The use of synthetic insecticides is one of the most common strategies for controlling disease vectors such as mosquitos. However, their overuse can result in serious risks to human health, to the ...environment, as well as to the selection of insecticidal resistant insect strains. The development of efficient and eco-friendly insect control is urgent, and essential oils have been presented as potential alternatives to synthetic insecticides. Moreover, nanoencapsulation techniques can enhance their efficiency by protecting from degradation and providing a controlled release rate.
We assessed the potential of chitosan nanoparticles in encapsulating Siparuna guianensis essential oil, and maintaining its efficiency and prolonging its activity for the control of Aedes aegypti larvae. The encapsulation was characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), with an encapsulation efficiency ranging from 84.8% to 88.0%. Toxicity studies have demonstrated efficacy against mosquito larvae over 50% for 19 days with 100% mortality during the first week. This persistent action is presumably due to the enhanced contact and slow and maintained release conferred by chitosan nanoparticles. Furthermore, the exposure of aquatic non-target organisms (e.g. embryos and small adult fishes) revealed adequate selectivity of these nanoparticles.
The encapsulation of S. guianensis essential oil in chitosan nanoparticles showed promising potential as a larvicide control alternative and should be considered within strategies for fighting Ae. aegypti.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Aim
Robotic techniques are being increasingly used in colorectal surgery. There is, however, a lack of training opportunities and structured training programmes. Robotic surgery has specific problems ...and challenges for trainers and trainees. Ergonomics, specific skills and user–machine interfaces are different from those in traditional laparoscopic surgery. The aim of this study was to establish expert consensus on the requirements for a robotic train‐the‐trainer curriculum amongst robotic surgeons and trainers.
Method
This is a modified Delphi‐type study involving 14 experts in robotic surgery teaching. A reiterating 19‐item questionnaire was sent out to the same group and agreement levels analysed. A consensus of 0.8 or higher was considered to be high‐level agreement.
Results
Response rates were 93–100% and most items reached high levels of agreement within three rounds. Specific requirements for a robotic faculty development curriculum included maximizing dual‐console teaching, theatre team training, nontechnical skills training, patient safety, user–machine interface training and telementoring.
Conclusion
A clear need for the development of a train‐the‐trainer curriculum has been identified. Further research is needed to assess feasibility, effectiveness and clinical impact of a robotic train‐the‐trainer curriculum.
Leptospira infection and shedding in cats in Thailand Sprißler, Fabienne; Jongwattanapisan, Prapaporn; Luengyosluechakul, Supol ...
Transboundary and emerging diseases,
March 2019, 2019-Mar, 2019-03-00, 20190301, Letnik:
66, Številka:
2
Journal Article
Recenzirano
In Thailand, leptospirosis is considered an emerging disease in humans and animals. Many species can shed pathogenic Leptospira, including domestic cats (felis catus), which might be able to pose a ...risk to humans. There are no studies on Leptospira infections in cats in Thailand, but in other countries, it was demonstrated that cats can shed pathogenic Leptospira with high prevalences. The aims of this study were to evaluate whether outdoor cats in Thailand shed pathogenic Leptospira in their urine, and to determine antibody prevalence and risk factors associated with Leptospira infection. Two hundred and sixty outdoor cats were prospectively recruited. Urine samples were tested by real‐time PCR targeting the lipL32 gene of pathogenic Leptospira. Urine was additionally cultured for 6 months in Ellinghausen‐McCullough‐Johnson‐Harris medium to grow Leptospira. Antibodies against 24 serovars (Anhoa, Australis, Autumnalis, Ballum, Bataviae, Bratislava, Broomi, Canicola, Celledoni, Copenhageni, Coxi, Cynopteri, Djasiman, Grippotyphosa, Haemolytica, Icterohaemorrhagiae, Khorat, Paidja, Patoc, Pomona, Pyrogenes, Rachmati, Saxkoebing, Sejroe) belonging to 16 serogroups were determined using microscopic agglutination tests. Risk factors were analysed by Fisher's exact test. Urine samples of 2/260 cats (0.8%; 95% confidence interval (CI): 0.1%–2.8%) were PCR‐positive, but none of the 260 urine samples were culture positive. Leptospira antibodies were detected in 14/260 cats (5.4%; 95% CI: 3.0%–8.6%) with titers ranging from 1:20 to 1:160 (serovars: Anhoa, Autumnalis, Celledoni, Copenhageni, Djasiman, Icterohaemorrhagiae, Patoc). Cats aged ≥4 years were significantly more often infected with Leptospira than younger cats. No other significant risk factors were found. In conclusion, outdoor cats in Thailand can shed DNA and, possibly, viable, pathogenic Leptospira in their urine, although at a much lower prevalence than expected when compared to countries with similar climate. Thus, cats can be a potential source of infection for people. Further studies are needed to determine the role of cats in transmitting this zoonotic disease in Thailand.
