Louisiana State University

About: Louisiana State University is a education organization based out in Baton Rouge, Louisiana, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 40206 authors who have published 76587 publications receiving 2566076 citations. The organization is also known as: LSU & Louisiana State University and Agricultural and Mechanical College.

A Paradigmatic and Methodological Examination of Information Systems Research from 1991 to 2001

Abstract: . The field of information systems (IS) has evolved for more than three decades. Although many schools of thought have emerged and even become well established, few historical analyses of research paradigms and methodologies have been undertaken. One of the rare exceptions is Orlikowski & Baroudi (1991). Yet, the IS research community has evolved substantially since 1991 in many aspects. A variety of journal outlets have emerged and become well established. More attention has been paid to paradigmatic and methodological issues. Political and professional contexts have also changed noticeably. Therefore, it should be an opportune time for the field to ask: ‘What changes are manifested in journal publications?’‘Is the field making progress regarding pluralism in IS research?’‘How will the field's publications practices change in the future?’ The purpose of this paper is to investigate these questions and, in turn, reflect on the paradigmatic and methodological progress made since 1991. We examined 1893 articles published in eight major IS publication outlets between 1991 and 2001. Our findings suggest that the long-term endeavours of interpretivist researchers might need to continue because the paradigmatic progress appears somewhat inconsequential; positivist research still dominates 81% of published empirical research. In particular, US journals, as opposed to European journals, tend to be more positivist, quantitative, cross-sectional and survey oriented. With respect to research design, survey research is still the most widely used method (41%), although case studies have gained substantial recognition (36%). Further, the increase of qualitative research (30%), empirical studies (61%) and longitudinal cases (33%) at the expense of laboratory experiments (18%) might suggest that IS researchers have become more interested in obtaining scientific knowledge in real world settings. In summary, we suggest that the field has been dominated by the positivist paradigm, despite calls to the contrary. Indeed, if the field was to truly embrace pluralism, it would have to find ways to fundamentally change the publication practices of the journal system, including the current tenure and promotion system, which pose considerable obstacles for the acceptance of alternative paradigms.

Astrophysical implications of the binary black hole merger gw150914

Abstract: The discovery of the gravitational-wave source GW150914 with the Advanced LIGO detectors provides the first observational evidence for the existence of binary black-hole systems that inspiral and merge within the age of the Universe. Such black-hole mergers have been predicted in two main types of formation models, involving isolated binaries in galactic fields or dynamical interactions in young and old dense stellar environments. The measured masses robustly demonstrate that relatively "heavy" black holes (≳25M⊙) can form in nature. This discovery implies relatively weak massive-star winds and thus the formation of GW150914 in an environment with metallicity lower than ∼1/2 of the solar value. The rate of binary black-hole mergers inferred from the observation of GW150914 is consistent with the higher end of rate predictions (≳1Gpc−3yr−1) from both types of formation models. The low measured redshift (z∼0.1) of GW150914 and the low inferred metallicity of the stellar progenitor imply either binary black-hole formation in a low-mass galaxy in the local Universe and a prompt merger, or formation at high redshift with a time delay between formation and merger of several Gyr. This discovery motivates further studies of binary-black-hole formation astrophysics. It also has implications for future detections and studies by Advanced LIGO and Advanced Virgo, and gravitational-wave detectors in space.

Antioxidant response to NaCl stress in salt-tolerant and salt-sensitive cultivars of cotton

Abstract: The mechanism(s) importing salt tolerance to plants remains unresolved. Although cotton (Gossypium hirsutum L.) is classified as salt-tolerant plant, variation in salt tolerance has been observed among different cultivars. The purpose of this study was to determine if more salt-tolerant cultivars contain higher constitutive or inducible levels of antioxidants than more salt-sensitive cultivars. Greenhouse-grown salt-tolerant (cv. Acaia 1517-88 and Acala 1517-SR2) and salt-sensitive (cv. Deltapine 50 and Stoneville 825) cotton plants treated with either 0 or 150 mM NaCl were analyzed for differences in growth and antioxidant capocities. The 150 mM NaCl treatment resulted in more than 40% reduction in growth of Deltapine 50 and Stoneville 825 and less than 30% reduction in the Acala cultivars. The more salt-tolerant cultivars had higher constitutive levels of catalase (121-215%) and u-tocopherol (312-420%). The salt treatment resulted in a 38 to 72% increase in peroxidase activity and a 55 to 101% increase in glutathione reductase activity in the Acala cultivars while the activities of these enzymes remained constant or decreased in the more sensitive cultivars. The Acala cultivars also exhibited a lower oxidized/reduced ascorbic acid ratio and a higher reduced/oxidized glutathione ratio than the more sensitive cultivars when grown at 150 mM NaCl. When subjected to a one-time salt treatment, lipid peroxidation in Deltapine 50 increased 51% over Acala 1517-88. These data indicate that protection from oxidative damage by higher levels of antioxidants and a more active ascorbate-glutathione cycle may be involved in tbe development of salt tolerance in cotton. Louisiana State Univ. in Shreveport and Louisiana State Univ. Agric. Center, Red River Res. Stn. Approved for publication by the Director of the Louisiana Agric. Exp. Stn. as manuscript no. 93-84-7172. Financial support was provided in part by Cotton Incorporated contract no. 91-723.

eIF-4E expression and its role in malignancies and metastases.

Abstract: The contribution of the mRNA cap-binding protein, eIF-4E, to malignant transformation and progression has been illuminated over the past decade. eIF-4E overexpression has been demonstrated in human tumors of the breast, head and neck, colon, prostate, bladder, cervix and lung, and has been related to disease progression. Overexpression of eIF-4E in experimental models dramatically alters cellular morphology, enhances proliferation and induces cellular transformation, tumorigenesis and metastasis. Conversely, blocking eIF-4E function by expression of antisense RNA, or overexpression of the inhibitory eIF-4E binding proteins (4E-BPs), suppresses cellular transformation, tumor growth, tumor invasiveness and metastasis. Although eIF-4E regulates the recruitment of mRNA to ribosomes, and thereby globally regulates cap-dependent protein synthesis, eIF-4E contributes to malignancy by selectively enabling the translation of a limited pool of mRNAs--those that generally encode key proteins involved in cellular growth, angiogenesis, survival and malignancy (e.g. cyclin D1, c-myc, vascular endothelial growth factor, matrix metalloprotease 9). A deeper understanding of the role of eIF-4E in regulating the translation of the diverse gene products involved in all aspects of malignancy will improve the capacity to exploit eIF-4E as a therapeutic target and as a marker for human cancer progression.

Synthesis and characterization of PLGA nanoparticles

Abstract: Poly(lactide-co-glycolide) (PLGA) nanoparticles of different physical characteristics (size, size distribution, morphology, zeta potential) can be synthesized by controlling the parameters specific to the synthesis method employed. The aim of this review is to clearly, quantitatively and comprehensively describe the top-down synthesis techniques available for PLGA nanoparticle formation, as well as the techniques commonly used for nanoparticle characterization. Many examples are discussed in detail to provide the reader with an extensive knowledge base on the important parameters specific to the synthesis method described and ways in which these parameters can be manipulated to control the nanoparticle physical characteristics.