Microbiological Degradation of Malodorous Substances of Swine Waste under Aerobic Conditions

Phenol, p-cresol, and volatile fatty acids (VFA; acetic, propionic, isobutyric, butyric, isovaleric, and valeric acids) were used as odor indicators of swine waste. Aeration of the waste allowed the indigenous microorganisms to grow and degrade these malodorous substances. The time required for degradation of these substances varied according to the waste used, and it was not necessarily related to their concentrations. Using a minimal medium which contained one of the malodorous compounds as sole carbon source, we have selected from swine waste microorganisms that can grow in the medium. The majority of these microorganisms were able to degrade the same substrate when inoculated in sterilized swine waste but with an efficiency varying from one strain to the other. None of these strains was able to degrade all malodorous substances studied. Within 6 days of incubation these selected strains degraded the following: Acinetobacter calcoaceticus, phenol and all VFA; Alcaligenes faecalis, p-cresol and all VFA; Corynebacterium glutamicum and Micrococcus sp., phenol, p-cresol, and acetic and propionic acids; Arthrobacter flavescens, all VFA. On a laboratory scale, the massive inoculation of swine waste with C. glutamicum or Micrococcus sp. accelerated degradation of the malodorous substances. However, this effect was not observed with all of the various swine wastes tested. These results suggest that an efficient deodorization process of various swine wastes could be developed at the farm level based on the aerobic indigenous microflora of each waste.     

Genetic variation in the Y chromosome and sex-biased DNA methylation in somatic cells in the mouse

Mammalian Genome - Several lines of evidence suggest that the presence of the Y chromosome influences DNA methylation of autosomal loci. To better understand the impact of the Y chromosome on...     

Comparative Analysis of the 16S to 23S Ribosomal Intergenic Spacer Sequences of Bacillus thuringiensis Strains and Subspecies and of Closely Related Species

Volume 61, no. 4, p. 1624, column 2, lines 38-41: The sentence should read "For example, at position 21, the G nucleotide (Fig. 1) was present in all the ISR B. thuringiensis subspecies except for B. thuringiensis subsp. tenebrionis (Te4), which contained an A." Page 1624, column 2, line 45: "Position 62" should read "position 11." Page 1624, column 2, line 47: "Position 90" should read "position 39." Page 1624, column 2, line 49: "Position 83" should read "position 32." Page 1625, column 1, line 3: "Position 83" should read "position 32." Page 1626, column 1, line 1: "Positions 62, 90, and 165, and one deletion at position 83" should read "positions 11, 39, and 114, and one deletion at position 32." [This corrects the article on p. 1623 in vol. 61.].     

Long Span DNA Paired-End-Tag (DNA-PET) Sequencing Strategy for the Interrogation of Genomic Structural Mutations and Fusion-Point-Guided Reconstruction of Amplicons

Structural variations (SVs) contribute significantly to the variability of the human genome and extensive genomic rearrangements are a hallmark of cancer. While genomic DNA paired-end-tag (DNA-PET) sequencing is an attractive approach to identify genomic SVs, the current application of PET sequencing with short insert size DNA can be insufficient for the comprehensive mapping of SVs in low complexity and repeat-rich genomic regions. We employed a recently developed procedure to generate PET sequencing data using large DNA inserts of 10–20 kb and compared their characteristics with short insert (1 kb) libraries for their ability to identify SVs. Our results suggest that although short insert libraries bear an advantage in identifying small deletions, they do not provide significantly better breakpoint resolution. In contrast, large inserts are superior to short inserts in providing higher physical genome coverage for the same sequencing cost and achieve greater sensitivity, in practice, for the identification of several classes of SVs, such as copy number neutral and complex events. Furthermore, our results confirm that large insert libraries allow for the identification of SVs within repetitive sequences, which cannot be spanned by short inserts. This provides a key advantage in studying rearrangements in cancer, and we show how it can be used in a fusion-point-guided-concatenation algorithm to study focally amplified regions in cancer.     

A reproducible method for producing and quantifying the stages of fracture repair.

