Buzz off! An evaluation of ultrasonic acoustic vibration for the disruption of marine micro-organisms on sensor-housing materials.

Biofouling is a process of ecological succession which begins with the attachment and colonization of micro-organisms to a submerged surface. For marine sensors and their housings, biofouling can be one of the principle limitations to long-term deployment and reliability. Conventional antibiofouling strategies using biocides can be hazardous to the environment, and therefore alternative chemical-free methods are preferred. In this study, custom-made testing assemblies were used to evaluate ultrasonic vibration as an antibiofouling process for marine sensor-housing materials over a 28-day time course. Microbial biofouling was measured based on (i) surface coverage, using fluorescence microscopy and (ii) bacterial 16S rDNA gene copies, using Quantitative polymerase chain reaction (PCR). Ultrasonic vibrations (20 KHz, 200 ms pulses at 2-s intervals; total power 16·08 W) significantly reduced the surface coverage on two plastics, poly(methyl methacrylate) and polyvinyl chloride (PVC) for up to 28 days. Bacterial gene copy number was similarly reduced, but the results were only statistically significant for PVC, which displayed the greatest overall resistance to biofouling, regardless of whether ultrasonic vibration was applied. Copper sheet, which has intrinsic biocidal properties was resistant to biofouling during the early stages of the experiment, but inhibited measurements made by PCR and generated inconsistent results later on. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, ultrasonic acoustic vibration is presented as a chemical-free, ecologically friendly alternative to conventional methods for the perturbation of microbial attachment to submerged surfaces. The results indicate the potential of an ultrasonic antibiofouling method for the disruption of microbial biofilms on marine sensor housings, which is typically a principle limiting factor in their long-term operation in the oceans. With increasing deployment of scientific apparatus in aquatic environments, including further offshore and for longer duration, the identification and evaluation of novel antifouling strategies that do not employ hazardous chemicals are widely sought.

Incline Treadmill Interval Training: Short vs. Long Bouts and the Effects on Distance Running Performance.

This study compared 6 weeks of incline treadmill interval training (INC) performed on a 10% treadmill grade using either sprint-like efforts or slower, longer bouts. 24 individuals were randomly assigned between 2 groups that each completed 2 INC and one 30-min level-grade sessions∙wk-1. Training intensities, bout durations and the number of intervals per INC session were the velocity associated with VO2max (Vmax), 30 s and 10-14 (INCShort n=12), and 68%Vmax, ~3 min and 4-6 (INCLong n=12), respectively. All 30-min sessions were at 65%Vmax. Pre- and post-testing assessed VO2max; lactate threshold (VLT); running economy; and time-to-exhaustion at various conditions including 80%Vmax and 20% grade (CFMod). Both groups improved significantly in all tests; additionally, INCShort improved significantly more so in VLT and CFMod despite INCLong performing more than 2 times the running each INC session (P<0.05). Mean effect size (ES) of the relative improvement in a majority of tests revealed a trivial to very large ES of INCShort vs. INCLong training (ES range: 0.05-4.05). We conclude sprint-like INC better than slower, longer INC at improving a key determinant of distance running performance (VLT), and better at preparing individuals for running on courses with a variety of grades.

Effects of two different knee tape procedures on lower-limb kinematics and kinetics in recreational runners.

The purpose of this study was to compare the effects of Mulligan's tape (MT) and kinesio tape (KT) with no tape (NT) on hip and knee kinematics and kinetics during running. Twenty-nine female recreational runners performed a series of 'run-throughs' along a 10-m runway under the three taping conditions. Two force plates and a 14-camera Vicon motion analysis system (Oxford Metrics, Inc., Oxford, UK) captured kinematic and kinetic data for each dependent variable from ground contact to toe off. Comparisons of each dependent variable under three taping conditions were assessed through Statistical Package for the Social Sciences (SPSS; SPSS, Inc., Chicago, Illinois, USA; P-value < 0.01) using repeated measure analyses of variance. For each dependent variable with a P-value < 0.01, repeated measures with pairwise comparisons and Bonferroni adjustment were conducted to compare the three taping conditions. MT induced a significant reduction in anterior and posterior hip forces, knee flexion angular velocity, knee extensor moments, and hip flexion and extension moments compared with NT and KT (P = 0.001). There was no difference in hip or knee, kinematics or kinetics, between KT and NT (P = 1.000). MT appears to influence hip and knee biomechanics during running in an asymptomatic sample, whereas KT appeared to be biomechanically not different from NT.

