scholarly journals Testing the behaviour of Australian brushtail possums (Trichosurus vulpecula) to candidate semiochemicals from conspecifics’ urine

2021 ◽  
Author(s):  
◽  
Lauren Mockett

<p>The Australian brushtail possum (Trichosurus vulpecula) is a prolific introduced mammalian pest. Current pest control methods involve traps and poisons, but are proving to be ineffective long term solutions. As semiochemical lures are thought to be more attractive than food-based lures at low densities, researchers are attempting to utilize semiochemicals for kill traps. The objectives of this thesis were to create a testing protocol for use in a research colony of possums and use that protocol to test the attractiveness of semiochemicals found in possum urine that had been positively associated with possum attraction and interest in urine.. I hypothesised that there would be an observer effect present in the colony due to the nature of the colony husbandry protocols. There was no statistically significant observer effect present in the colony for eating, interaction, sitting, grooming or enclosure use (front or back). However, there was a trend (across the colony) that sitting and grooming increased in the presence of an observer. From these results, I designed an active presentation protocol for testing semiochemicals. I predicted that the most attractive compounds would belong to the acids and alcohol chemical groups. Overall there was no statistically significant difference between the semiochemicals. However, when taken individually there was clear evidence that five of the semiochemicals (belonging to the ketone, alcohol and phenol chemical groups) were more attractive than their control and the standard lure. It has been shown in this thesis that the attractiveness of semiochemicals can be tested in a small research colony. However, limits on colony size greatly reduce statistical power. For future studies, I would recommend increasing the sample size or instead developing field-based bioassays capable of being repeated across a greater number of sites, populations and therefore, individual possums.</p>

2021 ◽  
Author(s):  
◽  
Lauren Mockett

<p>The Australian brushtail possum (Trichosurus vulpecula) is a prolific introduced mammalian pest. Current pest control methods involve traps and poisons, but are proving to be ineffective long term solutions. As semiochemical lures are thought to be more attractive than food-based lures at low densities, researchers are attempting to utilize semiochemicals for kill traps. The objectives of this thesis were to create a testing protocol for use in a research colony of possums and use that protocol to test the attractiveness of semiochemicals found in possum urine that had been positively associated with possum attraction and interest in urine.. I hypothesised that there would be an observer effect present in the colony due to the nature of the colony husbandry protocols. There was no statistically significant observer effect present in the colony for eating, interaction, sitting, grooming or enclosure use (front or back). However, there was a trend (across the colony) that sitting and grooming increased in the presence of an observer. From these results, I designed an active presentation protocol for testing semiochemicals. I predicted that the most attractive compounds would belong to the acids and alcohol chemical groups. Overall there was no statistically significant difference between the semiochemicals. However, when taken individually there was clear evidence that five of the semiochemicals (belonging to the ketone, alcohol and phenol chemical groups) were more attractive than their control and the standard lure. It has been shown in this thesis that the attractiveness of semiochemicals can be tested in a small research colony. However, limits on colony size greatly reduce statistical power. For future studies, I would recommend increasing the sample size or instead developing field-based bioassays capable of being repeated across a greater number of sites, populations and therefore, individual possums.</p>


1974 ◽  
Vol 38 (1) ◽  
pp. 191-198 ◽  
Author(s):  
Constance Bowe-Anders ◽  
John H. Herman ◽  
Howard P. Roffwarg

This study was designed to examine the effects of long-term perceptual alterations in color and illumination, which have been associated with changes in dream content, on physiological parameters of sleep. Subsequent to a period of sleep standardization, 3 Ss slept 4 or 5 baseline nights in the lab immediately followed by 4 or 5 experimental nights. Sleep was monitored polygtaphically. During all waking time on the experimental days, Ss wore goggles equipped with No. 29 Wratten color filters which screen all light save the red band. Ss were required to continue normal daily routines The variables assessed were: total minutes of REM sleep (REMS) and of NREMS stages 1, 2 and 3/4; latencies to initial stage 3/4 and to REMS, and the intensity of REMS. No variable showed a statistically significant difference between baseline and goggle conditions in any single S or in the group. Statistical power analysis did not indicate that the failure to achieve significance could be meaningfully attributed to the number of Ss. We conclude that significant perceptual readjustments in terms of color, illumination and peripheral vision, though strongly affecting dream content, do not result in measurable changes in the basic physiological parameters of sleep.


