On mitigating emissions leakage under biofuel policies

A reason for much pessimism about the environmental benefits of today's biofuels, essentially corn and sugarcane ethanol, is the so‐called indirect land‐use change (ILUC) emissions associated with expanding biofuel production. While there exist several simulation‐based estimates of indirect emissions, the empirical basis underlying key input parameters to such simulations is not beyond doubt, while empirical verification of indirect emissions is hard. Regardless, regulators have adopted global warming intensity ratings for biofuels based on those simulations and in some case are holding regulated firms accountable for (some forms of) leakage. Suffice to say that both the estimates of and the approach to regulating leakage are controversial. The objective of this study is therefore to review a wider economic in order to identify a broader set of policy options for mitigating emissions leakage. We find that controlling leakage by affixing responsibility to regulated firms lacks support in the broader literature, which emphasizes alternative approaches.     

Molecular characterization and diversity analysis of bacterial communities associated with Dialeurolonga malleswaramensis (Hemiptera: Aleyrodidae) adults using 16S rDNA amplicon pyrosequencing and FISH

Dialeurolonga malleswaramensis Sundararaj (Hemiptera: Aleyrodidae) is a phytophagous sap sucking insect. It infests Polyalthia longifolia, an important avenue tree of India, effective in alleviating noise pollution and having immense medicinal importance. Samples of this insect were collected from Polyalthia longifolia. The cytochrome c oxidase subunit I gene (mtCO1) helped in the molecular characterization of the insect. This study reports the bacterial diversity in D. malleswaramensis adults by high throughput 16S rDNA amplicon pyrosequencing. The major genera identified were Portiera and Arsenophonus. Other bacterial genera detected were uncultured alpha proteobacterium, Sphingopyxis and Methylobacterium. We also employed fluorescence in situ hybridization (FISH) in whole mount samples to confirm the presence of dominant endosymbionts Portiera and Arsenophonus to the bacteriocyte of D. malleswaramensis. This study concludes that combining techniques like 16S rDNA amplicon pyrosequencing and FISH reveal both dominant and rare bacteria. The data also predict the evolutionary position of this pest with respect to other whitefly species using a mitochondrial marker.     

Thylakoid membrane dynamics and state transitions in Chlamydomonas reinhardtii under elevated temperature

Photosynthesis Research - Moderately elevated temperatures can induce state transitions in higher plants by phosphorylation of light-harvesting complex II (LHCII). In this study, we exposed...     

Disruption of transforming growth factor beta-regulated laminin receptor function by expression of antisense laminin, a chain RNA in human colon cancer cells

Transforming growth factor beta1 (TGFbeta) simultaneously induces the expression of fibronectin, fibronectin receptor, laminin, and laminin receptor (alpha6beta1 integrin) in the human colon cancer cell line Moser (Int J Cancer, 57:742, 1994). Induction of fibronectin and induction of fibronectin receptor by TGFB are tightly coupled, and disrupting fibronectin induction disrupts the induction of fibronectin receptor and cellular adhesion to fibronectin (J Cellular Physiol, 170:138, 1997). We recently demonstrated the efficacy of using antisense chain-specific laminin RNA expression vectors to disrupt the induction by TGFP of the multichain laminin molecule (J Cellular Physiol, 178:296, 1999). We now show in this report that Moser cells used alpha6 and beta1 integrins to adhere to laminin, and, as is the fibronectin and fibronectin receptor system, disrupting the induction by TGFbeta of the ligand laminin by the expression of antisense laminin A chain RNA disrupted the induction of 125I-laminin binding and cellular adhesion to laminin. Disrupting laminin induction also blocked the induction of alpha6 and beta1 integrin laminin receptor by TGFbeta. We conclude that disrupting the induction of the ligand laminin by TGFbeta disrupts TGFbeta-regulated laminin receptor function by suppressing the induction of alpha6 and beta1 integrins. Therefore, targeted disruption of the ligand laminin may be an effective means in disrupting the function of both the ligand and its receptor in cells that utilize the laminin and laminin receptor system in malignant cell behavior.     