Effect of Mulligan's and Kinesio knee taping on adolescent ballet dancers knee and hip biomechanics during landing.

Taping is often used to manage the high rate of knee injuries in ballet dancers; however, little is known about the effect of taping on lower-limb biomechanics during ballet landings in the turnout position. This study investigated the effects of Kinesiotape (KT), Mulligan's tape (MT) and no tape (NT) on knee and hip kinetics during landing in three turnout positions. The effect of taping on the esthetic execution of ballet jumps was also assessed. Eighteen pain-free 12-15-year-old female ballet dancers performed ballet jumps in three turnout positions, under the three knee taping conditions. A Vicon Motion Analysis system (Vicon Oxford, Oxford, UK) and Advanced Mechanical Technology, Inc. (Watertown, Massa chusetts, USA) force plate collected lower-limb mechanics. The results demonstrated that MT significantly reduced peak posterior knee shear forces (P = 0.025) and peak posterior (P = 0.005), medial (P = 0.022) and lateral (P = 0.014) hip shear forces compared with NT when landing in first position. KT had no effect on knee or hip forces. No significant differences existed between taping conditions in all landing positions for the esthetic measures. MT was able to reduce knee and the hip forces without affecting the esthetic performance of ballet jumps, which may have implications for preventing and managing knee injuries in ballet dancers.

Structure of the 2,4'-dihydroxyacetophenone dioxygenase from Alcaligenes sp. 4HAP.

The enzyme 2,4'-dihydroxyacetophenone dioxygenase (DAD) catalyses the conversion of 2,4'-dihydroxyacetophenone to 4-hydroxybenzoic acid and formic acid with the incorporation of molecular oxygen. Whilst the vast majority of dioxygenases cleave within the aromatic ring of the substrate, DAD is very unusual in that it is involved in C-C bond cleavage in a substituent of the aromatic ring. There is evidence that the enzyme is a homotetramer of 20.3 kDa subunits, each containing nonhaem iron, and its sequence suggests that it belongs to the cupin family of dioxygenases. In this paper, the first X-ray structure of a DAD enzyme from the Gram-negative bacterium Alcaligenes sp. 4HAP is reported, at a resolution of 2.2 Å. The structure establishes that the enzyme adopts a cupin fold, forming dimers with a pronounced hydrophobic interface between the monomers. The catalytic iron is coordinated by three histidine residues (76, 78 and 114) within a buried active-site cavity. The iron also appears to be tightly coordinated by an additional ligand which was putatively assigned as a carbonate dianion since this fits the electron density optimally, although it might also be the product formate. The modelled carbonate is located in a position which is highly likely to be occupied by the α-hydroxyketone group of the bound substrate during catalysis. Modelling of a substrate molecule in this position indicates that it will interact with many conserved amino acids in the predominantly hydrophobic active-site pocket where it undergoes peroxide radical-mediated heterolysis.

Dance training intensity at 11-14 years is associated with femoral torsion in classical ballet dancers.

OBJECTIVE: To examine in a cross sectional study the influence of femoral torsion (FT) and passive hip external rotation (PER) on turnout (TO). Starting age, years of classical ballet training, and current and past dance training intensity were assessed to determine their influence on FT, PER, and TO in pre-professional female dancers. METHODS: Sixty four dancers (mean (SD) age 18.16 (1.80) years) were recruited from four different dance training programmes. They completed a dance history questionnaire. FT was measured using a clinical method. PER was measured with the subjects prone, and TO was measured with the subjects standing. RESULTS: Mean TO was 136 degrees, mean unilateral PER was 49.4 degrees, and mean FT was 18.4 degrees. A positive correlation was observed between PER combined (PERC) and TO (r = 0.443, p < 0.001). A negative association was found between FT combined (FTC) and PERC (r = -0.402, p = 0.001). No association was found between starting age or years of classical ballet training and FTC, PERC, or TO. Dancers who trained for six hours a week or more during the 11-14 year age range had less FT than those who trained less (mean difference 6 degrees, 95% confidence interval 1.4 to 10.3). Students currently training for longer had higher levels of TO (p < 0.001) but comparable PERC and FTC. CONCLUSION: FT is significantly associated with PERC. Dancers who trained for six hours a week or more at 11-14 years of age had significantly less FT. FTC had a significant influence on PERC, but no influence on the execution of TO.

