370 research outputs found
Two subpopulations of Crocosphaera watsonii have distinct distributions in the North and South Pacific
No full textCrocosphaera watsonii is a unicellular nitrogen (N2)-fixing cyanobacterium with ecological importance in oligotrophic oceans. In cultivated strains there are two phenotypes of C.?watsonii (large and small cells) with differences that could differentially impact biogeochemical processes. Recent work has shown the phenotypes diverged through loss or addition of type-specific genes in a fraction of their genomes, whereas the rest of the genomes were maintained at 99–100% DNA identity. Previous molecular assays for C.?watsonii abundances targeted the conserved regions and therefore could not differentiate between phenotypes, so their relative distributions in natural communities were unknown. To determine phenotype distributions, this study developed and applied type-specific quantitative polymerase chain reaction assays to samples from the North and South Pacific. Abundances of both Crocosphaera types declined sharply with depth between 45 and 75?m in both sites. In surface water small cells were 10–100 times more abundant than large cells in the N. Pacific, whereas in the S. Pacific the two phenotypes were nearly equal. Evidence for large cell aggregation was only found in N. Pacific samples. The differences in C.?watsonii sub-populations in the North and South Pacific have direct implications for biogeochemistry and carbon export in oligotrophic gyres
Metabolic versatility of the Riftia pachyptila endosymbiont revealed through metagenomics
No full textThe facultative symbiont of Riftia pachyptila, named here Candidatus Endoriftia persephone, has evaded culture to date, but much has been learned regarding this symbiosis over the past three decades since its discovery. The symbiont population metagenome was sequenced in order to gain insight into its physiology. The population genome indicates that the symbionts use a partial Calvin–Benson Cycle for carbon fixation and the reverse TCA cycle (an alternative pathway for carbon fixation) that contains an unusual ATP citrate lyase. The presence of all genes necessary for heterotrophic metabolism, a phosphotransferase system, and dicarboxylate and ABC transporters indicate that the symbiont can live mixotrophically. The metagenome has a large suite of signal transduction, defence (both biological and environmental) and chemotaxis mechanisms. The physiology of Candidatus Endoriftia persephone is explored with respect to functionality while associated with a eukaryotic host, versus free-living in the hydrothermal environment
Reply to Bench (1973)
No full textThe author is in agreement with Bench 1973 that without specific analysis one cannot be certain that the auditory output from a given loudspeaker matches the input to that speaker. However, issue is taken with Bench concerning the results obtained by Ashton 1971
R v Lord Chancellor, ex parte Witham [1998] QB 575, High Court (Queen’s Bench Division)
No full textEssential Cases: Public Law provides a bridge between course textbooks and key case judgments. This case document summarizes the facts and decision in R v Lord Chancellor, ex parte Witham [1998] QB 575, High Court (Queen’s Bench Division). The document also includes supporting commentary from author Thomas Webb.</p
R v Inspectorate of Pollution, ex parte Greenpeace Ltd (No. 2) [1994] 2 CMLR 548, High Court (Queen’s Bench Division)
No full textEssential Cases: Public Law provides a bridge between course textbooks and key case judgments. This case document summarizes the facts and decision in R v Inspectorate of Pollution, ex parte Greenpeace Ltd (No. 2) [1994] 2 CMLR 548, High Court (Queen’s Bench Division). The document also includes supporting commentary from author Thomas Webb.</p
Platelets and Hepatocellular Cancer: Bridging the Bench to the Clinics
No full textGrowing interest is recently being focused on the role played by the platelets in favoring hepatocellular cancer (HCC) growth and dissemination. The present review reports in detail both the experimental and clinical evidence published on this topic. Several growth factors and angiogenic molecules specifically secreted by platelets are directly connected with tumor progression and neo-angiogenesis. Among them, we can list the platelet-derived growth factor, the vascular endothelial growth factor, the endothelial growth factor, and serotonin. Platelets are also involved in tumor spread, favoring endothelium permeabilization and tumor cells' extravasation and survival in the bloodstream. From the bench to the clinics, all of these aspects were also investigated in clinical series, showing an evident correlation between platelet count and size of HCC, tumor biological behavior, metastatic spread, and overall survival rates. Moreover, a better understanding of the mechanisms involved in the platelet-tumor axis represents a paramount aspect for optimizing both current tumor treatment and development of new therapeutic strategies against HCC
R v Secretary of State for the Environment, ex parte Rose Theatre Trust Co. [1990] 1 QB 504, High Court (Queen’s Bench Division)
