The use of the plasma chemistry unit as an aid to the scanning electron microscope study of avian egg‐shell structure

1. In order to study the mammillary layer of the avian egg shell by scanning electron microscopy, it is necessary to separate the outer shell membrane from the calcified shell.

2. Chemical methods of effecting membrane removal are difficult to standardise due to variations in the strength of the membrane‐shell bond.

3. The use of reactive gas plasma provides an alternative, more efficient method for removing membranes without the risk of damage to underlying crystalline structures.     

A proposal to leverage high-quality veterinary diagnostic laboratory large data streams for animal health,public health,and One Health

Test data generated by ~60 accredited member laboratories of the American Association of Veterinary Laboratory Diagnosticians (AAVLD) is of exceptional quality. These data are captured by 1 of 13 laboratory information management systems (LIMSs) developed specifically for veterinary diagnostic laboratories (VDLs). Beginning ~2000, the National Animal Health Laboratory Network (NAHLN) developed an electronic messaging system for LIMS to automatically send standardized data streams for 14 select agents to a national repository. This messaging enables the U.S. Department of Agriculture to track and respond to high-consequence animal disease outbreaks such as highly pathogenic avian influenza. Because of the lack of standardized data collection in the LIMSs used at VDLs, there is, to date, no means of summarizing VDL large data streams for multi-state and national animal health studies or for providing near-real-time tracking for hundreds of other important animal diseases in the United States that are detected routinely by VDLs. Further, VDLs are the only state and federal resources that can provide early detection and identification of endemic and emerging zoonotic diseases. Zoonotic diseases are estimated to be responsible for 2.5 billion cases of human illness and 2.7 million deaths worldwide every year. The economic and health impact of the SARS-CoV-2 pandemic is self-evident. We review here the history and progress of data management in VDLs and discuss ways of seizing unexplored opportunities to advance data leveraging to better serve animal health, public health, and One Health.     

DNA barcoding for identification of cryptic species in the field and existing museum collections: a case study of Aethomys and Micaelamys (Rodentia: Muridae)

DNA barcoding has been proposed as a method for species identification. However, this method has been criticised for its over-reliance on a single mitochondrial gene. In this study, four mitochondrial gene regions and one nuclear gene region were used to investigate their different abilities to identify tissue associated with museum specimens of Aethomys chrysophilus, Aethomys ineptus and Micaelamys namaquensis. Aethomys chrysophilus and the more recently elevated A. ineptus are indistinguishable on morphological grounds; however, their ranges are largely parapatric with only one syntopic locality currently known. All of the mitochondrial gene regions were able to separate M. namaquensis from A. chrysophilus and A. ineptus, but they varied in their abilities to resolve differences between A. chrysophilus and A. ineptus. The sequence results identified a specimen from KwaZulu-Natal that was misclassified and should have been identified as A. ineptus. Seven specimens that had not been reclassified following the elevation of A. ineptus to species level were identified as A. ineptus. Individuals of A. chrysophilus from Malawi could not be classified as either A. chrysophilus or A. ineptus, and may be a hybrid or a new, distinct species. This study indicates that DNA barcoding may be used to separate M. namaquensis from A. chrysophilus and A. ineptus, and although it was not able to separate A. chrysophilus and A. ineptus, it did indicate specimens from Malawi may be a new cryptic species.     

Determinants of income-earning strategies and adoption of conservation practices in hillside communities in rural Honduras

Based on the results of participatory diagnostic surveys conducted in 95 rural communities in the hillsides of Honduras, we determine income earning strategies at the community level; identify their main determinants; and analyze the adoption of of conservation practices. Eight income-earning strategies were distinguished that reflect differences in comparative advantage between communities. We explain the choice of income earning strategy using a multinomial logit model that includes biophysical, economic, social and institutional variables. We use a probit model to show that adoption of conservation practices is determined by the type of income earning strategy, population density, market access, and organizational variables.     

