Pseudotrypanosoma elphinstonae sp n., a trichomonad symbiotic in Schedorhinotermes (Isoptera : Rhinotermitidae)

A new species of Pseudotrypanosoma, P. elphinstonae sp. n., is described which is symbiotic within the hindguts of the rhinotermitid termites Schedorhinotermes secundus and S. intermedius. P. elphinstonae possesses most of the features of the genus: 4 anterior flagella, prominent costa and recurrent flagellum forming an undulating membrane and simple bean-shaped parabasal body. The mastigont complex is of similar composition and arrangement to other trichomonads but the pelto-axostylar complex is greatly simplified being composed of a single layer of microtubules which do not over lap and cannot be distinguished into separate structures. The undulating membrane is much smaller than in related species; the costa is smaller and simpler and there are no microtubular bundles connecting it to the recurrent flagellum. Comparison of the ultrastructure of P. elphinstonae sp. n. with that of P. giganteum demonstrated that P. elphinstonae sp. n. in addition to being much smaller in size had a correspondingly simper ultrastructural organisation lacking several organelles which characterise the latter species.

Experimental human infection with the dog hookworm, Ancylostoma caninum

Objective: To investigate possible routes for human infection by the dog hookworm (Ancylostoma caninum). Design, setting and participant. Relatively small numbers of infective larvae were administered orally and percutaneously to an informed healthy volunteer (J K L) under medical supervision, at intervals between May 1998 and May 1999. Main outcome measures: Symptoms; weekly blood eosinophil counts; faecal microscopy. Results: A marked blood eosinophilia followed a single oral exposure to 100 infective larvae, while faecal examination remained negative. Eosinophil counts then declined gradually, although a rapid, spontaneous rise several months later, at the beginning of spring, possibly indicated reactivation of dormant larvae. Blood eosinophil numbers did not rise significantly after percutaneous infection with 200 larvae. A subsequent, smaller, oral inoculum of 20 larvae provoked an eosinophil response similar to that of the first experiment. Conclusions: Our findings suggest that, following ingestion, some infective larvae of A. caninum develop directly into adult worms in the human gut (as they do in dogs). While the percutaneous route might be the most common means of human exposure to canine hookworm larvae, leading generally to subclinical infection, oral infection may be more likely to provoke symptomatic eosinophilic enteritis.

Effect of changing data collection parameters on statistical motor unit number estimates

The effect of number of samples and selection of data for analysis on the calculation of surface motor unit potential (SMUP) size in the statistical method of motor unit number estimates (MUNE) was determined in 10 normal subjects and 10 with amyotrophic lateral sclerosis (ALS). We recorded 500 sequential compound muscle action potentials (CMAPs) at three different stable stimulus intensities (10–50% of maximal CMAP). Estimated mean SMUP sizes were calculated using Poisson statistical assumptions from the variance of 500 sequential CMAP obtained at each stimulus intensity. The results with the 500 data points were compared with smaller subsets from the same data set. The results using a range of 50–80% of the 500 data points were compared with the full 500. The effect of restricting analysis to data between 5–20% of the CMAP and to standard deviation limits was also assessed. No differences in mean SMUP size were found with stimulus intensity or use of different ranges of data. Consistency was improved with a greater sample number. Data within 5% of CMAP size gave both increased consistency and reduced mean SMUP size in many subjects, but excluded valid responses present at that stimulus intensity. These changes were more prominent in ALS patients in whom the presence of isolated SMUP responses was a striking difference from normal subjects. Noise, spurious data, and large SMUP limited the Poisson assumptions. When these factors are considered, consistent statistical MUNE can be calculated from a continuous sequence of data points. A 2 to 2.5 SD or 10% window are reasonable methods of limiting data for analysis. Muscle Nerve 27: 320–331, 2003

Movements of the ricefield rat, Rattus argentiventer, near a trap-barrier system in rice crops in West Java, Indonesia

The movements of the ricefield rats (Rattus argentiventer) near a trap-barrier system (TBS) were assessed in lowland flood-irrigated rice crops in West Java, Indonesia, to test the hypothesis that a TBS with a 'trap-crop' modifies the movements of rats within 200 m from the trap-crop. The home range use and locations of rat burrows were assessed using radiotelemetry at two sites, one with a TBS with trap-crop (Treatment site, the crop inside the fence was planted 3 weeks earlier than the surrounding crop) and the other with a TBS without trap-crop (Control site, the crop inside the fence was planted at the same time as the surrounding crop). Each TBS was a 50 x 50 m plastic fence with eight multiple-capture rat traps set at the base. More than 700 rats were caught in the TBS with trap-crop, whereas only 10 rats were caught in the TBS without trap-crop. The home range size of females was significantly smaller at the Treatment site (0.96 ha) than the Control site (2.99 ha), but there was no difference for males. Seventy-eight per cent of rats caught in the TBS and fitted with radiocollars had their daytime burrow locations within 200 m of the TBS. We could not determine if the rats caught in the TBS were residents or transients according to demographic parameters. Our results support the hypothesis that a TBS with a trap-crop protects the surrounding rice crop out to a distance of at least 200 m.

