Drosophila olfactory receptors as classifiers for volatiles from disparate real world applications

Olfactory receptors evolved to provide animals with ecologically and behaviourally relevant information. The resulting extreme sensitivity and discrimination has proven useful to humans, who have therefore co-opted some animals' sense of smell. One aim of machine olfaction research is to replace the use of animal noses and one avenue of such research aims to incorporate olfactory receptors into artificial noses. Here, we investigate how well the olfactory receptors of the fruit fly, Drosophila melanogaster, perform in classifying volatile odourants that they would not normally encounter. We collected a large number of in vivo recordings from individual Drosophila olfactory receptor neurons in response to an ecologically relevant set of 36 chemicals related to wine ('wine set') and an ecologically irrelevant set of 35 chemicals related to chemical hazards ('industrial set'), each chemical at a single concentration. Resampled response sets were used to classify the chemicals against all others within each set, using a standard linear support vector machine classifier and a wrapper approach. Drosophila receptors appear highly capable of distinguishing chemicals that they have not evolved to process. In contrast to previous work with metal oxide sensors, Drosophila receptors achieved the best recognition accuracy if the outputs of all 20 receptor types were used

Fractional flow reserve in below the knee arteries with critical limb ischemia and validation against gold-standard morphologic, functional measures and long term clinical outcomes.

INTRODUCTION: The aim of this study was to assess the applicability of fractional flow reserve measurement (FFR) in below-the-knee (BTK) arteries and to evaluate its correlation with non-invasive functional parameters before and after angioplasty. METHODS: We enrolled 39 patients with severe BTK arterial lesions. Inclusion criteria were critical limb ischemia (Rutherford 4-6) and angiographically proven arterial stenosis of the distal lower limb (percent diameter stenosis >/=70%). Exclusion criteria were chronic total occlusion, diabetic foot syndrome and non-viable distal lower limb. The transstenotic distal/proximal pressure ratio was measured under resting (Pd/Pa) and hyperemic (FFR) conditions induced by 40mg intra-arterial Papaverin and was compared with quantitative angiography-, laser Doppler- and duplex ultrasound-derived measurements before and after percutaneous angioplasty (PTA). RESULTS: Comparing measurements before and after PTA, we found significant improvements in the resting Pd/Pa values (0.79 [0.67-0.90] vs 0.90 [0.85-0.97]; p<0.001) and FFR values (0.60+/-0.19 vs 0.76+/-0.15; p<0.001), respectively. At baseline, Pd/Pa ratio and FFR were significantly albeit weakly correlated with % area stenosis (r:-0.31, p=0.05 and r:-0.31, p=0.05, respectively). After PTA, neither Pd/Pa nor FFR remained correlated with % area stenosis. Similarly, prior PTA, Pd/Pa ratio and FFR were significantly correlated with TcO2% and perfusion unit change (r:0.48, p<0.01 and r:0.34, p<0.05, respectively), but after intervention, these significant correlations vanished. Pd/Pa and FFR values did not show correlation with duplex ultrasound-derived measurements. At 1year, major adverse events (MAEs) and major adverse cardiovascular and cerebrovascular (MACCEs) were observed in 7 (17.9%) and in 9 (23.1%) patients, respectively. CONCLUSION: CLI due to severe BTK arterial disease was associated with several impediments of baseline pressure measurements which were significantly improved after successful PTA and stenting. Significant relationships between pressure data and functional and imaging parameters existed prior intervention but vanished after. Further studies are required to determine the clinical value of pre- and post-PTA pressure measurements in BTK arterial disease

Exploring the speed limits of liqui chromatography using shear-driven flows through 45 and 85 nm deep nano-channels

We explored the possibility to perform high speed and high efficiency liquid chromatographic separations in channels with a sub-100 nm depth. The mobile phase flow through these nano-channels was generated using the shear-driven flow principle to generate high speed flows which were the equivalent of a 12000 bar pressure-driven flow. It was found that the ultra-fast mass transfer kinetics prevailing in this range of small channel depths allow to drastically reduce the C-term contribution to band broadening, at least up to the upper speed limit of our current set-up (7 mm s−1 mobile phase velocity), leaving the inescapable molecular diffusion (i.e., B-term band broadening) as the sole detectable source of band broadening. Due to the greatly reduced mass transfer limitations, 50000 to 100000 theoretical plates could be generated in the span of 1 to 1.5 seconds. This is nearly two orders of magnitude faster than the best performing commercial pressure-driven UHPLC-systems. With the employed channel depths, we appear to have struck a practical lower limit for the channel miniaturization of shear-driven flows. Despite the use of channel substrates with the highest grades of optical flatness, the overall substrate waviness (on the order of some 5 to 10 nm) can no longer be neglected compared to the etched channel depth, which in turn significantly influenced the local retention factor and band broadening

