93 research outputs found
Review of State Legislative Sourcebook
Review of Hellebust, Lynn. State Legislative Sourcebook--1986: A Resource Guide to Legislative Information in the Fifty States
Effects of prolonged darkness and temperature on the lipid metabolism in the benthic diatom Navicula perminuta from the Arctic Adventfjorden, Svalbard
The Arctic represents an extreme habitat for phototrophic algae due to long periods of darkness caused by the polar night (~4 months darkness). Benthic diatoms, which dominate microphytobenthic communities in shallow water regions, can survive this dark period, but the underlying physiological and biochemical mechanisms are not well understood. One of the potential mechanisms for long-term dark survival is the utilisation of stored energy products in combination with a reduced basic metabolism. In recent years, water temperatures in the Arctic increased due to an ongoing global warming. Higher temperatures could enhance the cellular energy requirements for the maintenance metabolism during darkness and, therefore, accelerate the consumption of lipid reserves. In this study, we investigated the macromolecular ratios and the lipid content and composition of Navicula cf. perminuta Grunow, an Arctic benthic diatom isolated from the microphytobenthos of Adventfjorden (Svalbard, Norway), over a dark period of 8 weeks at two different temperatures (0 and 7 °C). The results demonstrate that N. perminuta uses the stored lipid compound triacylglycerol (TAG) during prolonged dark periods, but also the pool of free fatty acids (FFA). Under the enhanced temperature of 7 °C, the lipid resources were used significantly faster than at 0 °C, which could consequently lead to a depletion of this energy reserves before the end of the polar night. On the other hand, the membrane building phospho- and glycolipids remained unchanged during the 8 weeks darkness, indicating still intact thylakoid membranes. These results explain the shorter survival times of polar diatoms with increasing water temperatures during prolonged dark periods
Measuring soluble salts in soils via portable x-ray fluorescence spectrometry
Soil scientists have been using the same quantification methods for soluble salts for decades. Yet they have long struggled with an effective method for quantifying gypsum content, because current methods are fraught with problems. Saline soil has been historically defined as soil containing salts more soluble than gypsum (e.g., various combinations of Na+, Mg2+, Ca2+, K+, Cl-, SO42-, HCO3- and CO32-) to the extent that soil fertility is severely reduced across a wide array of climates and geological settings. Since salinity is not germane to specific soil characteristics such as texture or parent material, it can be challenging to predict salt concentrations within a profile. Given the success of previous studies using portable x-ray fluorescence (PXRF) as a tool for measuring soil characteristics, the evaluation of soluble salts in soil with PXRF seems timely. Not only does this newer technology offer more accurate, quantifiable data to investigators, it produces results in-situ, in seconds. Recent enhancements to PXRF spectrometers have provided better detection limits especially for lighter elements such as S and Cl, a key component of gypsum and other salts. Thus, this research aimed to test the effectiveness of PXRF as a means of directly quantifying gypsum and salinity in soils. A total of 102 soil samples containing a wide variety of gypsum (~2–95%) and 122 samples with various salt concentrations were subjected to both traditional laboratory analysis (thermogravimetry and electrical conductivity, respectively) and elemental analysis via PXRF. Simple and multiple linear regression were used to establish the relationship between the two data sets. Log transformation of some data sets was necessary to normalize the data. Using simple linear regression between laboratory and PXRF data, an R2 of 0.88 was produced for the gypsum data, and an R2 of 0.839 was produced for salinity data. Similarly, simple linear regression for laboratory-quantified gypsum vs. PXRF S produced an R2 of 0.91. Multiple linear regression of laboratory quantified gypsum vs. both PXRF S and Ca produced an R2 of 0.91, and 0.8669 for laboratory determined EC (dS m-1) vs. PXRF Cl, S, Ca, and K. No significant differences were observed between model generation and validation data sets. Overall, PXRF shows great promise for the direct quantification of soluble salts in soils
Have think tanks in Washington D.C. become politicized?
