34 research outputs found
How Much Sport is there in Sport Physiology? Practice and Ideas in the Stockholm School of Physiology at GCI, 1941â1969
Pheromone mating disruption of the pine sawfly Neodiprion sertifer : is the size of the treated area important?
Few attempts to control forest insects by means of pheromone mating disruption have been reported. The first such experiments with the European pine sawfly, Neodiprion sertifer (Hymenoptera: Diprionidae), resulted in nearly complete trap catch reduction, but no effects on population density or sex ratio were noted. Unmated females lay eggs, which develop into males only. Therefore, if mating disruption would be successful, a more male-biased sex ratio is expected the next generation. One possible explanation for the early results is that mated females disperse into the treated area, and thus obscure the effects of the treatment. In order to reduce the effect of such immigrating females, the treated area was increased in the experiment described here from the earlier used 0.5 â 4 ha to 25 ha. The acetate of erythro-3,7-dimethyl-2- pentadecanol was used for disruption and released from dispensers every 10 m. The influence on male orientation was monitored by pheromone traps, baited with the acetate of (2S,3S,7S)-3,7- dimethyl-2-pentadeanol and placed at 100 m interval along two perpendicular, 1500 m lines intersecting the treated area. The trap catch reduction was near 100% during the first month, but then declined to around 90% during the second month. Mating frequencies were checked by comparing the sex ratio of the next generation from within and outside the treatment area. No effect of the treatment on the sex ratio was detected, and the frequency of mated females could be assumed to be independent of treatment. Alternative hypotheses to explain the failure of pheromone mating disruption in N. sertifer are discussed
Tannin-iron impregnated thermomechanical pulp : Part II: Bleachability and brightness reversion
Tannins are polymeric, phenolic constituents found in the bark of pine and spruce. When reacting with iron ions, tannins form strongly coloured complexes. Thus, the presence of bark in the mechanical pulping process leads to decreased brightness of the pulp. In order to evaluate the effects of the presence of iron on the properties of pulp, we have impregnated thermomechanical pulp (TMP) with 30 parts per million (ppm i.e. mg/kg) iron either as Fe3+ or as tannin-iron complexes and studied how such treatments affect bleachability and heat-induced brightness reversion. The bleaching agents studied are hydrogen peroxide and sodium dithionite. Treatment of the tannin-iron impregnated pulp with 1% by weight of diethylenetriaminepentaacetic acid (DTPA) before bleaching with 4% hydrogen peroxide almost eliminated the brightness loss caused by the impregnation. Such a treatment also removed all of the added iron from both the tannin-iron and FeCl3 impregnated pulps. Approximately 5% more of the added peroxide was required for oxidation of the tannins in the tannin-iron impregnated pulp. Contrary to what was observed with peroxide bleaching, dithionite bleaching did not reduce the amount of iron in the pulps. Instead, the added iron and tannin-iron negatively affected the dithionite bleaching, even if the pulps were extracted with DTPA before bleaching. It should therefore be advantageous to first bleach with peroxide, which removes most of the iron, and then with dithionite. Compared with dithionite, peroxide yields a more efficient bleaching. The reason for this is that the former reduces the light absorption coefficient, the k-value, more efficiently in the whole visible spectrum, whereas dithionite reduces it mainly at shorter wavelengths. In our experiments, the addition of tannin-iron or FeCl3 to the untreated pulp did not increase heat-induced brightness reversion. This is Supported by the fact that although extraction of the samples with DTPA before bleaching lowered the iron content slightly, it-did not affect the brightness reversion. The initial brightness reversion of the dithionite bleached pulps was larger than that observed for the peroxide bleached pulps
Tannin-iron impregnated thermomechanical pulp : Part I: Effects of extractions and heat on brightness
Tannins are polyphenolic compounds found mainly in bark. When reacting with iron, they form strongly coloured complexes, which through contamination from the bark may induce a brightness decrease of mechanical pulps. Wood itself contains phenolic compounds, which can form coloured complexes with iron. We have investigated gallotannin as a model for metal-binding sites in the pulp. The behaviour of tannin-iron complexes in solution and in pulp has been studied. In aqueous solution, the tannin-iron complexes can be decolourised by the addition of diethylenetriaminepentaacetic acid (DTPA). The colour of the tannin-iron complexes was very pH-dependent. Thus in solution, these were decolourised at low pH and at high pH the spectral characteristics were changed substantially. We have studied the effects on brightness and heatinduced brightness loss of the impregnation of thermomechanical pulp (TMP) with 30 parts per million iron (ppm i.e. mg/kg) either as iron or tannin-iron as well as the possibility to decrease such effects by using various solvent extractions. The tannin-iron impregnation causes a decrease in ISO-brightness of approximately 3% and an increase in the light absorption coefficient (k) by approximately 2 m(2)/kg at the tannin-iron absorbance maximum. 