560 research outputs found
<Advanced Energy Utilization Division> Structural Energy Bioscience Research Section
3-1. Research Activities in 202
Twenty years of conservation and research findings of the Hawai‘i Island Hawksbill Turtle Recovery Project, 1989 - 2009
Reports were scanned in black and white at a resolution of 600 dots per inch and were converted to text using Adobe Paper Capture Plug-in.Prior to 1989, available information on nesting hawksbill turtles (Eretmochelys imbricata) in the Hawaiian Islands was minimal. From 1987 to 1990, personnel from Hawai‘i Volcanoes National Park conducted reconnaissance along the southern coastline of Hawai‘i Island to confirm evidence of nesting activity, identify hawksbill nesting beaches, and evaluate threats. Thereafter, the Hawai‘i Island Hawksbill Turtle Recovery Project (HIHTRP) was established to monitor and manage nesting sites, document nesting events, collect baseline data, ensure hatchlings safely reach the ocean, and mitigate threats. Between 1993 and 2009, the number of beaches monitored for nesting activity expanded from eight to 17, with variable coverage at each site. Flipper tagging of nesting adult females has occurred since 1991. Primary findings from twenty years of data collection include: 1) The southern coast of Hawai‘i Island has the highest documented hawksbill nesting activity in the Main Hawaiian Islands; 2) Nesting season (egg laying to hatchling emergence) begins in April and extends to February with a peak egg laying period from late-July to mid-September; 3) The mean seasonal cohort observed was 11.6 ± 1.2 (n= 18) with a range of 3 to 18 turtles; 4) The mean number of nests per turtle was 3.3 ± 0.2 per season (n= 20) with a range of 1 to 6 nests; 5) The mean remigration interval was 3.5 ± 0.1 years (n= 106) with a range of 2 to 10 years; 6) Nesting turtles demonstrated a high degree of nesting site fidelity, with 87% of individuals documented using only one nesting site. Forty-eight of these individuals were documented at the same beach in multiple years. Thirteen percent of nesting females were documented at multiple sites; 7) The mean nest to next crawl inter-nesting interval was 18.6 ± 0.1 days (n= 276) (range 13 to 24 days), while the mean nest to nest inter-nesting interval was 20 ± 0.2 days (n= 277) (range 13 to 30 days); 8) The mean incubation period was 62.5 ± 0.4 days (n= 446) with a range of 50 to 101 days; 9) The mean clutch size was 175.2 ± 1.5 eggs (n= 631) with a range of 78 to 274 eggs; 10) The mean nest hatch success of eggs was 71.9 ± 1.0% (n= 640) with a range of 0 to 100%; 11) Between 1991 and 2009, 100 adult females were tagged, with a mean of 5.3 ± 0.7 (n=19) and range of 1 to 11 per season; 12) Between 1988 and 2009 a total of 742 nests (most occurring at Kamehame, ‘Āpua Point, and Pōhue Bay) were documented with a mean of 35 ± 4.0 (n= 21) and range of 8 to 69 per season; 13) Between 1989 and 2009, over 80,775 hatchlings are estimated to have entered the Pacific Ocean from Hawai‘i Island; 14) Primary threats to nest and hatchling success all of which have been significantly addressed were non-native mammalian predators, alien plants, artificial lights, hatchling stranding, vehicular traffic, and incompatible recreational use of nesting beaches; 15) Volcanism including land subsidence remains as an uncontrollable factor
A novel gnd mutation leading to increased L-lysine production in Corynebacterium glutamicum
ArticleFems Microbiology Letters. 242(2): 265-274 (2005)journal articl
Complex sequencing rules of birdsong can be explained by simple hidden Markov processes
Complex sequencing rules observed in birdsongs provide an opportunity to
investigate the neural mechanism for generating complex sequential behaviors.
To relate the findings from studying birdsongs to other sequential behaviors,
it is crucial to characterize the statistical properties of the sequencing
rules in birdsongs. However, the properties of the sequencing rules in
birdsongs have not yet been fully addressed. In this study, we investigate the
statistical propertiesof the complex birdsong of the Bengalese finch (Lonchura
striata var. domestica). Based on manual-annotated syllable sequences, we first
show that there are significant higher-order context dependencies in Bengalese
finch songs, that is, which syllable appears next depends on more than one
previous syllable. This property is shared with other complex sequential
behaviors. We then analyze acoustic features of the song and show that
higher-order context dependencies can be explained using first-order hidden
state transition dynamics with redundant hidden states. This model corresponds
to hidden Markov models (HMMs), well known statistical models with a large
range of application for time series modeling. The song annotation with these
models with first-order hidden state dynamics agreed well with manual
annotation, the score was comparable to that of a second-order HMM, and
surpassed the zeroth-order model (the Gaussian mixture model (GMM)), which does
not use context information. Our results imply that the hierarchical
representation with hidden state dynamics may underlie the neural
implementation for generating complex sequences with higher-order dependencies
Growth monitoring of horticulture crops using unmanned aerial vehicle (Part 1) - field monitoring of potatoes
Background: Precision agricultural techniques using information such as precise crop growth conditions in fields have attracted attention recently. One technique uses remote sensing methods for field monitoring. Remote sensing for agriculture using satellites and aircraft has been used widely. Actually pilotless remote sensing is anticipated for use with test fields. Therefore, we investigated field monitoring techniques using unmanned aerial vehicles (UAVs) to obtain horticulture crop information.
