2,266 research outputs found
Jenis Laba-Laba (Araneae) Di Taman Wisata Alam Baumata Kecamatan Taebenu Kabupaten Kupang Nusa Tenggara Timur
Penelitian terkait laba-laba di Taman Wisata Alam Baumata (TWAB) berlangsung selama dua bulan yaitu bulan Agustus 2017. Tujuan dari penelitian ini adalah untuk mengetahui jenis laba-laba. Manfaat dari penelitian ini yaitu dapat berkontribusi bagi pihak pengelolah TWAB dalam melestarikan biodiversitas yang tersedia. Manfaat lain yaitu sebagai database keanekaragaman hayati laba-laba Nusantara khususnya di TWAB Kupang. Metode yang digunakan dalam penelitian ini berupa metode belt transek (transek sabuk) yang dikombinasikan dengan transek kuadran. Hasil penelitian dianalisis berdasarkan pada buku kunci determinasi serangga oleh Subyanto (1991) dan jurnal. Analisis keanekaragaman jenis dan kelimpahan jenis laba-laba menggunakan rumus Shannon-Wiener. Adapun spesies laba-laba yang ditemukan yakni: Gasteracantha cancriformis, Argiope appensa, Menemerus bivittatus, Latrodectus hesperus, Polcus phalangioides, Nephila inaurata, Nephila clavipes, Parasteatoda tepidorium, Hogna lenta, Scytodes thoracica, dan Heteropoda jugulans. Ke-sebelas spesies tergolong dalam famili :Araneidae, Salticidae, Theridiidae, pholcidae, Nephilidae, Lycosidae, Scytodidae dan Sparassidae. Nilai keanekaragaman laba-laba yang diperoleh 2,338 sedangkan tingkat kelimpahan spesies laba-laba adalah 0.118/m2. Berdasarkan Indeks keanekaragaman dan kelimpahan maka distribusi laba-laba di TWAB tergolong sedang.The research related to Spider at Baumata Nature Tourism Park (BNTP) lasted for one months that was August 2017. The purpose of this research is to know the type of spider. The benefit of this research is: it can contribute to the management of BNTP in preserving the available biodiversity. Another benefit is as a database of biodiversity of spider Archipelago, especially in BNTP Kupang. The used method in this research was the belt transect method (belt transect) which was combined with quadrant transect. The results were analyzed based on the key book of insect determination by Subyanto (1991) and the journal. The analysis of species variety and the profusion of the spider species used the Shannon-Wiener formula. The found spider species were: Gasteracantha cancriformis, Argiope appensa, Menemerus bivittatus, Latrodectus hesperus, Polcus phalangioides, Nephila inaurata, Nephila clavipes, Paratezati tepidorium, Hogna lenta, Scytodes thoracica, and Heteropoda jugulans. The eleven species belong to families of Araneidae, Salticidae, Theridiidae, pholcidae, Nephilidae, Lycosidae, Scytodidae and Sparassidae. The obtained spider variety value was 2,338 while the profusion extent of spider species was 0.118/m2. Based on the variety and profusion index, the spider distribution in BNTP is moderate
Optimizing the colour and fabric of targets for the control of the tsetse fly Glossina fuscipes fuscipes
Background:
Most cases of human African trypanosomiasis (HAT) start with a bite from one of the subspecies of Glossina fuscipes. Tsetse use a range of olfactory and visual stimuli to locate their hosts and this response can be exploited to lure tsetse to insecticide-treated targets thereby reducing transmission. To provide a rational basis for cost-effective designs of target, we undertook studies to identify the optimal target colour.
Methodology/Principal Findings:
On the Chamaunga islands of Lake Victoria , Kenya, studies were made of the numbers of G. fuscipes fuscipes attracted to targets consisting of a panel (25 cm square) of various coloured fabrics flanked by a panel (also 25 cm square) of fine black netting. Both panels were covered with an electrocuting grid to catch tsetse as they contacted the target. The reflectances of the 37 different-coloured cloth panels utilised in the study were measured spectrophotometrically. Catch was positively correlated with percentage reflectance at the blue (460 nm) wavelength and negatively correlated with reflectance at UV (360 nm) and green (520 nm) wavelengths. The best target was subjectively blue, with percentage reflectances of 3%, 29%, and 20% at 360 nm, 460 nm and 520 nm respectively. The worst target was also, subjectively, blue, but with high reflectances at UV (35% reflectance at 360 nm) wavelengths as well as blue (36% reflectance at 460 nm); the best low UV-reflecting blue caught 3Ă more tsetse than the high UV-reflecting blue.
