Associations among types of impulsivity, substance use problems and \u3ci\u3eNeurexin-3\u3c/i\u3e polymorphisms

Background—Some of the genetic vulnerability for addiction may be mediated by impulsivity. This study investigated relationships among impulsivity, substance use problems and six neurexin-3 (NRXN3) polymorphisms. Neurexins (NRXNs) are presynaptic transmembrane proteins that play a role in the development and function of synapses. Methods—Impulsivity was assessed with the Barratt Impulsiveness Scale Version 11 (BIS-11), the Boredom Proneness Scale (BPS) and the TIME paradigm; alcohol problems with the Michigan Alcoholism Screening Test (MAST); drug problems with the Drug Abuse Screening Test (DAST-20); and regular tobacco use with a single question. Participants (N = 439 Caucasians, 64.7% female) donated buccal cells for genotyping. Six NRXN3 polymorphisms were genotyped: rs983795, rs11624704, rs917906, rs1004212, rs10146997 and rs8019381. A dual luciferase assay was conducted to determine whether allelic variation at rs917906 regulated gene expression. Results—In general, impulsivity was significantly higher in those who regularly used tobacco and/or had alcohol or drug problems. In men, there were modest associations between rs11624704 and attentional impulsivity (p = .005) and between rs1004212 and alcohol problems (p = .009). In women, there were weak associations between rs10146997 and TIME estimation (p = .03); and between rs1004212 and drug problems (p = .03). The dual luciferase assay indicated that C and T alleles of rs917906 did not differentially regulate gene expression in vitro. Conclusions—Associations between impulsivity, substance use problems and polymorphisms in NRXN3 may be gender specific. Impulsivity is associated with substance use problems and may provide a useful intermediate phenotype for addiction

Associations among types of impulsivity, substance use problems and \u3ci\u3eNeurexin-3\u3c/i\u3e polymorphisms

Background—Some of the genetic vulnerability for addiction may be mediated by impulsivity. This study investigated relationships among impulsivity, substance use problems and six neurexin-3 (NRXN3) polymorphisms. Neurexins (NRXNs) are presynaptic transmembrane proteins that play a role in the development and function of synapses. Methods—Impulsivity was assessed with the Barratt Impulsiveness Scale Version 11 (BIS-11), the Boredom Proneness Scale (BPS) and the TIME paradigm; alcohol problems with the Michigan Alcoholism Screening Test (MAST); drug problems with the Drug Abuse Screening Test (DAST-20); and regular tobacco use with a single question. Participants (N = 439 Caucasians, 64.7% female) donated buccal cells for genotyping. Six NRXN3 polymorphisms were genotyped: rs983795, rs11624704, rs917906, rs1004212, rs10146997 and rs8019381. A dual luciferase assay was conducted to determine whether allelic variation at rs917906 regulated gene expression. Results—In general, impulsivity was significantly higher in those who regularly used tobacco and/or had alcohol or drug problems. In men, there were modest associations between rs11624704 and attentional impulsivity (p = .005) and between rs1004212 and alcohol problems (p = .009). In women, there were weak associations between rs10146997 and TIME estimation (p = .03); and between rs1004212 and drug problems (p = .03). The dual luciferase assay indicated that C and T alleles of rs917906 did not differentially regulate gene expression in vitro. Conclusions—Associations between impulsivity, substance use problems and polymorphisms in NRXN3 may be gender specific. Impulsivity is associated with substance use problems and may provide a useful intermediate phenotype for addiction

