307 research outputs found
The domestication of the probiotic bacterium Lactobacillus acidophilus
Lactobacillus acidophilus is a Gram-positive lactic acid bacterium that has had widespread historical use in the dairy industry and more recently as a probiotic. Although L. acidophilus has been designated as safe for human consumption, increasing commercial regulation and clinical demands for probiotic validation has resulted in a need to understand its genetic diversity. By drawing on large, well-characterised collections of lactic acid bacteria, we examined L. acidophilus isolates spanning 92 years and including multiple strains in current commercial use. Analysis of the whole genome sequence data set (34 isolate genomes) demonstrated L. acidophilus was a low diversity, monophyletic species with commercial isolates essentially identical at the sequence level. Our results indicate that commercial use has domesticated L. acidophilus with genetically stable, invariant strains being consumed globally by the human population
Retinal ganglion cell survival and axon regeneration in WldS transgenic rats after optic nerve crush and lens injury.
BACKGROUND: We have previously shown that the slow Wallerian degeneration mutation, whilst delaying axonal degeneration after optic nerve crush, does not protect retinal ganglion cell (RGC) bodies in adult rats. To test the effects of a combination approach protecting both axons and cell bodies we performed combined optic nerve crush and lens injury, which results in both enhanced RGC survival as well as axon regeneration past the lesion site in wildtype animals. RESULTS: As previously reported we found that the Wld(S) mutation does not protect RGC bodies after optic nerve crush alone. Surprisingly, we found that Wld(S) transgenic rats did not exhibit the enhanced RGC survival response after combined optic nerve crush and lens injury that was observed in wildtype rats. RGC axon regeneration past the optic nerve lesion site was, however, similar in Wld(S) and wildtypes. Furthermore, activation of retinal glia, previously shown to be associated with enhanced RGC survival and axon regeneration after optic nerve crush and lens injury, was unaffected in Wld(S) transgenic rats. CONCLUSIONS: RGC axon regeneration is similar between Wld(S) transgenic and wildtype rats, but Wld(S) transgenic rats do not exhibit enhanced RGC survival after combined optic nerve crush and lens injury suggesting that the neuroprotective effects of lens injury on RGC survival may be limited by the Wld(S) protein.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Getting It on Record: Issues and Strategies for Ethnographic Practice in Recording Studios
The recording studio has been somewhat neglected as a site for ethnographic fieldwork in the field of ethno-musicology and, moreover, the majority of published studies tend to overlook the specific concerns faced by the researcher within these contexts. Music recording studios can be places of creativity, artistry, and collaboration, but they often also involve challenging, intimidating, and fractious relations. Given that recording studios are, first and foremost, concerned with documenting musicians’ performances, we discuss the concerns of getting studio interactions “on record” in terms of access, social relations, and methods of data collection. This article reflects on some of the issues we faced when conducting our fieldwork within British music recording facilities and makes suggestions based on strategies that we employed to address these issues
Birch bark tar in early Medieval England:continuity of tradition or technological revival?
International audienc
The foreground transfer function for HI intensity mapping signal reconstruction: MeerKLASS and precision cosmology applications
Blind cleaning methods are currently the preferred strategy for handling
foreground contamination in single-dish HI intensity mapping surveys. Despite
the increasing sophistication of blind techniques, some signal loss will be
inevitable across all scales. Constructing a corrective transfer function using
mock signal injection into the contaminated data has been a practice relied on
for HI intensity mapping experiments. However, assessing whether this approach
is viable for future intensity mapping surveys where precision cosmology is the
aim, remains unexplored. In this work, using simulations, we validate for the
first time the use of a foreground transfer function to reconstruct power
spectra of foreground-cleaned low-redshift intensity maps and look to expose
any limitations. We reveal that even when aggressive foreground cleaning is
required, which causes negative bias on the largest scales, the
power spectrum can be reconstructed using a transfer function to within
sub-percent accuracy. We specifically outline the recipe for constructing an
unbiased transfer function, highlighting the pitfalls if one deviates from this
recipe, and also correctly identify how a transfer function should be applied
in an auto-correlation power spectrum. We validate a method that utilises the
transfer function variance for error estimation in foreground-cleaned power
spectra. Finally, we demonstrate how incorrect fiducial parameter assumptions
(up to bias) in the generation of mocks, used in the construction
of the transfer function, do not significantly bias signal reconstruction or
parameter inference (inducing bias in recovered values).Comment: 25 pages, 20 figures. See Figure 4 for the main demonstration of the
transfer function's performance for reconstructing signal loss from
foreground cleaning. Submitted to MNRAS for publicatio