Male CD-1 mice, 4 to 6 months of age, were used to establish a reproducible model to study the stages of fracture repair. A custom-designed fracture apparatus was constructed, and trials with it demonstrated its capacity to reliably reproduce a closed fracture of the tibia. Dietary and sleep habits in the treated mice were the same as unfractured control mice. Four stages of fracture repair were documented and the duration of each stage was quantifiable and reproducible. The last stage of fracture repair was completed by 21 days postfracture. The reproducibility of the fracture, the reproducibility of the times and stages of fracture repair, the relatively short time to complete the fracture repair process, and the minimal discomfort which allowed the mice to maintain a normal daily routine, suggest that this is an ideal animal model for studying the fracture repair process.     

In vitro regeneration of Gaillardia pulchella Foug.

Young leaf and internodal stem segments of Gaillardia pulchella, collected from wild species re-established in the greenhouse, were used to initiate callus on Murashige & Skoog medium supplemented with NAA (2.0 mgl⁻¹) and BA (0.4 mgl⁻¹). Callus formed after 10 to 14 days in the dark. Cultures were transferred to fresh medium and placed under lighted conditions where shoot formation occurred approximately 14 to 30 days after initiation. Callus sub-cultured at 14 to 21-day intervals continued to produce primordia for several weeks. Flowers were produced by regenerated shoots maintained on MS medium, but roots did not develop until the plantlets were transferred to soil conditions.     

Effect of climatic variation on the morphological characteristics of 37‐year‐old balsam fir provenances planted in a common garden in New Brunswick,Canada

The extent of the effect of projected changes in climate on trees remains unclear. This study investigated the effect of climatic variation on morphological traits of balsam fir [Abies balsamea (L.) Mill.] provenances sourced from locations spanning latitudes from 44° to 51°N and longitudes from 53° to 102°W across North America, growing in a common garden in eastern Canada. Lower latitude provenances performed significantly better than higher latitude provenances (p < .05) with regard to diameter at breast height (DBH), height (H), and crown width (CW), a distinction indicative of genotypic control of these traits. There was, however, no significant difference among provenances in terms of survival (p > .05), an indication of a resource allocation strategy directed at survival relative to productivity in higher latitude provenances as seen in their lower DBH, H, and CW compared to the lower latitude provenances. Temperature had a stronger relationship with DBH, H, and CW than precipitation, a reflection of adaptation to local conditions in populations of the species along latitudinal gradients. Both climatic variables had some effect on tree survival. These results suggest that the response of balsam fir to climatic variation will likely not be uniform in the species, but differ based on genetic characteristics between populations located in the northern and southern parts of the species’ range. Population differences in response to climatic variation may be evident earlier in growth traits, compared to survival in balsam fir. The findings of this study will facilitate modeling in the species that is reflective of genetic variation in response to climatic conditions, and guide provenance selection for utilization in terms of productivity or resilience as well as breeding programs directed at obtaining species that possibly combine both traits.     

The function of Ca channel subtypes in exocytotic secretion: new perspectives from synaptic and non-synaptic release

By mediating the Ca²⁺ influx that triggers exocytotic fusion, Ca²⁺ channels play a central role in a wide range of secretory processes. Ca²⁺ channels consist of a complex of protein subunits, including an ₁ subunit that constitutes the voltage-dependent Ca²⁺-selective membrane pore, and a group of auxiliary subunits, including β, γ, and ₂–δ subunits, which modulate channel properties such as inactivation and channel targeting. Subtypes of Ca²⁺ channels are constituted by different combinations of ₁ subunits (of which 10 have been identified) and auxiliary subunits, particularly β (of which 4 have been identified). Activity-secretion coupling is determined not only by the biophysical properties of the channels involved, but also by the relationship between channels and the exocytotic apparatus, which may differ between fast and slow types of secretion. Colocalization of Ca²⁺ channels at sites of fast release may depend on biochemical interactions between channels and exocytotic proteins. The aim of this article is to review recent work on Ca²⁺ channel structure and function in exocytotic secretion. We discuss Ca²⁺ channel involvement in selected types of secretion, including central neurotransmission, endocrine and neuroendocrine secretion, and transmission at graded potential synapses. Several different Ca²⁺ channel subtypes are involved in these types of secretion, and their function is likely to involve a variety of relationships with the exocytotic apparatus. Elucidating the relationship between Ca²⁺ channel structure and function is central to our understanding of the fundamental process of exocytotic secretion.