565 run. These effects are approximately ten times higher than those observed for the Pulp only impregnated with iron. Extraction with 1% by weight of DTPA provides a way to reduce the brightness decrease induced by the tanniniron complexes and the observed decrease can be attributed to removal of iron from the pulp. Acid extraction was the most efficient way to reduce the iron content in the pulps and to decoulorise the tannin-iron impregnated pulp. However, after acid extraction of iron impregnated Pulps, new chromophores were evidently formed. Addition of the reducing agent, sulphite, to extractions had no effect on the iron removal or the brightness of the impregnated pulps. The heat-induced brightness loss is not influenced by the addition of tannin-iron or iron. The brightness loss caused by heat was lower for pulps extracted with DTPA
Captures of male European pine sawflies (Hymenoptera : Diprionidae) in pheromone-baited traps in Kentucky
Using sticky traps baited with (2S, 3S, 7S)-3,7-dimethyl-2-pentadecyl acetate, we assessed the seasonal and diurnal flight activity of the European pine sawfly, Neodiprion sertifer (Geoffrey), in Fayette, Madison, and Livingston counties in Kentucky. At each site, two replicates of individual sticky traps were baited and suspended about 1 m high and spaced at least 20 m apart. Trap catch was affected by site (P = 0.001). A total of 326 European pine sawfly males were captured at the Fayette Co. site during the period 18 September to 12 November, representing 7% of the season total. No males of this species were caught at the other sites. During peak flight activity (1 to 15 October), we monitored traps at 2.5-h intervals over 4 d to determine diurnal flight patterns. Flight activity began after 1100 h and ceased by 1830 h, and was significantly affected by time of day. European pine sawfly flight activity was greatest between 1330 and 1330 h. We captured over 5,200 male sawflies at all three sites, with peak activity occurring in May, July, September and October
Monitoring European pine sawfly population densities with pheromone traps in young pine plantations
Field trials utilizing pheromone traps were evaluated to develop a population monitoring and predicting system for the European pine sawfly (Neodiprion sertifer). Larval density was censused in a transect across each study site. Three traps per site were baited with 100ÎŒg of (2S,3S,7S)-3,7-dimethyl-2-pentadecyl (diprionyl) acetate. During a two-year period traps loaded with 1, 10 and 100 ÎŒg of diprionyl acetate were compared. Correlations and coefficients of determination between numbers of captured males and larvae of the same or successive generations were seldom high. Between-generation relationships were significant, when population density was increasing. Having years with increasing densities in a row, the present monitoring method might provide warning of an outbreak
Article sex pheromone of the introduced pine sawfly, diprion similis, revisited to define a useful monitoring lure : Deviating chiral composition and behavioural responses compared to earlier reports
Extracts of Diprion similis females contained about 15 ng of the sex pheromone precursor 3,7âdimethylpentadecanâ2âol per female. After derivatisation with (S)â2âacetoxypropanoyl chloride, we found that the major stereoisomer in the extract was (2S,3R,7R)â3,7âdimethylpentadecanâ2âol. Small amounts of other stereoisomers of 3,7âdimethylpentadecanâ2âol were also identified in the extract, namely 1% of (2R,3S,7S), 0.3% (2R,3R,7R) and 0.4% of (2R,3R,7S). An unknown fifth substance showed a very similar spectrum to 3,7âdimethylpentadecanâ2âol, both in SIM and full scan mode. None of the earlier suggested behavioural synergistic isomers ((2S,3S,7S), (2S,3S,7R) and (2S,3R,7S)) were detected in the extracts. In field tests in Ontario, Canada, the earlier identified main pheromone component, viz. the propanoate of (2S,3R,7R)â3,7âdimethylpentadecanâ2âol, was tested alone and in combination with other stereoisomers, earlier reported to be synergistic. No synergistic effects were detected and the threo fourâisomer blend was as attractive as the pure main compound. Thus, one of the few examples of a diprionid sawfly using more than one substance in its sex pheromone could not be confirmed. The results also suggest that monitoring programs can use the more easily synthesized threoâblend without losing efficiency. Furthermore, the study suggests that other diprionid pheromones may benefit from a reinvestigation, to clarify possible synergistic effects of stereoisomers
Field Response of Male Pine Sawflies, Neodiprion sertifer (Diprionidae), to Sex Pheromone Analogs in Japan and Sweden.
