Microtubule stabilization reduces scarring and causes axon regeneration after spinal cord injury

Hypertrophic scarring and poor intrinsic axon growth capacity constitute major obstacles for spinal cord repair. These processes are tightly regulated by microtubule dynamics. Here, moderate microtubule stabilization decreased scar formation after spinal cord injury in rodents through various cellular mechanisms, including dampening of transforming growth factor-β signaling. It prevented accumulation of chondroitin sulfate proteoglycans and rendered the lesion site permissive for axon regeneration of growth-competent sensory neurons. Microtubule stabilization also promoted growth of central nervous system axons of the Raphe-spinal tract and led to functional improvement. Thus, microtubule stabilization reduces fibrotic scarring and enhances the capacity of axons to grow.     

A review of carbon isotopes of phytoliths: implications for phytolith-occluded carbon sources

Journal of Soils and Sediments - Phytolith-occluded carbon (PhytOC) is mainly derived from the products of photosynthesis, which can be preserved in soils and sediments for hundreds-to-thousands of...     

Effects of accelerators on mobility of 14C-2,4-dichlorophenoxy butyric acid in plant cuticles depends on type and concentration of accelerator

Effects of diethyl suberate (DESU), diethyl sebacate (DES), dibutyl suberate (DBSU), dibutyl sebacate (DBS), and tributyl phosphate (TBP) on diffusion of 14C-2,4-dichlorophenoxy butyric acid (2,4-DB) across cuticular membranes (CM) was studied. Astomatous CM were isolated enzymatically from Stephanotis floribunda Brongn. leaves, and diffusion was measured at 20 degrees C. The alkyl-substituted dicarboxylic acids constitute a homologous series with carbon numbers increasing from C12 to C18. Molecular weights increased only moderately from 230.0 (DESU) to 314.5 (DBS), while partition coefficients varied over orders of magnitude from 92 (DESU), to 1213 (DES), to 15,988 (DBSU), to 210,762 (DBS). All the above compounds turned out to be accelerators as they increased 2,4-DB mobility by up to 40-fold with accelerator concentrations in the CM ranging from only 9.2 to 105 g kg(-1). Efficacy (2,4-DB mobility in the presence/mobility in the absence of accelerators) increased with increasing concentrations of accelerators in CM or in reconstituted cuticular waxes. Plotting efficacy vs accelerator concentration in the CM resulted in straight lines, and their slopes increased in the order DBS (0.14), DBSU (0.31), DES (0.51), and DESU (0.85). Hence, DESU was the most powerful accelerator in this series as it increased 2,4-DB mobility in the CM about 6 times more than DBSU. Waxes constitute the major barrier in plant cuticles, and plots of efficacy vs accelerator concentration in Stephanotis wax were also linear, but compared to CM slopes were steeper by factors of 3.20 (DBS), 2.97 (DBSU), 2.70 (DES), and 1.62 (DESU). TBP was similarly effective as DESU, but plots of efficacy vs concentration were not linear, and curves approached a plateau at 60-80 g kg(-1). These data are discussed with regard to suitability of these accelerators for formulating systemic pesticides.     

The Role of Biological Efficacy Evaluation and Methodology in Registration

For both governmental agencies and industry, considerable advantages, especially from extrapolation of data within a country or between countries, can be derived from co-ordinated action in the efficacy testing of new compounds. This has been recognized at an early stage in Europe, i.e. by France (1952) and the Federal Republic of Germany, where methods have been devised in a common agreement between official services and pesticide manufacturers. The European Weed Research Council started work for international alignment on herbicide testing, whereas EPPO, in 1971, initiated collaborative studies on rodents¹⁾ (5 methods), fungi (5 methods), insects and mites (10 methods). These guide-lines, having been approved by the 35 EPPO Governments, are already published or will be published in the near future; a further 29 methods are presently under study. Since 197, contacts have been taken with the American Society for Testing and Materials in order to reach inter-regional agreement on testing methods.     

