Physiological ecology of Porphyra sporophytes: growth, photosynthesis, respiration and pigments

Thesis (M.S.) University of Alaska Fairbanks, 2000Growth, photosynthesis, respiration and photosynthetic pigments of the sporophytic stage for Alaskan Porphyra species were investigated in response to various environmental variables. Optimal conchocelis growth (7.6%) volume increase d⁻¹) of P. abbottae (Pa) occurred at 11C̊, 80 umol photons m⁻² s⁻¹ and 30ppt salinity. Porphyra torta (Pt) grew best (6.5%d⁻¹) at 15C̊, 80 umol photons m⁻² s⁻¹ and 30ppt. Porphyra pseudolinearis (Pi) generally had higher growth rates with optimal growth (8.8% d⁻¹) occurring at 7C̊, 160 umol photons m⁻² s⁻¹ and 30ppt. Salinities between 20 and 40ppt and irradiances between 20 and 40ppt and irradiances between 20 and 160 umol photons m⁻² s⁻¹ generally had little effect on growth rates, but there was virtually no growth at <10ppt. Plant hormones were shown to promote the growth of conchosporangia, which increased by 6.9-31.7% (for Pa), 4.7-25.7% for (Pe, P. pseudolanceolata) and 8.9-35.1% for (Pi). Concentrations between 0.4-1.6ppm of kinetin and indole-3-acetic acid at higher temperatures generally had higher stimulatory effects, but Pe had higher volume increase at lower temperatures. Irradiance, temperature and salinity influenced photosynthesis of the conchocelis. P-I curves, Pmax, Imax, and Ic varied with temperature and species. Higher photosynthesis generally occurred at 25-35ppt salinities. Pa had maximal photosynthesis at 11C̊ and 60 umol photons m⁻² s⁻¹, whereas Pi and Pt had maximal photosynthesis at higher temperatures and irradiances. The highest photosynthesis (240 umol O₂ production g dw⁻¹ h⁻¹) of Pa occurred at 11C̊, 60umol photons m⁻² s⁻¹ and 30ppt. Pi and Pt had optimal photosynthetic rates (200 and 210, respectively) at 15C̊, 120 umol photons m⁻2 s⁻¹ and 30ppt. Conchocelis had lower respiration rates (30-35) at 7C̊ than at 11 and 15C̊ (45-58 umol O₂ consumption g dw⁻¹ h⁻¹). All three species exhibited lowest respiration at salinities between 25-35ppt. Phycoerythrin (PE), phycocyanin (PC), carotenoid Ca) and chlorophyll a (Chl.a) contents were significantly affected by irradiance, nutrient concentration and culture duration. For Pa, Pi and Pt, maximal PE (63.2-95.1 mg/g.dw) and PC content (28.8-64.8 mg/g.dw) generally occurred at 10 umol photons m⁻² s⁻¹, f/4-f/2 nutrient concentration after 10-20 days, while Pe had highest PE (73.3 mg/g.dw) and PC content (70.2 mg/g.dw) at 10 umol photons m⁻² s⁻¹, f nutrient concentration after 60 days. For all four species, highest Ca (3.4 - 6.3) and Chl.a content (3.6 - 8.1 mg/g.dw) generally occurred at 0-10 umol photons m⁻² s⁻¹, f/4-f nutrient concentration. High irradiances, low nutrients and longer culture duration generally caused a decline of pigment content

Florid diffuse peritoneal deciduosis mimicking carcinomatosis in a primigravida patient: A case report and review of the literature

A case of a 27 year old G1P0 female with a dichorionic, diamniotic twin pregnancy presenting with premature rupture of membranes found to have omental caking and diffuse yellow-tan peritoneal nodules, clinically suspicious for carcinomatosis. The case work-up showed this to be an example of florid-diffuse peritoneal deciduosis mimicking carcinomatosis which has since resolved 4 months postpartum

Reduction in squamous cell carcinomas in mouse skin by dietary zinc supplementation.

Inadequate dietary Zn consumption increases susceptibility to esophageal and other cancers in humans and model organisms. Since Zn supplementation can prevent cancers in rodent squamous cell carcinoma (SCC) models, we were interested in determining if it could have a preventive effect in a rodent skin cancer model, as a preclinical basis for considering a role for Zn in prevention of human nonmelanoma skin cancers, the most frequent cancers in humans. We used the 7,12-dimethyl benzanthracene carcinogen/phorbol myristate acetate tumor promoter treatment method to induce skin tumors in Zn-sufficient wild-type and Fhit (human or mouse protein) knockout mice. Fhit protein expression is lost in \u3e50% of human cancers, including skin SCCs, and Fhit-deficient mice show increased sensitivity to carcinogen induction of tumors. We hypothesized that: (1) the skin cancer burdens would be reduced by Zn supplementation; (2) Fhit(-/-) (Fhit, murine fragile histidine triad gene) mice would show increased susceptibility to skin tumor induction versus wild-type mice. 30 weeks after initiating treatment, the tumor burden was increased ~2-fold in Fhit(-/-) versus wild-type mice (16.2 versus 7.6 tumors, P \u3c 0.001); Zn supplementation significantly reduced tumor burdens in Fhit(-/-) mice (males and females combined, 16.2 unsupplemented versus 10.3 supplemented, P = 0.001). Most importantly, the SCC burden was reduced after Zn supplementation in both strains and genders of mice, most significantly in the wild-type males (P = 0.035). Although the mechanism(s) of action of Zn supplementation in skin tumor prevention is not known in detail, the Zn-supplemented tumors showed evidence of reduced DNA damage and some cohorts showed reduced inflammation scores. The results suggest that mild Zn supplementation should be tested for prevention of skin cancer in high-risk human cohorts

STUDY ON PERMEABILITY AND ELECTRICAL RESISTIVITY OF RED CLAY CONTAMINATED BY CU2+

In order to study the permeability characteristics of heavy metal ions contaminated red clay and explore the rapid detection of permeability of heavy metal contaminated red clay. Through variable-head permeability test and electrical resistivity test (different voltages and methods), the effects of Cu2+ concentration and initial water content on hydraulic conductivity characteristic and resistivity of contaminated red clay was systematically investigated. The relationship between permeability characteristic and electrical resistivity was further explored by taking Cu2+ concentration and moisture content as the intermediate variable. The obtained results indicate that the different voltage has no obvious effect on the resistivity of the samples. The four-phase electrode method is more accurate than the two-phase electrode method. With increasing Cu2+ concentrations the hydraulic conductivity of specimens increases, however the permeability coefficient of contaminated soil decreases with increasing initial water content. In the resistivity test, with increasing of Cu2+ concentrations and water content, the resistivity of samples presented a downward trend, which is decreased sharply at first and then tended to be gentle. The relationship between hydraulic conductivity and resistivity of contaminated soil showed a good fitting curve no matter in different Cu2+ concentration or in different water content, but the fitting curves of them presented opposite trend