2021 ◽  
Vol 14 (2) ◽  
pp. 6-21
Author(s):  
Javier Santa-Cruz ◽  
Patricia Peñaloza ◽  
Maria V. Korneykova ◽  
Alexander Neaman

Ecotoxicological studies of soil metal toxicity conventionally rely on the use of uncontaminated soils gradually enriched with metals in the form of soluble salts. Although this method is very useful in many ways, it is continually complicated by the difficulty of extrapolating laboratory results to actual field-collected soils exposed to decades of contamination. Although many studies emphasize the importance of using field-contaminated soils for toxicity bioassays, the number of studies actually conducted based on this premise is relatively small. This review provides an in-depth recompilation of data on metal toxicity thresholds in field-contaminated soils. We have summarized the EC10, EC25, and EC50 values for metals, i.e., values of metal concentrations that reduce the response of specific organisms by 10%, 25%, and 50% of the value in uncontaminated soils. In our summary, most studies show that total metal content can predict organismal responses as well as bioavailable fractions. These results are consistent with the intensity/capacity/quantity concept proposed for plant nutrient uptake. In addition, microorganisms are thought to be more sensitive to metals than plants and invertebrates. However, our analysis shows that there is no statistically significant difference between the sensitivity of microorganisms and other organisms (plants and invertebrates) to any metal or metal pool. We expect that this information will be useful for environmental assessment and soil quality decisions. Finally, we encourage future studies to analyze dose-effect relationships in native field-collected soils with varying degrees of metal contamination from long-term anthropogenic pollution.


2020 ◽  
Vol 42 (1) ◽  
pp. 67
Author(s):  
Hannah Anderson ◽  
Leonie E. Valentine ◽  
Giles E. St. J. Hardy ◽  
Patricia A. Fleming

Forest canopy loss due to plant pathogens, insect or abiotic factors significantly alters habitat and resource availability for animals, which has flow-on effects for whole ecosystems. The tuart (Eucalyptus gomphocephala) has been in decline throughout its geographic range; this is likely associated with watertable and salinity changes, although a plant pathogen (Phytophthora multivora) has also been implicated. We examined the relative abundance of common brushtail possums (Trichosurus vulpecula) across 12 sites (each 0.72 ha) selected on the basis of the health of dominant tuart trees (six ‘healthy’ and six ‘declining’ sites). Habitat variables (understorey, tuart dimensions and density, tree hollows, tree-to-trap distance) and tuart tree health (crown loss, epicormic regrowth) were compared with possum abundance. Possums were detected at most sites. There was no significant difference between brushtail possum numbers at ‘healthy’ or ‘declining’ sites, although marginally more possums were recorded at declining sites (5.7 ± 1.5 (s.e.), n = 6 sites) compared with healthy sites (3.3 ± 0.7; Cohen’s effect size d = 0.80). Slightly higher abundance of possums was associated with sites that had a greater density of smaller-diameter but taller tuart trees. ‘Declining’ sites, with more epicormic regrowth and greater tree densities, may provide more palatable food resources for possums.


2018 ◽  
Vol 28 (01) ◽  
pp. 034-038 ◽  
Author(s):  
Al Rasyid ◽  
Mohammad Kurniawan ◽  
Taufik Mesiano ◽  
Rakhmad Hidayat ◽  
Salim Harris

