Does endurance fatigue increase the risk of injury when performing drop jumps?

Although from an athletic performance perspective it may be beneficial to undertake drop jump training when fatigued (principle of "specificity" of training), such endur-ance fatigue may expose the body to a greater risk of injury if it causes an increase in peak impact accelerations. This study aimed to determine if endurance fatigue resulted in an increase in tibial peak impact acceleration and an associated change in knee kinematics when completing plyometric drop jumps. Fifteen females performed drop jumps from 3 heights (15, 30, and 45 cm) when fatigued and nonfatigued. Treadmill running was used to induce endurance fatigue. The following variables were assessed: tibial peak impact acceleration, knee angle at initial ground contact, maximum angle of flexion, range of flexion, and peak knee angular velocity. Fatigue resulted in significantly greater (p < 0.05) tibial peak impact acceleration and knee flexion peak angular velocity in drop jumps from 15 and 30 cm, but not from 45 cm. Fatigue had no effect on any of the knee angles assessed. The neuromuscular system was affected negatively by endurance fatigue at 15 and 30 cm, indicating that coaches should be aware of a potential increased risk of injury in performing drop jumps when fatigued. Because from the greater drop height of 45 cm the neuromuscular system had a reduced capacity to attenuate the impact accelerations per se, whether nonfatigued or fatigued, this would suggest that this height may have been too great for the athletes examined

Characterization of an electron conduit between bacteria and the extracellular environment

A number of species of Gram-negative bacteria can use insoluble minerals of Fe(III) and Mn(IV) as extracellular respiratory electron acceptors. In some species of Shewanella, deca-heme electron transfer proteins lie at the extracellular face of the outer membrane (OM), where they can interact with insoluble substrates. To reduce extracellular substrates, these redox proteins must be charged by the inner membrane/periplasmic electron transfer system. Here, we present a spectro-potentiometric characterization of a trans-OM icosa-heme complex, MtrCAB, and demonstrate its capacity to move electrons across a lipid bilayer after incorporation into proteoliposomes. We also show that a stable MtrAB subcomplex can assemble in the absence of MtrC; an MtrBC subcomplex is not assembled in the absence of MtrA; and MtrA is only associated to the membrane in cells when MtrB is present. We propose a model for the modular organization of the MtrCAB complex in which MtrC is an extracellular element that mediates electron transfer to extracellular substrates and MtrB is a trans-OM spanning ß-barrel protein that serves as a sheath, within which MtrA and MtrC exchange electrons. We have identified the MtrAB module in a range of bacterial phyla, suggesting that it is widely used in electron exchange with the extracellular environment

Toward Sensor Modular Autonomy for Persistent Land Intelligence Surveillance and Reconnaissance (ISR)

Currently, most land Intelligence, Surveillance and Reconnaissance (ISR) assets (e.g. EO/IR cameras) are simply data collectors. Understanding, decision making and sensor control are performed by the human operators, involving high cognitive load. Any automation in the system has traditionally involved bespoke design of centralised systems that are highly specific for the assets/targets/environment under consideration, resulting in complex, non-flexible systems that exhibit poor interoperability. We address a concept of Autonomous Sensor Modules (ASMs) for land ISR, where these modules have the ability to make low-level decisions on their own in order to fulfil a higher-level objective, and plug in, with the minimum of preconfiguration, to a High Level Decision Making Module (HLDMM) through a middleware integration layer. The dual requisites of autonomy and interoperability create challenges around information fusion and asset management in an autonomous hierarchical system, which are addressed in this work. This paper presents the results of a demonstration system, known as Sensing for Asset Protection with Integrated Electronic Networked Technology (SAPIENT), which was shown in realistic base protection scenarios with live sensors and targets. The SAPIENT system performed sensor cueing, intelligent fusion, sensor tasking, target hand-off and compensation for compromised sensors, without human control, and enabled rapid integration of ISR assets at the time of system deployment, rather than at design-time. Potential benefits include rapid interoperability for coalition operations, situation understanding with low operator cognitive burden and autonomous sensor management in heterogenous sensor systems

A comparison of hospital readmission rates between two general physicians with different outpatient review practices

BACKGROUND: There has been a relentless increase in emergency medical admissions in the UK over recent years. Many of these patients suffer with chronic conditions requiring continuing medical attention. We wished to determine whether conventional outpatient clinic follow up after discharge has any impact on the rate of readmission to hospital. METHODS: Two consultant general physicians with the same patient case-mix but markedly different outpatient follow-up practice were chosen. Of 1203 patients discharged, one consultant saw twice as many patients in the follow-up clinic than the other (Dr A 9.8% v Dr B 19.6%). The readmission rate in the twelve months following discharge was compared in a retrospective analysis of hospital activity data. Due to the specialisation of the admitting system, patients mainly had cardiovascular or cerebrovascular disease or had taken an overdose. Few had respiratory or infectious diseases. Outpatient follow-up was focussed on patients with cardiac disease. RESULTS: Risk of readmission increased significantly with age and length of stay of the original episode and was less for digestive system and musculo-skeletal disorders. 28.7% of patients discharged by Dr A and 31.5 % of those discharged by Dr B were readmitted at least once. Relative readmission risk was not significantly different between the consultants and there was no difference in the length of stay of readmissions. CONCLUSIONS: Increasing the proportion of patients with this age- and case-mix who are followed up in a hospital general medical outpatient clinic is unlikely to reduce the demand for acute hospital beds

