Economic and environmental impact assessments of a stand-alone napier grass-fired combined heat and power generation system in the southeastern US

The International Journal of Life Cycle Assessment - Napier grass, one of the high yield perennial energy crops can be grown on marginal lands with minimal inputs, but with increased soil carbon...     

Quantum Dot Based Heterostructures for Unassisted Photoelectrochemical Hydrogen Generation

TiO₂ hollow nanowires (HNWs) and nanoparticles (NPs) constitute promising architectures for QDs sensitized photoanodes for H₂ generation. We sensitize these structures with CdS/CdSe quantum dots by two different methods (chemical bath deposition, CBD and succesive ionic layer adsorption and reaction, SILAR) and evaluate the performance of these photoelectrodes. Remarkable photocurrents of 4 mA·cm and 8 mA·cm^?2 and hydrogen generation rates of 40 ml·cm^?2·day^?1 and 80 ml·cm^?2·day^?1 have been obtained in a three electrode configuration with sacrificial hole scavengers (Na₂S and Na₂SO₃), for HNWs and NPs respectively, which is confirmed through gas analysis. More importantly, autonomous generation of H₂ (20 ml·cm^?2·day^?1 corresponding to 2 mA·cm^?2 photocurrent) is obtained in a two electrode configuration at short circuit under 100 mW·cm^?2 illumination, clearly showing that these photoanodes can produce hydrogen without the assistance of any external bias. To the best of the authors' knowledge, this is the highest unbiased solar H₂ generation rate reported for these of QDs based heterostructures. Impedance spectroscopy measurements show similar electron density of trap states below the TiO₂ conduction band while the recombination resistance was higher for HNWs, consistently with the much lower surface area compared to NPs. However, the conductivity of both structures is similar, in spite of the one dimensional character of HNWs, which leaves some room for improvement of these nanowired structures. The effect of the QDs deposition method is also evaluated. Both structures show remarkable stability without any appreciable photocurrent loss after 0.5 hour of operation. The findings of this study constitute a relevant step towards the feasibility of hydrogen generation with wide bandgap semiconductors/quantum dots based heterostructures.     

Infection of the isopod Tachaea spongillicola on freshwater prawns Macrobrachium spp. in southern India

This paper reports the infection of freshwater prawns belonging to the genus Macrobrachium by the isopod parasite Tachaea spongillicola in a freshwater river system of southeastern India.     

Decapod crustacean chelipeds: an overview

The structure, growth, differentiation and function of crustacean chelipeds are reviewed. In many decapod crustaceans growth of chelae is isometric with allometry level reaching unity till the puberty moult. Afterwards the same trend continues in females, while in males there is a marked spurt in the level of allometry accompanied by a sudden increase in the relative size of chelae. Subsequently they are differentiated morphologically into crusher and cutter making them heterochelous and sexually dimorphic. Of the two, the major chela is used during agonistic encounters while the minor is used for prey capture and grooming. Various biotic and abiotic factors exert a negative effect on cheliped growth. The dimorphic growth pattern of chelae can be adversely affected by factors such as parasitic infection and substrate conditions. Display patterns of chelipeds have an important role in agonistic and aggressive interactions. Of the five pairs of pereiopods, the chelae are versatile organs of offence and defence which also make them the most vulnerable for autotomy. Regeneration of the autotomized chelipeds imposes an additional energy demand called “regeneration load” on the incumbent, altering energy allocation for somatic and/or reproductive processes. Partial withdrawal of chelae leading to incomplete exuviation is reported for the first time in the laboratory and field inMacrobrachiumspecies.     

Sheltering behaviour of<Emphasis Type="Italic"> Macrobrachium nobilii</Emphasis> (Henderson and Matthai, 1910)

Shelter acquisition seems to be one of the main causes for agonistic interactions in the communal culturing of decapod crustaceans, leading to reduction in survival and growth-rate values. Understanding how to reduce aggressive behaviour among individuals by providing suitable shelters would promote production efficiency and welfare in such aquaculture environments. Factors influencing the sheltering behaviour of a freshwater prawn, Macrobrachium nobilii, were studied in laboratory conditions. Prior ownership significantly increased the ability to retain a shelter; males were significantly more likely to acquire and retain a shelter than females, except females carrying eggs. Various movements of the prawn while acquiring the shelter and the behaviour pattern involved in evicting an occupant are described. The size of the shelter selected by an animal is directly related to its body size. Regarding the choice of the colour of the shelter, juveniles and adults preferred dark shelters over light-coloured shelters and never chose a transparent shelter. Communicated by R.F. Oliveira     

Apoptosis during spontaneous and prostaglandin F(2alpha)-induced luteal regression in the buffalo cow (Bubalus bubalis): involvement of mitogen-activated protein kinases

