Plant methods:putting the spotlight on technological innovation in the plant sciences.

Plant Methods is a new journal for plant biologists, specialising in the rapid publication of peer-reviewed articles with a focus on technological innovation in the plant sciences. The aim of Plant Methods is to stimulate the development and adoption of new and improved techniques and research tools in plant biology. We hope to promote more consistent standards in the plant sciences, and make readily accessible laboratory and computer-based research tools available to the whole community. This will be achieved by publishing Research articles, Methodology papers and Reviews using the BioMed Central Open Access publishing model. The journal is supported by a prestigious editorial board, whose members all recognise the importance of technological innovation as a driver for basic science

Symmetries and reversing symmetries of polynomial automorphisms of the plane

The polynomial automorphisms of the affine plane over a field K form a group which has the structure of an amalgamated free product. This well-known algebraic structure can be used to determine some key results about the symmetry and reversing symmetry groups of a given polynomial automorphism.Comment: 27 pages, AMS-Late

The structure of reversing symmetry groups

We present some of the group theoretic properties of reversing symmetry groups, and classify their structure in simple cases that occur frequently in several well-known groups of dynamical systems.Comment: 12 page

Removal of Cyclohexane from a Contaminated Air stream using a Dense Phase Membrane Bioreactor

The purpose of this research was to determine the ability of a dense phase membrane bioreactor to remove cyclohexane, a volatile organic compound in JP-8 jet fuel, from a contaminated air stream using a biologically active film for degradation. The research answered questions regarding applications of membrane bioreactors, the ability of cyclohexane to diffuse through a dense phase membrane, growth of a viable microbial culture, and determination of the performance capabilities of the reactor. To answer these questions, a literature review was conducted and laboratory experiments were performed. Through the design, construction, and testing of the dense phase membrane bioreactor used for this research, it was determined that the reactor removed cyclohexane from a contaminated air stream at an average elimination capacity of 321.4 ± 76.2 g m-3 hr-1 with a 95% confidence interval. The successful removal of cyclohexane with the dense phase membrane bioreactor in this research effort filled a vacant niche in the scientific body of knowledge surrounding membrane bioreactor technology. Current technology applications, laboratory techniques, and data analysis are discussed

Assessment of the environmental toxicity and carcinogenicity of tungsten-based shot.

The toxicity of elemental tungsten released from discharged shot was assessed against previous studies that established a 1% toxic threshold for soil organisms. Extremely heavy theoretical shot loadings of 69,000 shot/ha were used to generate estimated environmental concentrations (EEC) for two brands of tungsten-based shot containing 51% and 95% tungsten. The corresponding tungsten EEC values were 6.5–13.5 mg W/kg soil, far below the 1% toxic threshold. The same shot loading in water produced tungsten EEC values of 2.1–4.4 mg W/L, levels that are not toxic under experimental conditions. Pure tungsten has not been shown to exhibit carcinogenic properties when ingested or embedded in animal tissues, but nickel, with which it is often alloyed, has known carcinogenicity. Given the large number of waterfowl that carry shot embedded in their body, it is advisable to screen lead shot substitutes for their carcinogenic potential through intra-muscular implantation

Effects of a Three-day Period of Intense, Intermittent Exercise on Oxidative Stress and Inflammation

It is documented that strenuous and prolonged exercise induces oxidative stress and inflammation, with the associated muscle damage and fatigue compromising performance. Little is known about the oxidant effects of intense, intermittent exercise, as performed daily by elite athletes competing in team sports. PURPOSE: To assess the short-term effects of a 3-day period of intense, intermittent exercise on biomarkers of oxidative stress and inflammation in trained athletes. METHODS: Ten trained athletes (age: 32.11±1.91yrs; mass: 66.33±1.95kg; maximal oxygen uptake (VO2max): 51.44±1.59mL·kg·minˉ1) completed a high-intensity, intermittent exercise protocol (90-minute intermittent treadmill run, ~70% VO2max) on three consecutive days and were compared to a control group (N=10). Blood samples were collected immediately pre (T1) and post (T2) the 3-day exercise protocol, then 21h- (T3) and 42h-post-exercise (T4); and assayed for Total Antioxidant Status (TAS), Thiobarbituric Acid Reactive Substances (TBARS), Interleukins (IL-6, IL-8 and IL-10), C-Reactive Protein (C-RP) and Lactate Dehydrogenase (LDH). Data were corrected for plasma volume change; results presented as M±SE. RESULTS: No significant differences were observed between the exercise and control group at T1 (TAS: 1.20±0.14mmol.L-1 vs. 1.18±0.11mmol.L-1; LDH: 302.14±16.24U/L vs. 295.27±31.26U/L; TBARS: 6.21±1.09μM vs. 5.88±1.00μM; and IL-6: 0.67±0.70pg/ml vs. 1.12±0.28pg/ml). The 3-day exercise period caused a significant increase in LDH (413.24±35.27U/L, P = 0.029), IL-6 (2.54±0.35pg/ml, P = 0.037) and TBARS (7.00±0.61μM, P = 0.042) at T2, with the effects of TBARS remaining above baseline at T4 (6.43±0.79μM, P = 0.043). TAS increased post-exercise with a significant difference observed between groups at T2 (1.86±0.21mmol.L-1 vs. 1.20±0.13mmol.L-1, P = 0.006), T3 (1.86±0.28mmol.L-1 vs. 1.30±0.14mmol.L-1, P = 0.010) and T4 (1.71±0.22mmol.L-1 vs. 1.17±0.13mmol.L-1, P = 0.014). IL-8, IL-10, and C-RP did not differ between groups. CONCLUSIONS: A 3-day period of intense, intermittent exercise increased oxidative stress and upregulated antioxidants in trained athletes, confirming the current model that exercise-induced oxidants play an important role in intracellular signaling pathways of endogenous antioxidants

