135 research outputs found
Harvesting, oil extraction, and conversion of local filamentous algae growing in wastewater into biodiesel
Algae are known to be a potential feedstock in the production of biodiesel fuel. Although much of the focus has been on microalgal species, macroalgae are also suitable as a source of lipids. In this study, a locally abundant (central Illinois) filamentous algae has been harvested from a water treatment plant; dried to about 10% of its initial weight; pulverized in a hammermill; and treated with methanol to extract the oil. The algae are a combination of several coexisting species including Cladophora sp. and Rhizoclonium. Oil yields ranged from 3% to 6%, by weight, of the dried mass. This oil was reacted by transesterification to yield fatty acid methyl esters (biodiesel fuel) with an overall mass conversion efficiency of 68%. A B5 blend of this algal biodiesel and petrodiesel was run in a 13.4-kW test engine. Measurements indicated similar performance compared to pure petrodiesel in terms of fuel efficiency and carbon dioxide and carbon monoxide exhaust emissions. Significantly, there was a 22% reduction in nitrogen oxides when using the B5 fuel. It has been demonstrated that filamentous macroalgae may be cultivated as biodiesel feedstock and have inherent advantages such as an ability to remove phosphorus and nitrogen compounds from wastewater, simplicity of harvesting, and natural resistance to local aquatic grazers and competing organisms
Complex Transitions Between C3 and C4 Photosynthesis During the Evolution of Paniceae: A Phylogenetic Case Study Emphasizing the Position of Steinchisma Hians (Poaceae), A C3-C4 Intermediate
A two-tiered, nested molecular phylogenetic study of panicoid grasses to explore character state transitions
between the C3 and C4 adaptive syndromes is presented. A broad survey of 92 panicoid species was sampled
for the grass-specific insert sequence in the chloroplast RNA polymerase locus (rpoC2), combining published
and unpublished sequences. This portion of the study also included an intensive phylogenetic investigation of
one clade of seven species that included Steinchisma hians, which is notable for exhibiting intermediacy between
the C3 and C4 photosynthetic types. Both rpoC2 data and previously published sequences of the F subunit of
an NADH-dependent dehydrogenase were analyzed together for this small group. A rigorous phylogenetic
investigation of S. hians and 13 other species of Panicoideae included in the broad survey was then performed
with sequences of both rpoC2 and the externally transcribed spacer region of the nuclear ribosomal repeat.
These 14 species were selected to maximize representation among photosynthetic subtypes. Combined analysis
resolved single origins of two photosynthetic subtypes. A reversion of C4 to C3 photosynthesis during the
evolution of the lineage that includes S. hians is identified. These and other recent results indicate that repeated
reversions from C4 to C3 have occurred. The C3 species Panicum laxum has a strongly supported sister group
relationship to S. hians (C3-C4). The most parsimonious interpretation is that S. hians represents an incipient
reversal from C3 to C4 photosynthesis, beginning with the capacity to compartmentalize photorespiratory
metabolism in the bundle sheath tissue
Phylogenetically Widespread Multiple Paternity in New World Natricine Snakes
We used microsatellite DNA markers to identify the extent to which multiple paternity within litters occurs
among species of New World natricine snakes. We selected seven species to represent the three major clades of
Natricinae and all three subclades of the gartersnake clade. Microsatellite DNA genotyping of dams and litters confirmed
multiple paternity within litters of six species, including Thamnophis radix, T. sauritus, Storeria dekayi, S.
occipitomaculata, Nerodia rhombifer, and Regina septemvittata. Multiple paternity was not evident in one litter of nine
Thamnophis melanogaster. Together with published data documenting multiple paternity in T. bulteri, T. elegans, T.
