4,837 research outputs found
Introduction: Special issue on genetic research of alcohol use disorder in diverse racial/ethnic populations
This special issue of The American Journal on Addictions is an extension of a workshop held at the Research Society on Alcoholism (2015) highlighting several important issues related to studies of the genetic bases of alcohol use disorder among racially/ethnically diverse populations. While not exhaustive in their coverage, the papers in this special issue focus on three important topics: (1) the importance of considering the social and environmental context in genetic analyses; (2) social and cultural considerations for engaging diverse communities in genetic research; and (3) methodologies related to phenotype development for use with racially/ethnically diverse populations. A brief overview of each paper included in these three sections is presented. The issue concludes with additional considerations for genetic research with racially/ethnically diverse population groups along with a commentary. (Am J Addict 2017;26:422â423
Ătude de l'enlĂšvement du Cd, Cu, Mn et Zn par solubilisation biologique dans les sĂ©diments lacustres fortement contaminĂ©s
Des essais en erlenmeyers de 0,5 L ont été faits afin d'évaluer les possibilités d'application d'un procédé de solubilisation biologique aux sédiments. Ce procédé utilise la capacité des thiobacilles de lixivier les métaux en milieu acide. Au cours des essais, l'influence, sur la solubilisation des métaux, de la quantité de substrat (FeSO4 à 7H2O), du pourcentage d'inoculum et de la teneur en solides totaux a été suivie. La concentration de substrat n'a pas d'effet sur l'enlÚvement du Cd, du Zn, du Mn et du Cu. Les taux d'enlÚvement moyens pour le Cd, Zn et Mn, sont, aprÚs 46 heures, de 70 à 90 %, 90 à 100 % et 64 à 72 % pour des concentrations de substrat variant de 0 à 30 % FeSO4 à 7H2O (poids sec/poids sec). A 29 et 46 heures, des coefficients de détermination (r2) de 0,46 et 0,59 entre le pH et la concentration de FeSO4 à 7H2O, et de 0,92 et 0,55 entre le POR et la concentration de FeSO4 à 7H2O ont été trouvés. A plus forte teneur en FeSO4 à 7H2O, le POR est moins élevé, surtout au début des essais. La présence des ions ferreux en plus grande quantité expliquerait les plus faibles valeurs du potentiel-rédox. A 20 % d'inoculum, la solubilisation des métaux est optimale avec une solubili- sation de 86 % pour le Cd et 73 % pour le Cu et le Mn. La forte corrélation entre le POR, le pH et le pourcentage d'inoculum (r2 à 29, 46 et 70 heures de 0,94, 0,94 et 0,63 pour le POR et le pourcentage d'inoculum et de 0,80, 0,69 et 0,60 pour le pH et le pourcentage d'inoculum), a permis d'établir une corrélation entre le POR, le pH et la solubilisation du Cu. Les seuils trouvés permettant une solubilisation du Cu supérieure à 10 % sont un pH de 3,75 et un POR de 260 mV.L'augmentation des solides totaux (ST) semble limiter le développement des thiobacilles et diminue les rendements de solubilisation du Cd (à 21 heures) et du Zn (à 45 heures). Ainsi, pour le Cd, les pourcentages de solubilisation passent de 71 % à 24 % pour 3 et 15 % ST, alors que dans le cas du Zn, ils diminuent de 94 % à 81 % pour 3 et 15 % ST. La solubilisation du Mn serait, pour sa part, plutÎt de type chimique.In the province of Québec, the St-Lawrence Seaway as well as the harbour areas undergo frequent dredging. Each year, more than 106 cubic metres of sediments must be dredged from the st-Lawrence river. The dredged sedirnents are generally dispersed in the water column. However, heavy metal contamination of these sediments may preclude open-water disposal and necessitate their confinement.The research work presented in this article applies to dredged sediments that are too contaminated for open-water disposal. In order to permit their safe disposal, it is necessary to have a method which effectively removes metals from these sediments. One of the effective methods of metal removal from contaminated sediments could be a microbial solubilization process, which was developed at INRS-Eau for sewage sludge decontamination and which has been tested on a pilot scale during the past year. In order to appty such a process to decontaminate sediments, it was necessary to study the influence of various factors affecting the microbial leaching process. This research verified the possibility of using a modified microbial leaching process to decontaminate sediments and also studied the influence of the enerry substrate, the microbial inoculum and the sediment total solids concentration on such a modified process.The experimental methodology consisted of mixing the contaminated sediment in a 500 ml Erlenmeyer flask for a period of 96 hours in the presence of thiobacillus inoculum and ferrous