Underpinning excellence in higher education – an investigation into the leadership, governance and management behaviours of high-performing academic departments

The changes in government funding alongside external pressures of increased international and national competition have meant that higher education institutions need to excel in a turbulent environment. The leadership, governance and management (LGM) of academic departments are key concerns. This study investigates the correlation between behaviours, attitudes and competencies at a department level and overall departmental performance in terms of hard data measures. The research question this paper seeks to address is: what are the LGM behaviours that are associated with high-performance in academic departments? More than 600 people across 50 academic departments in 5 UK universities were surveyed through the use of three research phases consisting of open-ended questionnaires, critical case sampled semi-structured interviews and a fixed-response survey. Synthesising the data and findings of the study revealed a thematic framework of eight broad themes that contribute to excellence in academic departments. These were in the areas of change management, research and teaching, communication, strategy and shared values, leadership, departmental culture, rewards and staffing. The behaviours associated with each of these themes were used to construct the Underpinning Excellence model

Structure of a bacterial cell surface decaheme electron conduit

Some bacterial species are able to utilize extracellular mineral forms of iron and manganese as respiratory electron acceptors. In Shewanella oneidensis this involves decaheme cytochromes that are located on the bacterial cell surface at the termini of trans-outer-membrane electron transfer conduits. The cell surface cytochromes can potentially play multiple roles in mediating electron transfer directly to insoluble electron sinks, catalyzing electron exchange with flavin electron shuttles or participating in extracellular intercytochrome electron exchange along “nanowire” appendages. We present a 3.2-Å crystal structure of one of these decaheme cytochromes, MtrF, that allows the spatial organization of the 10 hemes to be visualized for the first time. The hemes are organized across four domains in a unique crossed conformation, in which a staggered 65-Å octaheme chain transects the length of the protein and is bisected by a planar 45-Å tetraheme chain that connects two extended Greek key split ß-barrel domains. The structure provides molecular insight into how reduction of insoluble substrate (e.g., minerals), soluble substrates (e.g., flavins), and cytochrome redox partners might be possible in tandem at different termini of a trifurcated electron transport chain on the cell surface

AGN feedback and iron enrichment in the powerful radio galaxy, 4C+55.16

We present a detailed X-ray analysis of 4C+55.16, an unusual and interesting radio galaxy, located at the centre of a cool core cluster of galaxies. 4C+55.16 is X-ray bright (L(cluster)~10^45 erg/s), radio powerful, and shows clear signs of interaction with the surrounding intracluster medium. By combining deep Chandra (100 ks) with 1.4 GHz VLA observations, we find evidence of multiple outbursts from the central AGN, providing enough energy to offset cooling of the ICM (P_bubbles=6.7x10^44 erg/s). Furthermore, 4C+55.16 has an unusual intracluster iron distribution showing a plume-like feature rich in Fe L emission that runs along one of the X-ray cavities. The excess of iron associated with the plume is around 10^7M_sol. The metal abundances are consistent with being Solar-like, indicating that both SNIa and SNII contribute to the enrichment. The plume and southern cavity form a region of cool metal-rich gas, and at the edge of this region, there is a clear discontinuity in temperature (from kT~2.5 keV to kT~5.0 keV), metallicity (from ~0.4 solar to 0.8 solar), and surface brightness distribution, consistent with it being caused by a cold front. However, we also suggest that this discontinuity could be caused by cool metal-rich gas being uplifted from the central AGN along one of its X-ray cavities.Comment: 12 pages, 11 figures, 1 table, Accepted to MNRAS (minor revision

Stormbreaker8 and A3Wally Bacteriophage Genome Annotations

Stormbreaker8 and A3Wally are two novel bacteriophages isolated and purified on Microbacterium foliorum NRRL B-24224 by students in the Fall 2020 Discovery course. Stormbreaker8, an EA1 cluster lytic phage, was isolated from soil collected in Orange City, IA. Its circular permuted genome contains 41,751 base-pairs with 63.4% GC content. A3Wally, a GD cluster phage, was isolated from soil collected in Sioux Center, IA. Its genome is 60.1% GC, contains 194,724 base-pairs, and its ends are direct terminal repeats. Spring 2021 Genetics students annotated the genomes using bioinformatics software