Analysis of the SFR - M* plane at z<3: single fitting versus multi-Gaussian decomposition

The analysis of galaxies on the star formation rate - stellar mass (SFR-M*) plane is a powerful diagnostic for galaxy evolution at different cosmic times. We consider a sample of 24463 galaxies from the CANDELS/GOODS-S survey to conduct a detailed analysis of the SFR-M* relation at redshifts 0.5$\leqslant z<$3 over more than three dex in stellar mass. To obtain SFR estimates, we utilise mid- and far-IR photometry when available, and rest-UV fluxes for all the other galaxies. We perform our analysis in different redshift bins, with two different methods: 1) a linear regression fitting of all star-forming galaxies, defined as those with specific star formation rates $\rm log_{10}(sSFR/yr^{-1}) > -9.8$, similarly to what is typically done in the literature; 2) a multi-Gaussian decomposition to identify the galaxy main sequence (MS), the starburst sequence and the quenched galaxy cloud. We find that the MS slope becomes flatter when higher stellar mass cuts are adopted, and that the apparent slope change observed at high masses depends on the SFR estimation method. In addition, the multi-Gaussian decomposition reveals the presence of a starburst population which increases towards low stellar masses and high redshifts. We find that starbursts make up ~5% of all galaxies at z=0.5-1.0, while they account for ~16% of galaxies at 2$<z<$3 with log$_{10}(M^{*})=$8.25-11.25. We conclude that the dissection of the SFR-M* in multiple components over a wide range of stellar masses is necessary to understand the importance of the different modes of star formation through cosmic time.Comment: 15 pages, 12 figures, 1 table. Accepted for publication in A&A, after addressing referee report. Main changes with respect to v1: two new appendixes to investigate the impact of redshift outliers and to test a two-Gaussian component fit to the sSFR distribution. No conclusion change

’n Kritiese evaluasie van die Godsbeeld van Sally McFague

Sally McFague’s image of God: A critical evaluationIn the past decade, many feminist publications on the image of God have seen the light of day. This article concentrates on the viewpoint of Sally McFague in addressing the problem of God-language. It attempts to poin t ou t the positive and negative aspects of McFague’s images of God-as-Mother, God-as-Lover and God-as-Friend. Finally, it aims to pinpoint the value of the feminist viewpoint for theological discussion in general and the proclamation of the church today in particular

Major effect genes or loose confederations? The development of insecticide resistance in the malaria vector Anopheles gambiae

Insecticide use in public health and agriculture presents a dramatic adaptive challenge to target and non-target insect populations. The rapid development of genetically modulated resistance to insecticides is postulated to develop in two distinct ways: By selection for single major effect genes or by selection for loose confederations in which several factors, not normally associated with each other, inadvertently combine their effects to produce resistance phenotypes. Insecticide resistance is a common occurrence and has been intensively studied in the major malaria vector Anopheles gambiae, providing a useful model for examining how insecticide resistance develops and what pleiotropic effects are likely to emerge as a consequence of resistance. As malaria vector control becomes increasingly reliant on successfully managing insecticide resistance, the characterisation of resistance mechanisms and their pleiotropic effects becomes increasingly important

Simultaneous identification of the Anopheles funestus group and Anopheles longipalpis type C by PCR-RFLP

