Haldane-Andrews substrate inhibition kinetics for pilot scale thermophilic anaerobic degradation of sugarcane vinasse.

A pilot scale anaerobic degradation of sugarcane vinasse was carried out at various hydraulic retention time (HRT) in the Anaerobic Suspended Growth Closed Bioreactor (ASGCB) under thermophilic temperature. The performance and kinetics were evaluated through the Haldane-Andrews model to investigate the substrate inhibition potential of sugarcane vinasse. All parameters show great performance between HRT 35 and 25 days: chemical oxygen demand (COD) reduction efficiency (81.6 to 86.8%), volatile fatty acids (VFA) reduction efficiency (92.4 to 98.5%), maximum methane yield (70%) and maximum biogas production (19.35 L/day). Furthermore, steady state values from various HRT were obtained in the kinetic evaluation for: rXmax (1.20 /day), Ks (19.95 gCOD/L), Ki (7.00 gCOD/L) and [Formula: see text] (0.33 LCH4/gCOD reduction). This study shows that anaerobic degradation of sugarcane vinasse through ASGCB could perform well at high HRT and provides a low degree of substrate inhibition as compared to existing studies from literature.

Reciprocal N (15 NH4 + or 15 NO3 - ) transfer between nonN2 -fixing Eucalyptus maculata and N2 -fixing Casuarina cunninghamiana linked by the ectomycorrhizal fungus Pisolithus sp.

• Two-way N transfers mediated by Pisolithus sp. were examined by excluding root contact and supplying 15 NH4 + or 15 NO3 - to 6-month-old Eucalyptus maculata or Casuarina cunninghamiana grown in two-chambered-pots separated by 37 m screens. • Mycorrhizal colonization was 35% in Eucalyptus and 66% in Casuarina (c. 29% N2 -fixation). Using an environmental scanning electron microscope, living hyphae were observed to interconnect Eucalyptus and Casuarina. Biomass and N accumulation was greatest in nodulated mycorrhizal Casuarina/mycorrhizal Eucalyptus pairs, less in nonnodulated mycorrhizal Casuarina/mycorrhizal Eucalyptus pairs, and least in nonnodulated nonmycorrhizal Casuarina/nonmycorrhizal Eucalyptus pairs. • In nonnodulated mycorrhizal pairs, N transfers to Eucalyptus or to Casuarina were similar (2.4-4.1 mg per plant in either direction) and were 2.6-4.0 times greater than in nonnodulated nonmycorrhizal pairs. In nodulated mycorrhizal pairs, N transfers were greater to Eucalyptus (5-7 times) and to Casuarina (12-18 times) than in nonnodulated mycorrhizal pairs. Net transfer to Eucalyptus or to Casuarina was low in both nonnodulated nonmycorrhizal (< 0.7 mg per plant) and nonnodulated mycorrhizal pairs (< 1.1 mg per plant). In nodulated mycorrhizal pairs, net transfer to Casuarina was 26.0 mg per plant. • The amount and direction of two-way mycorrhiza-mediated N transfer was increased by the presence of Pisolithus sp. and Frankia, resulting in a net N transfer from low-N-demanding Eucalyptus to high-N-demanding Casuarina.

Utility of Ki-67 and p53 in distinguishing cervical intraepithelial neoplasia 3 from squamous cell carcinoma of the cervix.

The differentiation between cervical intraepithelial neoplasia 3 (CIN 3) and early squamous cell carcinoma (SCC) of the cervix may be difficult in certain situations. Identification of invasion beyond the basement membrane is the gold standard for the diagnosis of the latter. The objective of this study was to determine whether the use of Ki-67 and p53 could help in solving the above dilemma. This was a retrospective study on 61 cases of cervical neoplasms comprising of 25 cases of CIN 3 and 36 SCC. All cases were evaluated by immunohistochemistry using Ki-67 and p53 monoclonal antibodies. Results showed that the differences of Ki-67 and p53 expression between CIN 3 and SCC were statistically significant. In conclusion, Ki-67 and p53 may serve as helpful adjuncts to routinely-stained histological sections in differentiating between CIN 3 and SCC.

Nodulated N2-fixing Casuarina cunninghamiana is the sink for net N transfer from non-N2-fixing Eucalyptus maculata via an ectomycorrhizal fungus Pisolithus sp. using 15NH4+ or 15NO3- supplied as ammonium nitrate.

To determine the effects of nitrogen source on rates of net N transfer between plants connected by a common mycorrhizal network, we measured transfer of N supplied as 15NH4 14NO3 or 14NH4 15NO3 in three Casuarina/Eucalyptus treatments interconnected by a Pisolithus sp. The treatments were nonnodulated nonmycorrhizal/nonmycorrhizal; nonnodulated mycorrhizal/mycorrhizal; and nodulated mycorrhizal/mycorrhizal. Mycorrhization was 67% in Eucalyptus and 36% in Casuarina. N2 fixation supplied 38% of the N in Casuarina. Biomass, N and 15N contents were lowest in nonmycorrhizal plants and greatest in plants in the nodulated/mycorrhizal treatment. Nitrogen transfer was enhanced by mycorrhization and by nodulation, and was greater when N was supplied as 15NH4+ than 15NO3-. Nitrogen transfer rates were lowest in the nonmycorrhizal treatment for either 15N source, and greatest in the nodulated, mycorrhizal treatment. Transfer was greater to Casuarina than to Eucalyptus and where ammonium rather than nitrate was the N source. Irrespective of 15N source and of whether Casuarina or Eucalyptus was the N sink, net N transfer was low and was similar in both nonnodulated treatments. However, when Casuarina was the N sink in the nodulated, mycorrhizal treatment, net N transfer was much greater with 15NH4+ than with 15NO3-. High N demand by Casuarina resulted in greater net N transfer from the less N-demanding Eucalyptus. Net transfer of N from a non-N2-fixing to an N2-fixing plant may reflect the very high N demand of N2-fixing species.