The present study was conducted to evaluate whether the corpus luteum (CL) of the water buffalo (Bubalus bubalis) cow undergoes luteal regression by the process of apoptosis and to examine the involvement of mitogen-activated protein (MAP) kinases during prostaglandin (PG) F(2alpha)-induced luteolysis. Sections of CL from late in the estrous cycle, i.e., during spontaneous luteolysis, stained for 4',6'-diamidino-2-phenylindole revealed increased numbers of condensed nuclei, indicating cell death by apoptosis, which was confirmed further by the occurrence of pronounced oligonucleosome formation. For morphological and biochemical characterization during PGF(2alpha)-induced apoptosis, CL were collected at 0, 4, 12, and 18 h after injection of 750 micro g of Tiaprost, a synthetic analogue of PGF(2alpha), to midestrous buffalo cows. Serum progesterone concentrations fell within 4 h and decreased (P < 0.05) maximally by 18 h. Concomitant decreases (P < 0.05) in the levels of steroidogenic acute regulatory mRNA and protein were observed in CL during 12-18 h, with the more profound effect on mRNA levels. Quantitative analysis of the genomic DNA showed a >5-fold increase (P < 0.05) in the low molecular weight DNA fragments by 18 h postinjection. Immunoblot analysis of CL tissue lysates showed increased (P < 0.05) levels of phospho-Jun N-terminal kinase (JNK) 1 (4- to 14-fold during 4-18 h) and phospho-p38 (2- to 4-fold at 18 h). Immunohistochemical evaluation of CL sections revealed an increased nuclear localization of phospho-JNK after treatment. These findings demonstrate that the CL of the buffalo cow undergoes cell death by the process of apoptosis both during spontaneous and PGF(2alpha)-induced luteolysis and that MAP kinases are involved during PGF(2alpha)-mediated apoptosis in the CL.     

Effect of Lime Pretreatment on Granulation of Switchgrass

Densification of switchgrass into consistent and high-density solid feedstock will reduce the cost of transport, handling, and storage to produce fuels and chemicals. Development a novel, low-cost densification technology is critical for reducing the delivered cost of feedstock while improving the bulk flow properties of densified products. In this paper, a novel wet granulation technology was proposed to investigate the effect of lime pretreatment on the production of switchgrass granules. Granulation is a process of agglomerating fine powders by wetting powder surfaces with liquid binders and mild application of shear/vibrating forces. Switchgrass was size reduced into fine powders using a knife mill and pretreated with three lime loading rates (0.05, 0.1, 0.2 g/g of biomass) at 121 °C for 30 min and at room temperature (25 °C) for 72 h. The structural modification of pretreated samples was analyzed by scanning electron microscopy and autofluorescence microscopy. Pretreated samples were granulated using a pan granulator with pre-formulated starch binder. Granules made from 20 % (0.2 g/g of biomass) lime loading rate had significantly higher single granule density and angle of repose with lower binder requirement than that of untreated granules. Lime treatment did not significantly increase the bulk density and hardness of granules. Lime-treated granules had significantly higher ash content and lower gross calorific value than that of untreated granules. In overall, lime treatment was not attractive to produce granules for thermochemical conversion platform, but lime-treated granules could be used to produce liquid biofuels and platform chemicals in biochemical conversion platform.     

The Potential of C4 Perennial Grasses for Developing a Global BIOHEAT Industry

Unprecedented opportunities for biofuel development are occurring as a result of rising fossil fuel prices, the need to reduce greenhouse gases, and growing energy security concerns. An estimated 250 million hectares (ha) of farmland could be utilized globally to develop a bioenergy industry if efficient and economical perennial biomass crops and bioenergy conversion systems are employed. In temperate zones, C₄ or warm-season grass research and development efforts have found switchgrass (Panicum virgatum) and Miscanthus capable of producing biomass yields of 10 to 20 oven dried tonnes (ODT)/ha/yr, while in tropical areas Erianthus and napier grass (Pennisetum purpureum) are producing 25 to 35 ODT/ha/yr. The potential to annually produce 100 barrels of oil energy equivalent/ha with a 25:1 energy output to input ratio appears achievable with high-yielding, N-fixing warm-season grasses grown on marginal lands in the tropics. Commercialization of densified herbaceous plant species has been slow because of the relatively high alkali and chlorine contents of the feedstocks, which leads to clinker formation and the fouling of boilers. This challenge can be overcome by improving biomass quality through advances in plant breeding and cultural management to reduce the chlorine, alkali, and silica content and through the use of new combustion technologies.

Warm-season grasses can be readily densified provided suitable grinding and densification equipment and pressure are utilized. The major advantages of producing densified warm-season grasses for BIOHEAT include: it is the most efficient strategy to use marginal farmlands in most temperate and tropical climates to collect solar radiation; it has an excellent energy balance; the feedstocks can be used conveniently in a variety of energy applications; and it is relatively environmentally friendly. Densified warm-season grass biofuels are poised to become a major global fuel source because they can meet some heating requirements at less cost than all other alternatives available today.     

Inhibition of epidermal growth factor receptor by ferulic acid and 4-vinylguaiacol in human breast cancer cells

Objectives

To examine the potential of ferulic acid and 4-vinylguaiacol for inhibiting epidermal growth factor receptor (EGFR) in human breast cancer cells in vitro.

Results

Ferulic acid and 4-vinylguaiacol limit the EGF (epidermal growth factor)-induced breast cancer proliferation and new DNA synthesis. Western blot analysis revealed both ferulic acid and 4-vinylguaiacol exhibit sustained inhibition of EGFR activation through down-regulation of Tyr 1068 autophosphorylation. Molecular docking analysis shows ferulic acid forming hydrogen bond interaction with Lys 745 and Met 793 whereas, 4-vinylguaiacol forms two hydrogen bonds with Phe 856 and exhibits stronger hydrophobic interactions with multiple amino acid residues at the EGFR kinase domain.

Conclusions

Ferulic acid and 4-vinylguaiacol could serve as a potential structure for the development of new small molecule therapeutics against EGFR.