A study of physico-chemical characteristics of Ugborikoko/Okere stream as an index of pollution

A total of 8 samples were collected from strategic points along the Ugborikoko/Okere creek. The levels of the physico-chemical parameters and heavy metal pollutants were determined. Results of bothphysico-chemical characteristics and heavy metals revealed some degree of pollution in the creek. The mean values of pH, temperature, turbidity, conductivity, total dissolved solids, total suspended solids and chloride were 6.8, 30.3°C, 106.53 NTU, 471.45 ohms/cm, 354.56 mg/l, 123.56 mg/l and 78.11 mg/l respectively. The average value obtained for oil and grease was 14.13 ppm. The average value for the heavy metals were 2.258 ppm for iron, 0.0729 ppm for cadmium, 0.4225 ppm for zinc, 0.0997 ppm formanganese, 0.0236 ppm for copper, 0.2117 ppm for nickel. The results obtained indicated a significant level of pollution of the Ugborikoko/Okere creek. It was observed that the levels of iron, lead, chromium, cadmium, manganese and nickel in the samples were not in compliance with recommended standards set by world health organization for inland (fresh) and potable water

Multiplicity in Early Stellar Evolution

Observations from optical to centimeter wavelengths have demonstrated that multiple systems of two or more bodies is the norm at all stellar evolutionary stages. Multiple systems are widely agreed to result from the collapse and fragmentation of cloud cores, despite the inhibiting influence of magnetic fields. Surveys of Class 0 protostars with mm interferometers have revealed a very high multiplicity frequency of about 2/3, even though there are observational difficulties in resolving close protobinaries, thus supporting the possibility that all stars could be born in multiple systems. Near-infrared adaptive optics observations of Class I protostars show a lower binary frequency relative to the Class 0 phase, a declining trend that continues through the Class II/III stages to the field population. This loss of companions is a natural consequence of dynamical interplay in small multiple systems, leading to ejection of members. We discuss observational consequences of this dynamical evolution, and its influence on circumstellar disks, and we review the evolution of circumbinary disks and their role in defining binary mass ratios. Special attention is paid to eclipsing PMS binaries, which allow for observational tests of evolutionary models of early stellar evolution. Many stars are born in clusters and small groups, and we discuss how interactions in dense stellar environments can significantly alter the distribution of binary separations through dissolution of wider binaries. The binaries and multiples we find in the field are the survivors of these internal and external destructive processes, and we provide a detailed overview of the multiplicity statistics of the field, which form a boundary condition for all models of binary evolution. Finally we discuss various formation mechanisms for massive binaries, and the properties of massive trapezia.Comment: Accepted for publication as a chapter in Protostars and Planets VI, University of Arizona Press (2014), eds. H. Beuther, R. Klessen, C. Dullemond, Th. Hennin

Subregion-Specific Modulation of Excitatory Input and Dopaminergic Output in the Striatum by Tonically Activated Glycine and GABAA Receptors

The flow of cortical information through the basal ganglia is a complex spatiotemporal pattern of increased and decreased firing. The striatum is the biggest input nucleus to the basal ganglia and the aim of this study was to assess the role of inhibitory GABAA and glycine receptors in regulating synaptic activity in the dorsolateral striatum (DLS) and ventral striatum (nucleus accumbens, nAc). Local field potential recordings from coronal brain slices of juvenile and adult Wistar rats showed that GABAA receptors and strychnine-sensitive glycine receptors are tonically activated and inhibit excitatory input to the DLS and to the nAc. Strychnine-induced disinhibition of glutamatergic transmission was insensitive to the muscarinic receptor inhibitor scopolamine (10 μM), inhibited by the nicotinic acetylcholine receptor antagonist mecamylamine (10 μM) and blocked by GABAA receptor inhibitors, suggesting that tonically activated glycine receptors depress excitatory input to the striatum through modulation of cholinergic and GABAergic neurotransmission. As an end-product example of striatal GABAergic output in vivo we measured dopamine release in the DLS and nAc by microdialysis in the awake and freely moving rat. Reversed dialysis of bicuculline (50 μM in perfusate) only increased extrasynaptic dopamine levels in the nAc, while strychnine administered locally (200 μM in perfusate) decreased dopamine output by 60% in both the DLS and nAc. Our data suggest that GABAA and glycine receptors are tonically activated and modulate striatal transmission in a partially subregion-specific manner

