Spinorial relativistic rotator: The transformation from quasi-Newtonian to Minkowski coordinates

There exists a remarkably close relationship between the operator algebra of the Dirac equation and the corresponding operators of the spinorial relativistic rotator (an indecomposable object lying on a mass-spin Regge trajectory). The analog of the Foldy-Wouthuysen transformation (more generally, the transformation between quasi-Newtonian and Minkowski coordinates) is constructed and explicit results are discussed for the spin and position operators. Zitterbewegung is shown to exist for a system having only positive energies.

Indigofera linnaei-a problem legume across northern pastures

Indigofera linnaei (or Birdsville Indigo) is a native legume with widespread abundance in pastures across northern Australian, and occurs in all northern regions of Australia from the tropical Kimberleys and arid central Australia to subhumid coastal Queensland (Figure 1). I. linnaei in central Australia has been linked to canine fatalities due to the toxin indospicine. Indospicine, an analog of arginine, is an unusual non-protein amino acid found only in a number of Indigofera species including I. linnaei. Dogs are particularly sensitive to the heptatoxicity of indospicine, and while they do not themselves consume the plant, dogs have been poisoned indirectly through the consumption of indospicine-contaminated meat from horses and camels grazing in regions where I. linnaei is common (Hegarty and Pound 1988, FitzGerald et al 2011). I. linnaei is observed to occur in various forms from strongly prostrate in south-east Queensland to an erect shrub-like form growing to more than 50cm in height in some northern regions. It mostly occurs as a minor proportion of native pasture but denser stands develop under certain circumstances. The indospicine content of I. linnaei has not previously been reported outside of central Australia, and in this study we investigate the indospicine content of plant samples collected across various regions, including both prostrate and upright forms. All samples were collected in March-July, dried, milled and analysed by UPLC-MS/MS in an adaption of our method (Tan et al 2014). Indospicine was determined in all I. linnaei plant samples regardless of region or growth form (Table 1). Measured levels were in the range 159.5 to 658.8 mg/kg DM and indicate that this plant may pose a similar problem in all areas dependent on local seasonal abundance.

Response of Circular Footings to Vertical Vibrations

In this paper, analog solutions are presented for the response of a circular footing resting on an elastic half-space with uniform and parabolic contact pressure distributions and subjected to frequency dependent and frequency independent excitations. In addition, an analog solution to a rigid circular footing subjected to frequency dependent excitation is also presented. The results have been compared with the rigorous solution of Sung and the agreement is found to be good.

Application of ultraspherical polynomials to forced oscillations of a third-order non-linear system

In this paper the method of ultraspherical polynomial approximation is applied to study the steady-state response in forced oscillations of a third-order non-linear system. The non-linear function is expanded in ultraspherical polynomials and the expansion is restricted to the linear term. The equation for the response curve is obtained by using the linearized equation and the results are presented graphically. The agreement between the approximate solution and the analog computer solution is satisfactory. The problem of stability is not dealt with in this paper.

Hybrid Simulation of Queuing-System Dynamics

This paper presents a simple hybrid computer technique to study the transient behaviour of queueing systems. This method is superior to stand-alone analog or digital solution because the hardware requirement is excessive for analog technique whereas computation time is appreciable in the latter case. By using a hybrid computer one can share the analog hardware thus requiring fewer integrators. The digital processor can store the values, play them back at required time instants and change the coefficients of differential equations. By speeding up the integration on the analog computer it is feasible to solve a large number of these equations very fast. Hybrid simulation is even superior to the analytic technique because in the latter case it is difficult to solve time-varying differential equations.