Microcalcification crystallography as a potential marker of DCIS recurrence

Ductal carcinoma in-situ (DCIS) accounts for 20–25% of all new breast cancer diagnoses. DCIS has an uncertain risk of progression to invasive breast cancer and a lack of predictive biomarkers may result in relatively high levels (~ 75%) of overtreatment. To identify unique prognostic biomarkers of invasive progression, crystallographic and chemical features of DCIS microcalcifications have been explored. Samples from patients with at least 5-years of follow up and no known recurrence (174 calcifications in 67 patients) or ipsilateral invasive breast cancer recurrence (179 microcalcifications in 57 patients) were studied. Significant differences were noted between the two groups including whitlockite relative mass, hydroxyapatite and whitlockite crystal maturity and, elementally, sodium to calcium ion ratio. A preliminary predictive model for DCIS to invasive cancer progression was developed from these parameters with an AUC of 0.797. These results provide insights into the differing DCIS tissue microenvironments, and how these impact microcalcification formation

A 20-year review of the status and distribution of African wild dogs (Lycaon pictus) in South Africa

South Africa is one of only seven countries with a viable population of African wild dogs (Lycaon pictus). The national population in 2017 was 372 adults and yearlings and comprised three subpopulations: 1) Kruger National Park (Kruger), 2) an intensively managed metapopulation established through reintroductions into isolated, fenced reserves, and 3) a free-roaming population that occurs naturally outside protected areas. We assessed the long-term (four wild dog generations, ~20 years) trends in population size and growth rate within each of these three subpopulations. We found that Kruger supports a substantial population,which has declined over time.The metapopulation is the only subpopulation that has increased significantly over time (both in population size and number of packs), likely due to intensive conservation efforts and the reintroduction of wild dogs into 15 additional reserves since 1998. The free-roaming subpopulation has remained small but stable, even though the number of packs has declined due to anthropogenic threats. The overall national population has remained stable even though the number of packs has increased. Kruger has consistently supported the highest proportion of the national population over the last two decades. However, the contribution of the metapopulation has increased significantly over time. It is clear that despite differences in survey effort among the three subpopulations, South Africa has a small (~500) but stable population of wild dogs, with the metapopulation contribution becoming increasingly important. The circumstances in the country necessitate, and demonstrate the benefit of, intensive, adaptive management for the national population of wild dogs. While this assessment provides baseline information for the three subpopulations, wild dog conservation in South Africa would benefit greatly from equal survey effort and standardized methods to accurately assess long-term population trends.https://journals.co.za/journal/wild2pm2021Zoology and Entomolog

Jobs, game meat and profits : the benefits of wildlife ranching on marginal lands in South Africa

The private wildlife sector in South Africa must demonstrate value in the face of political pressures for economic growth, job creation and food security. Through structured survey questionnaires of landowners and managers from 276 private wildlife ranches, we describe patterns of wildlife-based land uses (WBLUs), estimate their financial and social contributions and compare these with livestock farming. We show that 46% of surveyed properties combined wildlife with livestock, 86% conducted two or more WBLUs and 80% conducted consumptive use activities. Intensive breeding was conducted on 46% of properties and covered 5.1% of their total land area. Revenues were higher on wildlife only properties than livestock farms, but we were unable to compare the profitability of wildlife and livestock due to data gaps for livestock. Profits from WBLUs were highly variable, while mean return on investment (ROI) was 0.068. Wildlife properties employed more people per unit area than livestock farms, properties conducting ecotourism employed more than twice as many people as non-ecotourism properties, and biltong hunting properties employed 50% fewer people than non-biltong hunting properties. Mean game meat production on wildlife only properties was 4.07 kg/ha, while the top producers harvested game meat at a level comparable with some extensive livestock farms. We suggest that the financial and social benefits of wildlife ranching on marginal land make this a viable land use, but that the contributions towards biodiversity conservation need to be quantified. The South African model could be a suitable option for other African countries seeking sustainable land use alternatives.http://www.elsevier.com/locate/biocon2021-05-01hj2021Centre for Wildlife ManagementMammal Research InstituteZoology and Entomolog

South Africa’s private wildlife ranches protect globally significant populations of wild ungulates