Central testing is used to select young bulls which are likely to contribute to increased net income of the commercial beef cattle herd. We present genetic parameters for growth and reproductive ...traits on performance-tested young bulls and commercial animals that are raised on pasture and in feedlots.
Records on young bulls and heifers in performance tests or commercial herds were used. Genetic parameters for growth and reproductive traits were estimated. Correlated responses for commercial animals when selection was applied on performance-tested young bulls were computed.
The 90% highest posterior density (HPD90) intervals for heritabilities of final weight (FW), average daily gain (ADG) and scrotal circumference (SC) ranged from 0.41 to 0.49, 0.23 to 0.30 and 0.47 to 0.57, respectively, for performance-tested young bulls on pasture, from 0.45 to 0.60, 0.20 to 0.32 and 0.56 to 0.70, respectively, for performance-tested young bulls in feedlots, from 0.29 to 0.33, 0.14 to 0.18 and 0.35 to 0.45, respectively, for commercial animals on pasture, and from 0.24 to 0.44, 0.13 to 0.24 and 0.35 to 0.57 respectively, for commercial animals in feedlots. The HPD90 intervals for genetic correlations of FW, ADG and SC in performance-tested young bulls on pasture (feedlots) with FW, ADG and SC in commercial animals on pasture (feedlots) ranged from 0.86 to 0.96 (0.83 to 0.94), 0.78 to 0.90 (0.40 to 0.79) and from 0.92 to 0.97 (0.50 to 0.83), respectively. Age at first calving was genetically related to ADG (HPD90 interval = -0.48 to -0.06) and SC (HPD90 interval = -0.41 to -0.05) for performance-tested young bulls on pasture, however it was not related to ADG (HPD90 interval = -0.29 to 0.10) and SC (HPD90 interval = -0.35 to 0.13) for performance-tested young bulls in feedlots.
Heritabilities for growth and SC are higher for performance-tested young bulls than for commercial animals. Evaluating and selecting for increased growth and SC on performance-tested young bulls is efficient to improve growth, SC and age at first calving in commercial animals. Evaluating and selecting performance-tested young bulls is more efficient for young bulls on pasture than in feedlots.
Growing energies of particles at modern or planned particle accelerator experiments as well as cosmic ray experiments require particle identification at gamma-factors (γ) of up to ∼105. At present ...there are no detectors capable of identifying charged particles with reliable efficiency in this range of γ. New developments in high granular pixel detectors allow one to perform simultaneous measurements of the energies and the emission angles of generated transition radiation (TR) X-rays and use the maximum available information to identify particles. First results of studies of TR energy-angular distributions using gallium arsenide (GaAs) sensors bonded to Timepix3 chips are presented. The results are compared with those obtained using a silicon (Si) sensor of the same thickness of 500 μm. The analysis techniques used for these experiments are discussed.
The objective was to use various nonlinear models to describe scrotal circumference (SC) growth in Guzerat bulls on three farms in the state of Minas Gerais, Brazil. The nonlinear models were: Brody, ...Logistic, Gompertz, Richards, Von Bertalanffy, and Tanaka, where parameter A is the estimated testis size at maturity, B is the integration constant, k is a maturating index and, for the Richards and Tanaka models, m determines the inflection point. In Tanaka, A is an indefinite size of the testis, and B and k adjust the shape and inclination of the curve. A total of 7410 SC records were obtained every 3 months from 1034 bulls with ages varying between 2 and 69 months (<240 days of age = 159; 241–365 days = 451; 366–550 days = 1443; 551–730 days = 1705; and >731 days = 3652 SC measurements). Goodness of fit was evaluated by coefficients of determination (R2), error sum of squares, average prediction error (APE), and mean absolute deviation. The Richards model did not reach the convergence criterion. The R2 were similar for all models (0.68–0.69). The error sum of squares was lowest for the Tanaka model. All models fit the SC data poorly in the early and late periods. Logistic was the model which best estimated SC in the early phase (based on APE and mean absolute deviation). The Tanaka and Logistic models had the lowest APE between 300 and 1600 days of age. The Logistic model was chosen for analysis of the environmental influence on parameters A and k. Based on absolute growth rate, SC increased from 0.019 cm/d, peaking at 0.025 cm/d between 318 and 435 days of age. Farm, year, and season of birth significantly affected size of adult SC and SC growth rate. An increase in SC adult size (parameter A) was accompanied by decreased SC growth rate (parameter k). In conclusion, SC growth in Guzerat bulls was characterized by an accelerated growth phase, followed by decreased growth; this was best represented by the Logistic model. The inflection point occurred at approximately 376 days of age (mean SC of 17.9 cm). We inferred that early selection of testicular size might result in smaller testes at maturity.