Purification and Regulatory Properties of Mung Bean (Vigna Radiata L.) Serine Hydroxymethyltransferase 1

Serine hydroxymethyltransferase, the first enzyme in the pathway for interconversion of C1 fragments, was purified to homogeneity for the first time from any plant source. The enzyme from 72-h mung bean (Vigna radiata L.) seedlings was isolated using Blue Sepharose CL-6B and folate-AH-Sepharose-4B affinity matrices and had the highest specific activity (1.33 micromoles of HCHO formed per minute per milligram protein) reported hitherto. The enzyme preparation was extremely stable in the presence of folate or L-serine. Pyridoxal 5'-phosphate, ethylenediaminetetraacetate and 2-mercaptoethanol prevented the inactivation of the enzyme during purification. The enzyme functioned optimally at pH 8.5 and had two temperature maxima at 35 and 55°C. The Km values for serine were 1.25 and 68 millimolar, corresponding to Vmax values of 1.8 and 5.4 micromoles of HCHO formed per minute per milligram protein, respectively. The K0.5 value for L-tetrahydrofolate (H4folate) was 0.98 millimolar. Glycine, the product of the reaction and D-cycloserine, a structural analog of D-alanine, were linear competitive inhibitors with respect to L-serine with Ki values of 2.30 and 2.02 millimolar, respectively. Dichloromethotrexate, a substrate analog of H4folate was a competitive inhibitor when H4folate was the varied substrate. Results presented in this paper suggested that pyridoxal 5'-phosphate may not be essential for catalysis.The sigmoid saturation pattern of H4folate (nH = 2.0), one of the substrates, the abolition of sigmoidicity by NADH, an allosteric positive effector (nH = 1.0) and the increase in sigmoidicity by NAD+ and adenine nucleotides, negative allosteric effectors (nH = 2.4) clearly established that this key enzyme in the folate metabolism was an allosteric protein. Further support for this conclusion were the observations that (a) serine saturation exhibited an intermediary plateau region; (b) partial inhibition by methotrexate, aminopterin, O-phosphoserine, DL-{alpha}-methylserine and DL-O-methylserine; (c) subunit nature of the enzyme; and (d) decrease in the nH value from 2.0 for H4folate to 1.5 in presence of L-serine. These results highlight the regulatory nature of mung bean serine hydroxymethyltransferase and its possible involvement in the modulation of the interconversion of folate coenzymes.

Structural assignment of monothiocarbonohydrazones by 1H NMR spectroscopy

Analysis of the 1H NMR spectra of several monothiocarbonohydrazones, some of them synthesized for the first time, shows that they exist as two structural isomers. Whereas, in general, the derivatives of aromatic aldehydes conform to a linear structure, the aliphatic carbonyl derivatives conform to heterocyclic or linear structures, depending on the size of the substituent groups. This dual behaviour is explained in terms of extended conjugation and steric hindrance.

Randomised controlled trial of three burns dressings for partial thickness burns in children

BACKGROUND This study compared the effects of three silver dressing combinations on small to medium size acute partial thickness burns in children, focusing on re-epithelialization time, pain and distress during dressing changes. METHOD Children (0-15 years) with clean, ≤ 10% total body surface area (TBSA) partial thickness burns who met the inclusion criteria were included in the study. Children received either (1) Acticoat™; (2) Acticoat™ with Mepitel™; or (3) Mepilex Ag™ dressings. Measures of burn re-epithelialization, pain, and distress were recorded at dressing changes every 3-5 days until full re-epithelialization occurred. RESULTS One hundred and three children were recruited with 96 children included for analysis. No infections were detected for the course of the study. When adjusted for burn depth, Acticoat™ significantly increased the expected days to full re-epithelialization by 40% (IRR = 1.40; 95% CI: 1.14-1.73, p < 0.01) and Acticoat™ with Mepitel™ significantly increased the expected days to full re-epithelialization by 33% (IRR = 1.33; 95% CI: 1.08-1.63, p ≤ 0.01) when compared to Mepilex Ag™. Expected FLACC scores in the Mepilex Ag™ group were 32% lower at dressing removal (p = 0.01) and 37% lower at new dressing application (p = 0.04); and scores in the Acticoat™ with Mepitel™ group were 23% lower at dressing removal (p = 0.04) and 40% lower at new dressing application (p < 0.01), in comparison to the Acticoat™ group. Expected Visual Analog Scale-Pain (VAS-P) scores were 25% lower in the Mepilex Ag™ group at dressing removal (p = 0.04) and 34% lower in the Acticoat™ with Mepitel™ group (p = 0.02) at new dressing application in comparison to the Acticoat™ group. There was no significant difference between the Mepilex Ag™ and the Acticoat™ with Mepitel™ groups at all timepoints and with any pain measure. CONCLUSION Mepilex Ag™ is an effective silver dressing, in terms of accelerated wound re-epithelialization time (compared to Acticoat™ and Acticoat™ with Mepitel™) and decreased pain during dressing changes (compared to Acticoat™), for clean, < 10% TBSA partial thickness burns in children.