<p>Abstract</p> <p>Background</p> <p><it>Anopheles longipalpis </it>is morphologically similar to the major African malaria vector <it>Anopheles funestus </it>at the adult stage although it is very different at the larval stage. Despite the development of the species-specific multiplex PCR assay for the <it>An. funestus </it>group, the genomic DNA of <it>Anopheles longipalpis </it>type C specimens can be amplified with the <it>Anopheles vaneedeni </it>and <it>Anopheles parensis </it>primers from this assay. The standard, species-specific <it>An. funestus </it>group PCR, results in the amplification of two fragments when <it>An. longipalpis </it>type C specimens are included in the analysis. This result can easily be misinterpreted as being a hybrid between <it>An. vaneedeni </it>and <it>An. parensis</it>. <it>Anopheles longipalpis </it>type C can be identified using a species-specific PCR assay but this assay is not reliable if other members of the <it>An. funestus </it>group, such as <it>An. funestus</it>, <it>An. funestus</it>-like and <it>An. parensis</it>, are included. The present study provides a multiplex assay that will identify <it>An. longipalpis </it>along with other common members of the African <it>An. funestus </it>group, including <it>Anopheles leesoni</it>.</p> <p>Methods</p> <p>A total of 70 specimens from six species (<it>An. funestus</it>, <it>An. funestus</it>-like, <it>An. parensis</it>, <it>Anopheles rivulorum</it>, <it>An. vaneedeni </it>and <it>An. leesoni</it>) in the <it>An. funestus </it>group and <it>An. longipalpis </it>type C from Malawi, Mozambique, South Africa and Zambia were used for the study. A restriction fragment length polymorphism (RFLP) assay was designed based on the DNA sequence information in the GenBank database.</p> <p>Results</p> <p>The enzyme, <it>EcoRI </it>digested only <it>An. longipalpis </it>type C and <it>An. funestus</it>-like after the species-specific <it>An. funestus </it>group PCR assay. The <it>An. longipalpis </it>and <it>An. funestus</it>-like digestion profiles were characterized by three fragments, 376 bp, 252 bp and 211 bp for <it>An. longipalpis </it>type C and two fragments, 375 bp and 15 bp for <it>An. funestus</it>-like.</p> <p>Conclusions</p> <p>An RFLP method for the group was developed that is more accurate and efficient than those used before. Hence, this assay would be useful for field-collected adult specimens to be identified routinely in malaria vector research and control studies.</p

Income and Subjective Financial Well-Being as Determining Factors of Life Satisfaction

The purpose of the investment is to improve the current level of life satisfaction by achieving investment goals. Investors tend to attain high levels of life satisfaction when their investment goals are achieved and lower levels of life satisfaction when goals are far from achievement. The idiosyncratic characteristics of an individual may often hamper the achievement of investment goals and ultimately influence the level of life satisfaction. These characteristics can either contribute towards low life satisfaction or high life satisfaction. Income and the subjective financial well-being play a determining role in whether an investor has a positive or negative life satisfaction. Hence, the aim of this study was to determine whether income and subjective financial well-being have an influence on the life satisfaction of investors. The results of this study reveal that a strong relationship exists between income, financial well-being, and life satisfaction. Investors who perceived themselves, to have high financial well-being were more likely to have high life satisfaction. On the contrary, investors with low perceived financial well-being were more likely to have low life satisfaction. Similar results were observed for income and life satisfaction since a positive relationship was also found

The effect of a single blood meal on the phenotypic expression of insecticide resistance in the major malaria vector Anopheles funestus

<p>Abstract</p> <p>Background</p> <p><it>Anopheles funestus </it>is a major malaria vector in southern Africa. Vector control relies on the use of insecticide chemicals to significantly reduce the number of malaria vectors by targeting that portion of the female population that takes blood meals and subsequently rests indoors. It has been suggested that the intake of a blood meal may assist female mosquitoes to tolerate higher doses of insecticide through vigour tolerance. It is hypothesized that during the process of blood digestion, detoxification mechanisms required for the neutralizing of harmful components in the blood meal may also confer an increased ability to tolerate insecticide intoxication through increased enzyme regulation.</p> <p>Methods</p> <p>Bottle bioassays using a range of concentrations of the pyrethroid insecticide permethrin were performed on pyrethroid susceptible and resistant laboratory strains of <it>An. funestus </it>in order to detect differences in insecticide susceptibility following a single blood meal. Based on these results, a discriminating dosage was identified (double the lowest dosage that resulted in 100% mortality of the susceptible strain). Blood-fed and unfed females drawn from the resistant strain of <it>An. funestus </it>were then assayed against this discriminating dose, and the percentage mortality for each sample was scored and compared.</p> <p>Results</p> <p>In the insecticide dose response assays neither the fully susceptible nor the resistant strain of <it>An. funestus </it>showed any significant difference in insecticide susceptibility following a blood meal, regardless of the stage of blood meal digestion. A significant increase in the level of resistance was however detected in the resistant <it>An. funestus </it>strain following a single blood meal, based on exposure to a discriminating dose of permethrin.</p> <p>Conclusion</p> <p>The fully susceptible <it>An. funestus </it>strain did not show any significant alteration in susceptibility to insecticide following a blood meal suggesting that vigour tolerance through increased body mass (and increased dilution of internalized insecticide) does not play a significant role in tolerance to insecticide intoxication. The increase in insecticide tolerance in the pyrethroid resistant strain of <it>An. funestus </it>following a blood meal suggests that insecticide detoxification mechanisms involved in insecticide resistance are stimulated by the presence of a blood meal prior to insecticide exposure, leading to enhanced expression of the resistance phenotype. This finding may be significant in terms of the methods used to control indoor resting populations of <it>An. funestus </it>if the mass killing effect of insecticide application proves increasingly inadequate against blood-feeding females already carrying the insecticide resistance phenotype.</p