Identification of endophytic fungi of grapevine with emphasis on the causal agents of grapevine trunk disease in the vineyards of Zanjan Province in Iran

Trunk disease is a major problem on grapevine in Zanjan province, causing serious decline, despite which its aetiology remains unknown. The purpose of this study was to investigate factors involved in grapevine decline in vineyards of Zanjan province. Samples were collected from twigs and branches of grapevines in the region between October and November 2018. Fungal isolates were identified based on morphological characteristics and ITS-rDNA sequence data for selected isolates. The frequency and diversity of the fungal community recovered from grapevines in Darreh Sejin in Zanjan province were higher than in other regions. A total of 112 fungal isolates comprising 22 species were recovered. Phaeoacremonium minimum, Microsphaeropsis olivacea and Kalmusia variispora were identified as the dominant species in the region examined and could be considered the main trunk pathogens of grapevines in Zanjan region. In inoculation tests, M. olivacea was proved to be pathogenic on grapevine for the first time in this study.     

Steroidal saponins from the leaves of Agave macroacantha

A new monodesmosidic spirostanol saponin, along with three known saponins was isolated from Agave macroacantha Zucc leaves. The structure of the new saponin was established as hecogenin-3-O-α-l-rhamnopyranosyl (1→4) β-d-xylopyranosyl (1→3)[β-d-glucopyranosyl (1→2)] β-d-glucopyranosyl (1→4) β-d-galactopyranoside. The ¹H and ¹³C resonances of the four compounds were assigned using a combination of 1D and 2D NMR techniques including ¹H, ¹³C, COSY, TOCSY, ROESY, HSQC and HMBC NMR and confirmed by mass spectrometry.     

Overestimation of canine albumin concentration with the bromcresol green method in heparinized plasma samples

Albumin concentrations are routinely measured in dogs with bromcresol green (BCG)-binding assays on automated chemistry analyzers. Several variables affect this assay, including the length of reaction time, sample type, and lack of specificity of BCG for albumin. We observed that albumin concentrations measured with BCG appeared higher in heparinized plasma samples in sick dogs. The objective of this study was to determine the effect of anticoagulant and assay procedure on BCG albumin concentrations in clinically ill dogs. We hypothesized that albumin concentrations would be overestimated in heparinized plasma compared with serum because of the combination of heparin and fibrinogen. Furthermore, we hypothesized that the overestimation would be influenced by assay parameters. Blood was collected from 32 clinically ill dogs into tubes containing heparin, citrate, or no anticoagulant. Citrate was chosen to assess the effect of fibrinogen in the absence of heparin. Albumin concentration was measured in all 3 sample types from each dog using 2 different BCG procedures on an automated chemistry analyzer. The BCG procedures (standard and modified) differed in the wavelengths used for absorbance readings (standard, 600/700; modified, 570/505) and the time point at which absorbance was measured (standard, 100 seconds; modified, 40 seconds). In addition, the modified method incorporated a sample blank. Globulin fractions, fibrinogen concentration, and indices of lipemia, hemolysis, and icterus were evaluated for their contribution to the overestimation of albumin concentration in heparinized plasma compared with serum samples. Albumin concentrations were significantly higher (P 相似文献   

Toxicity of cyanogen to insects of stored grain

Range-finding studies on the toxicity of cyanogen to all stages of five species of stored product Coleoptera are reported. The species were Rhyzopertha dominica (F), Sitophilus granarius (L), Sitophilus Oryzae (L), Tribolium castaneum (Herbst), Tribolium confusum Jacquelin du Val and Ephestia cautella (Walker). Exposures for 24 h to cyanogen at 1.3 mg litre(-1) controlled all external stages. Control of internal stages of Sitophilus species was achieved by a 5-day exposure to initial concentrations between 13.7 and 27.4 mg litre(-1), whereas R. dominica was controlled at 13.7 mg litre(-1). Cyanogen showed similar toxicity to all tested external stages and, in this respect, was more similar to methyl bromide than to phosphine. Its toxicity to insects increased with both relative humidity and concentration of carbon dioxide. Cyanogen was toxic to insects whether applied as a gas or in an aqueous solution.