39 research outputs found
Analysis Of Weather Conditions and Hydrodynamics in Taman Nasional Bunaken
Taman Nasional Bunaken (TNB) is located in North Sulawesi Province, Republic of Indonesia. TNB offers an exploration experience of marine tourism such as snorkeling and diving. This study was conducted to determine the statistics and correlation of weather parameters on hydrodynamics in the waters of the small island of TNB. This information can be used by marine tourism users. The weather data studied are wind direction and speed. The hydrodynamic conditions studied were wave height and ocean currents. Respondent surveys were also conducted on tourist users at the research sites. The wind direction for the period January - April is dominant from the Northeast, May - September is dominant from the East to the South, October tends to be evenly distributed from the East to the West, and November - December is dominant from the West. Significant wind speeds that occur in January, February, and March range from 18 – 36 knots. The average wave height shows a significant value in January – March, tends to be lower in April – June, fluctuates in July – November, and increases again in December. The maximum current velocity at a sea depth of 16.5 m is stronger than the maximum speed at a depth of 0.5 m and 8.0 m in January – April, and May August. The correlation value of wind speed and sea wave height is significant at 0.96 and the correlation between wind speed and the current speed is 0.74. These results indicate that there is a strong -very strong relationship between parameters. The survey results show that wind speed, wave height, and ocean currents have the same pattern. January, February, November, and December are the months of extreme or bad weather and hydrodynamic conditions.Keywords: Taman Nasional Bunaken, Weather, Hydrodynamics, CorrelationAbstrakTaman Nasional Bunaken (TNB) terletak di Provinsi Sulawesi Utara, Negara Republik Indonesia. TNB menawarkan pengalaman eksplorasi suasana wisata bahari seperti snorkling dan diving. Penelitian ini dilakukan untuk mengetahui statistik dan korelasi parameter cuaca terhadap hidrodinamika di perairan pulau kecil TNB. Informasi tersebut dapat digunakan oleh pengguna wisata bahari. Data cuaca yang diteliti adalah arah dan kecepatan angin. Kondisi hidrodinamika yang diteliti ialah tinggi gelombang dan arus laut. Survei responden juga dilakukan kepada pengguna wisata di lokasi penelitian. Arah angin periode Bulan Januari - April dominan dari arah Timur Laut, Bulan Mei – September dominan dari arah Timur hingga Selatan, Bulan Oktober cenderung merata dari arah Timur hingga Barat dan Bulan November – Desember dominan dari arah Barat. Kecepatan angin signifikan terjadi pada bulan Januari, Februari, dan Maret berkisar antara 18 – 36 Knot. Rata-rata tinggi gelombang menunjukan nilai signifikan pada bulan Januari – Maret, cenderung merendah pada bulan April – Juni, berfluktuasi pada bulan Juli – November dan meningkat kembali di bulan Desember. Kecepatan maksimum arus laut di kedalaman 16.5 m lebih kuat jika dibandingkan kecepatan maksimum di kedalaman 0.5 m dan 8.0 m pada bulan Januari – April serta bulan Mei – Agustus. Nilai korelasi kecepatan angin dan tinggi gelombang laut signifikan sebesar 0.96 serta korelasi kecepatan angin dan kecepatan arus sebesar 0.74. Hasil tersebut menunjukkan antar parameter memiliki hubungan yang kuat - sangat kuat. Hasil survei menunjukan kecepatan angin, tinggi gelombang dan arus laut mempunyai pola yang sama. Bulan Januari, Februari, November, dan Desember merupakan bulan-bulan terjadinya kondisi cuaca serta hidrodinamika ekstrem atau buruk.Kata kunci: Taman Nasional Bunaken, Cuaca, Hidrodinamika, Korelas
Delayed Onset of a Daytime Nap Facilitates Retention of Declarative Memory
BACKGROUND: Learning followed by a period of sleep, even as little as a nap, promotes memory consolidation. It is now generally recognized that sleep facilitates the stabilization of information acquired prior to sleep. However, the temporal nature of the effect of sleep on retention of declarative memory is yet to be understood. We examined the impact of a delayed nap onset on the recognition of neutral pictorial stimuli with an added spatial component. METHODOLOGY/PRINCIPAL FINDINGS: Participants completed an initial study session involving 150 neutral pictures of people, places, and objects. Immediately following the picture presentation, participants were asked to make recognition judgments on a subset of "old", previously seen, pictures versus intermixed "new" pictures. Participants were then divided into one of four groups who either took a 90-minute nap immediately, 2 hours, or 4 hours after learning, or remained awake for the duration of the experiment. 