The paper addresses the following research question: Have think tanks in Washington D.C. become politicized from 1910 to 2010, and if so why? “Politicization” is made empirically tangible with a new primary database of all D.C. think tanks existent over the last century. Public policy-oriented research and advocacy organizations are studied from an explicitly evolutionary approach for the first time. It is found that while think tanks steadily accumulated until the early 1970s, their numbers increased fivefold from the late 1970s onwards. D.C. think tanks have, in fact, become significantly politicized over time: ideological advocacy think tanks (embracing broadly “conservative” or “liberal” worldviews)
came to outnumber organizationally objective (“centrist or not identifiably ideological”)
academic or contract research think tanks. Most of today’s advocacy think tanks embrace
identifiably conservative ideologies. Based on chronological process tracing, it is shown that changes in the non-profit resource and tax environment, a relatively weak party system and frequent partisan polarization are important explanatory factors behind the politicization phenomenon. Far from living up to their constructive potential, it is argued, the capital city’s think tanks now frequently hysterize rather than scrutinize policymaking, applying politico-ideological principles of economic interventionism and social justice or, far more often, free markets, limited government and individual liberties to all things public policy. Main scholarly and practical implications of think tanks’ politicization are sounded out. (Hertie Student Paper Series is an online publication series of
Hertie School of Governance
The Constitutionality of Campaign Finance Regulation: Should Differences in a State\u27s Political History and Culture Matter?
In its Western Tradition Partnership decision, the Montana Supreme Court ruled that the constitutionality of state campaign finance restrictions should be reviewed with particular reference to the political history and traditions of the state enacting the regulation. In so holding, the Montana Court recognized that the states have different political cultures and that these different political cultures can lead to very different regulatory concerns. On this basis, the Montana Court concluded that a type of campaign finance restriction that may be unconstitutional when applied to national elections or to elections in one state might be constitutionally permissible when applied to elections in another. The United States Supreme Court did not take this argument seriously. It should have. The political cultures of the states are different, and applying a one-size-fits-all prescription to the constitutionality of campaign finance rules undercuts both this reality and sound principles and protections of federalism
Intrapopulation heterogeneity of cell volume for the alga <i>Attheya ussurensis</i> under stress conditions
Intrapopulation heterogeneity of cell volume is estimated for the diatom Attheya ussuriensis acclimated to 17.5 ‰ salinity after its transfer to the media with salinity 8.8 ‰ (hypoosmotic conditions), 35.0 ‰ (hyperosmotic conditions) and 17.5 ‰ (control) at different stages of growth, under conditions of different nutrients supply and interaction with the diatom Conticribra weissflogii . The samples of A. ussuriensis were collected in the Ussuri Bay (Japan Sea) from an area with pure culture of this species. The cell volume of A. ussurensis increased under conditions of optimal nutrient supply and decreased under shortage of nutrients, irrespective on salinity. However, the salinity influenced on variability of the cell volume; the intrapopulation heterogeneity was formed mainly by size variation of large cells. The cell volume probability distribution became more asymmetric at change of growth stages, for any salinity as well. Clustering of cell volume distribution did not depend on salinity and nutrient supply. Both asymmetry and clustering of cell volume distribution for A. ussuriensis were rather different between mono- and mixed cultures in hypo- and hyperosmotic conditions but were almost equal in the control
The Constitutionality of Campaign Finance Regulation: Should Differences in a State\u27s Political History and Culture Matter?
