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More efficient estimation of plant biomass

Question: The optimal use of the point intercept method (PIM) for efficient estimation of plant biomass has not been addressed although PIM is a commonly used method in vegetation analysis. In this study we compare results achieved using PIM at a range of efforts, we assess a method for calculating these results that are new with PIM and we provide a formula for planning the optimal use of PIM. Lo

Morphological and life history responses to predators in larvae of seven anurans

Amphibian larvae often face two major sources of mortality: pond desiccation and predation. Tadpoles of seven anuran species with different preferences for type of breeding habitat, on a hydroperiod scale, were tested for responses to the presence of predators by raising them experimentally in the presence and absence of a separately caged invertebrate predator that was fed on conspecific tadpoles

Probing of individual semiconductor nanowhiskers by TEM-STM

Along with rapidly developing nanotechnology, new types of analytical instruments and techniques are needed. Here we report an alternative procedure for electrical measurements on semiconductor nanowhiskers, allowing precise selection and visual control at close to atomic resolution. We use a combination of two powerful microscope techniques, scanning tunneling microscopy (STM) and simultaneous vi

Work Disability in Rheumatoid Arthritis -- Development over 15 Years and Evaluation of Predictive Factors Over Time.

Objective. To investigate work disability rates over 15 years in an early rheumatoid arthritis (RA) cohort and to evaluate predictive factors during the course of the study. Methods. All patients with early RA of working age (n = 148) were followed and treated at a team care unit. Mean disease duration at inclusion was 1 year. Work characteristics and disease-related variables were recorded annual

The use of leucine incorporation to determine the toxicity of phenols to bacterial communities extracted from soil

The toxicity of different phenols to the soil bacterial community was studied in the laboratory using the leucine incorporation technique. The effects of environmental factors such as pH, temperature and binding strength to soil particles were also assessed in order to deduce confounding effects due to the chemical and physical conditions in the soil from which the bacterial community was extracte

Prostate cancer as a first and second cancer: effect of family history

BACKGROUND: Diagnosis with prostate cancer has been reported to increase the risk of subsequent tumours. However, specific data on individuals with a parental history are not available so far. METHODS: On the basis of the nationwide Swedish Family-Cancer Database including 18,207 primary invasive prostate cancers, standardised incidence ratios (SIRs) were used to estimate the relative risks of sub

Three-dimensional pharmacology, a subject ranging from ignorance to overstatements.

Stereoselectivity has been known to play a role in drug action for 100 years or more. Nevertheless, chiral drugs have been developed and used as racemates, neglecting the fact that they comprise mixtures of two or more compounds which may have quite different pharmacological properties. A very limited access to pure enantiomers in the past has been responsible for this unsatisfactory state of affa

The inverted chevron plot measured by NMR relaxation reveals a native-like unfolding intermediate in acyl-CoA binding protein

The folding kinetics of bovine acyl-CoA binding protein was studied by N-15 relaxation dispersion measurements under equilibrium conditions. Relaxation dispersion profiles were measured at several concentrations of guanidine hydrochloride (GuHCl). The unfolding rate constant (k(u)) was determined under conditions favoring folding, for which the folding rate constant (k(f)) dominates the relaxation

A Floquet-Bloch Decomposition of Maxwell's Equations Applied to Homogenization

Using Bloch waves to represent the full solution of Maxwell's equations in periodic media, we study the limit where the material's period becomes much smaller than the wavelength. It is seen that for steady state fields, only a few of the Bloch waves contribute to the full solution. Effective material parameters can be explicitly represented in terms of dyadic products of the mean values of the no

Probing stability of the modular thermostable xylanase Xyn10A,

The thermophilic bacterium Rhodothermus marinus produces a modular xylanase (Xyn10A) consisting of two N-terminal carbohydrate-binding modules (CBMs), followed by a domain of unknown function, and a catalytic module flanked by a fifth domain. Both Xyn10A CBMs bind calcium ions, and this study explores the effect of these ions on the stability of the full-length enzyme. Xyn10A and truncated forms t

A comparison between the combustion of natural gas and partially reformed natural gas in an atmospheric lean premixed turbine-type combustor

A small-scale combustor was set up to analyze the combustion of natural gas and two mixtures of partially reformed natural gas. The partially reformed mixtures can be formed using biomass to feed the endothermic reforming reactions. Before combusting these mixtures in a gas turbine, experimental work was done on a primary zone combustion chamber to examine the combustor behavior when switching fro

Postnatally disturbed pancreatic islet cell distribution in human islet amyloid polypeptide transgenic mice

Objective: Islet amyloid polypeptide (IAPP)/amylin is produced by the pancreatic islet beta-cells, which also produce insulin. To study potential functions of IAPP, we have generated transgenic mice overexpressing human IAPP (hIAPP) in the beta-cells. These mice show a diabetic phenotype when challenged with an oral glucose load. In this study, we examined the islet cytoarchitecture in the hIAPP m

Monolithic macroporous albumin/chitosan cryogel structure: a new matrix for enzyme immobilization.

A novel monolithic macroporous material was developed by cross-linking hen egg albumin (HEA) and chitosan with glutaraldehyde at subzero temperatures. A macroporous cryogel structure allowed efficient mass transport of solutes within the material. In one application, albumin was partially replaced with active enzymes (glucose oxidase and horseradish peroxidase) resulting in the production of macro

Construction of polyamine-modified uridine and adenosine derivatives-evaluation of DNA binding capacity and cytotoxicity in vitro

We here report the synthesis of the two polyamine-based nucleoside derivatives 5-{[bis-(3-aminopropyl)amino]acetamido-1-propynyl}uridine and 2-{[bis-(3-aminopropyl)amino]-acetamido-1-propynyl}adenosine. The various polyamine derivatives have been used in thermal melting analysis using DNA from herring testes, and in cellular studies using four different cell lines. The compounds were all found to

Carbon sequestration in peatland: patterns and mechanisms of response to climate change

The response of peatlands to changes in the climatic water budget is crucial to predicting potential feedbacks on the global carbon (C) cycle. To gain insight on the patterns and mechanisms of response, we linked a model of peat accumulation to a model of peatland hydrology, then applied these models to empirical data spanning the past 5000 years for the large mire Store Mosse in southern Sweden.

Genotyping of single nucleotide polymorphisms using base-quenched probe: A method does not invariably depend on the deoxyguanosine nucleotide

Most available methods for detecting single nucleotide polymorphisms (SNPs) are based principally on the system that can produce an increased fluorescence signal during hybridization. In the current study, we demonstrate a method of base-quenched probe for polymerase chain reaction (PCR) genotyping that requires only a pair of primers and one fluorescent probe and does not invariably depend on the