6 hours after initial learning, participants were again tested on the remaining "old" pictures, with "new" pictures intermixed. CONCLUSIONS/SIGNIFICANCE: Interestingly, we found a stabilizing benefit of sleep on the memory trace reflected as a significant negative correlation between the average time elapsed before napping and decline in performance from test to retest (p = .001). We found a significant interaction between the groups and their performance from test to retest (p = .010), with the 4-hour delay group performing significantly better than both those who slept immediately and those who remained awake (p = .044, p = .010, respectively). Analysis of sleep data revealed a significant positive correlation between amount of slow wave sleep (SWS) achieved and length of the delay before sleep onset (p = .048). The findings add to the understanding of memory processing in humans, suggesting that factors such as waking processing and homeostatic increases in need for sleep over time modulate the importance of sleep to consolidation of neutral declarative memories
Fluctuations in spo0A Transcription Control Rare Developmental Transitions in Bacillus subtilis
Phosphorylated Spo0A is a master regulator of stationary phase development in the model bacterium Bacillus subtilis, controlling the formation of spores, biofilms, and cells competent for transformation. We have monitored the rate of transcription of the spo0A gene during growth in sporulation medium using promoter fusions to firefly luciferase. This rate increases sharply during transient diauxie-like pauses in growth rate and then declines as growth resumes. In contrast, the rate of transcription of an rRNA gene decreases and increases in parallel with the growth rate, as expected for stable RNA synthesis. The growth pause-dependent bursts of spo0A transcription, which reflect the activity of the spo0A vegetative promoter, are largely independent of all known regulators of spo0A transcription. Evidence is offered in support of a “passive regulation” model in which RNA polymerase stops transcribing rRNA genes during growth pauses, thus becoming available for the transcription of spo0A. We show that the bursts are followed by the production of phosphorylated Spo0A, and we propose that they represent initial responses to stress that bring the average cell closer to the thresholds for transition to bimodally expressed developmental responses. Measurement of the numbers of cells expressing a competence marker before and after the bursts supports this hypothesis. In the absence of ppGpp, the increase in spo0A transcription that accompanies the entrance to stationary phase is delayed and sporulation is markedly diminished. In spite of this, our data contradicts the hypothesis that sporulation is initiated when a ppGpp-induced depression of the GTP pool relieves repression by CodY. We suggest that, while the programmed induction of sporulation that occurs in stationary phase is apparently provoked by increased flux through the phosphorelay, bet-hedging stochastic transitions to at least competence are induced by bursts in transcription
THE INFLUENCE OF THE COLLAPSIBILITY OF VEINS ON VENOUS PRESSURE, INCLUDING A NEW PROCEDURE FOR MEASURING TISSUE PRESSURE
Phosphorylation of InhA inhibits mycolic acid biosynthesis and growth of Mycobacterium tuberculosis
International audienc
Targeting the von Hippel–Lindau E3 Ubiquitin Ligase Using Small Molecules To Disrupt the VHL/HIF-1α Interaction
E3 ubiquitin ligases, which bind protein targets, leading
to their
ubiquitination and subsequent degradation, are attractive drug targets
due to their exquisite substrate specificity. However, the development
of small-molecule inhibitors has proven extraordinarily challenging
as modulation of E3 ligase activities requires the targeting of protein–protein
interactions. Using rational design, we have generated the first small
molecule targeting the von Hippel–Lindau protein (VHL), the
substrate recognition subunit of an E3 ligase, and an important target
in cancer, chronic anemia, and ischemia. We have also obtained the
crystal structure of VHL bound to our most potent inhibitor, confirming
that the compound mimics the binding mode of the transcription factor
HIF-1α, a substrate of VHL. These results have the potential
to guide future development of improved lead compounds as therapeutics
for the treatment of chronic anemia and ischemia