Effect of fungal hyphae on the access of bacteria to phenanthrene in soil

The effect of fungal hyphae on the mobilization of soil-dwelling bacteria and their access to hydrophobic phenanthrene in soil was tested in columns containing air-filled agricultural soil. The experimental design included a spatial separation between zones of bacterial inoculation and contamination. Motile Pseudomonas putida PpG7 (NAH7) and fast-growing, hydrophilic Pythium ultimum were used as the model phenanthrene-degrading and vector organisms, respectively. Efficient translocation of strain PpG7 in the range of centimetres in presence of P. ultimum indicated that the fungal mycelia bridged air-filled pores and thereby provided a continuous network of water-paths that enabled bacteria to spread in the soil. Biodegradation of the soil-associated phenanthrene was found only in the presence of the fungal mycelia, hence proving that the fungal network facilitated the access of the bacteria to the contaminant. Our data suggest that the specific stimulation of indigenous fungi is a promising method to mobilize pollutant degrading bacteria and thereby improve soil bioremediation in-situ.     

Replacing corn with glycerol in diets for transition dairy cows

Expansion of the biofuels industry has increased the availability of glycerol as an alternative feed for dairy cows. The objective of this study was to determine the effects of glycerol on feed intake, milk production, rumen volatile fatty acids, and metabolic parameters in transition dairy cows. Multiparous Holstein cows were fed diets containing either high-moisture corn (n = 11) or glycerol (n = 12) from −28 to +56 d relative to calving. Glycerol was included at 11.5 and 10.8% of the ration dry matter for the pre- and postpartum diets, respectively. Prepartum feed intake was not changed by glycerol feeding (14.9 vs. 14.6 kg/d, control vs. glycerol) nor did postpartum feed intake differ (19.8 vs. 20.7 kg/d, control vs. glycerol). Overall milk yield did not differ (35.8 vs. 37 kg/d, control vs. glycerol) and milk composition, milk urea nitrogen, somatic cells, and energy balance were not different with glycerol feeding. Blood glucose content was decreased in cows fed glycerol during the prepartum period (59.1 vs. 53.4 mg/dL), and β-hydroxybutyrate concentration was increased (0.58 vs. 0.82 mmol/L, control vs. glycerol). Concentrations of blood nonesterified fatty acids did not differ between the treatment groups, and no response to glycerol for blood metabolites during the postpartum period was observed. Total rumen volatile fatty acid concentrations (mmol/L) did not differ between treatments, but proportions of rumen propionate and butyrate were greater for cows fed glycerol (22.7 vs. 28.6% of propionate, control vs. glycerol; and 11.5 vs. 15.3% of butyrate, control vs. glycerol) at the expense of acetate (61.4 vs. 51.5%, control vs. glycerol). These data indicate that glycerol is a suitable replacement for corn grain in diets for transition dairy cows.     

Graduate Student Literature Review: What do we know about the effects of clinical and subclinical hypocalcemia on health and performance of dairy cows?

This narrative literature review summarizes findings regarding the associations of clinical and subclinical hypocalcemia with postpartum health, reproduction, and milk production. To better understand the effects of hypocalcemia, we reviewed clinical and subclinical presentations of the condition and the dynamics of blood Ca concentration in the early postpartum period. We summarize and discuss the associations between hypocalcemia and performance of dairy cows. Up to 50% of dairy cows suffer from at least one disease event in the transition period. The important roles of calcium in muscle contraction and immune function make it a key component of metabolism, inflammation, and defense against infection. Although the effect of clinical hypocalcemia (milk fever) on health and performance is clear, the definition of subclinical hypocalcemia (SCH) and its consequences for health and performance are still ambiguous. Differences in study designs, sampling protocols, Ca concentration thresholds, and sample sizes that may be underpowered for health and reproduction outcomes lead to inconsistent conclusions on the effects of SCH. On current evidence, classification of SCH should be based on at least 2 measurements of blood calcium, using cutpoints supported with relevant data, which may vary depending on the outcome of interest. Arbitrary or poorly supported interpretative thresholds for blood Ca concentrations should be abandoned. Transient SCH appears to be associated with greater milk yield, whereas SCH that is present several days after calving is associated with lesser production and greater disease risk. However, when blood calcium is measured days after calving, primary effects of calcium metabolism may be confounded by feed intake, inflammation, or disease, which might either contribute to or be a consequence of hypocalcemia. Additional research is needed to refine sampling schemes to classify SCH, and to better inform the goals and means of prevention of SCH.     

Synthesis of SnFe<Subscript>2</Subscript>O<Subscript>4</Subscript> Nanomaterials Via High Energy Ball Milling of SnO (Stannous) and α-Fe<Subscript>2</Subscript>O<Subscript>3</Subscript> (Hematite) Solid Precursors

The synthesis of single phase tin-ferrite, SnFe₂O₄, from tin (II) oxide or stannous oxide (SnO), and hematite (α-Fe₂O₃) solid precursors was carried out via high energy ball milling (HEBM) under wet condition involving the addition of controlled amounts of acetone. The stoichiometric amounts of the precursor materials were ball milled continuously for up to 22 h in a Spex-8000D mill using a ball-to-powder ratio of 40:1, with hardened stainless steel balls in WC-lined jars. The time-dependent formation of the SnFe₂O₄ based on combined X-ray diffraction and room temperature Mössbauer spectroscopy (MS) measurements revealed reaction enhancements associated with particles size reduction. The 22 h milled material indicated that synthesized SnFe₂O₄ had a particle size of 10.91 nm, coercivity of 4.44 mT, magnetic saturation/remanent ratio (M _r/M _s) of 0.085, while its superparamagnetic behavior was confirmed based on the combined MS and vibrating sample magnetometer measurements.     