Dead layer on silicon p–i–n diode charged-particle detectors Wall, B.L.; Amsbaugh, J.F.; Beglarian, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2014, Letnik:
744
Journal Article
Recenzirano
Odprti dostop
Semiconductor detectors in general have a dead layer at their surfaces that is either a result of natural or induced passivation, or is formed during the process of making a contact. Charged ...particles passing through this region produce ionization that is incompletely collected and recorded, which leads to departures from the ideal in both energy deposition and resolution. The silicon p-i-n diode used in the KATRIN neutrino-mass experiment has such a dead layer. We have constructed a detailed Monte Carlo model for the passage of electrons from vacuum into a silicon detector, and compared the measured energy spectra to the predicted ones for a range of energies from 12 to 20 keV. The comparison provides experimental evidence that a substantial fraction of the ionization produced in the "dead" layer evidently escapes by diffusion, with 46% being collected in the depletion zone and the balance being neutralized at the contact or by bulk recombination. The most elementary model of a thinner dead layer from which no charge is collected is strongly disfavored.
New developments of pixel detectors based on GaAs sensors offer effective registration of the transition radiation (TR) X-rays and perform simultaneous measurements of their energies and emission ...angles. This unique feature opens new possibilities for particle identification on the basis of maximum available information about generated TR photons. Results of studies of TR energy-angular distributions using a 500 |j.m thick GaAs sensor attached to a Timepix3 chip are presented. Measurements, analysis techniques and a comparison with Monte Carlo (MC) simulations are described and discussed.
The objectives of the present study were to obtain posterior densities of genetic parameters for scrotal circumference (SC), testicular volume (TV), BW, and age at puberty, to determine their ...correlations, and to evaluate the inclusion of these traits as selection criteria for sexual precocity in Guzerat bulls. Two-trait analyses were performed including records of SC, TV, and BW at 365, 450, 550, 650, 730, 850, and 970 d of age with age at puberty of 1,783 Guzerat bulls born between 2000 and 2011. The (co)variance components were estimated using Bayesian methods. Posterior means of heritability ranged from 0.45 to 0.60 for SC, from 0.35 to 0.55 for TV, and from 0.39 to 0.60 for BW. Posterior means of heritabilities for age at puberty using the two-trait analysis with SC ranged from 0.46 to 0.55, those with TV ranged from 0.49 to 0.57, and those with BW ranged from 0.49 to 0.62. The genetic correlation between age at puberty and SC ranged from -0.52 to -0.85, those between age at puberty and TV ranged from -0.33 to -0.66, and those between age at puberty and BW ranged from -0.38 to -0.72. In general, the same trend was observed for the phenotypic correlation between age at puberty and SC, TV, and BW. The selection of the top 10% of young males for SC, TV, or BW caused a decrease in age at puberty, with the most favorable expected correlated response in age at puberty at 650 d of age (-119.95 ± 15.1 d per generation), 730 d of age (-82.20 ± 20.9), and 850 d of age (-93.68 ± 21.5), respectively. In conclusion, SC, TV, and BW can be used as selection criteria to improve early sexual development in Guzerat bulls, and SC measured at 650 d of age is the most advantageous indicative selection criterion for improvement of age at puberty in Guzerat young bulls.
Bilirubin, a byproduct of hemoglobin breakdown and purported anti-oxidant, is thought to be cancer preventive. We conducted complementary serological and Mendelian randomization (MR) analyses to ...investigate whether alterations in circulating levels of bilirubin are associated with risk of colorectal cancer (CRC). We decided a priori to perform analyses separately in men and women based on suggestive evidence that associations may differ by sex.
In a case-control study nested in the European Prospective Investigation into Cancer and Nutrition (EPIC), pre-diagnostic unconjugated bilirubin (UCB, the main component of total bilirubin) concentrations were measured by high-performance liquid chromatography in plasma samples of 1386 CRC cases and their individually matched controls. Additionally, 115 single-nucleotide polymorphisms (SNPs) robustly associated (P < 5 × 10
) with circulating total bilirubin were instrumented in a 2-sample MR to test for a potential causal effect of bilirubin on CRC risk in 52,775 CRC cases and 45,940 matched controls in the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO), the Colon Cancer Family Registry (CCFR), and the Colorectal Transdisciplinary (CORECT) study.
The associations between circulating UCB levels and CRC risk differed by sex (P
= 0.008). Among men, higher levels of UCB were positively associated with CRC risk (odds ratio OR = 1.19, 95% confidence interval CI = 1.04-1.36; per 1-SD increment of log-UCB). In women, an inverse association was observed (OR = 0.86 (0.76-0.97)). In the MR analysis of the main UGT1A1 SNP (rs6431625), genetically predicted higher levels of total bilirubin were associated with a 7% increase in CRC risk in men (OR = 1.07 (1.02-1.12); P = 0.006; per 1-SD increment of total bilirubin), while there was no association in women (OR = 1.01 (0.96-1.06); P = 0.73). Raised bilirubin levels, predicted by instrumental variables excluding rs6431625, were suggestive of an inverse association with CRC in men, but not in women. These differences by sex did not reach formal statistical significance (P
≥ 0.2).
Additional insight into the relationship between circulating bilirubin and CRC is needed in order to conclude on a potential causal role of bilirubin in CRC development.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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