Influence of contrast media dose and osmolality on the diagnostic performance of contrast fractional flow reserve

Background—Contrast fractional flow reserve (cFFR) is a method for assessing functional significance of coronary stenoses, which is more accurate than resting indices and does not require adenosine. However, contrast media volume and osmolality may affect the degree of hyperemia and therefore diagnostic performance. Methods and Results—cFFR, instantaneous wave–free ratio, distal pressure/aortic pressure at rest, and FFR were measured in 763 patients from 12 centers. We compared the diagnostic performance of cFFR between patients receiving low or iso-osmolality contrast (n=574 versus 189) and low or high contrast volume (n=341 versus 422) using FFR≤0.80 as a reference standard. The sensitivity, specificity, and overall accuracy of cFFR for the low versus iso-osmolality groups were 73%, 93%, and 85% versus 87%, 90%, and 89%, and for the low versus high contrast volume groups were 69%, 99%, and 83% versus 82%, 93%, and 88%. By receiver operating characteristics (ROC) analysis, cFFR provided better diagnostic performance than resting indices regardless of contrast osmolality and volume (P&lt;0.001 for all groups). There was no significant difference between the area under the curve of cFFR in the low- and iso-osmolality groups (0.938 versus 0.957; P=0.40) and in the low- and high-volume groups (0.939 versus 0.949; P=0.61). Multivariable logistic regression analysis showed that neither contrast osmolality nor volume affected the overall accuracy of cFFR; however, both affected the sensitivity and specificity. Conclusions—The overall accuracy of cFFR is greater than instantaneous wave–free ratio and distal pressure/aortic pressure and not significantly affected by contrast volume and osmolality. However, contrast volume and osmolality do affect the sensitivity and specificity of cFFR

Comparative efficacy of materials used in patients undergoing pulpotomy or direct pulp capping in carious teeth: A systematic review and meta-analysis.

OBJECTIVES Different materials have been used for capping the pulp after exposure during caries removal in permanent teeth. The purpose of this study was to collate and analyze all pertinent evidence from randomized controlled trials (RCTs) on different materials used in patients undergoing pulpotomy or direct pulp capping in carious teeth. MATERIALS AND METHODS Trials comparing two or more capping agents used for direct pulp capping (DPC) or pulpotomy were considered eligible. An electronic search of four databases and two clinical trial registries was carried out up to February 28, 2021 using a search strategy properly adapted to the PICO framework. Screening, data extraction, and risk of bias (RoB) assessment of primary studies were performed in duplicate and independently. The primary outcome was clinical and radiological success; secondary outcomes included continued root formation, tooth discoloration, and dentin bridge formation. RESULTS 21 RCTs were included in the study. The RoB assessment indicated a moderate risk among the studies. Due to significant clinical and statistical heterogeneity among the studies, performing network meta-analysis (NMA) was not possible. An ad hoc subgroup analysis revealed strong evidence of a higher success of DPC with Mineral Trioxide Aggregate (MTA) compared to calcium hydroxide (CH) (odds ratio [OR] = 3.10, 95% confidence interval [CI]: 1.66-5.79). MTA performed better than CH in pulp capping (both DPC and pulpotomy) of mature compared to immature teeth (OR = 3.34, 95% CI: 1.81-6.17). The GRADE assessment revealed moderate strength of evidence for DPC and mature teeth, and low to very low strength of evidence for the remaining subgroups. CONCLUSIONS Considerable clinical and statistical heterogeneity among the trials did not allow NMA. The ad hoc subgroup analysis indicated that the clinical and radiographic success of MTA was higher than that of CH but only in mature teeth and DPC cases where the strength of evidence was moderate. PROSPERO Registration: number CRD42020127239

