Carbohydrate and caffeine improves high intensity running of elite rugby league interchange players during simulated match play.

The study examined the effects of carbohydrate and caffeine ingestion on simulated rugby league interchange performance. Eight male elite rugby league forwards completed two trials of a rugby league simulation protocol for interchange players seven days apart in a randomized crossover design, ingesting either carbohydrate (CHO; 40 g·h-1) or carbohydrate and caffeine (CHO-C) (40 g·h-1 + 3 mg·kg-1) drink. Movement characteristics, heart rate, ratings of perceived exertion (RPE), and countermovement jump height (CMJ) were measured during the protocol. CHO-C resulted in likely to very likely higher mean running speeds (ES 0.43 to 0.75), distance in high intensity running (ES 0.41 to 0.64) and mean sprint speeds (ES 0.39 to 1.04) compared to CHO. Heart rate was possibly to very likely higher (ES 0.32 to 0.74) and RPE was likely to very likely lower (ES -0.53 to 0.86) with CHO-C. There was a likely trivial to possibly higher CMJ in CHO-C compared to CHO (ES 0.07 to 0.25). The co-ingestion of carbohydrate with caffeine has an ergogenic effect to reduce the sense of effort and increase high intensity running capability that might be employed to enhance interchange running performance in elite rugby league players

Grain‐scale dependency of metamorphic reaction on crystal plastic strain

The Breaksea Orthogneiss in Fiordland, New Zealand preserves water‐poor intermediate and mafic igneous rocks that were partially recrystallized to omphacite granulite and eclogite, respectively, at P ≈ 1.8 GPa and T ≈ 850°C. Metamorphic reaction consumed plagioclase and produced grossular‐rich garnet, jadeite‐rich omphacite, clinozoisite and kyanite. The extent of metamorphic reaction, identified by major and trace element composition and microstructural features, is patchy on the grain and outcrop scale. Domains of re‐equilibration coincide with areas that exhibit higher strain suggesting a causal link between crystal plastic strain and metamorphic reaction. Quantitative orientation analysis (EBSD) identifies gradual and stepped changes in crystal lattice orientations of igneous phenocrysts that are surrounded by homophase areas of neoblasts, characterized by high grain boundary to volume ratios and little to no internal lattice distortion. The narrow, peripheral compositional modification of less deformed garnet and omphacite phenocrysts reflects limited lattice diffusion in areas that lacked three‐dimensional networks of interconnected low‐angle boundaries. Low‐angle boundaries acted as elemental pathways (pipe diffusion) that enhanced in‐grain element diffusion. The scale of pipe diffusion is pronounced in garnet relatively to clinopyroxene. Strain‐induced mineral transformation largely controlled the extent of high‐T metamorphic reaction under relatively fluid‐poor conditions

Pan computed tomography for blunt polytrauma: Are we doing too many?

Background. Pan computed tomography (CT) is widely used in the evaluation of  patients with blunt polytrauma, but there is growing concern about the radiation risks imposed.Objectives. To ascertain whether we were possibly overutilising pan CT in our  trauma service, and whether we could safely cut down on scans without missing significant injuries.Methods. We audited all pan scans performed in the Metropolitan Trauma Service, Pietermaritzburg, South Africa, during the 12-month period 1 January - 31  December 2012. An analysis was done to determine what injuries were identified and how these findings influenced our management.Results. Of the 140 pan scans, 108 (77.1%) influenced management. These  included the following components: 62 brain scans (44.3%), 16 cervical spine scans (11.4%), 50 chest scans (35.7%) and 31 abdominal scans (22.1%). The remaining 32 pan scans (22.9%) did not influence management. However, it turned out that many of these ‘clinically negative’ scans were in fact clinically important, ruling out injury in patients in whom clinical assessment was regarded as unreliable: 3 patients (2.1%) were hypoxic and had to be sedated, intubated and ventilated; 14 (10.0%) had a Glasgow Coma Score (GCS) of <15; and 9 (6.4%) had major  distracting injuries. This left only 6 pan scans (4.3%) that were not regarded as clinically helpful.Conclusion. In our setting, the majority of pan scans influence management. By  ruling out significant injuries, clinically negative scans are valuable in patients who are obtunded, intubated and ventilated, or have major distracting injuries. In  patients with a GCS of 15, not sedated and ventilated and with no major distracting injuries, clinical assessment and alternative imaging modalities may suffice