Nitrogen in Current European Policies
Europe, and especially the European Union (EU), has many governmental policy ¿ measures aimed at decreasing unwanted reactivenitrogen (N r ) emissions from combustion, agriculture and urban wastes. Many of these policy measures have an ¿eff ects-basedapproach¿, and focus on single N r compounds, single sectors and either on air or waters.¿ Th is chapter addresses the origin, objectives and targets of EU policy measures related to Nr emissions, considers which instrumentsare being used to implement the policies and briefl y discusses the eff ects of the policy measures.Approaches¿ Th e chapter starts with a brief description of the basic elements of governmental policy measures.¿ A review of the main international conventions and EU policies related to emissions of Nr to air and water is then provided.¿ Finally the chapter provides a semi-quantitative assessment of the eff ectiveness and effi ciency of European policy measures.Key fi ndings/state of knowledge¿ International conventions and other treaties have played a key role in raising awareness and establishing policy measures for Nr emissionsabatement in EU through so-called Directives and Regulations.¿ Th ere are many diff erent EU Directives, oft en addressing individual Nr compounds from individual sectors (e.g. NOx emissions fromcombustion; NH 3 emissions from agriculture, pollution of groundwater and surface water by nitrates from agriculture, discharge oftotal nitrogen from urban sewage to surface waters).¿ Many EU Directives have been revised following review and evaluation. Th ere are increasing eff orts to cluster single EU Directives intolarger Framework Directives.¿ Compliance with, and eff ectiveness of, the Directives diff ers between sectors; it decreases in the order (i) reducing NO x emissions fromcombustion sources, (ii) reducing nitrogen (and especially Phosphorus) discharges to waters from industries and households, and (iii)reducing NH 3 emissions and NO 3 leaching from agriculture.¿ Th ere is not much literature on the diff erences in the eff ectiveness and effi ciencies of Directives; a number of factors seem to be involvedin eff ectiveness and effi ciency, but these have not yet been analysed in a coherent manner.Major uncertainties/challenges¿ Th ere is a huge diversity in N r emission sources and pathways, while the number of policy instruments is limited. Th ere is need to fi ndthe optimal mix of policy instruments targeted to the emission sources as well as the stakeholders involved.¿ It has been indicated that some EU Directives addressing emissions of nitrogen compounds from specifi c sources have antagonisticeff ects. Th e magnitude of these eff ects is not yet well known.¿ Th ere is a delay in the environmental and ecological responses following the introduction of Directives; these are due to legislativedelays, lack of enforcement and control, constraints in practice and because of biogeochemical hysteresis eff ects; these eff ects are notyet well understood quantitatively.¿ In general, only modest reductions in Nr emissions from agriculture have been achieved to date; this refl ects the need for more eff ectiveand effi cient policy measures and/or greater enforcement of current policies.Recommendations¿ To examine further the diff erences between sectors of the factors that contribute to the eff ectiveness and effi ciency of policy measuresfor the abatement of N r emissions.¿ T o explore further the eff ectiveness and effi ciency of more integrated N management and integrated policy measures for the abatementof adverse impacts of N r emissions.JRC.DDG.H.2-Climate change and air qualit
Intravenous xenogeneic transplantation of human adipose-derived stem cells improves left ventricular function and microvascular integrity in swine myocardial infarction model
OBJECTIVES:
The potential for beneficial effects of adipose-derived stem cells (ASCs) on myocardial perfusion and left ventricular dysfunction in myocardial ischemia (MI) has not been tested following intravenous delivery.
METHODS:
Surviving pigs following induction of MI were randomly assigned to 1 of 3 different groups: the placebo group (n = 7), the single bolus group (SB) (n = 7, 15 × 10(7) ASCs), or the divided dose group (DD) (n = 7, 5 × 10(7) ASCs/day for three consecutive days). Myocardial perfusion defect area and coronary flow reserve (CFR) were compared during the 28-day follow-up. Also, serial changes in the absolute number of circulating CD4(+) T and CD8(+) T cells were measured.
RESULTS:
The increases in ejection fraction were significantly greater in both the SB and the DD groups compared to the placebo group (5.4 ± 0.9%, 3.7 ± 0.7%, and -0.4 ± 0.6%, respectively), and the decrease in the perfusion defect area was significantly greater in the SB group than the placebo group (-36.3 ± 1.8 and -11.5 ± 2.8). CFR increased to a greater degree in the SB and the DD groups than in the placebo group (0.9 ± 0.2, 0.8 ± 0.1, and 0.2 ± 0.2, respectively). The circulating number of CD8(+) T cells was significantly greater in the SB and DD groups than the placebo group at day 7 (3,687 ± 317/µL, 3,454 ± 787/µL, and 1,928 ± 457/µL, respectively). The numbers of small vessels were significantly greater in the SB and the DD groups than the placebo group in the peri-infarct area.
CONCLUSIONS:
Both intravenous SB and DD delivery of ASCs are effective modalities for the treatment of MI in swine. Intravenous delivery of ASCs, with its immunomodulatory and angiogenic effects, is an attractive noninvasive approach for myocardial rescue
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