Analytical expressions for the deprojected Sersic model

The Sersic model has become the standard to parametrize the surface brightness distribution of early-type galaxies and bulges of spiral galaxies. A major problem is that the deprojection of the Sersic surface brightness profile to a luminosity density cannot be executed analytically for general values of the Sersic index. Mazure & Capelato (2002) used the Mathematica computer package to derive an expression of the Sersic luminosity density in terms of the Meijer G function for integer values of the Sersic index. We generalize this work using analytical means and use Mellin integral transforms to derive an exact, analytical expression for the luminosity density in terms of the Fox H function for all values of the Sersic index. We derive simplified expressions for the luminosity density, cumulative luminosity and gravitational potential in terms of the Meijer G function for all rational values of the Sersic index and we investigate their asymptotic behaviour at small and large radii. As implementations of the Meijer G function are nowadays available both in symbolic computer algebra packages and as high-performance computing code, our results open up the possibility to calculate the density of the Sersic models to arbitrary precision.Comment: 9 pages, accepted for publication in Astronomy and Astrophysic

X-ray Isophotes in a Rapidly Rotating Elliptical Galaxy: Evidence of Inflowing Gas

We describe two-dimensional gasdynamical computations of the X-ray emitting gas in the rotating elliptical galaxy NGC 4649 that indicate an inflow of about one solar mass per year at every radius. Such a large instantaneous inflow cannot have persisted over a Hubble time. The central constant-entropy temperature peak recently observed in the innermost 150 parsecs is explained by compressive heating as gas flows toward the central massive black hole. Since the cooling time of this gas is only a few million years, NGC 4649 provides the most acutely concentrated known example of the cooling flow problem in which the time-integrated apparent mass that has flowed into the galactic core exceeds the total mass observed there. This paradox can be resolved by intermittent outflows of energy or mass driven by accretion energy released near the black hole. Inflowing gas is also required at intermediate kpc radii to explain the ellipticity of X-ray isophotes due to spin-up by mass ejected by stars that rotate with the galaxy and to explain local density and temperature profiles. We provide evidence that many luminous elliptical galaxies undergo similar inflow spin-up. A small turbulent viscosity is required in NGC 4649 to avoid forming large X-ray luminous disks that are not observed, but the turbulent pressure is small and does not interfere with mass determinations that assume hydrostatic equilibrium.Comment: 21 pages, 9 figures, accepted for publication by Ap

Dwarf elliptical galaxies with kinematically decoupled cores

{We present, for the first time, photometric and kinematical evidence, obtained with FORS2 on the VLT, for the existence of kinematically decoupled cores (KDCs) in two dwarf elliptical galaxies; FS76 in the NGC5044 group and FS373 in the NGC3258 group. Both kinematically peculiar subcomponents rotate in the same sense as the main body of their host galaxy but betray their presence by a pronounced bump in the rotation velocity profiles at a radius of about 1". The KDC in FS76 rotates at 10+/-3km/s, with the host galaxy rotating at 15+/-6km/s; the KDC in FS373 has a rotation velocity of 6+/-2km/s while the galaxy itself rotates at 20+/-5km/s. FS373 has a very complex rotation velocity profile with the velocity changing sign at 1.5 R_e. The velocity and velocity dispersion profiles of FS76 are asymmetric at larger radii. This could be caused by a past gravitational interaction with the giant elliptical NGC5044, which is at a projected distance of 50kpc. We argue that these decoupled cores are most likely not produced by mergers in a group or cluster environment because of the prohibitively large relative velocities. A plausible alternative is offered by flyby interactions between a dwarf elliptical or its disky progenitor and a massive galaxy. The tidal forces during an interaction at the relative velocities and impact parameters typical for a group environment exert a torque on the dwarf galaxy that, according to analytical estimates, transfers enough angular momentum to its stellar envelope to explain the observed peculiar kinematics.Comment: 11 pages, 14 figures, accepted for publication in A&

Under-reporting bicycle accidents to police in the COST TU1101 international survey: Cross-country comparisons and associated factors