The blood volumes of the primary and secondary circulatory system in the Atlantic cod Gadus morhua L., using plasma bound Evans Blue and compartmental analysis

The volume of the primary (PCS) and secondary (SCS) circulatory system in the Atlantic cod Gadus morhua was determined using a modified dye dilution technique. Cod (N=10) were chronically cannulated in the second afferent branchial artery with PE-50 tubing. Evans Blue dye was bound to harvested fish plasma at a concentration of 1 mg dye ml(-1) plasma, and injected at a concentration of 1 mg kg(-1) body mass. Serial sampling from the cannula produced a dye dilution curve, which could be described by a double exponential decay equation. Curve analysis enabled the calculation of the primary circulatory and total distribution volume. The difference between these volumes is assumed to be the volume of the SCS. From the dilution curve, it was also possible to calculate flow rates between and within the systems. The results of these experiments suggest a plasma volume in the PCS of 3.42+/-0.89 ml 100 g(-1) body mass, and in the SCS of 1.68+/-0.35 ml 100 g(-1) body mass (mean +/- S.D.) or approximately 50% that of the PCS. Flow rates to the SCS were calculated as 2.7% of the resting cardiac output. There was an allometric relationship between body mass and blood volumes. Increasing condition factor showed a tendency towards smaller blood volumes of the PCS, expressed as percentage body mass, but this was not evident for the volume of the SCS.

Determination of the effect of lipophilicity on the in vitro permeability and tissue reservoir characteristics of topically applied solutes in human skin layers

In order to establish the relationship between solute lipophilicity and skin penetration (including flux and concentration behavior), we examined the in vitro penetration and membrane concentration of a series of homologous alcohols (C2-C10) applied topically in aqueous solutions to human epidermal, full-thickness, and dermal membranes. The partitioning/distribution of each alcohol between the donor solution, stratum corneum, viable epidermis, dermis, and receptor phase compartments was determined during the penetration process and separately to isolated samples of each tissue type. Maximum flux and permeability coefficients are compared for each membrane and estimates of alcohol diffusivity are made based on flux/concentration data and also the related tissue resistance (the reciprocal of permeability coefficient) for each membrane type. The permeability coefficient increased with increasing lipophilicity to alcohol C8 (octanol) with no further increase for C10 (decanol). Log vehicle:stratum corneum partition coefficients were related to logP , and the concentration of alcohols in each of the tissue layers appeared to increase with lipophilicity. No difference was measured in the diffusivity of smaller more polar alcohols in the three membranes; however, the larger more lipophilic solutes showed slower diffusivity values. The study showed that the dermis may be a much more lipophilic environment than originally believed and that distribution of smaller nonionized solutes into local tissues below a site of topical application may be estimated based on knowledge of their lipophilicity alone.

Voluntary disclosure of forward-looking earnings forecasts in Australia

This study examines the voluntary disclosure of future earnings information in annual reports for Australian listed companies. We find that most Australian companies in our sample do not provide quantitative earnings, forecasts in their annual reports, although more than half of the sample do disclose forward-looking information relating to earnings, without specifically disclosing point estimates for the future. These companies mostly supply qualitative information with a positive bias, while the remainder of the sample discloses no forward-looking information relating to earnings. Our findings also suggest that larger companies with less volatile earnings tend to provide more future earnings information than smaller companies with relatively volatile earnings.

An investigation of magnetic antennas for ground penetrating radar

For ground penetrating radar (GPR), smaller antennas would provide considerable practical advantages. Some of which are: portability; ease of use; and higher spatial sampling. A theoretical comparison of the fundamental limits of a small electric field antenna and a small magnetic field antenna shows that the minimum Q constraints are identical. Furthermore, it is shown that only the small magnetic loop antenna can be constructed to approach, arbitrarily closely, the fundamental minimum Q limit. This is achieved with the addition of a high permeability material which reduces energy stored in the magnetic fields. This is of special interest to some GPR applications. For example, applications requiring synthetic aperture data collection would benefit from the increased spatial sampling offered by electrically smaller antennas. Low frequency applications may also benefit, in terms of reduced antenna dimensions, by the use of electrically small antennas. Under these circumstances, a magnetic type antenna should be considered in preference to the typical electric field antenna. Numerical modeling data supports this assertion.