Immunological evaluation of the alcohol-soluble protein fraction from gluten-free grains in relation to celiac disease

Celiac disease (CD) is a gluten-sensitive enteropathy with an immune basis. We established the immune reactivity of the alcohol-soluble fraction from two minor cereals (tef and millet) and two pseudocereals (amaranth and quinoa) which are believed to be nontoxic based on taxonomy. Grains were examined in intestinal T-cell lines (iTCLs), cultures of duodenal explants from HLA-DQ2(+) CD patients and HLA-DQ8 transgenic mice for signs of activation. Our data indicated that tef, millet, amaranth, and quinoa did not show any immune cross-reactivity toward wheat gliadin, and therefore confirming their safety in the diet of CD patients.     

Analytical solution for the modeling of the natural time-dependent reduction of waterborne viruses injected into fractured aquifers

We propose an analytical solution in order to explain the processes that determine the fate and behavior of the viruses during transport in a fractured aquifer at Salento (Italy). The calculations yield the efficiency of filtration in fractures at a site near Nardo? (Southern Italy) in reducing the numbers of enteric viruses (i.e., Enteroviruses and Norovirus) in secondary municipal effluents that have been injected in the aquifer over the period 2006-2007. The model predicted, by a theoretical expression, the time-dependent rate of virus reduction, which was in good agreement with field data. The analytical solution yields the achievable "Log reduction credits" for virus reduction in wells located at the setback distances that are usually adopted in local drinking water regulations. The resulting new analytical formula for the time-dependent reduction of viruses during subsurface transport can easily be applied in health risk-based models used to forecast the spread of waterborne diseases and provides appropriate criteria (i.e., distances) needed to meet standards for the quality of drinking water derived from undisinfected groundwater.     

Enabling Heterogeneous Mobility in Android Devices

The fast growing of mobile Internet users with the ability of using a wide diversity of access technologies such as Wi-Fi, WiMAX and UMTS/LTE, and the increasing proliferation of mobile devices with heterogeneous network interfaces, require versatile mobility mechanisms providing seamless roaming across those access technologies. Mobility agents such as Mobile IP and Fast MIPv6 are common, however, these solutions still have limitations when dealing with multiple link-layer technologies. In this context, the emerging standard IEEE 802.21 provides a framework which enables mobile agents and network operators to improve the handover process in heterogeneous networks. In this context, this paper presents and discusses the design and implementation of a mobility-aware solution for an Android device, using the IEEE 802.21 framework. A modified Android user terminal is proposed to improve the handover process, assuming a make-before-break approach. Resorting to an experimental testbed, the obtained results show that the proposed solution is an effective contribution to successfully accomplish seamless mobility of Android-based devices operating in 3G and Wi-Fi networks.     

Use of Waste Bakelite as a Raw Material Resource for Recarburization in Steelmaking Processes

Bakelite is a thermoset plastic commonly found in electronic and automobile components. CaCO₃ is generally found in the polymer as a filler material. Since it cannot be remelted, the disposal of this material has become an environmental issue. The present study investigates a new route to utilize waste bakelite as a source of carbon in EAF steelmaking process. This paper reports the carbon dissolution behaviour of bakelite/coke blends into liquid steel at 1550 °C. The carbon pick up in the liquid steel after reaction with varying blends of bakelite/coke for 30 minutes ranged between 0.13 wt% to 0.17 wt%; these were generally higher than that observed from coke alone (0.1 wt%). The dissolution rate (K) was also found to improve and the observed trend was BK2 (0.045 × 10^?3 s^?1) > BK3 (0.023 × 10^?3 s^?1) > BK1 (0.005 × 10^?3 s^?1) > coke (0.003 × 10^?3 s^?1). The reaction products formed at the interface after 30 minutes of contact between liquid steel and bakelite/coke blends were observed to be a CaS‐Al₂O₃ complex. The presence of CaS in the interfacial layer due to the CaO in the ash, lowered melting temperature of the layer, thereby allowing for increased removal of the ash layer and greater carbon pick‐up. The CaO is formed from the decomposition of CaCO_3, and its presence was found to have a positive effect on modifying the properties of the coke, and thereby enhancing the carbon dissolution behaviour.     

Applications of spectral computer simulation to surface analysis of materials

This work involves surface analysis by nuclear techniques, which are non-destructive, and computer simulation. The energy analysis method for the nuclear reaction analysis is implemented. Energy spectra are computer simulated and compared to experimental data, giving target composition and concentration profile information. The simulations use, mainly, the target parameterization and the available nuclear data. The method is successfully applied to the determination of uniform concentration profiles of ¹²C, along considerable depths, for a thick target, and for a very thin film. Uniform concentration profiles of ¹⁶O are obtained from (d,p) and (d,α) reactions along large depths. A uniform step concentration profile of ¹⁸O in a thick oxide target is also obtained. Elastic scattering is used in the context of a thin Ag film. SEM proves to be a useful technique for checking surface topography.