Protection of Energy Transfer Process in Isolated Phycobilisome by "White Light" from Ultraviolet-B Induced Damage in the Cyanobacterium Spirulina Platensis

Effect of UV-B (1.9 W m^-2) alone or in combination with supplemental "white light". WL (20 W m^-2) exposure was studied on the energy transfer process of intact phycobilisomes isolated from Spirulina platensis. Exposure of UV-B or supplemental irradiation induced a decrease in room temperature fluorescence intensity and caused a shift towards shorter wavelengths. The low temperature fluorescence measurements showed that UV-B impairs energy transfer from phycocyanin to allophycocyanin B and the extent of damage may be reduced by the exposure to supplemental WL. This revised version was published online in June 2006 with corrections to the Cover Date.     

Enhanced rates of P700<Superscript>+</Superscript> dark-reduction in leaves of<Emphasis Type="Italic"> Cucumis sativus</Emphasis> L. photoinhibited at chilling temperature

The changes in electron transport within photosystem I (PSI) were studied in detached leaves of Cucumis sativus L. during the course of irradiation with moderate white light (300 mol photons m^–2 s^–1) at 4°C. When intact leaves were exposed to the combination of moderate light and low temperature, the amplitude of far-red light-induced P700 absorbance changes at 820 nm (A₈₂₀), a relative measure of PSI, progressively decreased as the light treatment time increased. Almost no oxidation of P700 was noticeable after 5 h. Methyl viologen accelerated the oxidation of P700 to a steady-state level and also increased the magnitudes of A₈₂₀ changes in photoinhibited leaves, reflecting the rapid removal of electrons from native carriers. Photoinhibition under moderate light and chilling temperature also accelerated the rate of P700⁺ reduction after far-red light excitation as the half-times of the two exponential components of P700⁺ decay curves decreased relative to the control ones. A detailed analysis of the kinetics of P700⁺ reduction using diuron alone or the combination of diuron and methyl viologen strongly favours an increased rate of electron donation from stromal reductants to PSI through the plastoquinone pool following photoinhibitory treatment. Importantly, the marked acceleration of P700⁺ re-reduction is the consequence of the irradiation of leaf segments at low temperature and not caused by chilling stress alone.Abbreviations A ₀ and A ₁ Primary acceptor chlorophyll and secondary electron acceptor phylloquinone - FR Far-red light - F _X , F _A , and F _B Iron–sulfur centers - MT Multiple-turnover flash - MV Methyl viologen - Ndh NAD(P)H-dehydrogenase - PQ Plastoquinone - PS Photosystem - P700 Reaction-center chlorophyll of PSI - ST Single-turnover flash     

Local and systemic inhibition of lung tumor growth after nanoparticle-mediated mda-7/IL-24 gene delivery

The human melanoma differentiation associated gene-7 (mda-7), also known as interleukin-24 (IL-24), is a novel gene with tumor suppressor, antiangiogenic, and cytokine properties. In vitro adenovirus-mediated gene transfer of the human mda-7/IL-24 gene (Ad-mda-7) results in ubiquitous growth suppression of human cancer cells with minimal toxicity to normal cells. Intratumoral administration of Ad-mda-7 to lung tumor xenografts results in growth suppression via induction of apoptosis and antiangiogenic mechanisms. Although these results are encouraging, one limitation of this approach is that its locoregional clinical application-systemic delivery of adenoviruses for treatment of disseminated cancer is not feasible at the present time. An alternative approach that is suitable for systemic application is non-viral gene delivery. We recently demonstrated that DOTAP:cholesterol (DOTAP:Chol) nanoparticles effectively deliver tumor suppressor genes to primary and disseminated lung tumors. In the present study, therefore, we evaluated nanoparticle-mediated delivery of the human mda-7/IL-24 gene to primary and disseminated lung tumors in vivo. We demonstrate that DOTAP:Chol efficiently delivers the mda-7/IL-24 gene to human lung tumor xenografts, resulting in suppression of tumor growth. Growth-inhibitory effects were observed in both primary (P=0.001) and metastatic lung tumors (P=0.02). Furthermore, tumor vascularization was reduced in mda-7/IL-24-treated tumors. Finally, growth was also inhibited in murine syngenic tumors treated with DOTAP:Chol-mda-7 nanoparticles (P=0.01). This is the first report demonstrating (1) systemic therapeutic effects of mda-7/IL-24 in lung cancer, and (2) antitumor effects of human mda-7 in syngeneic cancer models. Our findings are important for the development of mda-7/IL-24 treatments for primary and disseminated cancers.     