sulfate (FeSO4 ⹠7H2O) as the enerry substrate. Before each experiment sediments were adjusted to the desired total solids concentration with deionized water and were acidified with sulfuric acid to obtain the starting pH conditions.The solubilization of Cd, Cu, Zn and Mn was monitored at regular intervals in order to evaluate the influence of the various factors studied. Subsamples were removed, the sediments were digested and the metals were analyzed by inductively coupled plasma atomic emission spectrophotometry (ICP-AES). The elements analyzed were Al, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb,Zn as well as S, P and C. All the digestions and analyses performed made according to the APHA guidelines. The total solids, both volatile and inert, were also determined according to APHA method no.209F (APHA, 1985).Regarding the influence of the ferrous sulfate concentration on the application of the microbial leaching process, the removal rates of Cd, Zn and Mn did not vary more than 12 %. For all experiments, the final pH value approached 2,5. The oxidation-reduction potential (ORP) varied for all experiments from 462 to 560 mV. An energy source could therefore be present in the sediments, which would support the growth of thiobacillus bacteria.During the experiments conducted to study the influence of inoculum concentration on the microbial leaching process, it was found that the pH decreased from 3.5 to 2.4 and the ORP increased from 284 to 593 mV when the inoculum addition increased from 0 to 30 % (v/v). This tendency was also observed during the removal of Cd and above all, Cu. Between 0 and 20 % (v/v) inoculum concentration, Cd removal increased from 64 to 86 % whereas Cu removal increased from 20 to73 %. However, these two metals did not show any appreciable increase in solubilization when the inoculum was increased from 20 to 30 % (v/v). In the case of Mn, it was not possible to determine the solubilization pattern since the inoculum concentration did not influence the solubilization of this element, Between 0 and 30 % inoculum, the Mn removal varied from 56 to 73 %. Hence the microbial influence on Mn solubilization may be negligible.The study on the influence of total solids content on the microbial leaching process showed that the total solids concentration had an influence on pH and ORP. The final pH increased from 2.43 to 3.32 and ORP decreasedfrom 492 to 321 mV when the total solids content was varied from 3 to 15 % . The percent solubilization of Cd after 21 h was 7l %, 69 %, 43 %, 44 % and, 24 % at 3, 5, 7, 10 and 15 % total solids respectively, On the other hand, Zn solubilization after 45 h was 94 %, 90 %, 84 %, 97 % and 8l % for the same concentrations of total solids. An increase in total solids content decreased the solubilization efficiency of Cd (at t=2l h) and, to a lesser extent, Zn (att=48h). However,in the case of Mn, the maximum solubilization was achieved right at the beginning and varied little with time. Its solubilization varied between 61 and 70 % for 3 % total solids, between 67 and, 79 % for 5 % total dolids, between 52 and,62 % for 7 % totaf solids, between 57 and, 75 % for l0 % total solids and tretween 40 and 63 % for 15 % total solids. In general, for the sediments studied here, total solids content has little influence on Mn solubilization.In conclusion, use of a microbial leaching process to remove metals from contaminated sediments seems to be less complex than for sewage sludges, since the maximum removal of metals is achieved in less than 48 h in a bench-scale experiment. The average metal solubilization was above 80 % for Cd, 73 % for Cu, 90 % for Zn and 65 % for Mn. The development of thiobacillus does not seem to be dependent upon the presence of an added energy substrate. Only a minimal quantity of substrate, say 5 % ferrous sulfate (dry wt./dry wt.), is required in order to assure optimal conditions for thiobacillus growth. It is probable that with time, without ferrous sulfate, the microbial conditions would deteriorate due to exhaustion ofthe enerry substrate. A 20 % microbial inoculum seems to be enough to assure an efficient metal solubilization process. Except for Mn, the increase in total solids concentration had a negative influence on the metal solubilization. It is hence preferable to work with a total solids concentration of less than 5 %. Nevertheless, it should be noted that this percentage is more than that used for sewage sludge decontaminaton (around 2 % total solids)
A multi-site, double-blind, placebo-controlled pilot clinical trial to evaluate the efficacy of buspirone as a relapse-prevention treatment for cocaine dependence
ObjectiveâTo evaluate the potential efficacy of buspirone as a relapse-prevention treatment for cocaine dependence.
