5,325 research outputs found
Richtinggevende beelden voor energiezuinig telen in semigesloten kassen
In het kader van het ‘Versnellingsprogramma implementatie semigesloten kas’ hebben LNV en PT aan Wageningen UR en CropEye gevraagd een beeld te schetsen van de richting waarop energiezuinig telen in semigesloten kassen zich kan ontwikkelen. Dit is uitgewerkt in een teeltconcept voor tomaat, waarin met de helft van de hoeveelheid energie dezelfde productie wordt behaald als in een gangbare (onbelichte) teelt. Uitgangspunt was beschikbare technologie en kennis, die liefst modulair door de praktijk is in te passen. Het concept is middels workshops, expert consultancy, deskstudy en simulatiemodellen ontworpen en doorgerekend. Het teeltconcept kent een andere periode van teeltwisseling, instraling gekoppelde meerdaagse temperatuurintegratie, scherpere vochtregeling, dubbel scherm met temperatuur én straling afhankelijke regeling, luchtbevochtiging, luchtcirculatie, luchtbehandeling met buitenluchtaanzuiging en verwarming; en koeling, WKK, warmtepomp en aquifer. Met het totale systeem moet een productie van ca 60 kg per m2 per jaar mogelijk zijn bij een input van minder dan 20 m3 gas per m2 per jaar. Behalve aan technische en teelttechnische aspecten is in het project veel plantfysiologische kennis verzamel
A transition system semantics for the control-driven coordination language Manifold
AbstractCoordination languages are a new class of parallel programming languages which manage the interactions among concurrent programs. Basically, coordination is achieved either by manipulating data values shared among all active processes or by dynamically evolving the interconnections among the processes as a consequence of observations of their state changes. The latter, also called control-driven coordination, is supported by MANIFOLD. We present the formal semantics of a kernel of MANIFOLD, based on a two-level transition system model: the first level is used to specify the ideal behavior of each single component in a MANIFOLD system, whereas the second level captures their interactions. Although we apply our two-level model in this paper to define the semantics of a control-oriented coordination language, this approach is useful for the formal studies of other coordination models and languages as well
Spectroscopic Study of IRAS 19285+0517(PDS 100): A Rapidly Rotating Li-Rich K Giant
We report on photometry and high-resolution spectroscopy for IRAS 19285+0517.
The spectral energy distribution based on visible and near-IR photometry and
far-IR fluxes shows that the star is surrounded by dust at a temperature of
250 K. Spectral line analysis shows that the star is a K
giant with a projected rotational velocity = 9 2 km s.
We determined the atmospheric parameters: = 4500 K, log =
2.5, = 1.5 km s, and [Fe/H] = 0.14 dex. The LTE abundance
analysis shows that the star is Li-rich (log (Li) = 2.50.15),
but with essentially normal C, N, and O, and metal abundances. Spectral
synthesis of molecular CN lines yields the carbon isotopic ratio
C/C = 9 3, a signature of post-main sequence evolution and
dredge-up on the RGB. Analysis of the Li resonance line at 6707 \AA for
different ratios Li/Li shows that the Li profile can be fitted best
with a predicted profile for pure Li. Far-IR excess, large Li abundance,
and rapid rotation suggest that a planet has been swallowed or, perhaps, that
an instability in the RGB outer layers triggered a sudden enrichment of Li and
caused mass-loss.Comment: To appear in AJ; 40 pages, 9 figure
Erythropoietin, Fibroblast Growth Factor 23, and Death After Kidney Transplantation
Elevated levels of erythropoietin (EPO) are associated with an increased risk of death in renal transplant recipients (RTRs), but the underlying mechanisms remain unclear. Emerging data suggest that EPO stimulates production of the phosphaturic hormone fibroblast growth factor 23 (FGF23), another strong risk factor for death in RTRs. We hypothesized that the hitherto unexplained association between EPO levels and adverse outcomes may be attributable to increased levels of FGF23. We included 579 RTRs (age 51 ± 12 years, 55% males) from the TransplantLines Insulin Resistance and Inflammation Cohort study (NCT03272854). During a follow-up of 7.0 years, 121 RTRs died, of which 62 were due to cardiovascular cause. In multivariable Cox regression analysis, EPO was independently associated with all-cause (HR, 1.66; 95% CI 1.16-2.36; P = 0.005) and cardiovascular death (HR, 1.87; 95% CI 1.14-3.06; P = 0.01). However, the associations were abrogated following adjustment for FGF23 (HR, 1.28; 95% CI 0.87-1.88; P = 0.20, and HR, 1.45; 95% CI 0.84-2.48; P = 0.18, respectively). In subsequent mediation analysis, FGF23 mediated 72% and 50% of the association between EPO and all-cause and cardiovascular death, respectively. Our results underline the strong relationship between EPO and FGF23 physiology, and provide a potential mechanism underlying the relationship between increased EPO levels and adverse outcomes in RTRs
Biomass partitioning and root morphology of savanna trees across a water gradient.
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