Recovering the properties of high redshift galaxies with different JWST broad-band filters

Imaging with the James Webb Space Telescope (JWST) will allow for observing the bulk of distant galaxies at the epoch of reionisation. The recovery of their properties, such as age, color excess E(B-V), specific star formation rate (sSFR) and stellar mass, will mostly rely on spectral energy distribution fitting, based on the data provided by JWST's two imager cameras, namely the Near Infrared Camera (NIRCam) and the Mid Infrared Imager (MIRI). In this work we analyze the effect of choosing different combinations of NIRCam and MIRI broad-band filters, from 0.6 {\mu}m to 7.7 {\mu}m, on the recovery of these galaxy properties. We performed our tests on a sample of 1542 simulated galaxies, with known input properties, at z=7-10. We found that, with only 8 NIRCam broad-bands, we can recover the galaxy age within 0.1 Gyr and the color excess within 0.06 mag for 70% of the galaxies. Besides, the stellar masses and sSFR are recovered within 0.2 and 0.3 dex, respectively, at z=7-9. Instead, at z=10, no NIRCam band traces purely the {\lambda}> 4000 {\AA} regime and the percentage of outliers in stellar mass (sSFR) increases by > 20% (> 90%), in comparison to z=9. The MIRI F560W and F770W bands are crucial to improve the stellar mass and the sSFR estimation at z=10. When nebular emission lines are present, deriving correct galaxy properties is challenging, at any redshift and with any band combination. In particular, the stellar mass is systematically overestimated in up to 0.3 dex on average with NIRCam data alone and including MIRI observations improves only marginally the estimation.Comment: 21 pages, 11 figures, 4 tables. Accepted for publication at the ApJ

Cuticle thickening associated with pyrethroid resistance in the major malaria vector Anopheles funestus

BACKGROUND: Malaria in South Africa is primarily transmitted by Anopheles funestus Giles. Resistance to pyrethroid insecticides in An. funestus in northern Kwazulu/Natal, South Africa, and in neighbouring areas of southern Mozambique enabled populations of this species to increase their ranges into areas where pyrethroids were being exclusively used for malaria control. Pyrethroid resistance in southern African An. funestus is primarily conferred by monooxygenase enzyme metabolism. However, selection for this resistance mechanism is likely to have occurred in conjunction with other factors that improve production of the resistance phenotype. A strong candidate is cuticle thickening. This is because thicker cuticles lead to slower rates of insecticide absorption, which is likely to increase the efficiency of metabolic detoxification. RESULTS: Measures of mean cuticle thickness in laboratory samples of female An. funestus were obtained using scanning electron microscopy (SEM). These females were drawn from a laboratory colony carrying the pyrethroid resistance phenotype at a stable rate, but not fixed. Prior to cuticle thickness measurements, these samples were characterised as either more or less tolerant to permethrin exposure in one experiment, and either permethrin resistant or susceptible in another experiment. There was a significant and positive correlation between mean cuticle thickness and time to knock down during exposure to permethrin. Mean cuticle thickness was significantly greater in those samples characterised either as more tolerant or resistant to permethrin exposure compared to those characterised as either less tolerant or permethrin susceptible. Further, insecticide susceptible female An. funestus have thicker cuticles than their male counterparts. CONCLUSION: Pyrethroid tolerant or resistant An. funestus females are likely to have thicker cuticles than less tolerant or susceptible females, and females generally have thicker cuticles than males. In pyrethroid resistant An. funestus, this increase in cuticle thickness is likely to have developed as an auxiliary to the primary mode of pyrethroid resistance which is based on enzyme-mediated detoxification