The effect of a decaffeinated green tea extract formula on fat oxidation, body composition and exercise performance

Background: The cardio-metabolic and antioxidant health benefits of caffeinated green tea (GT) relate to its catechin polyphenol content. Less is known about decaffeinated extracts, particularly in combination with exercise. The aim of this study was therefore to determine whether a decaffeinated green tea extract (dGTE) positively influenced fat oxidation, body composition and exercise performance in recreationally active participants. Methods: Fourteen, recreationally active males participated in a double-blind, placebo-controlled, parallel design intervention (mean±SE; age = 21.4±0.3 yrs; weight = 76.37±1.73 kg; body fat = 16.84±0.97 %, peak oxygen consumption [V̇O2peak] = 3.00±0.10 L·min-1). Participants were randomly assigned capsulated dGTE (571 mg·d-1; n=7) or placebo (PL; n=7) for 4 weeks. Following body composition and resting cardiovascular measures, participants cycled for 1 hour at 50% V̇O2peak, followed by a 40 minute performance trial at week 0, 2 and 4. Fat and carbohydrate oxidation was assessed via indirect calorimetry. Pre-post exercise blood samples were collected for determination of total fatty acids (TFA). Distance covered (km) and average power output (W) were assessed as exercise performance criteria. Results: Total fat oxidation rates increased by 24.9 % from 0.241±0.025 to 0.301±0.009 g·min-1 with dGTE (P=0.05; ηp2 = 0.45) by week 4, whereas substrate utilisation was unaltered with PL. Body fat significantly decreased with dGTE by 1.63±0.16 % in contrast to PL over the intervention period (P<0.001; ηp2 = 0.84). No significant changes for FFA or blood pressure between groups were observed. dGTE resulted in a 10.9 % improvement in performance distance covered from 20.23±0.54 km to 22.43 ± 0.40 km by week 4 (P<0.001; ηp2 = 0.85). Conclusions: A 4 week dGTE intervention favourably enhanced substrate utilisation and subsequent performance indices, but did not alter TFA concentrations in comparison to PL. The results support the use of catechin polyphenols from dGTE in combination with exercise training in recreationally active volunteers

Assessing a commercially available sports drink on exogenous carbohydrate oxidation, fluid delivery and sustained exercise performance

Background: Whilst exogenous carbohydrate oxidation (CHOEXO) is influenced by mono- and disaccharide combinations, debate exists whether such beverages enhance fluid delivery and exercise performance. Therefore, this study aimed to ascertain CHOEXO, fluid delivery and performance times of a commercially available maltodextrin/ fructose beverage in comparison to an isocaloric maltodextrin beverage and placebo. Methods: Fourteen club level cyclists (age: 31.79 ± 10.02 years; height: 1.79 ± 0.06 m; weight: 73.69 ± 9.24 kg; VO2max: 60.38 ± 9.36 mL · kg·-1 min−1) performed three trials involving 2.5 hours continuous exercise at 50% maximum power output (Wmax: 176.71 ± 25.92 W) followed by a 60 km cycling performance test. Throughout each trial, athletes were randomly assigned, in a double-blind manner, either: (1) 1.1 g · min−1 maltodextrin + 0.6 g · min−1 fructose (MD + F), (2) 1.7 g · min−1 of maltodextrin (MD) or (3) flavoured water (P). In addition, the test beverage at 60 minutes contained 5.0 g of deuterium oxide (2H2O) to assess quantification of fluid delivery. Expired air samples were analysed for CHOEXO according to the 13C/12C ratio method using gas chromatography continuous flow isotope ratio mass spectrometry. Results: Peak CHOEXO was significantly greater in the final 30 minutes of submaximal exercise with MD + F and MD compared to P (1.45 ± 0.09 g · min−1, 1.07 ± 0.03 g · min−1and 0.00 ± 0.01 g · min−1 respectively, P < 0.0001), and significantly greater for MD + F compared to MD (P = 0.005). The overall appearance of 2H2O in plasma was significantly greater in both P and MD + F compared to MD (100.27 ± 3.57 ppm, 92.57 ± 2.94 ppm and 78.18 ± 4.07 ppm respectively, P < 0.003). There was no significant difference in fluid delivery between P and MD + F (P = 0.078). Performance times significantly improved with MD + F compared with both MD (by 7 min 22 s ± 1 min 56 s, or 7.2%) and P (by 6 min 35 s ± 2 min 33 s, or 6.5%, P < 0.05) over 60 km. Conclusions: A commercially available maltodextrin-fructose beverage improves CHOEXO and fluid delivery, which may benefit individuals during sustained moderate intensity exercise. The greater CHOEXO observed when consuming a maltodextrin-fructose beverage may support improved performance times

Periodic orbits of linear endomorphisms on the 2-torus and its lattices

Counting periodic orbits of endomorphisms on the 2-torus is considered, with special focus on the relation between global and local aspects and between the dynamical zeta function on the torus and its analogue on finite lattices. The situation on the lattices, up to local conjugacy, is completely determined by the determinant, the trace and a third invariant of the matrix defining the toral endomorphism.Comment: 22 page