443 research outputs found
Analisis Hubungan Keberadaan dan Kelimpahan Lamun dengan Kualitas Air di Pulau Karimunjawa, Jepara
Ekosistem lamun merupakan salah satu ekosistem penting di wilayah pesisir sebagai pendukung kehidupan biota di laut. Kerapatan jenis lamun dipengaruhi oleh faktor tempat tumbuh dari lamun tersebut. Penelitian dilakukan pada bulan Maret 2014 di Perairan Pulau Karimunjawa dengan tujuan untuk mengetahui jenis dan keberadaan lamun, persentase tutupan lamun, dan hubungan keberadaan dan kerapatan lamun dengan kualitas air di Pulau Karimunjawa. Metode penelitian adalah deskriptif dengan studi kasus untuk menggambarkan keadaan atau status fenomena suatu objek penelitian secara detail. Pengumpulan data dilakukan dengan sampling menggunakan kuadran transek. Materi yang digunakan adalah lamun yang ditemukan di lokasi penelitian, data yang diukur meliputi parameter fisika dan kimia seperti suhu, kecepatan arus, kedalaman, substrat, salinitas, DO, pH, nitrat, fosfat, dan amoniak. Hasil penelitian didapatkan 8 jenis lamun yaitu Cymodocea rotundata, Cymodocea serrulata, Enhalus acroides, Halodule pinifolia, Halodule uninervis, Halophilla minor, Halophila ovalis, dan Thalassia hemperichii. Persentase penutupan lamun di Pancoran Belakang yaitu 63,73 %, Legon Lele 31,65 %, dan Alang-alang 24,33%. Nilai koefisien korelasi (r) sebesar 0,755 yang menunjukkan terdapat hubungan erat antara kerapatan lamun dengan kualitas air. Seagrass ecosystem is one of the important ecosystem in coastal area that support biota life in the sea. Seagrass beds density influenced by the place where it\u27s grow. The research was conducted on March 2014 at Karimunjawa Island, in order to know the type of seagrass, seagrass cover percentage, and correlations of the existence and seagrass beds density with the water quality in the Karimunjawa Island. Research method is descriptive with case study to describe condition or status of research object on the phenomenon in detail. The material used was seagrass beds that found there and environment parameters include physical and chemical parameters such as temperature, current, depth, substrate, salinity, DO, pH, nitrate, phosphate, and ammoniac. The results obtained 8 seagrass species that are Cymodocea rotundata, Cymodocea serrulata, Enhalus acoroides, Halodule pinifolia Halodule uninervis, Halophila ovalis, Thalassia hemprichii. The seagrass cover percentage at Pancoran Belakang is 63,73 %, Legon Lele 31,65%, and Alang-alang 24,33%. The value of correlation coefficient (r) is 0,755 that show a close relation between seagrass density with water qualities
Exploring Relationships between Demersal Resources and Environmental Factors in the Ionian Sea (Central Mediterranean)
The relationships between the abundance of demersal resources, environmental variables, and fishing pressure in the north-western Ionian Sea in the last two decades were evaluated. Data on the density collected during seventeen trawl surveys carried out from 1985 to 2005 were used. The following species were considered:Aristaeomorpha foliacea, Nephrops norvegicus,andParapenaeus longirostrisfor crustaceans;Merluccius merluccius, Phycis blennoides,andMullus barbatusfor teleost fish. The recruitment index was also considered forN. norvegicus, P. longirostris, M. merlucciusandMullus barbatus. Six candidate models were evaluated for each density and recruitment data set either combining fishing effort with global (NAO) and regional (SST and precipitation) climatic indices, or models separately involving fishing effort, NAO, or regional climatic indices as the only predictive variable. Model selection was carried out using an information-theoretical approach that applies Akaike's Information Criterion (AIC). High changes over time were observed for the density data and recruitment indices in each species. Apart from hake abundance and recruitment data, for which a clear positive relationship with the NAO index alone was detected, the changes observed in the other species seem to be the consequence of the interaction between bottom-up effects linked to changes in physical environment and top-down ones due to the fishing pressure
The four serotypes of dengue recognize the same putative receptors in Aedes aegypti midgut and Ae. albopictus cells
BACKGROUND: Dengue viruses (DENV) attach to the host cell surface and subsequently enter the cell by receptor-mediated endocytosis. Several primary and low affinity co-receptors for this flavivirus have been identified. However, the presence of these binding molecules on the cell surface does not necessarily render the cell susceptible to infection. Determination of which of them serve as bona fide receptors for this virus in the vector may be relevant to treating DENV infection and in designing control strategies. RESULTS: (1) Overlay protein binding assay showed two proteins with molecular masses of 80 and 67 kDa (R80 and R67). (2) Specific antibodies against these two proteins inhibited cell binding and infection. (3) Both proteins were bound by all four serotypes of dengue virus. (4) R80 and R67 were purified by affinity chromatography from Ae. aegypti mosquito midguts and from Ae albopictus C6/36 cells. (5) In addition, a protein with molecular mass of 57 kDa was purified by affinity chromatography from the midgut extracts. (6) R80 and R67 from radiolabeled surface membrane proteins of C6/36 cells were immunoprecipitated by antibodies against Ae. aegypti midgut. CONCLUSION: Our results strongly suggest that R67 and R80 are receptors for the four serotypes of dengue virus in the midgut cells of Ae. aegypti and in C6/36 Ae. albopictus cells
Explaining LSND by a decaying sterile neutrino
We propose an explanation of the LSND evidence for electron antineutrino
appearance based on neutrino decay. We introduce a heavy neutrino, which is
produced in pion and muon decays because of a small mixing with muon neutrinos,
and then decays into a scalar particle and a light neutrino, predominantly of
the electron type. We require values of few eV, being the
neutrino--scalar coupling and the heavy neutrino mass, e.g. in the
range from 1 keV to 1 MeV and . Performing a fit to
the LSND data as well as all relevant null-result experiments, we show that all
data can be explained within this decay scenario. In the minimal version of the
decay model, we predict a signal in the upcoming MiniBooNE experiment
corresponding to a transition probability of the same order as seen in LSND. In
addition, we show that extending our model to two nearly degenerate heavy
neutrinos it is possible to introduce CP violation in the decay, which can lead
to a suppression of the signal in MiniBooNE running in the neutrino mode. We
briefly discuss signals in future neutrino oscillation experiments, we show
that our scenario is compatible with bounds from laboratory experiments, and we
comment on implications in astrophysics and cosmology.Comment: 23 pages, 5 figures, minor improvements, matches published versio
Can âeugenicsâ be defended?