Conformations of Heterochiral and Homochiral Proline-Pseudoproline Segments in Peptides: Context Dependent Cis-Trans Peptide Bond Isomerization

The pseudoproline residue (Psi Pro, L-2,2-dimethyl-1,3-thiazolidine-4-carboxylic acid) has been introduced into heterochiral diproline segments that have been previously shown to facilitate the formation of beta-hairpins, containing central two and three residue turns. NMR studies of the octapeptide Boc-Leu-Phe-Val-(D)Pro-Psi Pro-Leu-Phe-Val-OMe (1), Boc-Leu-Val-Val-(D)Pro-Psi Pro-Leu-Val-Val-OMe (2), and the nonapeptide sequence Boc-Leu-Phe-Val-(D)Pro-Psi Pro-(D)Ala-Leu-Phe-Val-OMe (3) established well-registered beta-hairpin structures in chloroform solution, with the almost exclusive population of the trans conformation for the peptide bond preceding the Psi Pro residue. The beta-hairpin conformation of 1 is confirmed by single crystal X-ray diffraction. Truncation of the strand length in Boc-Val-(D)Pro-Psi Pro-Leu-OMe (4) results in air increase in the population of the cis conformer, with a cis/trans ratio of 3.65. Replacement of Psi Pro in 4 by (L)Pro in 5, results in almost exclusive population of the trans form, resulting in an incipient beta-hairpin conformation, stabilized by two intramolecular hydrogen bonds. Further truncation of the sequence gives an appreciable rise in the population of cis conformers in the tripeptide piv-(D)Pro-Psi Pro-Leu-OMe (6). In the homochiral segment Piv-Pro Psi Pro-Leu-OMe (7) only the cis form is observed with the NMR evidence strongly supporting a type VIa beta-turn conformation, stabilized by a 4 -> 1 hydrogen bond between the Piv (CO) and Leu (3) NH groups. The crystal structure of the analog peptide 7a (Piv-Pro-Psi(H,CH3)Pro-Leu-NHMe) confirms the cis peptide bond geometry for the Pro-Psi(H,CH3)pro peptide bond, resulting in a type VIa beta-turn conformation.

The pulse response of non-linear third order systems

The response of a third order non-linear system subjected to a pulse excitation is analysed. A transformation of the displacement variable is effected. The transformation function chosen is the solution of the linear problem subjected to the same pulse. With this transformation the equation of motion is brought into a form in which the method of variation of parameters is applicable for the solution of the problem. The method is applied to a single axis gyrostabilized platform subjected to an exponentially decaying pulse. The analytical results are compared with digital and analog computer solutions.

Conformational study of valinomycin: a molecular dynamics approach

Valinomycin is a highly flexible cyclic dodecadepsipeptide that transports ions across membranes. Such a flexibility in the conformation is required for its biological function since it has to encounter a variety of environments and liganding state. Exploration of conformational space of this molecule is therefore important and is one of the objectives of the present study that has been carried out by means of high temperature Molecular Dynamics. Further, the stability of the known bracelet-like structure of the uncomplexed valinomycin and the inherent flexibility around this structure has been investigated. The uncomplexed form of valinomycin has been simulated at 75–100 K for 1 ns in order to elucidate the average conformational properties. An alanine-analog of valinomycin has been simulated under identical conditions in order to evaluate the effect of sidechain on the conformational properties, The studies confirm the effect of sidechain on conformational equilibrium.