Conclusions/Significance:
Insecticide-treated targets to control G. f. fuscipes should be blue with low reflectance in both the UV and green bands of the spectrum. Targets that are subjectively blue will perform poorly if they also reflect UV strongly. The selection of fabrics for targets should be guided by spectral analysis of the cloth across both the spectrum visible to humans and the UV region
Complex statistics and diffusion in nonlinear disordered particle chains.
We investigate dynamically and statistically diffusive motion in a Klein-Gordon particle chain in the presence of disorder. In particular, we examine a low energy (subdiffusive) and a higher energy (self-trapping) case and verify that subdiffusive spreading is always observed. We then carry out a statistical analysis of the motion, in both cases, in the sense of the Central Limit Theorem and present evidence of different chaos behaviors, for various groups of particles. Integrating the equations of motion for times as long as 10(9), our probability distribution functions always tend to Gaussians and show that the dynamics does not relax onto a quasi-periodic Kolmogorov-Arnold-Moser torus and that diffusion continues to spread chaotically for arbitrarily long times
A Semi-Classical Analysis of Order from Disorder
We study in this paper the Heisenberg antiferromagnet with nearest neighbours
interactions on the Husimi cactus, a system which has locally the same topology
as the Kagom\'e lattice. This system has a huge classical degeneracy
corresponding to an extensive number of degrees of freedom.We show that unlike
thermal fluctuations, quantum fluctuations lift partially this degeneracy and
favour a discrete subset of classical ground states. In order to clarify the
origin of these effects, we have set up a general semi-classical analysis of
the order from disorder phenomenon and clearly identified the differences
between classical and quantum fluctuations. This semi-classical approach also
enables us to classify various situations where a selection mechanism still
occurs. Moreover, once a discrete set of ground states has been preselected,
our analysis suggests that tunelling processes within this set should be the
dominant effect underlying the strange low energy spectrum of Kagom\'e-like
lattices.Comment: 49 pages, Latex, 12 PS figure
Double-impulse magnetic focusing of launched cold atoms.
We have theoretically investigated three-dimensional focusing of a launched cloud of cold atoms using a pair of magnetic lens pulses (the alternate-gradient method). Individual lenses focus radially and defocus axially or vice versa. The performance of the two possible pulse sequences are compared and found to be ideal for loading both 'pancake' and 'sausage' shaped magnetic/optical microtraps. It is shown that focusing aberrations are considerably smaller for double-impulse magnetic lenses compared to single-impulse magnetic lenses. An analysis of clouds focused by the double-impulse technique is presented
Nonchaotic Stagnant Motion in a Marginal Quasiperiodic Gradient System
A one-dimensional dynamical system with a marginal quasiperiodic gradient is
presented as a mathematical extension of a nonuniform oscillator. The system
exhibits a nonchaotic stagnant motion, which is reminiscent of intermittent
chaos. In fact, the density function of residence times near stagnation points
obeys an inverse-square law, due to a mechanism similar to type-I
intermittency. However, unlike intermittent chaos, in which the alternation
between long stagnant phases and rapid moving phases occurs in a random manner,
here the alternation occurs in a quasiperiodic manner. In particular, in case
of a gradient with the golden ratio, the renewal of the largest residence time
occurs at positions corresponding to the Fibonacci sequence. Finally, the
asymptotic long-time behavior, in the form of a nested logarithm, is
theoretically derived. Compared with the Pomeau-Manneville intermittency, a
significant difference in the relaxation property of the long-time average of
the dynamical variable is found.Comment: 11pages, 5figure
Asymptotic behavior of small solutions for the discrete nonlinear Schr\"odinger and Klein-Gordon equations
We show decay estimates for the propagator of the discrete Schr\"odinger and
Klein-Gordon equations in the form \norm{U(t)f}{l^\infty}\leq C
(1+|t|)^{-d/3}\norm{f}{l^1}. This implies a corresponding (restricted) set of
Strichartz estimates. Applications of the latter include the existence of
excitation thresholds for certain regimes of the parameters and the decay of
small initial data for relevant norms. The analytical decay estimates are
corroborated with numerical results.Comment: 13 pages, 4 figure
Lyapunov instability of fluids composed of rigid diatomic molecules
We study the Lyapunov instability of a two-dimensional fluid composed of
rigid diatomic molecules, with two interaction sites each, and interacting with
a WCA site-site potential. We compute full spectra of Lyapunov exponents for
such a molecular system. These exponents characterize the rate at which
neighboring trajectories diverge or converge exponentially in phase space.