The Assessment of Total Energy Expenditure During a 14-Day In-Season Period of Professional Rugby League Players Using the Doubly Labelled Water Method

Rugby League is a high-intensity collision sport competed over 80 min. Training loads are monitored to maximize recovery and assist in the design of nutritional strategies although no data are available on the total energy expenditure (TEE) of players. We therefore assessed resting metabolic rate (RMR) and TEE in six Super League players over 2 consecutive weeks in-season including one game per week. Fasted RMR was assessed followed by a baseline urine sample before oral administration of a bolus dose of hydrogen (deuterium 2H) and oxygen (18O) stable isotopes in the form of water (2H218O). Every 24 hr thereafter, players provided urine for analysis of TEE via DLW method. Individual training load was quantified using session rating of perceived exertion (sRPE) and data were analyzed using magnitude-based inferences. There were unclear differences in RMR between forwards and backs (7.7 ± 0.5 cf. 8.0 ± 0.3 MJ, respectively). Indirect calorimetry produced RMR values most likely lower than predictive equations (7.9 ± 0.4 cf. 9.2 ± 0.4 MJ, respectively). A most likely increase in TEE from Week 1 to 2 was observed (17.9 ± 2.1 cf. 24.2 ± 3.4 MJ) explained by a most likelyincrease in weekly sRPE (432 ± 19 cf. 555 ± 22 AU), respectively. The difference in TEE between forward and backs was unclear (21.6 ± 4.2 cf. 20.5 ± 4.9 MJ, respectively). We report greater TEE than previously reported in rugby that could be explained by the ability of DLW to account for all match and training-related activities that contributes to TEE

Hanging-related injury in Pietermaritzburg, South Africa

BACKGROUND: Hanging is a common form of self-harm, and emergency care physicians will not infrequently be called upon to manage a survivor.Despite the relative frequency of the injury, there is a paucity of literature on the topic and the spectrum and incidence of associated injuries are poorly described. OBJECTIVES: To review experience with management of victims of hanging at a major trauma centre in South Africa. METHODS: All patients treated by the Pietermaritzburg Metropolitan Trauma Service following a hanging incident between December 2012 and December 2018 were identified from the Hybrid Electronic Medical Registry. Basic demographics were recorded, and the management and outcome of each patient were noted. RESULTS: During the 6-year period under review, a total of 154 patients were seen following a hanging incident. The mean age was 29.4 years. There were 24 females (15.6%) and 130 males (84.4%). The vast majority (n=150; 97.5%) had attempted suicide, and only 4 hangings (2.5%) were accidental. A total of 92 patients (60.9%) had consumed alcohol prior to the incident. There were 23 patients with a Glasgow Coma Score (GCS) 12 (mild TBI). A total of 7 patients (4.5%) required intensive care unit admission, and 25 (16.2%) required intubation. The following extracranial injuries were documented on computed tomography scans: hyoid bone fractures (n=2), cervical spine fracture (n=10), mandible fracture (n=4) and oesophageal injury (n=1). Intracranial pathology was evident on 27.0% of scans, with the most common finding being global cerebral ischaemia. The mortality rate was 2.5% (4/154). CONCLUSIONS: Hanging is a common mechanism of self-harm. It is associated with significant injuries and mortality. The acute management of hanging should focus on airway protection followed by detailed imaging of the head and neck. Further work must attempt to include mortuary data on hanging

Discrepancy in clinical outcomes of patients with gunshot wounds in car hijacking: a South African experience

