Dairy manure as a potential source of crop nutrients and environmental contaminants

Although animal manure is applied to agricultural fields for its nutrient value, it may also contain potential contaminants. To determine the variability in such contaminants as well as in valuable nutrients, nine uncomposted manure samples from Idaho dairies collected during 2.5 years were analyzed for macro- and micro-nutrients, hormones, phytoestrogens, antibiotics, veterinary drugs, antibiotic resistance genes, and genetic elements involved in the spread of antibiotic resistance. Total N ranged from 6.8 to 30.7 (C:N of 10 to 21), P from 2.4 to 9.0, and K from 10.2 to 47.7 g/kg manure. Zn (103 – 348 mg/kg) was more abundant than Cu (56 – 127 mg/kg) in all samples. Phytoestrogens were the most prevalent contaminants detected, with concentrations fluctuating over time, reflecting animal diets. This is the first study to document the presence of flunixin, a non-steroidal anti-inflammatory drug, in solid stacked manure from regular dairy operations. Monensin was the most frequently detected antibiotic. Progesterones and sulfonamides were regularly detected. We also investigated the relative abundance of several types of plasmids involved in the spread of antibiotic resistance in clinical settings. Plasmids belonging to the IncI, IncP, and IncQ1 incompatibility groups were found in almost all manure samples. IncQ1 plasmids, class 1 integrons, and sulfonamide resistance genes were the most widespread and abundant genetic element surveyed, emphasizing their potential role in the spread of antibiotic resistance. The benefits associated with amending agricultural soils with dairy manure must be carefully weighed against the potential negative consequences of any manure contaminants.     

Urban agriculture,civil interfaces and moving beyond difference: the experiences of plot holders in Dublin and Belfast

Recent literature suggests that a “shared politics of place” attained through joint activities fosters social integration and provides people with a means to practise co-operation [Baumann, G., 1996. Contesting culture: discourses of identity in multi-ethnic London. Cambridge: Cambridge University Press; Sanjek, R., 1998. The future of us all: race & neighbourhood policies in New York City. Ithaca, NY: Cornell University Press; Sennett, R., 2012. Together: the rituals, pleasures and politics of cooperation. UK: Penguin]. Such a “shared politics of place” is most likely to occur in the context of public space conceptualised broadly as “the setting for everyday spatial behaviour of individuals and communities, emphasizing ordinary activities of citizens” [Lownsbrough, H. and Beunderman, J., 2007. Equally spaced? Public space and interaction between diverse communities. London: Demos, p. 8]. Here we explore one element of such public space – urban agriculture sites – with a view to identifying the extent to which a “shared politics of place” can be created and nurtured among the cultivating citizenry. The paper draws on data collected on allotment gardening sites in two urban contexts: Dublin (Ireland) and Belfast (Northern Ireland) over the period 2009–2013. We demonstrate the centrality of allotment cultivation to the generation of solidarity, mutuality and trust among participating citizens. Individuals engaging in allotment gardening in both Dublin and Belfast create and sustain civil interfaces – dismantling barriers, exchanging knowledge, challenging stereotypes, generating empathy and getting on with the business of simply getting on with their lives. The modus operandi of allotment gardening is predicated on a willingness to disregard social and ethno-national categorisations while on site. This is not to deny that such differences exist and persist, but allotments offer a “space of potential” where those differences are, at least for a time, rendered less salient.     

Estimating species occurrence, abundance, and detection probability using zero-inflated distributions

Researchers have developed methods to account for imperfect detection of species with either occupancy (presence absence) or count data using replicated sampling. We show how these approaches can be combined to simultaneously estimate occurrence, abundance, and detection probability by specifying a zero-inflated distribution for abundance. This approach may be particularly appropriate when patterns of occurrence and abundance arise from distinct processes operating at differing spatial or temporal scales. We apply the model to two data sets: (1) previously published data for a species of duck, Anas platyrhynchos, and (2) data for a stream fish species, Etheostoma scotti. We show that in these cases, an incomplete-detection zero-inflated modeling approach yields a superior fit to the data than other models. We propose that zero-inflated abundance models accounting for incomplete detection be considered when replicate count data are available.     

Fluorides in groundwater and its impact on health

Fluoride is a naturally occurring toxic mineral present in drinking water and causes yellowing of teeth, tooth problems etc. Fluorspar, Cryolite and Fluorapatite are the naturally occurring minerals, from which fluoride finds its path to groundwater through infiltration. In the present study two groundwater samples, Station I and Station II at Hyderabad megacity, the capital of Andhra Pradesh were investigated for one year from January 2001 to December 2001. The average fluoride values were 1.37 mg/l at Station I and 0.91 mg/l at Station II. The permissible limit given by BIS (1983) 0.6-1.2 mg/l and WHO (1984) 1.5 mg/l for fluoride in drinking water. The groundwaters at Station I exceeded the limit while at Station II it was within the limits. The study indicated that fluoride content of 0.5 mg/l is sufficient to cause yellowing of teeth and dental problems.     