The pine sawfly Neodiprion sertifer (Geoffroy) uses the acetate or propionate of (2S,3S,7S)-3,7-dimethyl-2-pentadecanol (diprionol) as pheromone components, with the (2S,3R,7R)-isomer being antagonistic, synergistic, or inactive according to the population tested. In this study, we tested the attraction of males to the acetates of three analogs of diprionol, each missing one methyl group, viz. (2S,7S)-7-methyl-2-pentadecanol, (2S,6S)-2,6-dimethyl-1-tetradecanol, and (2S,3S)-3-methyl-2-pentadecanol. None of the analogs alone, or in combination with diprionol acetate, was attractive in Sweden, even at 100 times the amount of diprionol acetate attractive to N. sertifer. In Japan, the acetate of (2S,3S)-3-methyl-2-pentadecanol attracted males when tested in amounts 10-20 times higher than the acetate pheromone component. The acetate esters of the (2S,3R)-analog and the (2S,3R,7R)-isomer of diprionol also were tested in combination with the pheromone compound (acetate ester). Both compounds caused an almost total trap-catch reduction in Sweden, whereas in Japan they appear to have relatively little effect on trap capture when added to diprionol acetate. Butyrate and iso-butyrate esters of diprionol were unattractive to N. sertifer in Sweden. In summary, there exists geographic variation in N. sertifer in responses to both diprionyl acetate and some of its analogs
Sex pheromone of the pine sawfly Macrodiprion nemoralis (Hymenoptera : Diprionidae): Identification of (2S,3R,7R,9S)-3,7,9-trimethyl-2-tridecanol as the precursor for the active pheromone acetate
The main component of the sex pheromone precursor in females of Macrodiprion nemoralis was identified as a threo-3,7,9-trimethyl-2-tridecanol isomer, approximately 800 pg per female, by gas chromatography-mass spectrometry. Comparison of mass spectrometric ion chromatograms showed that the natural compound in the female extract has the same retention time and mass spectrum as one of the two synthetic three peaks. The acetate of the synthetic 16-isomer mixture caught a large number of males in the field. confirming the structure of the active pheromone. Comparison of gas chromatograms of the natural female extract with the eight synthetic three stereoisomers showed that the pheromone is the (2S,3R,7R,9S)-stereoisomer of 3,7,9-trimethyl-2-tridecyl acetate
Associations between lean maturity in primary care and musculoskeletal complaints among staff. A longitudinal study
Objective. We had two aims: 1) to determine the prevalence of musculoskeletal complaints among staff in primary care 2) to determine to what extent Lean maturity of the primary care unit can predict musculoskeletal complaints one year later. Design. Descriptive, correlational, and longitudinal design. Setting. Primary care units in mid-Sweden. Participants. In 2015, staff members responded to a web survey addressing Lean maturity and musculoskeletal complaints. The survey was completed by 481 staff members (response rate 46%) at 48 units; 260 staff members at 46 units also completed the survey in 2016. Outcome measures. Associations with musculoskeletal complaints were determined both for Lean maturity in total, and for four Lean domains entered separately in a multivariate model, i.e., Philosophy, Processes, People and partners, and Problem-solving.    Results. The shoulders (12-month prevalence 58%), neck (54%), and low back (50%) were the most common sites of 12-months retrospective musculoskeletal complaints at baseline. Shoulders, neck, and low back also showed the most complaints for the preceding 7 days (37%, 33%, and 25%, respectively). The prevalence of complaints was similar at the 1-year follow-up. Total lean maturity in 2015 was not associated with musculoskeletal complaints, neither cross-sectionally nor one year later, for shoulders (one-year ÎČ: -0.002, 95% CI -.03 to .02), neck (ÎČ: 0.006, 95% CI -.01 to .03), low back (ÎČ: 0.004, 95% CI -.02 to .03) and upper back (ÎČ: 0.002, 95% CI -.02; .02). Conclusion. The prevalence of musculoskeletal complaints among primary care staff was high and did not change within a year. The extent of Lean maturity at the care unit was not associated with complaints among staff, neither in cross-sectional analyses nor in a one-year predictive analysi