In recent years, bioethical discourse around the topic of âgenetic enhancementâ has become increasingly politicized. We fear there is too much focus on the semantic question of whether we should call particular practices and emerging bio-technologies such as CRISPR âeugenicsâ, rather than the more important question of how we should view them from the perspective of ethics and policy. Here, we address the question of whether âeugenicsâ can be defended and how proponents and critics of enhancement should engage with each other
Status and perspectives of short baseline studies
The study of flavor changing neutrinos is a very active field of research. I
will discuss the status of ongoing and near term experiments investigating
neutrino properties at short distances from the source. In the next few years,
the Double Chooz, RENO and Daya Bay reactor neutrino experiments will start
looking for signatures of a non-zero value of the mixing angle
with much improved sensitivities. The MiniBooNE experiment is investigating the
LSND anomaly by looking at both the and
appearance channels. Recent results on
cross section measurements will be discussed briefly.Comment: 6 pages, 2 figures, to appear in the proceedings of the 11th
International Conference on Topics in Astroparticle and Underground Physics
(TAUP 2009), Rome, Italy, 1-5 July 200
Internet of things
Manual of Digital Earth / Editors: Huadong Guo, Michael F. Goodchild, Alessandro Annoni .- Springer, 2020 .- ISBN: 978-981-32-9915-3Digital Earth was born with the aim of replicating the real world within the digital world. Many efforts have been made to observe and sense the Earth, both from space (remote sensing) and by using in situ sensors. Focusing on the latter, advances in Digital Earth have established vital bridges to exploit these sensors and their networks by taking location as a key element. The current era of connectivity envisions that everything is connected to everything. The concept of the Internet of Things(IoT)emergedasaholisticproposaltoenableanecosystemofvaried,heterogeneous networked objects and devices to speak to and interact with each other. To make the IoT ecosystem a reality, it is necessary to understand the electronic components, communication protocols, real-time analysis techniques, and the location of the objects and devices. The IoT ecosystem and the Digital Earth (DE) jointly form interrelated infrastructures for addressing todayâs pressing issues and complex challenges. In this chapter, we explore the synergies and frictions in establishing an efïŹcient and permanent collaboration between the two infrastructures, in order to adequately address multidisciplinary and increasingly complex real-world problems. Although there are still some pending issues, the identiïŹed synergies generate optimism for a true collaboration between the Internet of Things and the Digital Earth
The use of chest ultrasonography in suspected cases of COVID-19 in the emergency department
Aim: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus-specific reverse transcriptase-polymerase chain reaction (RT-PCR) represents the diagnostic gold standard. We explored the value of chest ultrasonography to predict positivity to SARS-CoV-2 on RT-PCR in suspected COVID-19 cases. Patients & methods: Consecutive patients with suspect COVID-19 were included if they had fever and/or history of cough and/or dyspnea. Lung ultrasound score (LUSS) was computed according to published methods. Results: A total of 76 patients were included. A 3-variable model based on aspartate transaminase (AST) > upper limit of normal, LUSS >12 and body temperature >37.5°C yielded an overall accuracy of 91%. Conclusion: A simple LUSS-based model may represent a powerful tool for initial assessment in suspected cases of COVID-19. The gold standard for diagnosis of COVID-19 is RT-PCR. During a pandemic emergency, it may be useful to identify suspect symptomatic patients who may safely be observed without undergoing testing for COVID-19. In this work, a simple model based on the findings of lung ultrasound, AST levels and fever showed an overall accuracy of 91% to predict the results of RT-PCR
Measurement of Total and Differential Cross Sections of Neutrino and Antineutrino Coherent Production on Carbon
Neutrino induced coherent charged pion production on nuclei,
, is a rare inelastic interaction in
which the four-momentum squared transfered to the nucleus is nearly zero,
leaving it intact. We identify such events in the scintillator of MINERvA by
reconstructing |t| from the final state pion and muon momenta and by removing
events with evidence of energetic nuclear recoil or production of other final
state particles. We measure the total neutrino and antineutrino cross sections
as a function of neutrino energy between 2 and 20 GeV and measure flux
integrated differential cross sections as a function of , and
. The dependence and equality of the neutrino and
anti-neutrino cross-sections at finite provide a confirmation of Adler's
PCAC hypothesis
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