The Effects of Frozen Storage and Repeated Freeze-Thawing on Salmonella in Varied Concentrations of Waste Activated Sludge

Commonly, waste activated sludge is applied to farmland as a fertilizer supplement and soil conditioner. The use of waste activated sludge is not only an efficient way of sludge disposal, but also an economical one. Much concern has been raised about the safety of such a practice. Harmful pathogens, like Salmonella, are commonly present in waste material. Treatment at wastewater plants is successful in eliminating these organisms from final effluent, but the solids generated are full of indigenous microorganisms, including Salmonella. Work of this paper attempts to determine the safety of the sludge product after simulated winter conditions present throughout the United States (particularly in the Midwest) and the effects those conditions might have on the bacterial population of the resultant sludge. Conditions of refrigeration (4C), frozen storage (-25C), and repeated freezing and thawing were controlled under varied concentrations of waste activated sludge (0, 5, and 10 percent) on Salmonella paratyphi A. Initially low (ca. 3.1x105 cells/ml) and high (ca. 4.7x107 cells/ml) concentrations of cells were established and bacterial counts were taken at one week intervals to determine the survival of these cells under the three conditions. Initial concentrations of the bacterial population seem to have no apparent influence on their survival rate. Storage under refrigeration, frozen, and repeated freeze-thawing strongly influence the survival of cells, with freezing and thawing producing the greatest mortality over time and refrigeration having the least affect. Greater concentrations of solids seemed to protect and increase the survival of Salmonella over time for low populations of cells, while for high populations of cells the presence of solids tended to increase mortality. The explanation seems to be attributed to the association of cells with solids, more so when the cell concentration is high than when it is low

Long-range corrected DFT calculations of charge-transfer integrals in model metal-free phthalocyanine complexes

An assessment of several widely used exchange--correlation potentials in computing charge-transfer integrals is performed. In particular, we employ the recently proposed Coulomb-attenuated model which was proven by other authors to improve upon conventional functionals in the case of charge-transfer excitations. For further validation, two distinct approaches to compute the property in question are compared for a phthalocyanine dimer

Gravitational Waves from Gravitational Collapse

Gravitational wave emission from the gravitational collapse of massive stars has been studied for more than three decades. Current state of the art numerical investigations of collapse include those that use progenitors with realistic angular momentum profiles, properly treat microphysics issues, account for general relativity, and examine non--axisymmetric effects in three dimensions. Such simulations predict that gravitational waves from various phenomena associated with gravitational collapse could be detectable with advanced ground--based and future space--based interferometric observatories.Comment: 68 pages including 13 figures; revised version accepted for publication in Living Reviews in Relativity (http://www.livingreviews.org

Geoeconomic variations in epidemiology, ventilation management, and outcomes in invasively ventilated intensive care unit patients without acute respiratory distress syndrome: a pooled analysis of four observational studies

Background: Geoeconomic variations in epidemiology, the practice of ventilation, and outcome in invasively ventilated intensive care unit (ICU) patients without acute respiratory distress syndrome (ARDS) remain unexplored. In this analysis we aim to address these gaps using individual patient data of four large observational studies. Methods: In this pooled analysis we harmonised individual patient data from the ERICC, LUNG SAFE, PRoVENT, and PRoVENT-iMiC prospective observational studies, which were conducted from June, 2011, to December, 2018, in 534 ICUs in 54 countries. We used the 2016 World Bank classification to define two geoeconomic regions: middle-income countries (MICs) and high-income countries (HICs). ARDS was defined according to the Berlin criteria. Descriptive statistics were used to compare patients in MICs versus HICs. The primary outcome was the use of low tidal volume ventilation (LTVV) for the first 3 days of mechanical ventilation. Secondary outcomes were key ventilation parameters (tidal volume size, positive end-expiratory pressure, fraction of inspired oxygen, peak pressure, plateau pressure, driving pressure, and respiratory rate), patient characteristics, the risk for and actual development of acute respiratory distress syndrome after the first day of ventilation, duration of ventilation, ICU length of stay, and ICU mortality. Findings: Of the 7608 patients included in the original studies, this analysis included 3852 patients without ARDS, of whom 2345 were from MICs and 1507 were from HICs. Patients in MICs were younger, shorter and with a slightly lower body-mass index, more often had diabetes and active cancer, but less often chronic obstructive pulmonary disease and heart failure than patients from HICs. Sequential organ failure assessment scores were similar in MICs and HICs. Use of LTVV in MICs and HICs was comparable (42\ub74% vs 44\ub72%; absolute difference \u20131\ub769 [\u20139\ub758 to 6\ub711] p=0\ub767; data available in 3174 [82%] of 3852 patients). The median applied positive end expiratory pressure was lower in MICs than in HICs (5 [IQR 5\u20138] vs 6 [5\u20138] cm H2O; p=0\ub70011). ICU mortality was higher in MICs than in HICs (30\ub75% vs 19\ub79%; p=0\ub70004; adjusted effect 16\ub741% [95% CI 9\ub752\u201323\ub752]; p<0\ub70001) and was inversely associated with gross domestic product (adjusted odds ratio for a US$10 000 increase per capita 0\ub780 [95% CI 0\ub775\u20130\ub786]; p<0\ub70001). Interpretation: Despite similar disease severity and ventilation management, ICU mortality in patients without ARDS is higher in MICs than in HICs, with a strong association with country-level economic status. Funding: No funding