No full textEssential Cases: Public Law provides a bridge between course textbooks and key case judgments. This case document summarizes the facts and decision in R v Secretary of State for the Environment, ex parte Rose Theatre Trust Co. [1990] 1 QB 504, High Court (Queen’s Bench Division). The document also includes supporting commentary from author Thomas Webb.</p
Test Bench and Frequency Response of a Magnetic Antenna used in GIS PD Measurements
No full textGas insulated substations (GIS) have increased in the electric power system in recent years and is expected to continue increasing in the following years. The GIS has remarkable advantages over air insulated substation in offshore windfarms where the installation space is limited. The outlying location of the GIS demands a robust monitoring system. It is well known from literature that partial discharge (PD) measurements are an accepted method for insulation diagnosis and in many cases a required part of the acceptance protocol for many high voltage (HV) assets. In a recent investigation, a new concept of PD measurements in GIS using a Very High Frequency (VHF) Sensor (so-called Magnetic Antenna) has been demonstrated. Unlike Ultra High Frequency (UHF) technology, the presented PD sensor has a sensitivity better than 5 pC and yield an estimation of the charge magnitude, thus providing information about the severity of the insulation degradation. In this paper, a test bench for the characterization of the magnetic antenna is proposed. The magnetic antenna and a traditional UHF antenna are tested in the frequency domain up to 1 GHz, and in the time domain using different wave-shapes. Additionally, using the test bench, it is demonstrated the homogeneity of the PD current propagating in the GIS in the transverse electromagnetic (TEM) mode. The charge is estimated using the double integral voltage method, showing low errors. The results from the research gives a preface for further investigation in the design of the magnetic antenna.High Voltage Technology GroupDC systems, Energy conversion & Storag
Connecting does not necessarily mean learning: Course handbooks as mediating tools in school-university partnerships
No full textThis is the author's accepted manuscript (titled "Course handbooks as mediating tools in learning to teach"). The final published article is available from the link below. Copyright @ 2011 American Association of Colleges for Teacher Education.Partnerships between schools and universities in England use course handbooks to guide student teacher learning during long field experiences. Using data from a yearlong ethnographic study of a postgraduate certificate of education programme in one English university, the function of course handbooks in mediating learning in two high school subject departments (history and modern foreign languages) is analyzed. Informed by Cultural Historical Activity Theory, the analysis focuses on the handbooks as mediating tools in the school-based teacher education activity systems. Qualitative differences in the mediating functions of the handbooks-in-use are examined and this leads to a consideration of the potential of such tools for teacher learning in school–university partnerships. Following Zeichner’s call for rethinking the relationships between schools and universities, the article argues that strong structural connections between different institutional sites do not necessarily enhance student teacher learning
The influence of calculation method and relative strength on the load-velocity relationship in bench press exercise [Author version]
No full textPurpose: The objective of this study was: (1) to compare the effect of
the calculation method using average (Avalue), and best value (Bvalue)
of MPV on the LVprofile during the barbell bench press exercise in elite
handball players. In addition, (2) to analyze and compare the
relationship between the individual coefficient of variation (CVind) of an
incremental load protocol in the bench press exercise with relative
strength (Frel) in professional handball players.
Methods: Nine-teen elite international handball players (age 18 [1] y;
body mass 93 [14] kg; height 191 [6] cm) performed an incremental
test during the barbell bench press exercise. General and individual
LVprofile, Frel, and CVind were modelled through mean propulsive
velocity and two calculation models (Avalue, vs Bvalue).
Results: There were significant differences (p<0.05) between both
conditions (Bvalue vs. Avalue). There was an inverse relationship
between the Frel and the CVind (r = -0.66, p < 0.001). When CVind was
>10% significant differences were found between the two calculations
method (Avalue, vs Bvalue). However, no significant differences were
found between Avalue, vs Bvalue when the CVind was <10%.
Conclusions: The calculation method used to assess the barbell bench
press LVprofile impacts the nature of the relationship. Regardless CVind
values, Avalue is a good choice to determine the LVprofile when the
CVind is >10%, if the CVind is <10%, Bvalue will be the better option to
determine the LVprofilePreprintCiencias de la Actividad Física y del Deport
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