Quadriceps activation in closed and in open kinetic chain exercise

Purpose: For treatment of various knee disorders, muscles are trained in open or closed kinetic chain tasks. Coordination between the heads of the quadriceps muscle is important for stability and optimal joint loading for both the tibiofemoral and the patellofemoral joint. The aim of this study was to examine whether the quadriceps femoris muscles are activated differently in open versus closed kinetic chain tasks. Methods: Ten healthy men and women (mean age 28.5 +/- 0.7) extended the knees isometrically in open and closed kinetic chain tasks in a reaction time paradigm using moderate force. Surface electromyography (EMG) recordings were made from four different parts of the quadriceps muscle. The onset and amplitude of EMG and force data were measured. Results: In closed chain knee extension, the onset of EMG activity of the four different muscle portions of the quadriceps was more simultaneous than in the open chain. In open chain, rectus femoris (RF) had the earliest EMG onset while vastus medialis obliquus was activated last (7 +/- 13 ms after RF EMG onset) and with smaller amplitude (40 +/- 30% of maximal voluntary contraction (MVC)) than in closed chain (46 +/- 43% MVC). Conclusions: Exercise in closed kinetic chain promotes more balanced initial quadriceps activation than does exercise in open kinetic chain. This may be of importance in designing training programs aimed toward control of the patellofemoral joint.

Direct electrochemistry of a bacterial sulfite dehydrogenase

Sulfite dehydrogenase from Starkeya novella is an alphabeta heterodimer comprising a 40.6 kDa subunit (containing the Mo cofactor) and a smaller 8.8 kDa heme c subunit. The enzyme catalyses the oxidation of sulfite to sulfate with the natural electron acceptor being cytochrome c(550). Its catalytic mechanism is thought to resemble that found in eukaryotic sulfite oxiclases. Using protein film voltammetry and redox potentiometry, we have identified both Mo- and heme-centered redox responses from the enzyme immobilized on a pyrolytic graphite working electrode: E-m,E-8 (Fe-III/II) +177 mV; E-m,E-8 (Mo-VI/V) +211 mV and E(m,)8 (Mo-V/IV) -118 mV vs NHE; Upon addition of sulfite to the electrochemical cell a steady-state voltammogram is observed and an apparent Michaelis constant (K-m) of 26(l) muM was determined for the enzyme immobilized on the working electrode surface, which is comparable with the value obtained from solution assays.

Ocular scanning and perceptual size distortion in hemispatial neglect: effects of prism adaptation and sequential stimulus presentation

When asked to compare two lateralized shapes for horizontal size, neglect patients often indicate the left stimulus to be smaller. Gainotti and Tiacci (1971) hypothesized that this phenomenon might be related to a rightward bias in the patients' gaze. This study aimed to assess the relation between this size underestimation and oculomotor asymmetries. Eye movements were recorded while three neglect patients judged the horizontal extent of two rectangles. Two experimental manipulations were performed to increase the likelihood of symmetrical scanning of the stimulus display. The first manipulation entailed a sequential, rather than simultaneous presentation of the two rectangles. The second required adaptation to rightward displacing prisms, which is known to reduce many manifestations of neglect. All patients consistently underestimated the left rectangle, but the pattern of verbal responses and eye movements suggested different underlying causes. These include a distortion of space perception without ocular asymmetry, a failure to view the full leftward extent of the left stimulus, and a high-level response bias. Sequential presentation of the rectangles and prism adaptation reduced ocular asymmetries without affecting size underestimation. Overall, the results suggest that leftward size underestimation in neglect can arise for a number of different reasons. Incomplete leftward scanning may perhaps be sufficient to induce perceptual size distortion, but it is not a necessary prerequisite.