MethodâA randomized, double-blind, placebo-controlled, 16-week pilot trial conducted at six clinical sites between August 2012 and June 2013. Adult crack cocaine users meeting DSM-IVTR criteria for current cocaine dependence scheduled to be in inpatient/residential substance use disorder (SUD) treatment for 12â19 days when randomized, and planning to enroll in local outpatient treatment through the end of the active treatment phase were randomized to buspirone titrated to 60 mg/day (n=35) or to placebo (n=27). All participants received psychosocial treatment as usually provided by the SUD treatment programs in which they were enrolled. Outcome measures included maximum days of continuous cocaine abstinence (primary), proportion of cocaine use days, and days-to-first-cocaine-use during the outpatient treatment phase (study weeks 4â15) as assessed by self-report and urine drug screens.
ResultsâThere were no significant treatment effects on maximum continuous days of cocaine abstinence or days to first cocaine use. In the females (n=23), there was a significant treatment-bytime interaction effect (X2 (1)=6.06, p=.01), reflecting an increase in cocaine use by the buspirone, relative to placebo, participants early in the outpatient treatment phase. A similar effect was not detected in the male participants (n=39; X2 (1)=0.14, p=.70).
ConclusionsâThe results suggest that buspirone is unlikely to have a beneficial effect on preventing relapse to cocaine use and that buspirone for cocaine-dependent women may worsen their cocaine-use outcomes.
Trial RegistrationâClinical Trials.gov http://www.clinicaltrials.gov; Identifier: NCT0164115
Neutron Transfer Studied with a Radioactive beam of 24Ne, using TIARA at SPIRAL
A general experimental technique for high resolution studies of nucleon
transfer reactions using radioactive beams is briefly described, together with
the first new physics results that have been obtained with the new TIARA array.
These first results from TIARA are for the reaction 24Ne(d,p)25Ne, studied in
inverse kinematics with a pure radioactive beam of 100,000 pps from the SPIRAL
facility at GANIL. The reaction probes the energies of neutron orbitals
relevant to very neutron rich nuclei in this mass region and the results
highlight the emergence of the N=16 magic number for neutrons and the
associated disappearance of the N=20 neutron magic number for the very neutron
rich neon isotopes.Comment: Proceedings of the Carpathian Summer School of Physics,
Mamaia-Constanta, Romania, 13-24 June 200
ALDH2*2 and peer drinking in East Asian college students
Background: The ALDH2*2 allele (A-allele) at rs671 is more commonly carried by Asians and is associated with alcohol-related flushing, a strong adverse reaction to alcohol that is protective against drinking. Social factors, such as having friends who binge drink, also contribute to drinking in Asian youth. Objectives: This study examined the interplay between ALDH2*2, peer drinking, and alcohol consumption in college students. We hypothesized that the relationship between ALDH2*2 and standard grams of ethanol per month would vary based on the level of peer drinking. Methods: Subjects (N = 318, 63.25% female) were East Asian college students in the United States who reported drinking alcohol. Data were from the freshman year of a university survey that included a saliva DNA sample. ALDH2*2 status was coded ALDH2*2(+) (A/G and A/A genotypes) and ALDH2*2(â) (G/G genotype). Peer drinking was studentsâ perception of how many of their friends âgot drunkâ. Results: Main effects of ALDH2*2(â) and having more friends who got drunk were associated with greater alcohol consumption. The ALDH2*2 Ă peer drunkenness interaction showed a stronger positive association with alcohol consumption for ALDH2*2(â) versus ALDH2*2(+) at increasing levels of peer drunkenness. Follow-up comparisons within each peer drunkenness level identified significantly higher alcohol consumption for ALDH2*2(â) compared to ALDH2*2(+) at the all friends got drunk level.
