Physiological and Perceptual Responses of a Guard Passing Test and a Simulated Brazilian Jiu-Jitsu Combat: A Pilot Study.

ABSTRACT: Rufino, HVdO, Franchini, E, Forte, LDM, da Silva, TBO, Meireles, CLS, and Soares, YM. Physiological and perceptual responses of a guard passing test and a simulated Brazilian jiu-jitsu combat: a pilot study. J Strength Cond Res XX(X): 000-000, 2024-Brazilian jiu-jitsu (BJJ) is a grappling combat sport characterized by high-intensity efforts during the scoring actions interspersed by low-intensity actions or pause during the referee stoppage. Therefore, understanding of the physiological response to a BJJ match and BJJ-specific test can contribute to both athletes testing and training prescription. Thus, the present study aimed to compare the physiological and perceptual responses to a guard passing test (GPT) and to a simulated BJJ combat (simulated combat [SC]). For that, 7 male BJJ athletes performed a BJJ SC and the GPT at different days at random order. GPT was composed by 6 sets of all-out guard passing movements. Heart rate, blood lactate concentration ([La]), and rate of perceived exertion (RPE) were measured immediately after SC and after each set of GPT. RPE increased after sets 4, 5, and 6 compared with set 1, with no differences to SC (p < 0.001). In additionally, no differences were observed between [La] or heart rate after SC to GPT. Results suggests that GPT is an efficient training protocol that elicits similar physiological and perceptual responses to BJJ combat. Future studies should investigate GPT reliability and validity for performance assessment.

Thermal Imaging Metrology Using High Dynamic Range Near-Infrared Photovoltaic-Mode Camera.

The measurement of a wide temperature range in a scene requires hardware capable of high dynamic range imaging. We describe a novel near-infrared thermal imaging system operating at a wavelength of 940 nm based on a commercial photovoltaic mode high dynamic range camera and analyse its measurement uncertainty. The system is capable of measuring over an unprecedently wide temperature range; however, this comes at the cost of a reduced temperature resolution and increased uncertainty compared to a conventional CMOS camera operating in photodetective mode. Despite this, the photovoltaic mode thermal camera has an acceptable level of uncertainty for most thermal imaging applications with an NETD of 4-12 °C and a combined measurement uncertainty of approximately 1% K if a low pixel clock is used. We discuss the various sources of uncertainty and how they might be minimised to further improve the performance of the thermal camera. The thermal camera is a good choice for imaging low frame rate applications that have a wide inter-scene temperature range.

Valence band engineering of GaAsBi for low noise avalanche photodiodes.

Avalanche Photodiodes (APDs) are key semiconductor components that amplify weak optical signals via the impact ionization process, but this process' stochastic nature introduces 'excess' noise, limiting the useful signal to noise ratio (or sensitivity) that is practically achievable. The APD material's electron and hole ionization coefficients (α and ß respectively) are critical parameters in this regard, with very disparate values of α and ß necessary to minimize this excess noise. Here, the analysis of thirteen complementary p-i-n/n-i-p diodes shows that alloying GaAs with ≤ 5.1 % Bi dramatically reduces ß while leaving α virtually unchanged-enabling a 2 to 100-fold enhancement of the GaAs α/ß ratio while extending the wavelength beyond 1.1 µm. Such a dramatic change in only ß is unseen in any other dilute alloy and is attributed to the Bi-induced increase of the spin-orbit splitting energy (∆so). Valence band engineering in this way offers an attractive route to enable low noise semiconductor APDs to be developed.

Deep-level defects in n-type GaAsBi alloys grown by molecular beam epitaxy at low temperature and their influence on optical properties.