sirtalis, and N. sipedon, these results confirm the phylogenetically widespread occurrence of multiple paternity among
New World natricines, emphasizing the need to consider phylogenetic (historical) explanations when analyzing snake
mating systems
Cell Wall Enzymes in Zygnema circumcarinatum UTEX 1559 Respond to Osmotic Stress in a Plant-Like Fashion
Fitzek E, Orton L, Entwistle S, et al. Cell Wall Enzymes in Zygnema circumcarinatum UTEX 1559 Respond to Osmotic Stress in a Plant-Like Fashion. FRONTIERS IN PLANT SCIENCE. 2019;10: 732.Previous analysis of charophyte green algal (CGA) genomes and transcriptomes for specific protein families revealed that numerous land plant characteristics had already evolved in CGA. In this study, we have sequenced and assembled the transcriptome of Zygnema circumcarinatum UTEX 1559, and combined its predicted protein sequences with those of 13 additional species [five embryophytes (Emb), eight charophytes (Cha), and two chlorophytes (Chl) as the outgroup] for a comprehensive comparative genomics analysis. In total 25,485 orthologous gene clusters (OGCs, equivalent to protein families) of the 14 species were classified into nine OGC groups. For example, the Cha+Emb group contains 4,174 OGCs found in both Cha and Emb but not Chl species, representing protein families that have evolved in the common ancestor of Cha and Emb. Different OGC groups were subjected to a Gene Ontology (GO) enrichment analysis with the Chl+Cha+Emb group (including 5,031 OGCs found in Chl and Cha and Emb) as the control. Interestingly, nine of the 20 top enriched GO terms in the Cha+Emb group are cell wall-related, such as biological processes involving celluloses, pectins, lignins, and xyloglucans. Furthermore, three glycosyltransferase families (GT2, 8, 43) were selected for in-depth phylogenetic analyses, which confirmed their presence in UTEX 1559. More importantly, of different CGA groups, only Zygnematophyceae has land plant cellulose synthase (CesA) orthologs, while other charophyte CesAs form a CGA-specific CesA-like (Csl) subfamily (likely also carries cellulose synthesis activity). Quantitative real-time-PCR experiments were performed on selected GT family genes in UTEX 1559. After osmotic stress treatment, significantly elevated expression was found for GT2 family genes ZcCesA, ZcCslC and ZcCslA-like (possibly mannan and xyloglucan synthases, respectively), as well as for GT8 family genes (possibly pectin synthases). All these suggest that the UTEX 1559 cell wall polysaccharide synthesis-related genes respond to osmotic stress in a manner that is similar to land plants
Successful pharmaceutical-grade streptozotocin (STZ)-induced hyperglycemia in a conscious tethered baboon (Papio hamadryas) model
Background Non-human primate (NHP) diabetic models using chemical
ablation of b-cells with STZ have been achieved by several research groups.
Chemotherapeutic STZ could lead to serious adverse events including nephrotoxicity, hepatotoxicity, and mortality.
Methods We implemented a comprehensive therapeutic strategy that
included the tether system, permanent indwelling catheter implants, an
aggressive hydration protocol, management for pain with IV nubain and
anxiety with IV midazolam, moment-by-moment monitoring of glucose levels post-STZ administration, and continuous intravenous insulin therapy.
Results A triphasic response in blood glucose after STZ administration was
fully characterized. A dangerous hypoglycemic phase was also detected in all
baboons. Other significant findings were hyperglycemia associated with low
levels of plasma leptin, insulin and C-peptide concentrations, hyperglucagonemia, and elevated non-esterified fatty acids (NEFA) concentrations.
Conclusions We successfully induced frank diabetes by IV administering a
single dose of pharmaceutical-grade STZ safely and without adverse events
in conscious tethered baboons
Genomes of multicellular algal sisters to land plants illuminate signaling network evolution
Zygnematophyceae are the algal sisters of land plants. Here we sequenced four genomes of filamentous Zygnematophyceae, including chromosome-scale assemblies for three strains of Zygnema circumcarinatum. We inferred traits in the ancestor of Zygnematophyceae and land plants that might have ushered in the conquest of land by plants: expanded genes for signaling cascades, environmental response, and multicellular growth. Zygnematophyceae and land plants share all the major enzymes for cell wall synthesis and remodifications, and gene gains shaped this toolkit. Co-expression network analyses uncover gene cohorts that unite environmental signaling with multicellular developmental programs. Our data shed light on a molecular chassis that balances environmental response and growth modulation across more than 600 million years of streptophyte evolution
Combination of contrast with stress echocardiography: A practical guide to methods and interpretation
Contrast echocardiography has an established role for enhancement of the right heart Doppler signals, the detection of intra-cardiac shunts, and most recently for left ventricular cavity opacification (LVO). The use of intravenously administered micro-bubbles to traverse the myocardial microcirculation in order to outline myocardial viability and perfusion has been the source of research studies for a number of years. Despite the enthusiasm of investigators, myocardial contrast echocardiography (MCE) has not attained routine clinical use and LV opacification during stress has been less widely adopted than the data would support. The purpose of this review is to facilitate an understanding of the involved imaging technologies that have made this technique more feasible for clinical practice, and to guide its introduction into the practice of the non-expert user
Evaluation of stunned and infarcted canine myocardium by real time myocardial contrast echocardiography
Real-Time Three-Dimensional Echocardiographic Assessment of Severity of Mitral Regurgitation Using Proximal Isovelocity Surface Area and Vena Contracta Area Method. Lessons We Learned and Clinical Implications
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