Insights into an undescribed high-elevation lake (6,170 m a.s.l.) on Volcán Llullaillaco: A physical and microbiological view

1. High elevation lakes are extreme ecosystems and serve as sentinels of various global changes.
2. An expedition to Volcán Llullaillaco in 1996 discovered an unstudied high-elevation lake (6,170 m a.s.l.) that probably was formed as a result of the past eruptive events or climatic processes such as glacial retreat in the lake basin.
3. This article describes an initial physical characterization of the lake and its microbial communities derived from two sampling expeditions in 2013 and 2016.
4. The microbial community in the lake, with an area between 1.2 and 1.4 ha and a depth of 6.8 m, was dominated by Proteobacteria, Actinobacteria and Haloarchaea. In addition, 26 bacterial isolates were identified within the genera Subtercola, Xylophilus, Rhodanobacter, Mesorhizobium and Pseudomonas.
5. Lago Llullaillaco is one of the highest recorded lakes in the world, and this study highlights the unique microbial diversity of this aquatic ecosystem and the importance of its preservation to understand the complex biological processes under polyextreme conditions.

     

Evaluation of Three In Vitro Enzyme Assays for Estimating Protein Digestibility in the Pacific White Shrimp Penaeus vannamei1

Abstract— In vitro enzyme assays are rapid, inexpensive techniques for estimating protein digestibility of feed ingredients. Three assays—the Lazo single-enzyme assay with porcine trypsin; the Hsu multi-enzyme assay with porcine trypsin, α-chymotrypsin, and peptidase; and the Satterlee multi-enzyme assay with porcine trypsin, α-chymotrypsin, peptidase, and bacterial protease—were used to estimate relative protein digestibility (RPD) of selected feed ingredients used in diets for the Pacific white shrimp Penaeus vannamei. Ingredients tested were casein, gelatin, rice bran, shrimp meal, soybean meal, wheat gluten, and six varieties of fish meal. A highly significant, inverse, linear relationship existed between final pH in each of the enzyme assays and in vivo apparent protein digestibility of the ingredient in P. vannamei feeding trials. Ranking of RPD coefficients obtained in the Lazo single-enzyme assay followed closely the ranking of published in vivo apparent protein digestibility coefficients for the same ingredients in P. vannamei digestibility trials. Results indicated that a single-enzyme assay with porcine trypsin identified differences in protein digestibility of feedstuffs in vitro as well as the two multi-enzyme assays tested. The porcine-trypsin, single-enzyme assay appears to be a potentially useful tool for evaluating protein quality and relative protein digestibility of feedstuffs for P. vannamei.     

Survey of potato spindle tuber viroid in seed potato growing areas of the United States

Fourteen United States (U.S.) seed potato certification agencies surveyed all U.S. seed potato growing areas for presence of the potato spindle tuber viroid (PSTVd). The survey included general surveillance, which involved searching for the occurrence of PSTVd in state seed potato certification records from 1990 through 2000, and a field survey, which involved testing selected crops for PSTVd infection by nucleic acid dot blot hybridization during 1999 through 2001. No PSTVd incident was documented in any of the state certification records, nor was PSTVd detected in the field surveys. All U.S. seed-growing areas were determined to be free of PSTVd. It is concluded that PSTVd has been eradicated and freedom from potato spindle tuber viroid has been successfully maintained in all of the seed potato growing areas in the United States.     

A selective activity-dependent requirement for dynamin 1 in synaptic vesicle endocytosis

Dynamin 1 is a neuron-specific guanosine triphosphatase thought to be critically required for the fission reaction of synaptic vesicle endocytosis. Unexpectedly, mice lacking dynamin 1 were able to form functional synapses, even though their postnatal viability was limited. However, during spontaneous network activity, branched, tubular plasma membrane invaginations accumulated, capped by clathrin-coated pits, in synapses of dynamin 1-knockout mice. Synaptic vesicle endocytosis was severely impaired during strong exogenous stimulation but resumed efficiently when the stimulus was terminated. Thus, dynamin 1-independent mechanisms can support limited synaptic vesicle endocytosis, but dynamin 1 is needed during high levels of neuronal activity.     

Isolation of equine herpesvirus-2 from the lung of an aborted fetus.

This study describes the isolation of equine herpesvirus-2 (EHV-2) from the lung of an aborted equine fetus in Argentina. The isolated virus was confirmed as EHV-2 by indirect immunofluorescence using a rabbit anti-EHV-2 polyclonal antiserum and by virus-neutralization test using an equine polyclonal antibody against EHV-2. Restriction endonuclease DNA fingerprinting with BamHI also confirmed the identity of the virus as EHV-2. Furthermore, viral nucleic acid was detected by polymerase chain reaction from the original lung sample and from the DNA obtained from cells infected with the virus isolate. This work constitutes the first reported isolation of EHV-2 from an aborted equine fetus. The presence of EHV-2 in the lung of the aborted fetus would indicate that this virus is capable of crossing the placental barrier. However, no cause-effect relationship was established between the EHV-2 isolate and the abortion.     