Quam. These exponents characterize the rate at which neighboring trajectories
diverge or converge exponentially in phase space. Qualitative different degrees
of freedom -- such as rotation and translation -- affect the Lyapunov spectrum
differently. We study this phenomenon by systematically varying the molecular
shape and the density. We define and evaluate ``rotation numbers'' measuring
the time averaged modulus of the angular velocities for vectors connecting
perturbed satellite trajectories with an unperturbed reference trajectory in
phase space. For reasons of comparison, various time correlation functions for
translation and rotation are computed. The relative dynamics of perturbed
trajectories is also studied in certain subspaces of the phase space associated
with center-of-mass and orientational molecular motion.Comment: RevTeX 14 pages, 7 PostScript figures. Accepted for publication in
Phys. Rev.
Pengaruh Skarifikasi Kimia Terhadap Perkecambahan Benih Jambu Mete (Anacardium occidentale L.)
Cashew is a plant that has the potential to help the welfare of farmers in the economic field. In general, cashew has a high economic value. Other benefits of cashew from the roots, stems and leaves can be used as medicine (Prihatman, 2000) and fruit and seeds to be a food source with high nutritional value.This study aims to determine the rate of cashew seed germination and optimum concentration by giving HCl and H2SO4. This research uses factorial pattern.The first factor is HCl with 4 levels of treatment consisting of 0%, 35%, 40%, 45% and 50%. The second factor is H2SO4 with 4 treatment levels consisting of 0%, 35%, 40%, 45% and 50%, and 4 controls.Each treatment consisted of 4 replications. Observation parameters in this study include germination, germination speed, and the average daily germination value. Empirical data obtained were analyzed using ANOVA (F test), followed by DMRT test at 5% level, if Fcount>Ftable (α=0.05). Based on ANOVA results, HCl administration significantly affected all observed parameters while H2SO4 and the interaction between HCl and H2SO4 did not significantly affect germination, germination speed and average daily germination value.DMRT test showed the fastest germination speed was found in the A4 treatment. The treatment with the highest value on the parameter observed was the average daily germination value in the A4 treatment. Thus it can be concluded that the HCl solution has a significant effect on each observation parameter. Whereas H2SO4 and the interaction between HCl and H2SO4 had no significant effectJambu mete merupakan tanaman yang berpotensi membantu kesejahteraan petani dibidang ekonomi. Secara umum jambu mete memiliki nilai ekonomi yang tinggi. Manfaat lain dari jambu mete mulai dari akar, batang dan daun dapat digunakan sebagai obat-obatan (Prihatman, 2000) serta buah dan biji menjadi sumber makanan dengan nilai gizi yang tinggi. Penelitian ini bertujuan untuk mengetahui laju perkecambahan benih jambu mete dan konsentrasi optimum dengan pemberian HCl dan H2SO4. Penelitian ini menggunakan RAL pola faktorial. Faktor pertama berupa HCl dengan 4 taraf perlakuan terdiri atas 0%, 35%, 40 % , 45% dan 50%. Faktor kedua berupa H2SO4 dengan 4 taraf perlakuan terdiri atas 0%, 35%, 40 % , 45% dan 50%, dan 4 kontrol. Setiap perlakuan terdiri dari 4 ulangan. Parameter pengamatan dalam penelitian ini meliputi daya kecambah, kecepatan berkecambah, dan nilai rata-rata perkecambahan harian. Data empiris yang diperoleh dianalisis menggunakan ANOVA (uji F), dilanjutkan dengan uji DMRT pada taraf 5%, Jika FhitungFtabel (α=0,05). Berdasarkan hasil ANOVA, pemberian HCl berpengaruh nyata terhadap seluruh parameter pengamatan sedangkan H2SO4 dan interaksi antara HCl dan H2SO4 tidak berpengaruh nyata terhadap daya kecambah, kecepatan berkecambah dan nilai rata-rata perkecambahan harian. Uji DMRT menunjukan kecepatan berkecambah tercepat terdapat pada perlakuan A4. Perlakuan dengan nilai tertinggi pada parameter pengamatan nilai rata-rata perkecambahan harian pada perlakuan A4. Dengan demikian dapat disimpulkan bahwa larutan HCl berpengaruh nyata pada setiap parameter pengamatan. Sedangkan H2SO4 dan interaksi antara HCl dan H2SO4 tidak berpengaruh nyata
Axially symmetric solutions in f(R)-gravity
Axially symmetric solutions for f (R)-gravity can be derived starting from
exact spherically sym- metric solutions achieved by Noether symmetries. The
method takes advantage of a complex coordi- nate transformation previously
developed by Newman and Janis in General Relativity. An example is worked out
to show the general validity of the approach. The physical properties of the
solution are also considered.Comment: 13 pages, 1 figure, to appear in Classical and Quantum Gravity 201
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