Redox potential of the haem c group in the quinocytochrome, lupanine hydroxylase, an enzyme located in the periplasm of a Pseudomonas sp.

The quinocytochrome c, lupanine hydroxylase, was shown to be located in the periplasm of a Pseudomonas sp. The midpoint redox potential of the haem in the purified enzyme was measured by potentiometric titration and shown to be +193 mV. PQQ was removed from the enzyme by isoelectric focusing to give inactive apoenzyme. This resulted in a shift in the midpoint redox potential of the haem to +98 mV. Full activity was recovered by the addition of PQQ to apoenzyme that also restored the original potential.

Preliminary X-ray study of p-cresol methylhydroxylase (flavocytochrome c) from Pseudomonas putida N.C.I.B. 9869.

Single crystals of p-cresol methylhydroxylase, a flavocytochrome c from Pseudomonas putida, have been prepared. The crystals are orthorhombic, space group P212121 with unit cell parameters; a = 140.3 A, b = 130.6 A and c = 74.1 A. They contain a single non-symmetric dimer per asymmetric unit and diffract to at least 2.5 A resolution.

Dynamic soft tissue mobilisation increases hamstring flexibility in healthy male subjects.

OBJECTIVES: The purpose of this study was to investigate the effect of dynamic soft tissue mobilisation (STM) on hamstring flexibility in healthy male subjects. METHODS: Forty five males volunteered to participate in a randomised, controlled single blind design study. Volunteers were randomised to either control, classic STM, or dynamic STM intervention. The control group was positioned prone for 5 min. The classic STM group received standard STM techniques performed in a neutral prone position for 5 min. The dynamic STM group received all elements of classic STM followed by distal to proximal longitudinal strokes performed during passive, active, and eccentric loading of the hamstring. Only specific areas of tissue tightness were treated during the dynamic phase. Hamstring flexibility was quantified as hip flexion angle (HFA) which was the difference between the total range of straight leg raise and the range of pelvic rotation. Pre- and post-testing was conducted for the subjects in each group. A one-way ANCOVA followed by pairwise post-hoc comparisons was used to determine whether change in HFA differed between groups. The alpha level was set at 0.05. RESULTS: Increase in hamstring flexibility was significantly greater in the dynamic STM group than either the control or classic STM groups with mean (standard deviation) increase in degrees in the HFA measures of 4.7 (4.8), -0.04 (4.8), and 1.3 (3.8), respectively. CONCLUSIONS: Dynamic soft tissue mobilisation (STM) significantly increased hamstring flexibility in healthy male subjects.

Redox potential of the cytochrome c in the flavocytochrome p-cresol methylhydroxylase.

The redox potential of the cytochrome c in 5 flavocytochrome c proteins, all p-cresol methylhydroxylases purified from species of Pseudomonas, was measured. All gave similar values ranging from 226-250 mV. Two of the enzymes, from Pseudomonas putida NC1B 9866 and NC1B 9869, were resolved into their flavoprotein and cytochrome subunits and the redox potentials of the isolated cytochrome c subunits measured. The values for these were 60-70 mV below those for the whole enzymes but, in both cases, reconstitution of active enzyme by addition of the flavoprotein subunit restored the original potential.

Periplasmic location of p-cresol methylhydroxylase in Pseudomonas putida.

The cellular location of the flavocytochrome c, p-cresol methylhydroxylase was investigated in two strains of Pseudomonas putida. In both cases the enzymes were shown to be located in the periplasmic fraction by their release during treatment of the bacteria with EDTA and lysozyme in a solution containing a high concentration of sucrose. For strain NCIB 9869 the finding is in accord with the suggestion that the physiological acceptor for the enzyme is azurin as this too was shown to be located mostly in the periplasm.

The role of His117 in the redox reactions of azurin from Pseudomonas aeruginosa.

The electron-transfer properties of H117G- and wild-type azurin were compared by applying both as electron acceptors in the conversion of 4-ethylphenol by 4-ethylphenol methylenehydroxylase (4-EPMH). The reactivity of H117G-azurin was determined in the absence and presence of imidazoles, which can substitute the missing fourth ligand. In the absence of imidazoles, H117G-azurin reacted directly with 4-ethylphenol; this reaction was abolished in the presence of imidazoles. The enzymatic reduction of H117G-azurin by 4-EPMH was 40 times slower than that of wild-type azurin. The rate of this reaction was enhanced by some imidazoles, diminished by others. In all cases the reduction of H117G-azurin was irreversible. These results demonstrate that His117 is vital for electron transfer and effectively protects the copper site against aspecific reactions.

