Siembras del berro y su relación con la fascioliasis en Puerto Rico

Watercress, Nasturtium officinale, is an edible semi-aquatic plant. It is considered to be the principal source of infection for human fascioliasis in Puerto Rico and elsewhere in the world. Commercially grown and natural watercress areas on the island were examined to determine the existing conditions which would contribute to the dissemination of Fasciola hepatica. The factors considered were: 1) the presence of the snail intermediate host (infected and uninfected) in the cress cultivation areas; 2) the presence of parasitized mammals in the area where contaminated fecal matter could be washed into the cress growing sites; 3) the presence of viable metacercariae encysted on watercress; and 4) human consumption of watercress from contaminated sites. The nine commercial watercress cultivation sites examined were found free of infected snails, free of watercress with viable metacercariae, and free of infected mammals in the area. On the other hand, of the 18 natural, unattended watercress growing sites, seven were found with infected snails, six of the sites had watercress with viable metacercaria, and nine of the sites had susceptible animals in the area.Nasturtium officinale, R. Br. (Gray's Manual) es una planta semiacuática que se consume como ensalada en Puerto Rico. El consumo de berro es un medio de infección de la Fasciola hepatica al ingerir metacercarias enquistadas en la planta. Se estudiaron las zonas donde se cultiva el berro comercialmente y silvestre del norte para determinar qué factores contribuyen a diseminar la Fasciola hepatica. Se consideraron los factores que siguen: 1) la presencia de caracoles hospederos intermediarios infectados o no infectados; 2) la presencia de animales susceptibles y parasitados; 3) la presencia de metacercarias enquistadas en la planta; y 4) el consumo de berro en la comunidad de las zonas contaminadas. Los resultados de las muestras de caracoles Lymnaea cubensis, berro y seis muestras de heces de los nueve viveros comerciales fueron negativos a formas larvarias y huevos de la Fasciola hepatica; siete de los 18 viveros naturales tenían caracoles infectados. De estos siete, seis fueron positivos a metacercaria. En dos viveros naturales de berro había animales susceptibles, lo cual puede representar una fuente de infección

Biogeochemical controls and isotopic signatures of nitrous oxide production by a marine ammonia-oxidizing bacterium

