7,277 research outputs found
The Prevalence and Control of Bacillus and Related Spore-Forming Bacteria in the Dairy Industry
peer-reviewedMilk produced in udder cells is sterile but due to its high nutrient content, it can be a good growth substrate for contaminating bacteria. The quality of milk is monitored via somatic cell counts and total bacterial counts, with prescribed regulatory limits to ensure quality and safety. Bacterial contaminants can cause disease, or spoilage of milk and its secondary products. Aerobic spore-forming bacteria, such as those from the genera Sporosarcina, Paenisporosarcina, Brevibacillus, Paenibacillus, Geobacillus and Bacillus, are a particular concern in this regard as they are able to survive industrial pasteurization and form biofilms within pipes and stainless steel equipment. These single or multiple-species biofilms become a reservoir of spoilage microorganisms and a cycle of contamination can be initiated. Indeed, previous studies have highlighted that these microorganisms are highly prevalent in dead ends, corners, cracks, crevices, gaskets, valves and the joints of stainless steel equipment used in the dairy manufacturing plants. Hence, adequate monitoring and control measures are essential to prevent spoilage and ensure consumer safety. Common controlling approaches include specific cleaning-in-place processes, chemical and biological biocides and other novel methods. In this review, we highlight the problems caused by these microorganisms, and discuss issues relating to their prevalence, monitoring thereof and control with respect to the dairy industry.NG is funded by the Teagasc Walsh Fellowship Scheme and through the Irish Dairy Levy funded project ‘Thermodur-Out.
Advanced Cyberinfrastructure for Science, Engineering, and Public Policy
Progress in many domains increasingly benefits from our ability to view the
systems through a computational lens, i.e., using computational abstractions of
the domains; and our ability to acquire, share, integrate, and analyze
disparate types of data. These advances would not be possible without the
advanced data and computational cyberinfrastructure and tools for data capture,
integration, analysis, modeling, and simulation. However, despite, and perhaps
because of, advances in "big data" technologies for data acquisition,
management and analytics, the other largely manual, and labor-intensive aspects
of the decision making process, e.g., formulating questions, designing studies,
organizing, curating, connecting, correlating and integrating crossdomain data,
drawing inferences and interpreting results, have become the rate-limiting
steps to progress. Advancing the capability and capacity for evidence-based
improvements in science, engineering, and public policy requires support for
(1) computational abstractions of the relevant domains coupled with
computational methods and tools for their analysis, synthesis, simulation,
visualization, sharing, and integration; (2) cognitive tools that leverage and
extend the reach of human intellect, and partner with humans on all aspects of
the activity; (3) nimble and trustworthy data cyber-infrastructures that
connect, manage a variety of instruments, multiple interrelated data types and
associated metadata, data representations, processes, protocols and workflows;
and enforce applicable security and data access and use policies; and (4)
organizational and social structures and processes for collaborative and
coordinated activity across disciplinary and institutional boundaries.Comment: A Computing Community Consortium (CCC) white paper, 9 pages. arXiv
admin note: text overlap with arXiv:1604.0200
Incommensurate Transverse Anisotropy Induced by Disorder and Spin-Orbit-Vibron Coupling in Mn12-acetate
It has been shown within density-functional theory that in Mn-acetate
there are effects due to disorder by solvent molecules and a coupling between
vibrational and electronic degrees of freedom. We calculate the in-plane
principal axes of the second-order anisotropy caused by the second effect and
compare them with those of the fourth-order anisotropy due to the first effect.
We find that the two types of the principal axes are not commensurate with each
other, which results in a complete quenching of the tunnel-splitting
oscillation as a function of an applied transverse field.Comment: Will be presented at MMM conference 200
Recommended from our members
Why does early childhood deprivation increase the risk for depression and anxiety in adulthood? A developmental cascade model
Abstract Background: Using data from the English & Romanian Adoptees (ERA) study we recently reported that early time-lmited exposure to severe institutional deprivation is
associated with early onset and persistent neurodevelopmental problems and later
onset emotional problems. Here we examine possible reasons for the late
emergence of emotional problems in this cohort. Our main focus is on testing a
developmental cascade mediated via the functional impact of early-appearing
neurodevelopmental problems on late adolescent functioning. We also explore a
second putative pathway via sensitization to stress. Methods: The ERA study includes 165 Romanian individuals who spent their early lives in grossly depriving institutions and were subsequently adopted into UK
families, along with 52 UK adoptees with no history of deprivation. Age six years
symptoms of neurodevelopmental problems and age 15 anxiety/depression
symptoms were assessed via parental reports. Young adult symptoms of depression
and anxiety were assessed by both parent and self-reports; young adults also
completed measures of stress reactivity , exposure to adverse life events and
functioning in work and interpersonal relationships. Results: The path between early institutional deprivation and adult emotional problems was mediated via the impact of early neurodevelopmental problems on
unemployment and poor friendship functioning during the transition to adulthood.