Domain truncation studies reveal that the streptokinase-plasmin activator complex utilizes long range protein-protein interactions with macromolecular substrate to maximize catalytic turnover

To explore the interdomain co-operativity during human plasminogen (HPG) activation by streptokinase (SK), we expressed the cDNAs corresponding to each SK domain individually (alpha, beta, and gamma), and also their two-domain combinations, viz. alphabeta and betagamma in Escherichia coli. After purification, alpha and beta showed activator activities of approximately 0.4 and 0.05%, respectively, as compared with that of native SK, measured in the presence of human plasmin, but the bi-domain constructs alphabeta and betagamma showed much higher co-factor activities (3.5 and 0.7% of native SK, respectively). Resonant Mirror-based binding studies showed that the single-domain constructs had significantly lower affinities for "partner" HPG, whereas the affinities of the two-domain constructs were remarkably native-like with regards to both binary-mode as well as ternary mode ("substrate") binding with HPG, suggesting that the vast difference in co-factor activity between the two- and three-domain structures did not arise merely from affinity differences between activator species and HPG. Remarkably, when the co-factor activities of the various constructs were measured with microplasminogen, the nearly 50-fold difference in the co-factor activity between the two- and three-domain SK constructs observed with full-length HPG as substrate was found to be dramatically attenuated, with all three types of constructs now exhibiting a low activity of approximately 1-2% compared to that of SK.HPN and HPG. Thus, the docking of substrate through the catalytic domain at the active site of SK-plasmin(ogen) is capable of engendering, at best, only a minimal level of co-factor activity in SK.HPN. Therefore, apart from conferring additional substrate affinity through kringle-mediated interactions, reported earlier (Dhar et al., 2002; J. Biol. Chem. 277, 13257), selective interactions between all three domains of SK and the kringle domains of substrate vastly accelerate the plasminogen activation reaction to near native levels.     

Control of energy dissipation and photochemical activity in photosystem I by NADP-dependent reversible conformational changes

Addition of NADP(+) to thylakoid membranes or isolated photosystem I (PSI) submembrane fractions quenched chlorophyll fluorescence by up to 40% at low or room temperature. This quenching was reversed by NADPH. Similar quenching was also observed with the addition of heparin or thenoyltrifluoroacetone (TTFA), inhibitors that bind ferredoxin:NADP(+) reductase (FNR) and prevent reduction of NADP(+). The NADP(+)-induced quenching coincided with a reversible conformational change of the secondary protein structure in the PSI submembrane fractions where 20% of the alpha-helix conformations were transformed mainly into beta-sheet-like structures. Further, P700 photooxidation was retarded due to this conformational change, and about 25% of the centers could not be photooxidized, these changes being also reversible with addition of NADPH. The above modifications in the presence of NADP(+) also increased photodamage processes under strong illumination, and NADPH protected it. Conformational modification of FNR upon binding of NADP(+) or NADPH is proposed to trigger the macromolecular changes in a larger part of the protein complex of PSI. The conformational changes must increase the intermolecular distances and change the mutual orientation between the various cofactors in the PSI complex. This new control mechanism of energy dissipation and photochemical activity by NADP(+)/NADPH is proposed to increase the turnover rate of PSI under conditions when both linear and cyclic electron transport activities must be supported.