INTRODUCTION: Discrepancy in outcomes between urban and rural trauma patients is well known. We reviewed our institutional experience with the management of gunshot wounds (GSWs) in the specific setting of car hijacking and focused on clinical outcome between rural and urban patients. METHODS: A retrospective review was conducted at a major trauma centre in South Africa over an 8-year period for all patients who presented with any form of GSWs in car hijacking settings. Specific clinical outcomes were compared between rural and urban patients. RESULTS: A total of 101 patients were included (74% male, mean age 34 years). Fifty-five per cent were injured in rural areas and the remaining 45% (45/101) were in the urban district. Mean time from injury to arrival at our trauma centre was 11 hours for rural and 4 hours for urban patients (p < 0.001). Seventy-six per cent (76/101) sustained GSWs to multiple body regions. Sixty-three of the 101 (62%) patients required one or more operative interventions. In individual logistic regressions adjusted for sex and number of regions injured, rural patients were 9 (95% CI: 1.9-44.4) and 7 (95% CI: 2.124.5) times more likely than urban patients to have morbidities or required admissions to intensive care respectively. The risk of death in rural patients was 36 (95% CI: 4.5-284.6) times higher than that of urban patients. CONCLUSIONS: Patients who sustained GSWs in carjacking incidents that occurred in rural areas are associated with significantly greater morbidity and mortality compared with their urban counterparts. Delay to definitive care is likely to be the significant contributory factor, and improvement in prehospital emergency medical service is likely to be beneficial in improving patient outcome

A review of blunt pelvic injuries at a major trauma centre in South Africa.

BACKGROUND: The collective five-year experience with the acute management of pelvic trauma at a busy South African trauma service is reviewed to compare the usefulness and applicability of current grading systems of pelvic trauma and to review the compliance with current guidelines regarding pelvic binder application during the acute phase of resuscitation. METHODS: A retrospective review was conducted over a 5-year period from December 2012 to December 2017 on all polytrauma patients who presented with a pelvic fracture. Mechanism of injury and presenting physiology and clinical course including pelvic binder application were documented. Pelvic fractures were graded according to the Young- Burgess and Tile systems. RESULTS: There was a cohort of 129 patients for analysis. Eighty-one were male and 48 female with a mean age was 33.6 ± 13.1 years. Motor vehicle-related collisions (MVCs) were the main mechanism of injury (50.33%) and pedestrian vehicle collisions (PVCs) were the second most common (37.98%). The most common associated injuries were abdominal injuries (41%), chest injury (37%), femur fractures (21%), tibia fractures (15%) and humerus fracture (14.7%). Thirty patients in this cohort (23%) underwent a laparotomy. They were mainly in the Tile B (70%) and lateral compression (63%) groups. Nine patients underwent pelvic pre-peritoneal packing. Thirty-five (27%) patients were admitted to ICU. Fifteen (12%) patients died. The Young-Burgess classification had a greater accuracy in predicting death than the Tile classification. Forty per cent of deaths occurred in ICU, 33% died secondary to a traumatic brain injury (TBI). Twenty per cent died in casualty and 6.6% in the operating room from ongoing haemorrhage. A pelvic binder was not applied in 66% of patients. In the 34% of patients who had a pelvic binder applied, it was applied post CT scan in 24.8%, in the pre-hospital setting in 7.2%, and on arrival in 2.4% of patients. In 73% of deaths, a binder was not applied, and of those deaths, 54% showed signs of haemodynamic instability. CONCLUSION: It would appear that our application of pelvic binders in patients with acute pelvic trauma is ad hoc. Appropriate selection of patients, who may benefit from a binder and it's timely application, has the potential to improve outcome in these patients

The coming and going of a marl lake: multi-indicator palaeolimnology reveals abrupt ecological change and alternative views of reference conditions