Relationship between fecal crude protein concentration and diet organic matter digestibility in cattle

The positive relationship between fecal CP concentration and diet OM digestibility in cattle, which is based on increasing undigested microbial CP and decreasing fecal OM as OM digestibility increases, may be used as an indirect method for estimating diet OM digestibility from fecal CP concentration. Results of digestibility trials (445 individual observations) conducted at Hohenheim and Braunschweig, Germany, and at Gumpenstein, Austria, were used to study the relationship between CP concentration in feces (x, g/kg OM) and OM digestibility (y, %). The best fit was obtained with the curvilinear relationship y = ai -107.7e(-0.01515 x x), with a1 = 79.76 and a2 = 72.86 (R2 = 0.82; residual SD = 2.7; SE = 0.13), which takes into account the effects of location (i = 1 for Braunschweig and Hohenheim, and i = 2 for Gumpenstein). Dietary CP and crude fat concentration, and DMI had no effect on fecal CP content, whereas crude fiber content, proportion of concentrate in the diet, and forage type significantly affected CP concentration in feces; however, the magnitude of these effects was less than 2 percentage units, and the direction of the effect of proportion of concentrate in the diet was not uniform. The curvilinear relationship between fecal CP concentration (observed range, 100 to 300 g/kg of OM) and diet OM digestibility (observed range = 57 to 80%) may be used to estimate diet OM digestibility, particularly for field trials, as it requires no feed samples and does not physically restrict the animal.     

Rapid detection of canine parvovirus in feces using monoclonal antibodies and enzyme-linked immunosorbent assay

Monoclonal antibodies were used to develop a double antibody enzyme-linked immunosorbent assay for the detection of canine parvovirus (CPV) antigen in fecal samples. The assay was specific for the hemagglutinating protein of CPV and detected as little as 1.5 ng of virus within a 15-minute incubation period. The use of monoclonal antibodies against 2 epitopes on the CPV antigen permitted the simultaneous addition of test sample and enzyme-conjugated antibody, thus considerably simplifying the manipulations required for the assay. Results were visually determined without special instrumentation. Clinical studies revealed greater than 95% correlation between enzyme-linked immunosorbent assay results and hemagglutination titers.     

The use of digital image analysis and real‐time PCR fine‐tunes bioassays for quantification of Cercospora leaf spot disease in sugar beet breeding

Cercospora leaf spot, caused by the fungus Cercospora beticola, is a major fungal sugar beet disease worldwide and the cause of significant yield losses. The disease is most successfully countered by the introduction of genetic tolerance into elite sugar beet hybrids. To this end, breeding programmes require high quality biological assays allowing discrimination of minor differences between plants within a segregating population. This study describes the successful implementation of image analysis software in the bioassays for quantification of necrotic lesions at different stages of C. beticola infection, allowing selection on minor phenotypic differences during the sugar beet breeding process for C. beticola resistance. In addition, a real‐time PCR assay was developed for the quantification of C. beticola pathogen biomass in infected beet canopy. The use of both techniques, even in an early stage of infection, fine‐tunes current bioassays, allowing more accurate and efficient selection of resistant breeding material.     

Dipolar antiferromagnetism and quantum criticality in LiErF₄

Magnetism has been predicted to occur in systems in which dipolar interactions dominate exchange. We present neutron scattering, specific heat, and magnetic susceptibility data for LiErF(4), establishing it as a model dipolar-coupled antiferromagnet with planar spin-anisotropy and a quantum phase transition in applied field H(c|| = 4.0 ± 0.1 kilo-oersteds. We discovered non-mean-field critical scaling for the classical phase transition at the antiferromagnetic transition temperature that is consistent with the two-dimensional XY/h(4) universality class; in accord with this, the quantum phase transition at H(c) exhibits three-dimensional classical behavior. The effective dimensional reduction may be a consequence of the intrinsic frustrated nature of the dipolar interaction, which strengthens the role of fluctuations.     

A systematic survey of loss-of-function variants in human protein-coding genes

Genome-sequencing studies indicate that all humans carry many genetic variants predicted to cause loss of function (LoF) of protein-coding genes, suggesting unexpected redundancy in the human genome. Here we apply stringent filters to 2951 putative LoF variants obtained from 185 human genomes to determine their true prevalence and properties. We estimate that human genomes typically contain ~100 genuine LoF variants with ~20 genes completely inactivated. We identify rare and likely deleterious LoF alleles, including 26 known and 21 predicted severe disease-causing variants, as well as common LoF variants in nonessential genes. We describe functional and evolutionary differences between LoF-tolerant and recessive disease genes and a method for using these differences to prioritize candidate genes found in clinical sequencing studies.