Water table waves in an unconfined aquifer: Experiments and modeling

[1] Comprehensive measurements are presented of the piezometric head in an unconfined aquifer during steady, simple harmonic oscillations driven by a hydrostatic clear water reservoir through a vertical interface. The results are analyzed and used to test existing hydrostatic and nonhydrostatic, small-amplitude theories along with capillary fringe effects. As expected, the amplitude of the water table wave decays exponentially. However, the decay rates and phase lags indicate the influence of both vertical flow and capillary effects. The capillary effects are reconciled with observations of water table oscillations in a sand column with the same sand. The effects of vertical flows and the corresponding nonhydrostatic pressure are reasonably well described by small-amplitude theory for water table waves in finite depth aquifers. That includes the oscillation amplitudes being greater at the bottom than at the top and the phase lead of the bottom compared with the top. The main problems with respect to interpreting the measurements through existing theory relate to the complicated boundary condition at the interface between the driving head reservoir and the aquifer. That is, the small-amplitude, finite depth expansion solution, which matches a hydrostatic boundary condition between the bottom and the mean driving head level, is unrealistic with respect to the pressure variation above this level. Hence it cannot describe the finer details of the multiple mode behavior close to the driving head boundary. The mean water table height initially increases with distance from the forcing boundary but then decreases again, and its asymptotic value is considerably smaller than that previously predicted for finite depth aquifers without capillary effects. Just as the mean water table over-height is smaller than predicted by capillarity-free shallow aquifer models, so is the amplitude of the second harmonic. In fact, there is no indication of extra second harmonics ( in addition to that contained in the driving head) being generated at the interface or in the interior.

Growth of papaya nodal and rooted shoot cultures as affected by ACC, STS, culture vessel size and incubation conditions

Nodal shoot cultures of 'Clone 003', a selected Australian papaya cultivar, were cultured on modified De Fossard medium supplemented with chemicals that either promote ethylene evolution or inhibit action while in culture. Nodal shoot cultures grown in the presence of 1-aminocyclopropane carboxylic acid (ACC, 1.0 mM) resulted in a significant reduction in percent fresh and dry weights, shoot length, leaf area, petiole length and chlorophyll content, but leaf development was significantly increased. In contrast, nodal cultures grown in the presence of silver thiosulphate (STS, 0.5 mM) significantly produced the highest percentage of fresh and dry weights, shoot length, leaf production, leaf area expansion, petiole length and leaf chlorophyll content. Nodal cultures and rooted whole plantlets placed in medium-sized (125 mL) culture vessels had significantly better growth than those cultures placed in small (70 mL) or in large (250 mL) vessels. Cultures grown in medium-sized vessels had higher fresh and dry weights, longer shoots, more leaves and larger leaf area than those cultures placed in smaller or larger vessels. Similarly, values for said growth parameters and for chlorophyll content of the nodal and rooted whole plantlets were higher when they were incubated under high light intensity of 120 mumol m(-2)s(-1) at a prevailing temperature of either 20+/-1 C or 25+/-1 C.

Trends in physical activity participation and the impact of integrated campaigns among Australian adults, 1997-99

Objectives: To determine whether awareness of the moderate physical activity message and prevalence of participation changed among Australian adults between 1997 and 1999, and if changes differed across Australia. Methods: Data were compared on awareness of the moderate physical activity message and on physical activity participation from identical national physical activity surveys in 1997 and 1999. Results: In 1999, following integrated public health efforts, recognition of the Active Australia campaign was substantially higher in NSW/ACT (61.7%) than elsewhere (29.3%). Knowledge about benefits of moderate activity increased between 1997 and 1999, more so in States with public health campaigns. National participation in 'sufficient physical activity' declined between 1997 and 1999, from 63% to 57%, but the decline was smaller in NSW/ACT (4.4%) than in the other States (6.0%). Conclusions and implications: Declining trends in physical activity in Australia require increased public health investments, including strategic planning and public education, such as occurred in NSW (1997/98).

In search of the ultimate ionosonde deduced equator

A further progress has been made in defining the ionosonde deduced equator (IDE) which characterises a latitudinal transition from the northern to southern hemisphere. It is now possible to define the global IDE location as the locus of the average position between geographic and geomagnetic equators. A more complete insight to the phenomenon of the third equator (i.e. after geographic and geomagnetic equators) was made possible due to availability of ionospheric height (h'F) data from three stations positioned close to the IDE in the American and the far-east sectors. The IDE ionospheric signature (or E-type signature), detected at these stations, consists of bi-annual h'F height increases. This signature however is not consistently observed during solar cycle and at times, particularly at sunspot minimum, a weak hemispheric signature is observed (i.e. the northern or southern hemisphere signature). In general, the height increase at the IDE are considerably smaller (by a factor of 4) than at other equatorial locations, indicating that the ionosphere at the IDE location becomes less disturbed. It is suggested that the equatorial longitudinal regions which can be associated with more consistent E-type signature are located in the central Pacific and at the east coast of America, close to the intersection points of the geographic and geomagnetic equators. (C) 2003 Elsevier Ltd. All rights reserved.