Eutrophication is the most pressing threat to highly calcareous (marl) lakes in Europe. Despite their unique chemistry and biology, comprehensive studies into their unimpacted conditions and eutrophication responses are underrepresented in conservation literature. A multi-indicator palaeolimnological study spanning ca. 1260–2009 was undertaken at Cunswick Tarn (UK), a small, presently eutrophic marl lake, in order to capture centennial timescales of impact. Specific aims were to (1) establish temporal patterns of change (gradual/abrupt) across biological groups, thereby testing theories of resistance of marl lake benthic communities to enrichment, and (2) compare the core record of reference condition with prevailing descriptions of high ecological status. Analyses of sediment calcium (Ca), phosphorus (P), pigments, diatoms, testate amoebae, cladocerans, and macrofossils, revealed three abrupt changes in ecosystem structure. The first (1900s), with biomass increases in charophytes and other benthic nutrient-poor indicators, supported ideas of resistance to eutrophication in Chara lakes. The second transition (1930s), from charophyte to angiosperm dominance, occurred alongside reductions in macrophyte cover, increases in eutrophic indicators, and a breakdown in marling, in support of ideas of threshold responses to enrichment. Core P increased consistently into the 1990s when rapid transitions into pelagic shallow lake ecology occurred and Cunswick Tarn became biologically unidentifiable as a marl lake. The moderate total P at which these changes occurred suggests high sensitivity of marl lakes to eutrophication. Further, the early record challenges ideas of correlation between ecological condition, charophyte biomass and sediment Ca. Instead, low benthic production, macrophyte cover, and Ca sedimentation, was inferred. Management measures must focus on reducing external nutrient and sediment loads at early stages of impact in order to preserve marl lakes

The role of rewilding in mitigating hydrological extremes: State of the evidence

Landscape rewilding has the potential to help mitigate hydrological extremes by allowing natural processes to function. Our systematic review assessed the evidence base for rewilding-driven mitigation of high and low flows. The review uncovers a lack of research directly addressing rewilding, but highlights research in analogue contexts which can, with caution, indicate the nature of change. There is a lack of before-after studies that enable deeper examination of temporal trajectories and legacy effects, and a lack of research on the scrub and shrubland habitats common in rewilding projects. Over twice as much evidence is available for high flows compared to low flows, and fewer than one third of studies address high and low flows simultaneously, limiting our understanding of co-benefits and contrasting effects. Flow magnitude variables are better represented within the literature than flow timing variables, and there is greater emphasis on modeling for high flows, and on direct measurement for low flows. Most high flow studies report a mitigating effect, but with variability in the magnitude of effect, and some exceptions. The nature of change for low flows is more complex and suggests a higher potential for increased low flow risks associated with certain trajectories but is based on a very narrow evidence base. We recommend that future research aims to: capture effects on both high and low flow extremes for a given type of change; analyze both magnitude and timing characteristics of flow extremes; and examine temporal trajectories (before and after data) ideally using a full before-after-control-impact design. This article is categorized under: Human Water > Value of Water Science of Water > Hydrological Processes Science of Water > Water Extremes Water and Life > Conservation, Management, and Awareness

Development of anthropometric characteristics in professional Rugby League players: Is there too much emphasis on the pre-season period?

Rugby League is a team sport requiring players to experience large impact collisions, thus requiring high amounts of muscle mass. Many players (academy and senior) strive to increase muscle mass during the pre-season, however, quantification of changes during this period have not been thoroughly investigated. We therefore assessed changes in body-composition using Dual X-Ray Absorptiometry (DXA) in eleven academy players over three successive pre-seasons and ninety-three senior players from four different European Super League clubs prior to, and at the end of, a pre-season training period. There was no meaningful change in lean mass of the academy players during any of the pre-season periods (year 1 = 72.3 ± 7.1–73.2 ± 7.2kg; ES 0.05, year 2 = 74.4 ± 6.9–75.5 ± 6.9kg; ES 0.07, year 3 = 75.9 ± 6.7–76.8 ± 6.6kg; ES 0.06) with small changes only occurring over the three-year study period (72.3–75.9kg; ES = 0.22). Senior players showed trivial changes in all characteristics during the pre-season period (total mass = 95.1–95.0kg; ES −0.01, lean mass = 74.6–75.1kg; ES 0.07, fat mass = 13.6–12.9kg; ES −0.17, body fat percentage = 14.8–14.1%; ES −0.19). These data suggest that academy players need time to develop towards profiles congruent with senior players. Moreover, once players reach senior level, body-composition changes are trivial during the pre-season and therefore teams may need to individualise training for players striving to gain muscle mass by reducing other training loads