AbstractStroke is the leading cause of death and disability in the world as well as in Indonesia. Initial stroke severity is an important factor that affects short- and long-term stroke outcomes. This cross-sectional study was conducted in Cipto Mangunkusumo Hospital from July 2017 to January 2018 to investigate the factors that affect stroke severity. A total of 77 acute ischemic stroke patients were divided into three groups, which include low blood homocysteine levels (< 9 μmol/L), moderate blood homocysteine levels (9–15 μmol/L), and high blood homocysteine levels (> 15 μmol/L). The acquired data were analyzed using Kruskal–Wallis test and a significant difference of initial National Institute of Health Stroke Scale (NIHSS) and blood homocysteine levels (H = 13.328, p = 0.001) were seen, with a mean rank of 25.86 for low blood homocysteine levels, 33.69 for moderate blood homocysteine levels, and 48.94 for high blood homocysteine levels. The patients were then divided into two groups based on the NIHSS (≤5 and > 5) to calculate the risk correlation of blood homocysteine levels and NIHSS by using regression. We found that patients with high blood homocysteine levels had 14.4 times higher risk of having NIHSS > 5 compared with those with low blood homocysteine levels (p = 0.002, 95% confidence interval [CI] [2.714–76.407]), and 3.9 times higher risk compared with those with moderate blood homocysteine levels (p = 0.011, 95% CI [1.371–11.246]). We concluded that homocysteine is a risk factor for a higher stroke severity. Future studies to evaluate the usefulness of homocysteine-lowering therapy in stroke patients are recommended.


Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.


2020 ◽  
Vol 132 (5) ◽  
pp. 1405-1413 ◽  
Author(s):  
Michael D. Staudt ◽  
Holger Joswig ◽  
Gwynedd E. Pickett ◽  
Keith W. MacDougall ◽  
Andrew G. Parrent

OBJECTIVEThe prevalence of trigeminal neuralgia (TN) in patients with multiple sclerosis (MS-TN) is higher than in the general population (idiopathic TN [ITN]). Glycerol rhizotomy (GR) is a percutaneous lesioning surgery commonly performed for the treatment of medically refractory TN. While treatment for acute pain relief is excellent, long-term pain relief is poorer. The object of this study was to assess the efficacy of percutaneous retrogasserian GR for the treatment of MS-TN versus ITN.METHODSA retrospective chart review was performed, identifying 219 patients who had undergone 401 GR procedures from 1983 to 2018 at a single academic institution. All patients were diagnosed with medically refractory MS-TN (182 procedures) or ITN (219 procedures). The primary outcome measures of interest were immediate pain relief and time to pain recurrence following initial and repeat GR procedures. Secondary outcomes included medication usage and presence of periprocedural hypesthesia.RESULTSThe initial pain-free response rate was similar between groups (p = 0.726): MS-TN initial GR 89.6%; MS-TN repeat GR 91.9%; ITN initial GR 89.6%; ITN repeat GR 87.0%. The median time to recurrence after initial GR was similar between MS-TN (2.7 ± 1.3 years) and ITN (2.1 ± 0.6 years) patients (p = 0.87). However, there was a statistically significant difference in the time to recurrence after repeat GR between MS-TN (2.3 ± 0.5 years) and ITN patients (1.2 ± 0.2 years; p < 0.05). The presence of periprocedural hypesthesia was highly predictive of pain-free survival (p < 0.01).CONCLUSIONSPatients with MS-TN achieve meaningful pain relief following GR, with an efficacy comparable to that following GR in patients with ITN. Initial and subsequent GR procedures are equally efficacious.


2021 ◽  
Vol 4 (Supplement_1) ◽  
pp. 234-236
Author(s):  
P Willems ◽  
J Hercun ◽  
C Vincent ◽  
F Alvarez