In its Western Tradition Partnership decision, the Montana Supreme Court ruled that the constitutionality of state campaign finance restrictions should be reviewed with particular reference to the political history and traditions of the state enacting the regulation. In so holding, the Montana Court recognized that the states have different political cultures and that these different political cultures can lead to very different regulatory concerns. On this basis, the Montana Court concluded that a type of campaign finance restriction that may be unconstitutional when applied to national elections or to elections in one state might be constitutionally permissible when applied to elections in another. The United States Supreme Court did not take this argument seriously. It should have. The political cultures of the states are different, and applying a one-size-fits-all prescription to the constitutionality of campaign finance rules undercuts both this reality and sound principles and protections of federalism
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Heterotrophic bacteria associated with a feed algae for oyster larvae
Aerobic heterotrophic bacteria associated with oyster larvae feed
algae Isochrysis galbana, Monochrysis lutheri and Pseudoisochrysis
paradoxa were isolated and enumerated. The bacterial numbers ranged
from 7.8x10³ to 3.9x10⁶ CFU per ml. The bacteria associated with
Pseudoisochrysis sp. were identified and the majority of isolates
belonged to genera Leucothrix (51%). Also present were members of
Pseudomonas III sp. (19.1%), atypical Moraxella sp. (16.8%), Moraxella
sp. (7.2%) and Flavobacterium sp. (5.9%).
The growth of bacteria on marine agar was fastidious and took four
days to form visible colonies. None of the bacterial isolates grew in
buffered salt broth in which the algae had been grown. Marine broth
supplemented with 0.1% beef extract best supported the growth of the
isolates, while ferric citrate (3x10⁻⁴ M) supported their growth in
buffered salt broth.
The role of algae as a solid support for bacteria was investigated
by studying the attachment of bacteria on glass slides suspended in the
growth medium. The percent of Leucothrix sp. attached to the slide was
2.1-3.0%. This was four to six times greater than that of Staphylococcus
(0.5%), an organism well known for its commensal growth on skin
and mucus membranes of man and animal.
Hydrophobic attraction, which is thought to play an important role
in the orientation of bacteria to solid surfaces, was studied by measuring
the adsorption of bacteria on hydrocarbons introduced to a bacterial
suspension. Leucothrix sp. exhibited the strongest affinity, whereas
Flavobacterium sp. and Pseudomonas sp. adsorbed the least.
An attempt to obtain an axenic culture of algae by antibiotic
treatment was unsuccessful due to the detrimental effect of antibiotics
to both algae and bacteria
Effects of High-Molecular-Weight Dissolved Organic Matter on Nitrogen Dynamics in the Mississippi River Plume
The dynamics of N and its interactions with labile dissolved organic C (DOC), bacteria, and phytoplankton were studied to determine potential effects of dissolved organic matter (DOM) and light on N dynamics in surface waters of the Mississippi River (USA) plume in the Gulf of Mexico. Bacterial uptake of added labeled N compounds ( 15NH4+ or 15N-labeled dissolved free amino acids. DFAA) was stimulated more by high-molecular-weight (HMW, \u3el kDa) DOM than by low-molecular-weight (LMW, \u3c l kDa) DOM. An index that inversely indicated the presence of labile DOC was defined as the fraction of assimilated Amino acid-15N that was Recovered as 15N -Ammonium (ANRA), following the additions of high-levels (4 µM) of 15N -DFAA. ANRA ratios were high in the absence of other available carbon sources because heterotrophic bacteria were forced to use the added amino acids as a carbon source for respiration rather than as a nutrient source for biomass formation. In dynamic light/dark experiments, conducted with in situ populations of organisms, uptake rates of added 15NH4+ were significantly enhanced both by the presence of light and by the addition of HMW DOM. Uptake rates of added 15N -labeled DFAA were increased by the addition of HMW DOM but not by light. ANRA ratios were consistently lower in the presence of added HMW DOM than in controls. Added HMW DOM thus appeared to stimulate the incorporation of assimilated DFAA into bacterial biomass. Bacterial growth rates were relatively high in both light and dark bottles with DFAA additions and in light bottles with HMW DOM plus NH4+ additions, but they remained comparatively low in dark bottles with added NH4+ These results are consistent with the idea that bacterial N dynamics in these euphotic waters may be tightly coupled to photosynthetic activities over short time scales
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