Reversing biodiversity loss is a global imperative that requires setting aside sufficient space for species. In South Africa, an estimated area of 20 million ha is under wildlife ranching, a form of private land enterprise that adopts wildlife-based land uses for commercial gain. This land has potential to contribute towards biodiversity conservation, but the extent to which this occurs has not been evaluated. Using structured questionnaires of 226 wildlife ranchers, we assessed how the sector contributes towards the conservation of ungulates and elephants (hereafter herbivores). Overall, 40 herbivore species were present across the sample, where individual ranches had a mean of 15.0 (± 4.8) species, 1.9 (± 1.5) threatened species, and 3.6 (± 3.1) extralimital species per property. In comparison to 54 state PAs, wildlife ranches had significantly higher species richness, more threatened species but more extralimital species when property/reserve size was controlled for. Ranches conducting trophy hunting had similar species richness and numbers of extralimital species per ha, but fewer threatened species when compared to ranches conducting ecotourism. We estimate that 4.66–7.25 million herbivores occur on ranches nationally, representing one of the few examples on earth where indigenous mammal populations are thriving and demonstrating how sustainable use can lead to rewilding. We discuss the potential negative impacts of widespread game fencing on landscape fragmentation and gene flow, as well as how the widespread occurrence of extralimital species may lead to hybridisation, biotic homogenisation, and changes to vegetation dynamics. Despite these challenges, commercial wildlife ranching offers a viable option for conserving large mammalian herbivore biodiversity.Supplementary File 1. Online resources 1 and 2.Supplementary File 2. Online resources 3 and 4.Supplementary File 3. Online resource 5.The Green Fund/Development Bank of South Africa.http://link.springer.com/journal/10531hj2022Centre for Veterinary Wildlife StudiesMammal Research InstituteProduction Animal StudiesZoology and Entomolog

Optimising the cost of roadkill surveys based on an analysis of carcass persistence

Reliable estimates of wildlife mortality due to wildlife-vehicle collisions are key to understanding its impact on wildlife populations and developing strategies to prevent or reduce collisions. Standardised approaches for monitoring roadkill are needed to derive robust and unbiased estimates of mortality that are comparable across different study systems and ecological contexts. When designing surveys, there is a trade-off between survey frequency (and hence logistical effort and financial cost) and carcass detection. In this regard, carcass persistence (the period a carcass remains detectable before being removed by decomposition or scavengers) is important; the longer a carcass persists, the greater the likelihood it will be detected with lower survey effort by conducting more infrequent surveys. Using multi-taxon carcass data collected over a month of repeated driven surveys, combined with five covariates (species functional group, body weight, carcass position on road, carcass condition [either flattened or not after impact], and rainfall prior to each survey), we explored the drivers of carcass persistence with the overall aim of providing information to optimise the design of carcass surveys along linear infrastructure. Our methodological approach included a survival analysis to determine carcass persistence, linear regressions to test the effect of covariates, a subsampling analysis (using field data and a simulation exercise) to assess how the proportion of carcasses detected changes according to survey frequency, and an analysis to compare the costs of surveys based on study duration, transect length and survey frequency. Mean overall carcass persistence was 2.7 days and was significantly correlated with position on road and within-functional group body weight. There was no evidence for a significant effect of rainfall, while the effect of carcass condition was weakly non-significant. The proportion of carcasses detected decreased sharply when survey intervals were longer than three days. However, we showed that survey costs can be reduced by up to 80% by conducting non-daily surveys. Expanding on the call for a standardised methodology for roadkill surveys, we propose that carcass persistence be explicitly considered during survey design. By carefully considering the objectives of the survey and characteristics of the focal taxa, researchers can substantially reduce logistical costs. In addition, we developed an R Shiny web app that can be used by practitioners to compare survey costs across a variety of survey characteristics. This web app will allow practitioners to easily assess the trade-off between carcass detection and logistical effort.De Beers Group of Companies, Oppenheimer Generations, and Mopane Bush Lodge. This research was initiated by the Endangered Wildlife Trust, with funding from Bridgestone South Africa.https://www.elsevier.com/locate/jenvman2022-05-08hj2022Mammal Research Institut