Abstract Background The natural history of primary sclerosing cholangitis (PSC) in children seems to differ from PSC in adults. However, studies on this matter have been limited by short follow-up periods and inconsistent classification of patients with autoimmune cholangitis (AIC) (or overlap syndrome). Consequently, it remains unclear if long-term outcomes are affected by the clinical phenotype. Aims The aims of this is study are to describe the long-term evolution of PSC and AIC in a pediatric cohort with extension of follow-up into adulthood and to evaluate the influence of phenotype on clinical outcomes. Methods This is a retrospective study of patients with AIC or PSC followed at CHU-Sainte-Justine, a pediatric referral center in Montreal. All charts between January 1998 and December 2019 were reviewed. Patients were classified as either AIC (duct disease on cholangiography with histological features of autoimmune hepatitis) or PSC (large or small duct disease on cholangiography and/or histology). Extension of follow-up after the age of 18 was done for patients followed at the Centre hospitalier de l’Université de Montréal. Clinical features at diagnosis, response to treatment at one year and liver-related outcomes were compared. Results 40 patients (27 PSC and 13 AIC) were followed for a median time of 71 months (range 2 to 347), with 52.5% followed into adulthood. 70% (28/40) had associated inflammatory bowel disease (IBD) (78% PSC vs 54% AIC; p=0.15). A similar proportion of patients had biopsy-proven significant fibrosis at diagnosis (45% PSC vs 67% AIC; p=0.23). Baseline liver tests were similar in both groups. At diagnosis, all patients were treated with ursodeoxycholic acid. Significantly more patients with AIC (77% AIC vs 30 % PSC; p=0.005) were initially treated with immunosuppressive drugs, without a significant difference in the use of Anti-TNF agents (0% AIC vs 15% PSC; p= 0.12). At one year, 55% (15/27) of patients in the PSC group had normal liver tests versus only 15% (2/13) in the AIC group (p=0.02). During follow-up, more liver-related events (cholangitis, liver transplant and cirrhosis) were reported in the AIC group (HR=3.7 (95% CI: 1.4–10), p=0.01). Abnormal liver tests at one year were a strong predictor of liver-related events during follow-up (HR=8.9(95% CI: 1.2–67.4), p=0.03), while having IBD was not (HR=0.48 (95% CI: 0.15–1.5), p=0.22). 5 patients required liver transplantation with no difference between both groups (8% CAI vs 15% CSP; p=0.53). Conclusions Pediatric patients with AIC and PSC show, at onset, similar stage of liver disease with comparable clinical and biochemical characteristics. However, patients with AIC receive more often immunosuppressive therapy and treatment response is less frequent. AIC is associated with more liver-related events and abnormal liver tests at one year are predictor of bad outcomes. Funding Agencies None


2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
A Fung ◽  
A Ward ◽  
K Patel ◽  
M Krkovic

Abstract Introduction Infection is a major complication of open fractures. Antibiotic-impregnated calcium sulfate (AICS) beads are widely used as an adjuvant to systemic antibiotics. Whilst their efficacy in the secondary prevention of infection is established, we present the first retrospective study evaluating AICS beads in the primary prevention of infection in open fractures. Method 214 open femur and tibia fractures in 207 patients were reviewed over a seven-year period. 148 fractures received only systemic antibiotic prophylaxis. 66 fractures also received AICS beads. The occurrence of acute infection (wound infection and acute osteomyelitis) was recorded, as well as that of long-term complications (chronic osteomyelitis, non-union and death). Results Fractures that received AICS with systemic antibiotics had an overall acute infection rate of 42% (28/66), compared to 43% (63/148) in fractures that received only systemic antibiotics (p &gt; 0.05). There was no significant difference in infection rate even when fractures were stratified by Gustilo-Anderson grade. There was also no significant difference in the rate of long-term complications. Conclusions Our results indicate that the adjuvant use of AICS beads is not effective for the primary prevention of acute infection or long-term complications in open leg fractures. Further research is needed to elucidate the factors influencing the outcomes of AICS use.


2021 ◽  
Vol 7 (5) ◽  
pp. 369
Author(s):  
Joseph Cherabie ◽  
Patrick Mazi ◽  
Adriana M. Rauseo ◽  
Chapelle Ayres ◽  
Lindsey Larson ◽  
...  

Histoplasmosis is a common opportunistic infection in people with HIV (PWH); however, no study has looked at factors associated with the long-term mortality of histoplasmosis in PWH. We conducted a single-center retrospective study on the long-term mortality of PWH diagnosed with histoplasmosis between 2002 and 2017. Patients were categorized into three groups based on length of survival after diagnosis: early mortality (death < 90 days), late mortality (death ≥ 90 days), and long-term survivors. Patients diagnosed during or after 2008 were considered part of the modern antiretroviral therapy (ART) era. Insurance type (private vs. public) was a surrogate indicator of socioeconomic status. Out of 54 PWH infected with histoplasmosis, overall mortality was 37%; 14.8% early mortality and 22.2% late mortality. There was no statistically significant difference in survival based on the availability of modern ART (p = 0.60). Insurance status reached statistical significance with 38% of survivors having private insurance versus only 8% having private insurance in the late mortality group (p = 0.05). High mortality persists despite the advent of modern ART, implicating a contribution from social determinants of health, such as private insurance. Larger studies are needed to elucidate the role of these factors in the mortality of PWH.


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