Structure--activity relationships of lysophosphatidic acid: conformationally restricted backbone mimetics.

Lysophosphatidic acid (LPA) has associated with it an intriguing cell biology that is thought to be mediated through its interaction with G-protein coupled receptor(s). In an effort to extend the structure-activity relationships of LPA, we have produced a series of LPA analogues in which the glycerol core in LPA was replaced with conformationally restricted aryl substructures. The aryl substructures encompassed aminophenol, resorcinol, dihydroxy benzophenone, and tocopherol systems. The benzophenone moiety was investigated both as a conformationally restricting substructure for LPA and as a possible photoreactive alkylating agent for the LPA receptor(s). All LPA analogues were evaluated for their potency and efficacy in mobilizing calcium ions from internal stores in MDA MB-231 cells. Ten of the 14 analogues exhibited activity in this assay at doses up to 5 microM; none of the compounds exhibited nonreceptor-mediated lytic activity at this maximal concentration. The receptor response showed surprising tolerance for manipulation in the backbone region of LPA, although none of the compounds were equipotent to LPA. This tolerance for a variety of structures has given us new leads into the realization of novel agonists and antagonists of the LPA receptor(s).

Quantitative telomerase expression in glioblastomas shows regional variation and down-regulation with therapy but no correlation with patient outcome.

Despite the nearly ubiquitous expression of telomerase in almost all types of malignant human tumors, studies have shown widely varying positivity in the highest-grade glioma, the glioblastomas (GBMs), ranging from 26% to 100% of tumors analyzed. We have previously shown significant variability in positive versus negative telomerase expression from region to region within the same GBM. In this study, we hypothesized that application of new quantitative methodology would extend our previous observations and identify whether there is heterogeneity in levels of protein expression even within areas positive for telomerase in high-grade gliomas. Finally, we sought to correlate quantitative telomerase expression with patient outcome and therapeutic response. Quantitative analysis was achieved by polymerase chain-based TRAP assay with phosphorimager analysis and compared with clinical information obtained from 19 patients, most with primary, untreated GBMs. Results showed up to 3-fold variability in telomerase levels across multiple regional samples from the same patient, as well as between patients. In 5 of 6 patients with recurrent tumors who had received intervening radiation therapy or chemotherapy, telomerase was downregulated in the second, post-therapy sample. These data provide in vivo corroboration of recent in vitro experiments showing telomerase downregulation after radiation therapy or chemotherapy treatment of cell lines. Our finding of variability in levels of telomerase expression in GBMs parallels the known heterogeneity of these tumors for histologic features and cell growth-related factors. Statistical analysis showed no relationship between TRAP score and either time to clinical progression or time to death.

Bacillus Calmette-Guérin contact immunotherapy of local and metastatic deposits of rat tumors.

Adjuvant contact therapy with BCG can be used to control tumor deposits at local subcutaneous sites and at other sites, particularly pulmonary metastases and pleural tumor growths. This treatment method is generally quantitatively more effective than general immunostimulation, or active immunotherapy that employs vaccines of adjuvant and tumor cells. Furthermore, this treatment is effective in hosts that lack full immunocompetence, making it still feasible in immunosuppressed patients. The current evidence indicates that local activation of host macrophages is probably the essential effector mechanism of adjuvant contact therapy.

Effects of the pesticide amitraz and its metabolite BTS 27271 on insulin and glucagon secretion from the perfused rat pancreas: involvement of alpha2D-adrenergic receptors.