Conclusion: There was evidence of a stronger effect for ALDH2*2(â) compared to ALDH2*2(+) with greater alcohol use when students were more exposed to peer drinking. Findings contribute to a growing literature on the interrelationships between genetic influences and more permissive environments for alcohol consumption
Asymptotic solvers for ordinary differential equations with multiple frequencies
We construct asymptotic expansions for ordinary differential equations with highly oscillatory forcing terms, focusing on the case of multiple, non-commensurate frequencies. We derive an asymptotic expansion in inverse powers of the oscillatory parameter and use its truncation as an exceedingly effective means to discretize the differential equation in question. Numerical examples illustrate the effectiveness of the method
Archivists and Faculty Collaborative Course Development
This article describes an innovative collaboration and partnership between archivists and a faculty member to enhance teaching and learning on a college campus. For archivists, instruction is often relegated to a secondary function with well-worn show-and-tell sessions that feature collection highlights. However, in a dynamic university environment, these traditional teaching methods are not sufficient for the needs of faculty in their teaching, students in their learning, or archivists seeking broader uses for their collections
Monthly mean wind stress and Sverdrup transport in the North Atlantic: A comparison of the Hellerman-Rosenstein and Isemer-Hasse climatologies
The monthly mean wind stress climatology of Hellerman and Rosenstein (HR) is compared with the climatology of Isemer and Hasse (IH), which represents a version of the Bunker atlas (BU) for the North Atlantic based on revised parameterizations. The drag coefficients adopted by IH are 21% smaller than the values of BU and HR, and the calculation of wind speed from marine estimates of Beaufort force (Bft) is based on a revised Beaufort equivalent scale similar to the scientific scale recommended by WMO. The latter choice significantly increases wind speed below Bft 8, and effectively counteracts the reduction of the drag coefficients.
Comparing the IH stresses with HR reveals substantially enhanced magnitudes in the trade wind region throughout the year. At 15°N the mean easterly stress increases from about 0.9 (HR) to about 1.2 dyn cmâ1 (IH). Annual mean differences are smaller in the region of the westerlies. In winter, the effect due to the reduced drag coefficient dominates and leads to smaller stress values in IH; during summer season the revision of the Beaufort equivalents is more effective and leads to increased stresses.
Implications of the different wind stress climatologies for forcing the large-scale ocean circulation are discussed by means of the Sverdrup transport streamfunction (Ïs): Throughout the subtropical gyre a significant intensification of Ïs takes place with IH. At 27°N, differences of more than 10 Sv (1 Sv ⥠106 m3 sâ1) are found near the western boundary. Differences in the seasonality of Ïs are more pronounced in near-equatorial regions where IH increase the amplitude of the annual cycle by about 50%. An eddy-resolving model of the North Atlantic circulation is used to examine the effect of the different wind stresses on the seasonal cycle of the Florida Current. The transport predicted by the numerical model is in much better agreement with observations when the circulation is forced by IH than by HR, regarding both the annual mean (29.1 Sv vs 23.2 Sv) and the seasonal range (6.3 Sv vs 3.4 Sv)
Modern theoretical and technical approaches in plant morphology
Morphology is deeply rooted in organismal biology, which in recent years has gone through a steady decline in interest both at research institutions and funding agencies. In parallel with this development, morphology as a discipline has been marginalized and nowadays many think of it as just a classical and largely obsolete field of research. However, this is far from the truth. Thanks to modern theoretical concepts and novel technical applications, plant morphology has much to contribute to modern botanical and evolutionary research. In our presentation, we will first outline the application of High Resolution X-Ray Computed Tomography (HRXCT) to the study of plant structure. The ideal way to describe the morphological phenotype of a given organism is to build a three dimensional (3D) model, which may then be interpreted with respect to other types of data, e.g., metabolite content or functional groups of pollinators. We have developed simple but efficient lab protocols using contrasting agents such as phosphotungstate and bismuth tartrate that allow for the streamlined acquisition of high resolution phenotypic data and 3D-representations even of soft plant tissues such as floral organs, ovules, and meristematic tissues. To illustrate this, we will outline selected ongoing studies in comparative plant science that make use of high resolution tomography. In the second part of our talk, we will present a project on the floral morphospace. A striking feature of morphological variation is that due to developmental, functional, and phylogenetic constraints, not all theoretically possible architectures have been explored during evolution. A modern approach to studying the evolution of realized forms among possible ones is to construct morphospaces, i.e. theoretical, mathematical spaces describing and relating organismal phenotypes. Although widely applied in zoology, morphospace analyses and related approaches have so far been largely disregarded in botany, with notable exceptions in the field of pollination biology. Here, we use a morphospace approach to describe and quantify the morphological diversity (disparity) of flowers in the asterid order Ericales. To do so, we have built a dataset containing 37 floral characters for more than 380 species (275 genera) representative of the entire order. We have used non-parametric representations and statistics methods based on distance matrices to build and analyze a morphospace, in which we compare the relative positions of the different ericalean families. We quantify and interpret the disparity among these groups in the light of their taxonomic diversity, their evolutionary history, and their ecology. In addition, we analyze patterns of disparity between sterile, male, and female floral organs
- âŠ