“Our market is our community”: women farmers and civic agriculture in Pennsylvania,USA

Civic agriculture is characterized in the literature as complementary and embedded social and economic strategies that provide economic benefits to farmers at the same time that they ostensibly provide socio-environmental benefits to the community. This paper presents some ways in which women farmers practice civic agriculture. The data come from in-depth interviews with women practicing agriculture in Pennsylvania. Some of the strategies women farmers use to make a living from the farm have little to do with food or agricultural products, but all are a product of the process of providing a living for farmers while meeting a social need in the community. Most of the women in our study also connect their business practices to their gender identity in rural and agricultural communities, and redefine successful farming in opposition to traditional views of economic rationality.     

Prevalence and factors associated with fecal shedding of Giardia spp. in domestic cats

The prevalence of cats shedding Giardia cysts (13.6%) in the present study was found to be higher than previously reported (1% to 11%) and may reflect a higher sensitivity for the diagnostic test used. The presence of Cryptosporidium spp. oocysts, coccidial oocysts, and a clinical history of chronic (>2 weeks) gastrointestinal signs were significantly associated with the presence of Giardia spp. cysts in the feces. There were no associations between the presence of Giardia spp. cysts and type of housing, acute gastrointestinal signs, vomiting, gender, source of cat (i.e., animal shelter versus private breeder), or gastrointestinal parasites other than Cryptosporidium spp. and intestinal coccidial agents.     

Where to shoot your pilodyn: within tree variation in basic density in plantation Eucalyptus globulus and E. nitens in Tasmania

Longitudinal patterns of within tree variation for basic density were determined for plantation Eucalyptus globulus (ages 5 and 10 years) and E. nitens (ages 5, 10 and 15 years) growing in three geographic areas in Tasmania. Each tree was sampled by taking discs from a combination of percentage heights (0, 10, 20 ___ 70%) and fixed height samples (0.5 m, 0.7 m ___ 1.5 m). At each of the fixed heights, a single pilodyn reading was taken from each of 4 aspects. Weighted whole tree density was calculated from the percentage height samples and used for correlation and regression analysis with the fixed height samples. Both species showed an initial drop in density between the felling cut (zero height) and 0.5 m, followed by a linear increase in density between 10% and 70% of tree height. Slope of fitted regressions were parallel within species but differed significantly between the species (1.14 kg/m³ and 1.62 kg/m³ per 1% increase in height above 10% for E. globulus and E. nitens, respectively). Density at all fixed heights was highly correlated with whole tree values for E. globulus, but results were variable across sites for E. nitens. Both species were found to contain trees which produced aberrant pilodyn readings. For E. globulus, the optimal sampling height was 1.3 m above ground and the mean pilodyn reading was found to predict whole tree density with an accuracy of ±21 kg/m³. For E. nitens, optimal sampling height was 1.5 m above ground. However, pilodyn readings around the stem were not very repeatable and correlations with whole tree density were lower, resulting in the accuracy of prediction of whole tree density being ±26 kg/m³.     

The source of Saturn's G ring

The origin of Saturn's narrow G ring has been unclear. We show that it contains a bright arc located 167,495.6 +/- 1.3 km from Saturn's center. This longitudinally localized material is trapped in a 7:6 corotation eccentricity resonance with the satellite Mimas. The cameras aboard the Cassini spacecraft mainly observe small (1 to 10 micrometers) dust grains in this region, but a sharp decrease in the flux of energetic electrons measured near this arc requires that it also contain larger (centimeter- to meter-sized) bodies whose total mass is equivalent to that of a approximately 100-meter-wide ice-rich moonlet. Collisions into these bodies may generate dust, which subsequently drifts outward to populate the rest of the G ring. Thus, the entire G ring could be derived from an arc of debris held in a resonance with Mimas.     

Escherichia coli dihydrodipicolinate synthase and dihydrodipicolinate reductase: kinetic and inhibition studies of two putative herbicide targets

Dihydrodipicolinate synthase (DHDPS) (EC 4.2.1.52) and dihydrodipicolinate reductase (DHDPR) (EC 1.3.1.26) have attracted much recent attention as potential herbicide targets. DHDPS was feedback-inhibited by (S)-lysine; inhibition was reversible and uncompetitive with respect to both (S)-ASA and pyruvate. Homoserine lactone was a reversible non-competitive inhibitor of DHDPS with respect to both (S)-ASA and pyruvate. (R)-Cysteine sulfinic acid and (S)-glutamic acid were reversible uncompetitive inhibitors of DHDPS with respect to (S)-ASA. (S)-Aspartic acid was a reversible mixed-type inhibitor. Dipicolinic acid was a reversible competitive inhibitor of DHDPR with respect to the substrate (4S)-4-hydroxy-2,3,4,5-tetrahydro-(2S)-dipicolinic acid, as was isophthalic acid. Δ³-Tetrahydroisophthalic acid was a moderate inhibitor of both DHDPS and DHDPR. These compounds represent possible leads in the development of novel herbicides. © 1999 Society of Chemical Industry     

Implications of nutrient enrichment for the conservation and management of seagrass Zostera muelleri meadows

相似文献   

Nitrogen absorption,translocation and distribution from urea applied in autumn to leaves of young potted apple (Malus domestica) trees

We studied the absorption, assimilation, translocation and distribution of nitrogen (N) from urea applied in autumn to leaves of 1-year-old potted Fuji/M26 apple (Malus domestica Borkh) trees. In early October, all leaves of each tree were painted with either 3% urea (enriched to 10 atom % with 15N) or water (control trees). Four trees were harvested before the treatment and N and amino acid contents were determined. Four trees from each treatment were harvested at 2, 4, 7, 10, 15 and 20 days after urea or water application. Total N, amino acids and 15N in leaves, bark, xylem, shank and roots were analyzed to determine uptake and mobilization of N from urea. Most uptake of 15N by leaves occurred during the first 2 days following application of urea. The mean rate of absorption during these 2 days was 0.29 g m-2 day-1. Amino acids in leaves, bark and roots increased significantly after urea application compared with control values. The highest concentrations of amino acids in leaves and bark occurred 4 days after application, whereas the highest concentrations of amino acids in roots occurred 10 days after application. Total 15N content in leaves peaked 2 days after urea application and then decreased, whereas 15N content in roots and bark increased throughout the experiment. Total 15N content in xylem and shank was low. Leaves absorbed 35% of the 15N applied as urea, and 63.6% of absorbed 15N was translocated out of leaves within 20 days after urea application. We conclude that N from urea was converted to amino acids in leaves after foliar application in autumn, and roots and bark were the main sinks of N from urea applied to leaves.