Police crash reports are often the main source for official data in many countries. However, with the exception of fatal crashes, crashes are often underreported in a biased manner. Consequently, the countermeasures adopted according to them may be inefficient. In the case of bicycle crashes, this bias is most acute and it probably varies across countries, with some of them being more prone to reporting accidents to police than others. Assessing if this bias occurs and the size of it can be of great importance for evaluating the risks associated with bicycling. This study utilized data collected in the COST TU1101 action “Towards safer bicycling through optimization of bicycle helmets and usage”. The data came from an online survey that included questions related to bicyclists' attitudes, behaviour, cycling habits, accidents, and patterns of use of helmets. The survey was filled by 8655 bicyclists from 30 different countries. After applying various exclusion factors, 7015 questionnaires filled by adult cyclists from 17 countries, each with at least 100 valid responses, remained in our sample. The results showed that across all countries, an average of only 10% of all crashes were reported to the police, with a wide range among countries: from a minimum of 0.0% (Israel) and 2.6% (Croatia) to a maximum of a 35.0% (Germany). Some factors associated with the reporting levels were type of crash, type of vehicle involved, and injury severity. No relation was found between the likelihood of reporting and the cyclist's gender, age, educational level, marital status, being a parent, use of helmet, and type of bicycle. The significant under-reporting – including injury crashes that do not lead to hospitalization – justifies the use of self-report survey data for assessment of bicycling crash patterns as they relate to (1) crash risk issues such as location, infrastructure, cyclists' characteristics, and use of helmet and (2) strategic approaches to bicycle crash prevention and injury reduction.Fil: Shinar, D.. Ben Gurion University of the Negev; IsraelFil: Valero Mora, Pedro. Universidad de Valencia; EspañaFil: van Strijp Houtenbos, M.. Institute For Road Safety Research; Países BajosFil: Haworth, N.. Queensland University of Technology; AustraliaFil: Schramm, A.. Queensland University of Technology; AustraliaFil: de Bruyne, G.. Universiteit Antwerp; BélgicaFil: Cavallo, V.. No especifíca;Fil: Chliaoutakis, J.. No especifíca;Fil: Pereira Dias, Joao. Instituto Superior Tecnico; PortugalFil: Ferraro, Ottavia Eleonora. Universita Degli Studi Di Pavia; ItaliaFil: Fyhri, Aslak. No especifíca;Fil: Sajatovic, Anika Hursa. No especifíca;Fil: Kuklane, Kalev. Lund University; SueciaFil: Ledesma, Ruben Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Psicología Básica, Aplicada y Tecnología. Universidad Nacional de Mar del Plata. Facultad de Psicología. Instituto de Psicología Básica, Aplicada y Tecnología.; ArgentinaFil: Calvé Mascarell, Oscar. Ben Gurion University of the Negev; IsraelFil: Morandi, A.. Universita Degli Studi Di Pavia; ItaliaFil: Muser, Markus. No especifíca;Fil: Otte, Diettmar. No especifíca;Fil: Papadakaki, M.. No especifíca;Fil: Sanmartín, J.. Universidad de Valencia; EspañaFil: Dulf, D.. No especifíca;Fil: Saplioglu, M.. No especifíca;Fil: Tzamalouka, Georgia. No especifíca

Insulin-like growth factor I activates the invasion suppressor function of E-cadherin in MCF-7 human mammary carcinoma cells in vitro.

The calcium-dependent cell-cell adhesion molecule E-cadherin has been shown to counteract invasion of epithelial neoplastic cells. Using three monoclonal antibodies, we have demonstrated the presence of E-cadherin at the surface of human MCF-7/6 mammary carcinoma cells by indirect immunofluorescence coupled to flow cytometry and by immunocytochemistry. Nevertheless, MCF-7/6 cells failed to aggregate in a medium containing 1.25 mM CaCl2, and they were invasive after confrontation with embryonic chick heart fragments in organ culture. Treatment of MCF-7/6 cells with 0.5 microgram ml-1 insulin-like growth factor I (IGF-I) led to homotypic aggregation within 5 to 10 min and inhibited invasion in vitro during at least 8 days. The effect of IGF-I on cellular aggregation was insensitive to cycloheximide. However, monoclonal antibodies that interfered with the function of either the IGF-I receptor (alpha IR3) or E-cadherin (HECD-1, MB2) blocked the effect of IGF-I on aggregation. The effects of IGF-I on aggregation and on invasion could be mimicked by 1 microgram ml-1 insulin, but not by 0.5 microgram ml-1 IGF-II. The insulin effects were presumably not mediated by the IGF-I receptor, since they could not be blocked by an antibody against this receptor (alpha IR3). Our results indicate that IGF-I activates the invasion suppressor role of E-cadherin in MCF-7/6 cells