True value: Calculating and communicating the value of library labor

We have seen a multitude of methods used to calculate and communicate the value of libraries to society. However, most of the existing techniques—such as return on investment or individual receipts that provide cost savings information to patrons—focus on the value of resources and services: that is, the products provided to library users and related stakeholders. None of these calculations quantitatively consider the value inherent in the labor necessary to provide those resources and services and make them available. This project draws on critical design (Dunne 1999; Bardzell & Bardzell 2013)—a specific form of activist research inquiry that uses the creation of provocative artifacts to challenge established assumptions, shift perspectives, and think in new ways—to uncover and communicate the value of library labor. Using the results of a nationwide survey distributed to librarians and library workers in varying contexts, we are creating an interactive website that will allow library users and other stakeholders to calculate the value of library services, including the value of labor. Without this fundamental consideration, librarianship will always lack successful communication of true calculation of value—one that may lead to increased understanding of the full range of what libraries offer society

Rarely acknowledged and often unrecognized: Exploring emotional labor across library work tasks

In the seminal work on emotional labor (EL), Arlie Hochschild (1983, 2012) defines EL as “the management of feeling to create a publicly observable facial and bodily display.” EL is “sold for a wage” (Hochschild, 2012). To date, there have been a few studies on emotional labor in librarianship. Julien and Genuis (2009) found EL to have a central place in the experiences of instructional librarians. Shuler and Morgan (2013) interviewed reference librarians, finding they are expected to perform EL yet are not formally trained to do so. Matteson and Miller (2013) surveyed librarians nationwide, with statistical analysis confirming EL present in librarianship. Matteson et al. (2015) asked MLIS holders to reflect via diary entries on performed EL. The results of these studies have clearly demonstrated EL as a part of librarianship. To further advance the study of EL in librarianship, our work offers a quantitative perspective on EL across different types of library labor. We used a nationwide survey, recording types of library work performed, EL labor relative to task performed, with a section for open-ended comments. We sought to include all library workers, with a shorter questionnaire that still covers the established components of EL, such as hiding negative emotion. We will discuss how EL happens across the librarianship, with specific attention to differences to EL amongst various library tasks and between academic and public libraries based on the results of the survey, and implications for future studies

The Formation of Brown Dwarfs as Ejected Stellar Embryos

We conjecture that brown dwarfs are substellar objects because they have been ejected from small newborn multiple systems which have decayed in dynamical interactions. In this view, brown dwarfs are stellar embryos for which the star formation process was aborted before the hydrostatic cores could build up enough mass to eventually start hydrogen burning. The disintegration of a small multiple system is a stochastic process, which can be described only in terms of the half-life of the decay. A stellar embryo competes with its siblings in order to accrete infalling matter, and the one that grows slowest is most likely to be ejected. With better luck, a brown dwarf would therefore have become a normal star. This interpretation of brown dwarfs readily explains the rarity of brown dwarfs as companions to normal stars (aka the ``brown dwarf desert''), the absence of wide brown dwarf binaries, and the flattening of the low mass end of the initial mass function. Possible observational tests of this scenario include statistics of brown dwarfs near Class 0 sources, and the kinematics of brown dwarfs in star forming regions while they still retain a kinematic signature of their expulsion. Because the ejection process limits the amount of gas brought along in a disk, it is predicted that substellar equivalents to the classical T Tauri stars should be very rare.Comment: 8 pages, 1 figure, Accepted by the Astronomical Journa

S-nitrosylation of the zinc finger protein SRG1 regulates plant immunity

Upon pathogen infection plants accumulate nitric oxide which subsequently regulates defence gene expression. Here, the authors show that S-nitrosylation of the zinc finger transcription factor SRG1 affects transcriptional suppression and contributes to activation of defence responses

Invisible Labor, Invisible Value : Unpacking Traditional Assessment of Academic Library Value

Il s\u27agit d\u27un article sur l’évaluation de la valeur des bibliothèques universitaires aux États-Unis