substantially affects the most viable alternative to placebo-controlled trials: actively controlled equivalence/noninferiority trials. To a great extent, this situation was prompted by numerous previous trials of this type that were marked by fundamental methodological flaws and consequent false claims, inconsistencies, and potential harm to patients. As the development and use of generic drugs continue to escalate, along with concurrent pressure to control medical costs by substituting less-expensive therapies for established ones, any claim that a new drug, intervention, or therapy is "equivalent" to another should not be accepted without close scrutiny. Adherence to proper methods in conducting studies of equivalence will help investigators to avoid false claims and inconsistencies. These matters will be addressed in the third article of this three-part series
Improving patient experience and safety at transitions of care through the Your Care Needs You (YCNY) intervention: a study protocol for a cluster randomised controlled feasibility trial
Background
Patients, particularly older people, often experience safety issues when transitioning from hospital to home. Although the evidence is currently equivocal as to how we can improve this transition of care, interventions that support patient involvement may be more effective. The ‘Your Care Needs You’ (YCNY) intervention supports patients to ‘know more’ and ‘do more’ whilst in hospital in order that they better understand their health condition and medications, maintain their daily activities, and can seek help at home if required. The intervention aims to reduce emergency hospital readmissions and improve safety and experience during the transition to home.
Methods
As part of the Partners At Care Transitions (PACT) programme of research, a multi-centred cluster randomised controlled trial (cRCT) will be conducted to explore the feasibility of the YCNY intervention and trial methodology. Data will be used to refine the intervention and develop a protocol for a definitive cRCT.
Ten acute hospital wards (the clusters) from varying medical specialties including older peoples’ medicine, trauma and orthopaedics, cardiology, intermediate care, and stroke will be randomised to deliver YCNY or usual care on a 3:2 basis. Up to 200 patients aged 75 years and over and discharged to their own homes will be recruited to the study. Patients will complete follow-up questionnaires at 5-, 30-, and 90-days post-discharge and readmission data up to 90-days post-discharge will be extracted from their medical records.
Study outcomes will include measures of feasibility (e.g. screening, recruitment, and retention data) and processes required to collect routine data at a patient and ward level. In addition, interviews and observations involving up to 24 patients/carers and 28 staff will be conducted to qualitatively assess the acceptability, usefulness, and feasibility of the intervention and implementation package to patients and staff. A separate sub-study will be conducted to explore how accurately primary outcome data (30-day emergency hospital readmissions) can be gathered for the definitive cRCT.
Discussion
This study will establish the feasibility of the YCNY intervention which aims to improve safety and experience during transitions of care. It will identify key methodological and implementation issues that need to be addressed prior to assessing the effectiveness of the YCNY intervention in a definitive cluster randomised controlled trial.
Trial registration
UK Clinical Research Network Portfolio: 42191; ISTCRN: ISRCTN51154948. Registered 16/07/2019
Carotid Plaque-RADS: A Novel Stroke Risk Classification System
Background: Carotid artery atherosclerosis is highly prevalent in the general population and is a well-established risk factor for acute ischemic stroke. Although the morphological characteristics of vulnerable plaques are well recognized, there is a lack of consensus in reporting and interpreting carotid plaque features. Objectives: The aim of this document is to establish a consistent and comprehensive approach for imaging and reporting carotid plaque by introducing the Plaque–Reporting and Data System (RADS) score. Methods: A panel of experts recognized the necessity to develop a classification system for carotid plaque and its defining characteristics. Using a multimodality analysis approach, the Plaque-RADS categories were established through consensus, drawing on existing published reports. Results: The authors present a universal classification that is applicable to both researchers and clinicians. The Plaque-RADS score offers a morphological assessment in addition to the prevailing quantitative parameter of “stenosis.” The Plaque-RADS score spans from grade 1 (indicating complete absence of plaque) to grade 4 (representing complicated plaque). Accompanying visual examples are included to facilitate a clear understanding of the Plaque-RADS categories. Conclusions: Plaque-RADS is a standardized and reliable system of reporting carotid plaque composition and morphology via different imaging modalities, such as ultrasound, computed tomography, and magnetic resonance imaging. This scoring system has the potential to help in the precise identification of patients who may benefit from exclusive medical intervention and those who require alternative treatments, thereby enhancing patient care. A standardized lexicon and structured reporting promise to enhance communication between radiologists, referring clinicians, and scientists
Reduced Expression of Fumarate Hydratase in Clear Cell Renal Cancer Mediates HIF-2α Accumulation and Promotes Migration and Invasion
Germline mutations of FH, the gene that encodes for the tricarboxylic acid TCA (TCA) cycle enzyme fumarate hydratase, are associated with an inherited form of cancer referred to as Hereditary Leiomyomatosis and Renal Cell Cancer (HLRCC). Individuals with HLRCC are predisposed to the development of highly malignant and lethal renal cell carcinoma (RCC). The mechanisms of tumorigenesis proposed have largely focused on the biochemical consequences of loss of FH enzymatic activity. While loss of the tumor suppressor gene von Hippel Lindau (VHL) is thought to be an initiating event for the majority of RCCs, a role for FH in sporadic renal cancer has not been explored. Here we report that FH mRNA and protein expression are reduced in clear cell renal cancer, the most common histologic variant of kidney cancer. Moreover, we demonstrate that reduced FH leads to the accumulation of hypoxia inducible factor- 2α (HIF-2α), a transcription factor known to promote renal carcinogenesis. Finally, we demonstrate that overexpression of FH in renal cancer cells inhibits cellular migration and invasion. These data provide novel insights into the tumor suppressor functions of FH in sporadic kidney cancer
A case management report: a collaborative perioperative surgical home paradigm and the reduction of total joint arthroplasty readmissions
- …