Sorghum Pasta and Noodles: Technological and Nutritional Aspects

Plant Foods for Human Nutrition - Sorghum is a major cereal crop with various agronomic advantages, contains health-promoting compounds and is gluten-free. There is a growing tendency to use...     

Comparative performance of tests using cytosolic or outer membrane antigens of Brucella for the serodiagnosis of canine brucellosis

Although some ELISA tests using cytoplasmic or outer membrane antigens of Brucella have been developed to improve the diagnosis of canine brucellosis, the performance of these assays has not been compared. In the present study three ELISA tests using lipopolysaccharide (LPS)-free cytoplasmic proteins (CPs) of Brucella abortus, the lumazine synthase (LS) of Brucella spp. or a hot-saline (HS) extract of Brucella canis containing outer membrane antigens were used to test sera from dogs with suspected or confirmed brucellosis (n=36) and from dogs with pathological conditions other than brucellosis (n=212). In the first group the proportion of positive results was 92, 92 and 81% for the ELISAs with HS, CP and LS, respectively, and 94% of the samples were positive by at least one ELISA test. Three dogs that were negative by agglutination (2ME-RSAT) had a positive result by at least one ELISA, and this discrepancy was attributed to the lower analytical sensitivity of agglutination tests. This hypothesis was confirmed by a serological follow-up of seven dogs recently infected with B. canis in three of which the illness was diagnosed earlier by one or more ELISA tests than by 2ME-RSAT. Among dogs having pathological conditions other than brucellosis, specificities were 94.3, 96.7 and 96.7% for the ELISAs with HS, CP and LS, respectively. This study shows that HS-ELISA and CP-ELISA are highly specific and sensitive for the diagnosis of canine brucellosis and can detect the infection by B. canis shortly after the exposure to the pathogen.     

Reconstructing the history of human impacts on coastal biodiversity in Chile: constraints and opportunities

• 1. Although Chile is at the forefront in evaluating experimentally the importance of human harvesting impacts on coastal biodiversity, there are no evaluations of such impacts on a long‐term historical basis (tens to thousands of years). Different types of archival information (i.e. contemporaneous, archaeological, and palaeontological) were used to carry out a research programme based on the historical assessment of the impacts and intensity of resource extraction on coastal biodiversity along the Chilean coast.
• 2. In addition to recent scientific literature, different sources of contemporaneous information (e.g. museum collections, old reports and accounts) can reveal the human impacts observed in the more recent past. Furthermore, the large number of prehistoric shell middens along the entire Chilean coast offer access to ～11 000 years of history along the entire coast, although the faunal composition, structure, and dynamics of most of them remain largely unstudied.
• 3. Finally, the rich and widespread fossil record of some marine groups provides the opportunity to reconstruct the structure and dynamics of benthic communities during different phases of human influence (e.g. pre‐human, prehistoric harvesting, and modern harvesting).
• 4. Preliminary comparisons of fossil versus modern bivalve assemblages suggest marked changes in the species composition. Human impacts seem very recent and shifts in the structure of benthic assemblages may have occurred only a few centuries/decades ago.
• 5. In contrast, prehistoric harvesting, although intense, was apparently not enough to cause a profound impact on coastal ecosystems. The approach herein envisaged can provide the basis to build a historical baseline to evaluate the human impacts on the coastal biodiversity in the region. Copyright © 2009 John Wiley & Sons, Ltd.

     

Effects of blood collection for transfusion on arterial blood pressure, heart rate, and PCV in cats

BACKGROUND: Collection of 50 mL of blood (standard unit) in cats is a common procedure. There are several studies on the health status of donors, but to our knowledge there are no reports on the effects of blood collection on the feline donor. HYPOTHESIS: Collection of a standard unit of blood from cats does not significantly change arterial blood pressure (BP), mean arterial pressure (MAP), systolic arterial pressure (SAP), diastolic arterial pressure (DAP), PCV, and heart rate (HR) in healthy blood donor cats. ANIMALS: Twenty-six healthy blood donor cats (6 spayed females and 20 castrated males). METHODS: An oscillometric method was used to measure MAP, SAP, DAP, and to quantify HR before and after blood collection; PCV was obtained before and immediately after blood collection. RESULTS: Despite a significant decrease (P < .05) in all variables (ie, BP, PCV, HR) after blood collection, no adverse events were observed. CONCLUSIONS AND CLINICAL IMPORTANCE: The collection of a unit of blood for transfusion from healthy donor cats weighing more than 5 kg appears to be safe, but this procedure leads to a decrease in arterial BP, PCV, and HR.