Nitrous oxide (N2O)[N subscript 2 O] is a trace gas that contributes to the greenhouse effect and stratospheric ozone depletion. The N2O [N subscript 2 O] yield from nitrification (moles N2O-N [N subscript 2 O - N] produced per mole ammonium-N consumed) has been used to estimate marine N2O [N subscript 2 O] production rates from measured nitrification rates and global estimates of oceanic export production. However, the N2O [N subscript 2 O] yield from nitrification is not constant. Previous culture-based measurements indicate that N2O [N subscript 2 O] yield increases as oxygen (O2) [O subscript 2] concentration decreases and as nitrite (NO2−) [NO subscript 2 overscore] concentration increases. Here, we have measured yields of N2O [N subscript 2 O] from cultures of the marine β-proteobacterium [beta-proteobacterium] Nitrosomonas marina C-113a as they grew on low-ammonium (50 μM)[50 mu M] media. These yields, which were typically between 4 × 10−4 [10 superscript -4] and 7 × 10−4 [10 superscript -4] for cultures with cell densities between 2 × 102 [10 super script 2] and 2.1 × 104 [10 superscript 4] cells ml−1 [ml superscript -1], were lower than previous reports for ammonia-oxidizing bacteria. The observed impact of O2 [O subscript 2] concentration on yield was also smaller than previously reported under all conditions except at high starting cell densities (1.5 × 106 cells ml−1) [1.5 x 10 superscript 6 cells ml superscript -1], where 160-fold higher yields were observed at 0.5% O2 [O subscript 2](5.1 μM [mu M] dissolved O2 [O subscript 2]) compared with 20% O2 [O subscript 2] (203 μM [mu M] dissolved O2 O subscript 2]). At lower cell densities (2 × 102 [10 superscript 2] and 2.1 × 104 [10 superscript 4] cells ml−1 [ml superscript -1]), cultures grown under 0.5% O2 [O subscript 2] had yields that were only 1.25- to 1.73-fold higher than cultures grown under 20% O2 [O subscript 2]. Thus, previously reported many-fold increases in N2O [N subscript 2 O] yield with dropping O2 [O subscript 2] could be reproduced only at cell densities that far exceeded those of ammonia oxidizers in the ocean. The presence of excess NO2− [NO subscript 2 overscore] (up to 1 mM) in the growth medium also increased N2O [N subscript 2 O] yields by an average of 70% to 87% depending on O2 [O subscript 2] concentration. We made stable isotopic measurements on N2O [N subscript 2 O] from these cultures to identify the biochemical mechanisms behind variations in N2O [N subscript 2 O] yield. Based on measurements of δ15Nbulk [delta superscript 15 N superscript bulk], site preference (SP = δ15Nα−δ15Nβ [delta superscript 15 N superscript alpha - delta superscript 15 N superscript beta]), and δ18O [delta superscript 18 O] of N2O [N subscript 2 O] (δ18O-N2O [delta superscript 18 O - N subscript 2 O]), we estimate that nitrifier-denitrification produced between 11% and 26% of N2O [N subscript 2 O] from cultures grown under 20% O2 [O subscript 2] and 43% to 87% under 0.5% O2 [O subscript 2]. We also demonstrate that a positive correlation between SP and δ18O-N2O [delta superscript 18 O - N subscript 2 O] is expected when nitrifying bacteria produce N2O [N subscript 2 O]. A positive relationship between SP and δ18O-N2O [delta superscript 18 O - N subscript 2 O] has been observed in environmental N2O [N subscript 2 O] datasets, but until now, explanations for the observation invoked only denitrification. Such interpretations may overestimate the role of heterotrophic denitrification and underestimate the role of ammonia oxidation in environmental N2O [N subscript 2 O] production

Pretransitional Optical Activity In Chiral Smectic Liquid Crystals

Pretransitional optical activity measurements in smectic liquid crystals of both law and high chirality are reported. In the low chirality sample, p-(n-(decyloxybenzylidene)-p-amino-(2-methylbutyl)cin-namate (DOBAMBC), the results indicate that the optical activity in both the isotropic phase just above the smectic A phase and in the smectic A phase just above the smectic C* phase can be explained in terms of a Landau-deGennes free energy with no coupling between the chiral modes. In the high chirality sample, 1-methylheptyl 4′-[(4″-tetradecyloxyphenyl)propioloyloxy]biphenyl-4-carboxylate (14P|M7), the data in the isotropic phase above the recently discovered smectic A* phase cannot be explained in this way, even when coupling between the chiral modes is considered. Whether this is due to some feature of the smectic A* phase or is simply the result of strong coupling between the orientational and positional order parameters is a question which remains unanswered

UA & Sociocultural WG: Summary of 5 Priority Tasks

Presentation on the five priority areas including toolkit/tools, customer-based focused assessment on tools and needs and assessments of other stakeholders, personas/scenarios, policies and best practices, and development of a feedback mechanism

Reasonable efforts? Implementation of the reunification exception provisions of ASFA

The Adoption and Safe Families Act (ASFA) of 1997 includes provisions to deny reunification services under specified conditions and gives states latitude to develop any number of additional “aggravated circumstances” in which parents need not be offered services. California legislators have developed a relatively large number of conditions enabling agencies to bypass reunification services. Based upon a case record review involving 1,055 parents, this study attempts to identify the proportion of parents eligible for a reunification bypass, the proportion recommended to the courts, and the proportion of parents who were denied reunification services, and examines the characteristics of parents associated with reunification bypass recommendations. Based upon focus groups and interviews with child welfare and judicial personnel in six counties, the study also examines the implementation of reunification bypass provisions. Implications for public policy and practice are provided