The Effects of Frozen Storage and Repeated Freeze-Thawing on Salmonella in Varied Concentrations of Waste Activated Sludge

Commonly, waste activated sludge is applied to farmland as a fertilizer supplement and soil conditioner. The use of waste activated sludge is not only an efficient way of sludge disposal, but also an economical one. Much concern has been raised about the safety of such a practice. Harmful pathogens, like Salmonella, are commonly present in waste material. Treatment at wastewater plants is successful in eliminating these organisms from final effluent, but the solids generated are full of indigenous microorganisms, including Salmonella. Work of this paper attempts to determine the safety of the sludge product after simulated winter conditions present throughout the United States (particularly in the Midwest) and the effects those conditions might have on the bacterial population of the resultant sludge. Conditions of refrigeration (4C), frozen storage (-25C), and repeated freezing and thawing were controlled under varied concentrations of waste activated sludge (0, 5, and 10 percent) on Salmonella paratyphi A. Initially low (ca. 3.1x105 cells/ml) and high (ca. 4.7x107 cells/ml) concentrations of cells were established and bacterial counts were taken at one week intervals to determine the survival of these cells under the three conditions. Initial concentrations of the bacterial population seem to have no apparent influence on their survival rate. Storage under refrigeration, frozen, and repeated freeze-thawing strongly influence the survival of cells, with freezing and thawing producing the greatest mortality over time and refrigeration having the least affect. Greater concentrations of solids seemed to protect and increase the survival of Salmonella over time for low populations of cells, while for high populations of cells the presence of solids tended to increase mortality. The explanation seems to be attributed to the association of cells with solids, more so when the cell concentration is high than when it is low

Inheritance of resistance to anthracnose stalk rot of corn

Inheritance of resistance to anthracnose stalk rot (ASR) of corn (Zea mays L.), caused by Colletotrichum graminicola was studied in eight crosses involving two resistant inbred lines DW1035 ((MP305 x FRB73\sp{\lbrack 5\rbrack })\sb{\rm S8}) and DW890 ((MP305 x FRB73\sp{\lbrack 5\rbrack })\sb{\rm S8}), and four susceptible inbred lines FRB73, B84, FRMo17, and C103. In 1987, the crosses consisted of the parental lines, F\sb1, F\sb2, and both backcross generations. In 1988 and 1989 the study included F\sb3 and backcross selfed lines. Individual observed stalk rot reactions within a particular generation were classified as resistant or susceptible by discriminant analysis. Expected stalk rot distributions were determined using a partitioning method for a single, dominant gene hypothesis. The observed distributions were compared for goodness-of-fit to the expected distributions using a chi-square test for homogeneity. Support exists with the FRB73 x DW1035 and B84 x DW890 crosses for a single, dominant gene for ASR resistance, but environmental stresses in 1988 and 1989 significantly hindered the ability to obtain conclusive evidence, especially in the B84 x DW1035 population. The data also suggest differences between the resistant inbred lines DW1035 and DW890. Use of FRMo17 and C103 as susceptible parents to interpret the inheritance of a stalk rot with DW1035 and DW890 were complicated by the inability to distinguish the resistant and susceptible parents as two distinct classes.U of I OnlyETDs are only available to UIUC Users without author permissio