Reactivity of chlorine dioxide with amino acids, peptides, and proteins

Amino acids, proteins, and peptides are found ubiquitously in waters. They can form harmful byproducts during water treatment by reaction with disinfectants. Chlorination and chloramination of water containing natural organic matter is known to result in the production of toxic substances, often referred to as disinfection byproducts. The main advantage of using chlorine dioxide (ClO₂) over other known chlorine-containing disinfectants is the minimization of the formation of harmful trihalomethanes. Because ClO₂ is a promising alternative to other chlorine-containing disinfectants, the chemistry of ClO₂ interactions with amino acids, proteins, and peptides should be understood to ensure the safety of potable water supplies. Here, we present an overview of the aqueous chemistry of ClO₂ and its reactivity with amino acids, peptides, and proteins. The kinetics and products of the reactions are reviewed. Only a few amino acids have been reported to be reactive with ClO₂, and they have been found to follow second-order kinetics for the overall reaction. The rate constants vary from 10^?2 to 10^7?M^?1?s^?1 and follow an order of reactivity: cysteine?>?tyrosine?>?tryptophan?>?histidine?>?proline. For reactions of histidine, tryptophan, and tyrosine with ClO₂, products vary depending largely on the molar ratios of ClO₂ with the specific amino acid. Products of ClO₂ oxidation differ with the presence or absence of oxygen in the reaction mixture. Excess molar amounts of ClO₂ relative to amino acids are associated with the production of low molecular weight compounds. The oxidation of the biochemically important compounds bovine serum albumin and glucose-6-phosphate dehydrogenase by ClO₂ suggests a denaturing of proteins by ClO₂ by an attack on tryptophan and tyrosine residues and relates to the inactivation of microbes by ClO₂.     

Diffusion of PAH and PCB from contaminated sediments with and without mineral capping; measurement and modelling

A novel laboratory microcosm test was developed to measure the diffusion of native PAHs and PCBs from sediments in the presence and absence of a capping layer. Diffusive flux of 15 PAHs and 7 PCBs from uncapped sediment from Oslo harbour was 3.8+/-0.9 microg m(-2)d(-1) and 0.010+/-0.003 microg m(-2)d(-1), respectively. The flux from sediments capped with 1cm mineral cap (crushed limestone or crushed gneiss (0-2mm)), observed during the first 410 d, was 3.5-7.3% of the flux from uncapped sediments. By measuring freely dissolved pore water concentrations of 10 PAHs the flux in the microcosm was modelled with steady state and transient diffusion models. The measured flux from uncapped sediment was 27-290% of modelled steady state flux. Good agreement was also found between the measured flux of pyrene from capped sediment and the flux modelled with the transient model when fitting only with the distribution coefficients for pyrene between the cap material and water (Kd_pyr). Fitted Kd_pyr, (210 and 23 l kg(-1) for limestone and gneiss, respectively) was in the same order of magnitude as K(d) calculated from organic carbon content in the cap materials (68 and 14 l kg(-1) respectively). Calculation of the efficiency of a hypothetical cap with 10 cm diffusion path shows that the increased diffusion path length alone can yield a flux reduction >99% through a strong increase in the stagnant diffusive boundary layer from <1 to 100mm.     

Prenatal application of fluorescent in situ hybridization (FISH) for identification of a mosaic Y-chromosome marker,IDIC(Yp)

An amniocentesis was performed at 13.3 weeks' gestation for advanced maternal age. A mosaic sex chromosome pattern was found: of 50 cells examined, 34 had a 45,X karyotype. In 14 cells with a modal number of 46, a recognizable Y was substituted by a small non-fluorescent marker. C-banding identified the marker as an isodicentric in 12 cells. In two cells, the non-fluorescent marker appeared to be monocentric and looked like a non-fluorescent del (Yq), but could have been an isodicentric Y with inactivation of one of the centromeres. Two cells with a modal number of 47 showed two copies of the monocentric marker. Fluorescent in situ hybridization with an alpha satellite Y-specific centromeric probe confirmed the Y-chromosome origin of the markers and allowed for more accurate prenatal diagnostic information.     

LEHR superfund stormwater runoff and putah creek mercury issues

Stormwater runoff from the University of California, Davis/U.S. Department of Energy Laboratory for Energy‐Related Health Research (UCD/US DOE LEHR) Superfund site located on the University of California campus in Davis, California, has been found to contain over 500 ng/L of total recoverable mercury, which is about ten times the California Toxics Rule criterion. This stormwater runoff is discharged to Putah Creek, which is Clean Water Act Section 303(d) listed as impaired for excessive mercury bioaccumulation in edible fish. A discussion is presented on the potential impact of the mercury in stormwater runoff from LEHR leading to excessive bioaccumulation of mercury in Putah Creek fish. The mercury in the stormwater runoff is derived from former flooding of the soils near the creek, which contains mercury derived from abandoned upstream mercury mines located in the Coast Range Vaca Hills to the west of LEHR. The implications of this situation for implementing a Total Maximum Daily Load (TMDL) to control mercury in stormwater runoff to Putah Creek are presented. © 2009 Wiley Periodicals, Inc.