Deep-level defects in n-type GaAs1-x Bi x having 0 ≤ x ≤ 0.023 grown on GaAs by molecular beam epitaxy at substrate temperature of 378 °C have been injvestigated by deep level transient spectroscopy. The optical properties of the layers have been studied by contactless electroreflectance and photoluminescence. We find that incorporating Bi suppresses the formation of GaAs-like electron traps, thus reducing the total trap concentration in dilute GaAsBi layers by over two orders of magnitude compared to GaAs grown under the same conditions. In order to distinguish between Bi- and host-related traps and to identify their possible origin, we used the GaAsBi band gap diagram to correlate their activation energies in samples with different Bi contents. This approach was recently successfully applied for the identification of electron traps in n-type GaAs1-x N x and assumes that the activation energy of electron traps decreases with the Bi (or N)-related downward shift of the conduction band. On the basis of this diagram and under the support of recent theoretical calculations, at least two Bi-related traps were revealed and associated with Bi pair defects, i.e. (VGa+BiGa)-/2- and (AsGa+BiGa)0/1-. In the present work it is shown that these defects also influence the photoluminescence properties of GaAsBi alloys.

Severe sepsis and septic shock in patients with pre-existing non-cardiac pulmonary hypertension: contemporary management and outcomes.

OBJECTIVE: To review treatment and outcomes of septic shock in patients with pulmonary hypertension (PH) managed at a tertiary care institution. DESIGN, SETTING AND PATIENTS: We identified consecutive patients with non-cardiac PH (non-Group 2 in the World Health Organization classification) who were treated for septic shock in four intensive care units at a tertiary care institution between July 2004 and July 2007. Patients with a left ventricular ejection fraction < 50%, diastolic dysfunction, pericardial effusion or significant valve disease were excluded. Descriptive statistics were used to analyse the data. MAIN OUTCOME MEASURES: Hospital mortality, duration of vasopressor and ventilatory support, length of hospital and ICU stay. RESULTS: The final group for analysis comprised 82 patients. The major causes of PH were chronic obstructive pulmonary disease, interstitial lung disease and portopulmonary hypertension. PH was mild in 46 patients (56%), moderate in 21 (26%) and severe in 15 (18%). Vasopressor treatment was initiated in 69 patients (84%) within the first 48 hours: noradrenaline was most commonly used (53 patients, 65%), and 51 patients (62%) were treated with more than one agent. Sixty-seven patients (82%) were mechanically ventilated, and 33 (40%) required renal replacement therapy. Fortythree patients (52%) survived to hospital discharge; 23 (28%) remained alive at 1 year. Hospital mortality increased with severity of PH: 28% in mild, 67% in moderate and 80% in severe PH. Nonsurvivors were more likely to have plateau pressures beyond 30 cm H(2)O while mechanically ventilated within the first 48 hours in the ICU (56% v 29%, P = 0.03), to develop atrial fibrillation (AF) (46% v 12%, P < 0.001), and to require longer vasopressor support (mean, 5.3 v 2.6 days, P = 0.003). In a multivariate logistic regression analysis, severity of PH (odds ratio [OR], 1.55; 95% CI, 1.04-2.46; P = 0.04), new-onset AF (OR, 6.51; 95% CI, 2.24-22.07; P < 0.001) and longer duration of vasopressor support (OR, 1.15; 95% CI, 1.03-1.34; P = 0.04) were associated with increased hospital mortality. CONCLUSIONS: The severity of PH, new-onset AF, and longer vasopressor support were associated with poor outcomes in patients with PH who developed severe sepsis and septic shock.

Feasibility of early diagnosis and treatment of acute chest syndrome in sickle cell anaemia--a case report.

Acute chest syndrome is a serious complication and one of the causes of mortality in sickle cell disease. Twenty eight year old male was admitted in our hospital with fever, severe chest pain and haemolytic crisis. He was treated with intravenous antibiotics, fluids, parenteral analgesics and blood transfusion. Severe hypoxemia developed after 72 hours of hospitalization. The patient was transferred to the intensive care unit of our hospital. Oxygen therapy and ionotropic support were initiated. Vital parameters and organ functions returned to normal after treatment.