The study purpose was to investigate the direct effect of amitraz, a formamidine insecticide/acaricide, and its active metabolite BTS 27271 on insulin and glucagon secretion from the perfused rat pancreas. Amitraz and BTS 27271 (0.01, 0.1, 1, and 10 micromol/L) inhibited insulin secretion in a concentration-dependent manner. Amitraz increased glucagon secretion at 10 micromol/L, whereas BTS 27271 increased glucagon secretion at 1 and 10 micromol/L. Amitraz- and BTS 27271-induced decreases in insulin secretion and increases in glucagon secretion were not abolished during the 10-minute washout period. During the arginine treatment, both amitraz and BTS 27271 groups (0.1, 1, and 10 micromol/L) had lower insulin secretion and higher glucagon secretion than the control group. Idazoxan, an alpha2A/2D-adrenergic receptor (AR) antagonist, prevented the inhibitory effect of amitraz on insulin secretion in a concentration-dependent manner, but prazosin, an alpha1- and alpha2B/2C-AR antagonist, failed to antagonize the effect of amitraz. These results demonstrate that (1) amitraz and BTS 27271 inhibit insulin and stimulate glucagon secretion from the perfused rat pancreas, (2) amitraz inhibits insulin secretion by activation of alpha2D-ARs, since rats have alpha2D- but not alpha2A-ARs, and (3) amitraz and BTS 27271 may have a high binding affinity to the alpha2D-ARs of pancreatic islets.

Lower limb and back injury patterns of elite netball players.

The purpose of this study was to investigate the relationships between lower limb and back injuries with perceived landing patterns and podiatric variables for injured and uninjured elite netball players. 228 players of a possible 240 participants at the 1988 Australian netball championships completed injury questionnaires and were assessed for injury status. Approximately 92% of those who were part of the injury surveys were also given a podiatric assessment. Pearson chi 2 and unpaired t-tests were used to assess relationships between injury status in 2 groups (history of injury, and injuries sustained during the championships) and perceived landing patterns during play and podiatric variables. A significant association was found between history of lower limb and back injuries and level of competition. Open age netballers reported more injuries than the younger players. During each championship, a similar number of players (23%) were injured irrespective of playing level. 71% of these players sustained a grade 1 injury, 15.4% a grade 2 injury and 13.5% presented with severe grade 3 injuries. 2 players were diagnosed with an anterior cruciate ligament injury and a further 3 players sustained a fracture during the championships. Most of the injuries were ligamentous (40.5%) with some overuse tendinitis (11.5%) problems. The injury history profiles of the elite players surveyed showed that ankle and knee injuries were the most common lower limb injuries with incidences of 58 and 22%, respectively. More than a quarter of the players had overuse type injuries (24% retropatellar pain, 38% shin soreness) and 33% complained of back problems during their careers. 18 significant relationships were found between injuries sustained during a player's career and podiatric measures. Only 22.5% of a player's foot types were classified as normal while 42% presented with rearfoot varus and 20% were grouped into pronated foot postures.

Time structure analysis of behavioral acts using a computer pattern recognition system.

The spontaneous behavior of rats was monitored, classified and analyzed using a recently developed computer pattern recognition system. The K-function, a parameter developed for statistical research on spatial point processes and patterns, is used to analyze the temporal structure of behavioral acts or the joint relationship of separate acts. Forty male rats were observed in two experiments. In Experiment 1 untreated rats were observed and the temporal structure of their behavior was analyzed to establish an estimate of the false-positive error rate appropriate for use in such analyses. In Experiment 2, 20 control rats and 20 rats exposed to 2.0 mg/kg d-amphetamine were monitored using the computer pattern recognition system. The data from Experiment 1 showed that the false-positive rate was approximately ten percent or less. Experiment 2 demonstrated that the temporal structure of spontaneous motor behavior of amphetamine-treated rats was significantly disrupted.

Pattern recognition of rat behavior.

Analysis of animal behavior has been an arduous task requiring a human observer to record and classify individual motor acts. A computer pattern recognition system is introduced which simplifies this task by minimizing the need for human intervention. This system uses two video cameras with horizontal and vertical views of the behavior of a control and an experimental rat as they explore a simple environment for 15 minutes. Their behavior is sampled at a rate of one frame/second. Data from the video cameras are then converted into a form acceptable to Micro Vax I and VAX 11/750 computers. Each video picture is reduced to a 256 by 256 array, and ultimately each 15 minute observation session generates 28,800 blocks of information at 512 bytes each. Using a mathematically complete set of moments to the fourth order and the associated scalar invariants, the computer is programmed to identify the five major body positions of the rat including standing, sitting, rearing, walking and lying down. The computer also is programmed to identify the behaviors of grooming, head turning, whole body turning, looking, smelling, sniffing and washing face. This computer pattern recognition system not only speeds up behavioral classification, it alleviates the much criticized subjectivity introduced by human observers.