The findings with regard to early deprivation, later life stress reactivity and emotional
problems were inconclusive.
Conclusions: Our analysis suggests that the risk for adult depression and anxiety following extreme institutional deprivation is explained through the effects of early neurodevelopmental problems on later social and vocational functioning. Future research should more fully examine the role of stress susceptibility in this model
The Influence of Motion and Stress on Optical Fibers
We report on extensive testing carried out on the optical fibers for the
VIRUS instrument. The primary result of this work explores how 10+ years of
simulated wear on a VIRUS fiber bundle affects both transmission and focal
ratio degradation (FRD) of the optical fibers. During the accelerated lifetime
tests we continuously monitored the fibers for signs of FRD. We find that
transient FRD events were common during the portions of the tests when motion
was at telescope slew rates, but dropped to negligible levels during rates of
motion typical for science observation. Tests of fiber transmission and FRD
conducted both before and after the lifetime tests reveal that while
transmission values do not change over the 10+ years of simulated wear, a clear
increase in FRD is seen in all 18 fibers tested. This increase in FRD is likely
due to microfractures that develop over time from repeated flexure of the fiber
bundle, and stands in contrast to the transient FRD events that stem from
localized stress and subsequent modal diffusion of light within the fibers.
There was no measurable wavelength dependence on the increase in FRD over 350
nm to 600 nm. We also report on bend radius tests conducted on individual
fibers and find the 266 microns VIRUS fibers to be immune to bending-induced
FRD at bend radii of R > 10cm. Below this bend radius FRD increases slightly
with decreasing radius. Lastly, we give details of a degradation seen in the
fiber bundle currently deployed on the Mitchell Spectrograph (formally VIRUS-P)
at McDonald Observatory. The degradation is shown to be caused by a localized
shear in a select number of optical fibers that leads to an explosive form of
FRD. In a few fibers, the overall transmission loss through the instrument can
exceed 80%.Comment: 19 pages, 22 figure
Preventing infection in general surgery: improvements through education of surgeons by surgeons.
Surgical patients are at particular risk of healthcare-associated infection (HCAI) due to the presence of a surgical site leading to surgical site infection (SSI), and because of the need for intravascular access resulting in catheter-related bloodstream infection (CRBSI). A two-year initiative commenced with an initial audit of surgical practice; this was used to inform the development of a targeted educational initiative by surgeons specifically for surgical trainees. Parameters assessed during the initial audit and a further audit after the educational initiative were related to intra- and postoperative aspects of the prevention of SSIs, as well as care of peripheral venous catheters (PVCs) in surgical patients. The proportion of prophylactic antibiotics administered prior to incision across 360 operations increased from 30.0% to 59.1% (P72h (10.6% vs 3.1%,
Recommended from our members
Chronic Kidney Disease Increases Cerebral Microbleeds in Mouse and Man.
Brain microbleeds are increased in chronic kidney disease (CKD) and their presence increases risk of cognitive decline and stroke. We examined the interaction between CKD and brain microhemorrhages (the neuropathological substrate of microbleeds) in mouse and cell culture models and studied progression of microbleed burden on serial brain imaging from humans. Mouse studies: Two CKD models were investigated: adenine-induced tubulointerstitial nephritis and surgical 5/6 nephrectomy. Cell culture studies: bEnd.3 mouse brain endothelial cells were grown to confluence, and monolayer integrity was measured after exposure to 5-15% human uremic serum or increasing concentrations of urea. Human studies: Progression of brain microbleeds was evaluated on serial MRI from control, pre-dialysis CKD, and dialysis patients. Microhemorrhages were increased 2-2.5-fold in mice with CKD independent of higher blood pressure in the 5/6 nephrectomy model. IgG staining was increased in CKD animals, consistent with increased blood-brain barrier permeability. Incubation of bEnd.3 cells with uremic serum or elevated urea produced a dose-dependent drop in trans-endothelial electrical resistance. Elevated urea induced actin cytoskeleton derangements and decreased claudin-5 expression. In human subjects, prevalence of microbleeds was 50% in both CKD cohorts compared with 10% in age-matched controls. More patients in the dialysis cohort had increased microbleeds on follow-up MRI after 1.5 years. CKD disrupts the blood-brain barrier and increases brain microhemorrhages in mice and microbleeds in humans. Elevated urea alters the actin cytoskeleton and tight junction proteins in cultured endothelial cells, suggesting that these mechanisms explain (at least in part) the microhemorrhages and microbleeds observed in the animal and human studies
- …