Methods: In 2016, aerial images were taken on July 12, 24, and 31. For sensing tests, potato plants were set on 11 test blocks on July 31. Image analysis was done using a composite photograph of an Ortho image comprising about 150 aerial photographic images.
Results and conclusion: Composite aerial photographs of the Ortho image showed potato leaf etiolation and differences of vegetation. The G/R ratio of aerial images decreased as the plant stage advanced. This monitoring system can elucidate potato field plant conditions from aerial photographic images that include information about test blocks
Reductive Catalytic Fractionation of Corn Stover Lignin
Reductive catalytic fractionation (RCF) has emerged as an effective biomass pretreatment strategy to depolymerize lignin into tractable fragments in high yields. We investigate the RCF of corn stover, a highly abundant herbaceous feedstock, using carbon-supported Ru and Ni catalysts at 200 and 250 °C in methanol and, in the presence or absence of an acid cocatalyst (H₃PO₄ or an acidified carbon support). Three key performance variables were studied: (1) the effectiveness of lignin extraction as measured by the yield of lignin oil, (2) the yield of monomers in the lignin oil, and (3) the carbohydrate retention in the residual solids after RCF. The monomers included methyl coumarate/ferulate, propyl guaiacol/syringol, and ethyl guaiacol/syringol. The Ru and Ni catalysts performed similarly in terms of product distribution and monomer yields. The monomer yields increased monotonically as a function of time for both temperatures. At 6 h, monomer yields of 27.2 and 28.3% were obtained at 250 and 200 °C, respectively, with Ni/C. The addition of an acid cocatalysts to the Ni/C system increased monomer yields to 32% for acidified carbon and 38% for phosphoric acid at 200 °C. The monomer product distribution was dominated by methyl coumarate regardless of the use of the acid cocatalysts. The use of phosphoric acid at 200 °C or the high temperature condition without acid resulted in complete lignin extraction and partial sugar solubilization (up to 50%) thereby generating lignin oil yields that exceeded the theoretical limit. In contrast, using either Ni/C or Ni on acidified carbon at 200 °C resulted in moderate lignin oil yields of ca. 55%, with sugar retention values >90%. Notably, these sugars were amenable to enzymatic digestion, reaching conversions >90% at 96 h. Characterization studies on the lignin oils using two-dimensional heteronuclear single quantum coherence nuclear magnetic resonance and gel permeation chromatrography revealed that soluble oligomers are formed via solvolysis, followed by further fragmentation on the catalyst surface via hydrogenolysis. Overall, the results show that clear trade-offs exist between the levels of lignin extraction, monomer yields, and carbohydrate retention in the residual solids for different RCF conditions of corn stover.National Science Foundation (U.S.) (1454299
Properties and nature of Be stars: 27. Orbital and recent long-term variations of the Pleiades Be star Pleione = BU Tauri
Radial-velocity variations of the H-alpha emission measured on the steep
wings of the H-alpha line, prewhitened for the long-time changes, vary
periodically with a period of (218.025 +/- 0.022)d, confirming the suspected
binary nature of the bright Be star Pleione, a member of the Pleiades cluster.
The orbit seems to have a high eccentricity over 0.7, but we also briefly
discuss the possibility that the true orbit is circular and that the
eccentricity is spurious owing to the phase-dependent effects of the
circumstellar matter. The projected angular separation of the spectroscopic
orbit is large enough to allow the detection of the binary with large optical
interferometers, provided the magnitude difference primary - secondary is not
too large. Since our data cover the onset of a new shell phase up to
development of a metallic shell spectrum, we also briefly discuss the recent
long-term changes. We confirm the formation of a new envelope, coexisting with
the previous one, at the onset of the new shell phase. We find that the full
width at half maximum of the H-alpha profile has been decreasing with time for
both envelopes. In this connection, we briefly discuss Hirata's hypothesis of
precessing gaseous disk and possible alternative scenarios of the observed
long-term changes
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