Effects of unilateral vocal fold paralysis treatment with fascia augmentation on airflow mechanics, tracheal sounds and voice acoustics

Data on the influence of unilateral vocal fold paralysis on breathing, especially other than information obtained by spirometry, are relatively scarce. Even less is known about the effect of its treatment by vocal fold medialization. Consequently, there was a need to study the issue by combining multiple instruments capable of assessing airflow dynamics and voice. This need was emphasized by a recently developed medialization technique, autologous fascia injection; its effects on breathing have not previously been investigated. A cohort of ten patients with unilateral vocal fold paralysis was studied before and after autologous fascia injection by using flow-volume spirometry, body plethysmography and acoustic analysis of breathing and voice. Preoperative results were compared with those of ten healthy controls. A second cohort of 11 subjects with unilateral vocal fold paralysis was studied pre- and postoperatively by using flow-volume spirometry, impulse oscillometry, acoustic analysis of voice, voice handicap index and subjective assessment of dyspnoea. Preoperative peak inspiratory flow and specific airway conductance were significantly lower and airway resistance was significantly higher in the patients than in the healthy controls (78% vs. 107%, 73% vs. 116% and 182% vs. 125% of predicted; p = 0.004, p = 0.004 and p = 0.026, respectively). Patients had a higher root mean square of spectral power of tracheal sounds than controls, and three of them had wheezes as opposed to no wheezing in healthy subjects. Autologous fascia injection significantly improved acoustic parameters of the voice in both cohorts and voice handicap index in the latter cohort, indicating that this procedure successfully improved voice in unilateral vocal fold paralysis. Peak inspiratory flow decreased significantly as a consequence of this procedure (from 4.54 ± 1.68 l to 4.21 ± 1.26 l, p = 0.03, in pooled data of both cohorts), but no change occurred in the other variables of flow-volume spirometry, body-plethysmography and impulse oscillometry. Eight of the ten patients studied by acoustic analysis of breathing had wheezes after vocal fold medialization compared with only three patients before the procedure, and the numbers of wheezes per recorded inspirium and expirium increased significantly (from 0.02 to 0.42 and from 0.03 to 0.36; p = 0.028 and p = 0.043, respectively). In conclusion, unilateral vocal fold paralysis was observed to disturb forced breathing and also to cause some signs of disturbed tidal breathing. Findings of flow volume spirometry were consistent with variable extra-thoracic obstruction. Vocal fold medialization by autologous fascia injection improved the quality of the voice in patients with unilateral vocal fold paralysis, but also decreased peak inspiratory flow and induced wheezing during tidal breathing. However, these airflow changes did not appear to cause significant symptoms in patients.

Unusual Anisotropic Effects from 1,3-Dipolar Cycloadducts of 4-Azidomethyl Coumarins

4-Bromomethylcoumarins (1) reacted with sodium azide in aqueous acetone to give 4-azidomethyl-coumarins (2), which underwent 1,3-dipolar cycloaddition with acetylenic dipolarophiles to give triazoles (3). These triazoles (3) have been found to exhibit interesting variations in the chemical shifts of C-3-H and C-4-methylene protons. Protonation studies indicate that the shielding effect of the C-3-H of coumarin is due to pi-electrons of the triazole ring, further supported by diffraction and computational studies.

Decentralized sequential change detection using physical layer fusion

We study the problem of decentralized sequential change detection with conditionally independent observations. The sensors form a star topology with a central node called fusion center as the hub. The sensors transmit a simple function of their observations in an analog fashion over a wireless Gaussian multiple access channel and operate under either a power constraint or an energy constraint. Simulations demonstrate that the proposed techniques have lower detection delays when compared with existing schemes. Moreover we demonstrate that the energy-constrained formulation enables better use of the total available energy than a power-constrained formulation.

