Specific detection and differentiation of two subspecies of Fusobacterium necrophorum by PCR

The phylogenic relationships of two subspecies of Fusobacterium necrophorum were investigated by randomly amplified polymorphism DNA-polymerase chain reaction (RAPD-PCR). With each of the 12 random primers, the DNA fingerprints generated were subjected to cluster analysis for dendrograms. The analysis indicated that twelve strains were organized into two major clusters, and that all strains of each subspecies were confined to one cluster. Furthermore, two of the random primers examined each generated a unique band in F. n. necrophorum strains. We cloned these specific bands and determined the nucleotide sequences. A search for amino acid sequence homologies revealed that the two specific fragments had significant homology to the rpoB gene of Lactococcus lactis subsp. lactis and the hemagglutinin-related protein gene of Ralstonia solanacearum, respectively. New specific primers designed for the rpoB gene were able to amplify 900bp fragments from both subspecies. However, the specific primers designed for the hemagglutinin-related protein gene amplified only a 250bp fragment of the genome of the F. n. necrophorum strains, suggesting that this gene is unique to F. n. necrophorum. These results were further confirmed by dot blot hybridization. Finally, a one-step duplex PCR technique in a single tube for the rapid detection and differentiation of the F. necrophorum subspecies was developed.     

Suitability of Two Methods for Determination of Point of Zero Charge (PZC) of Adsorbents in Soils

The points of zero charge (PZC) of manganese oxide (MnO₂), titanium dioxide (TiO₂), aluminum (Al) laterite, ferruginous (Fe) laterite, aluminum oxide (Al₂O₃), and a commercial activated carbon sample (AC001) were determined using acid-base potentiometric (PT) and mass titration (MT). The MT technique has been used extensively for carbonaceous materials but less for soils. In addition, little work has been done on the PZC of these metal oxides and carbon materials under similar experimental conditions concurrently. Our aim is to buttress the ease of MT usage over PT in routine laboratory analysis. The experimental PZC measured by acid-base potentiometric and mass titrations respectively were 4.97 and 4.11 for MnO₂; 5.38 and 5.74 for TiO₂; 4.19 and 4.08 for Al laterite; and 4.45 and 4.10 for Fe laterite. For Al₂O₃ and activated carbon, mass titration gave 7.53 and 8.41 respectively. Calculated standard deviations between the means of PT and MT were less than 1, and Student’s t-test at 95% confidence interval (CI) gave a P value of 0.135, suggesting that there is no significant difference between PT and MT and buttressing the reliability of the experimental procedures. In routine laboratory work, mass titration should be preferred for PZC measurement of (hydr)oxides and soil materials because it saves time.     

Effects of Carboxymethylcelluloses （CMC） on Some Hydraulic Properties of Sandy Soil

The property of hydrophilic polymers capable absorbing huge volumes of water led to many practical applications of these new materials in arid regions for improving the water retention in sandy soils. Effects of four carboxymethylcelluloses (CMC), mixed at various rates with the sandy soil, on the water-holding capacity and hydraulic conductivity (KS ) when leached with distilled water (simulating rain), tap water, and saline water were evaluated. The maximum water absorption of CMCs ranged between 80 and 100 kg ? kg-1 of polymer; however, the absorbent swelling capacity decreased significantly with increasing the salt concentration in the solution. The water absorption capacity of CMCs decreased significantly when incorporated in the sandy soil compared to that of the absorbent alone. Application of CMC increased significantly the available water content up to 3 ± 0.5 times. All soils treated with CMCs showed a significant lower in KS compared to the control soil. Meanwhile, KS was found increased with increasing the salt concentration in the leaching solution. This understanding of characteristics of the absorbents and the interactions among absorbents, soil, and irrigation water quality would be of help in water management of sandy soil.     

Patterns of Broadband Efficiency in the U.S

Data envelopment analysis is used to assess the efficiency of broadband Internet adoption and use in the U.S. Analyses at the state level from 2005 to 2007 suggest that broadband adoption and use is not equally efficient across the U.S. states. Although the instantaneous efficiencies are relatively high for many states, the changes in total factor productivity suggest that the efficiency of broadband adoption and use still increases over time. Moreover, it is observed that efficiency values are often spatially autocorrelated, which suggests spatial dependency from spillovers or interstate competition. This leads to a particular spatial diffusion pattern in broadband adoption. Although states have different strategies in support of broadband expansion they need to identify their shortcomings and use the appropriate mix of inputs (and outputs) to improve their efficiencies.     

Identification of the thymidine kinase gene of infectious laryngotracheitis virus.

An an initial step in the development of a recombinant poultry infectious laryngotracheitis virus (ILTV) vaccine, we report on the identification, cloning, and sequencing of a thymidine kinase (tk) gene from a virulent U.S. field isolate of ILTV. Degenerate oligonucleotide primers for the consensus nucleotide (ATP) binding site and the nucleoside (thymidine) binding site of other herpesvirus tk genes were used in the polymerase chain reaction (PCR) to amplify a fragment of ILTV DNA. The 344-base-pair (bp) amplified fragment was cloned into plasmid pKSII and used in Southern hybridizations to locate the ILTV tk gene on a 2.4-kb HindIII fragment. Upon cloning and sequencing this fragment, a 1089-bp open reading frame was identified, which is predicted to encode a protein demonstrating 27.9% amino acid homology to the herpes simplex virus type 1 (HSV-1) thymidine kinase protein. Analysis of the sequence revealed one region of difference from that reported for the Thorne strain of ILTV. In addition, the portion of the TK protein corresponding to the nucleotide binding domain is highly conserved among the avian herpesviruses.     

A compound from smoke that promotes seed germination

Exposure of seeds to aerosol smoke or crude smoke extracts stimulates the germination of a number of fire-dependent and fire-independent plant species. We now report the identity of a germination-promoting compound present in plant- and cellulose-derived smoke. The structure of this compound, deduced from spectroscopic analysis and confirmed by synthesis, was shown to be that of the butenolide 3-methyl-2H-furo[2,3-c]pyran-2-one (1). Here we show that 1 promotes germination of a number of plant species at a level similar to that observed with plant-derived smoke water.     

Identification and functional characterization of brainstem cannabinoid CB2 receptors

The presence and function of CB2 receptors in central nervous system (CNS) neurons are controversial. We report the expression of CB2 receptor messenger RNA and protein localization on brainstem neurons. These functional CB2 receptors in the brainstem were activated by a CB2 receptor agonist, 2-arachidonoylglycerol, and by elevated endogenous levels of endocannabinoids, which also act at CB1 receptors. CB2 receptors represent an alternative site of action of endocannabinoids that opens the possibility of nonpsychotropic therapeutic interventions using enhanced endocannabinoid levels in localized brain areas.