Thermally dynamic examination of local order in nanocrystalline hydroxyapatite

The main mineral component of bone is hydroxyapatite, a commonly nanocrystalline material which presents many challenges for those trying to characterize it. Here, local structure is analyzed using X-ray total scattering for synthetic samples, to enable a better understanding of the nanocrystalline nature of hydroxyapatite. Two samples were measured dynamically during heat treatment from 25°C to 800°C, and were analyzed using small box modelling. Analysis of sequential measurements when dwelling at key temperatures showed a significant relationship between time and temperature, indicating a process occurring more slowly than thermal expansion. This indicates a decrease in B-type CO32- substitution between 550°C and 575°C and an increase in A-type CO32- substitution above 750°C. A greater understanding of local, intermediate, and long-range order of this complex biomineral during heat treatment can be of interest in several sectors, such as in forensic, biomedical and clinical settings for the study of implant coatings and bone diseases including osteoporosis and osteoarthritis.Engineering and Physical Sciences Research Council (EPSRC): EP/T034238/1. This work was also partly supported by a Royal Society and Wolfson Foundation (RSWF/R1/180012). This work was carried out with the support of the Diamond Light Source, instrument I15-1 (proposal cy24283)

The Cepheid Distance to the Narrow-Line Seyfert 1 Galaxy NGC 4051

We derive a distance of $D = 16.6 \pm 0.3$~Mpc ($\mu=31.10\pm0.04$~mag) to the archetypal narrow-line Seyfert 1 galaxy NGC 4051 based on Cepheid Period--Luminosity relations and new Hubble Space Telescope multiband imaging. We identify 419 Cepheid candidates and estimate the distance at both optical and near-infrared wavelengths using subsamples of precisely-photometered variables (123 and 47 in the optical and near-infrared subsamples, respectively). We compare our independent photometric procedures and distance-estimation methods to those used by the SH0ES team and find agreement to 0.01~mag. The distance we obtain suggests an Eddington ratio $\dot{m} \approx 0.2$ for NGC 4051, typical of narrow-line Seyfert 1 galaxies, unlike the seemingly-odd value implied by previous distance estimates. We derive a peculiar velocity of $-490\pm34$~km~s$^{-1}$ for NGC 4051, consistent with the overall motion of the Ursa Major Cluster in which it resides. We also revisit the energetics of the NGC 4051 nucleus, including its outflow and mass accretion rates.Comment: 15 pages, 12 figures, 6 tables, accepted for publication in Ap

Synthesis, structural, DFT calculations and biological studies of rhodium and iridium complexes containing azine Schiff-base ligands

The reaction of [Cp*MCl2]2 (M = Rh/Ir) with N-Nʹ azine Schiff-base ligands (L1-L4) leads to the formation of mononuclear cationic half-sandwich complexes having the general formula [Cp*M(L)Cl]+ (1–8), (M = Rh/Ir and L = (2-hydroxy-4-methoxybenzylidene)2- pyridylamidrazone (L1), (2-hydroxybenzylidene)2-pyridylamidrazone (L2), (1-(2-hydroxyphenyl)ethylidene)2-pyridylamidrazone (L3) and (1-phenylethylidene)2-pyridylamidrazone (L4). All these complexes were isolated as their hexafluorophosphate salts and fully characterized by spectroscopic and analytical techniques. The molecular structure of complexes (1), (3), (4), (7) and (8) have been determined by single crystal X-ray crystallographic studies which displayed the coordination of the ligand to the metal in a bidentate N∩N fashion through nitrogen atom of pyridine and one azine nitrogen. The chemo-sensitivity activities of the complexes were evaluated against HT-29 (human colorectal cancer) cell line and non-cancer cell line ARPE-19 (human retinal epithelial cells) which revealed that the complexes are moderately cytotoxic to cancer cells over human cells although complex 5 was the most potent among all the compounds. Theoretical studies carried out using DFT and TD-DFT at B3LYP level shows good agreement with the experimental results