Primary Dislocation of the Patella : A Clinical Study

A total of 177 patients with primary dislocation of the patella (PDP) were admitted to two trauma centers in Helsinki, Finland during 1991 to 1992. The inclusion criteria were: 1. Acute (≤14 days old) first-time lateral dislocation of the patella. 2. No previous knee operations or major knee injuries. 3. No ligament injuries to be repaired. 4. No osteochondral fractures requiring fixation. 50 patients were excluded. 30 of these excluded patients would have met the inclusion criteria, 19 patients received treatment by consultants not involved in the study, 7 refused to participate and 4 had an erroneous randomization. 127 patients including, 82 females, were then randomized to have either tailor-made operative procedure (group O) or conservative treatment (group C). The aftercare was similar for both groups. The mean age of the patients was 20 (9-47) years. All patients were subjected to analysis of trauma history (starting position and knee movement during the dislocation), examination under anesthesia (EUA) and arthroscopy. 70 patients (52 females) were randomized by their odd year of birth to operative group O and 57 patients (30 females) by their even year of birth to conservative group C. The diagnosis of PDP was based on locked dislocation in 68 patients, on dislocatability in EUA in 47 patients, and on subluxation in EUA combined with typical intra-articular lesions in 12 patients. In group O, 63 patients had exploration of the injuries on the medial side of the knee and tailor made reconstruction added with lateral release in 54 cases. The medial injury was operated by suturing in 39 patients, by duplication in 18 patients and by additional augmentation of the medial patellofemoral ligament (MPFL) with adductor magnus tenodesis in 6 patients. 7 patients, without locking in trauma history and only subluxation in EUA had only lateral release for realignment. In adductor magnus tenodesis the proximal end of the distal tendinous part was rerouted to the upper medial border of the patella. In the conservative group C, the treatment was adjusted to the extent of patellar displacement in EUA. Patients with dislocation in EUA had 3 weeks’ immobilization with the knee in slight flexion. Mobilization was started with a soft patellar stabilizing orthosis (PSO) used for additional three weeks. The patients with subluxation in EUA wore an orthosis for six weeks. The aftercare was similar in group O. The outcome was similar in both groups. After an average of 25 (20-45) months´ follow-up, the subjective result was better in group C in respect of the mean Hughston VAS knee score (87 for group O and 90 for group C, p=0.04, visual analog scale), but similar in terms of the patient’s own overall opinion and the mean Lysholm II knee score. Recurrent instability episodes occurred in 18 patients in group O and in 20 patients in group C. After an average of 7 (6-9) years´ follow-up, the groups did not show statistical difference either in respect of the patient’s own overall opinion, or the mean Hughston VAS and Kujala knee scores. The proportions of stable patellae was 25/70 (36%) in group O and 17/57 (30%) in group O (p=0.5). In a multivariate risk analysis, there was a correlation between low Kujala score (<90) as dependent parameter and female gender (OR: 3.5; 95% CI: 1.4-9.0), and loose body on primary radiographs (OR: 4.1; 95% CI: 1.2-15). Recurrent instability correlated with young age at the time of PDP (OR: 0.9; 95% CI: 0.8-1.0/year). Girls with open tibial apophysis had the worst prognosis for instability (88%; 95% CI: 77-98). The most common mechanisms in trauma history of the patients were movement to flexion from a straight start (78%) and movement to extension from a well-bent start (8%). Spontaneous relocation of the patella had taken place in 13/39 of girls, in 11/21 of boys, in 26/42 of women and in 17/24 of men with skeletal maturity of the tibia. The dislocation in EUA was non-rotating in 96/126 patients followed by outward rotating dislocation in 14/126 patients. Operative treatment policy in PDP is not recommended. Locking tendency of the patella in PDP depended on the skeletal maturation. Recurrence rate after PDP was higher than expected.