Chance long-distance or human-mediated dispersal? How Acacia s.l. farnesiana attained its pan-tropical distribution

Acacia s.l. farnesiana, which originates from Mesoamerica, is the most widely distributed Acacia s.l. species across the tropics. It is assumed that the plant was transferred across the Atlantic to southern Europe by Spanish explorers, and then spread across the Old World tropics through a combination of chance long-distance and human-mediated dispersal. Our study uses genetic analysis and information from historical sources to test the relative roles of chance and human-mediated dispersal in its distribution. The results confirm the Mesoamerican origins of the plant and show three patterns of human- mediated dispersal. Samples from Spain showed greater genetic diversity than those from other Old World tropics, suggesting more instances of transatlantic introductions from the Americas to that country than to other parts of Africa and Asia. Individuals from the Philippines matched a population from South Central Mexico and were likely to have been direct, trans-Pacific introductions. Australian samples were genetically unique, indicating that the arrival of the species in the continent was independent of these European colonial activities. This suggests the possibility of pre-European human- mediated dispersal across the Pacific Ocean. These significant findings raise new questions for biogeographic studies that assume chance or transoceanic dispersal 2 for disjunct plant distributions

Quantum phase retrieval of a Rydberg wave packet using a half-cycle pulse

A terahertz half-cycle pulse was used to retrieve information stored as quantum phase in an $N$-state Rydberg atom data register. The register was prepared as a wave packet with one state phase-reversed from the others (the "marked bit"). A half-cycle pulse then drove a significant portion of the electron probability into the flipped state via multimode interference.Comment: accepted by PR

Community Structure of Gastropod in Bahowo Mangrove Ecotourism Area

This article describes the structure of the gastropod community in the Bahowo Mangrove Ecotourism Area, Manado. From 30 sample units (squared) analyzed, obtained 185 individual gastropods belonging to 27 species with an average density of 6.17 individuals/m2. The Shannon index value (H') is quite high at 3.038, the evenness index (E) is also high at 0.922, and the dominance index (D) is low at 0.078. This variation in gastropod community structure occurs between transects. In Transect 1 there are 15 species with an average density of 7.6 individuals/m2. The most dominant species in this transect was Tectus fenestratus with a density of 1.6 individuals/m2 and a relative abundance of 21.05%. In Transect 2 there are 7 species with an average density of 2.6 individuals/m2. The most dominant species in this transect was Angaria delphinus with a density of 0.6 individuals/m2 and a relative abundance of 23.08%. On Transect 3 there are 9 species with an average density of 8.3 individuals/m2. The most dominant species in this transect was Terebralia sulcata with a density of 2.7 individuals/m2 and a relative abundance of 32.53%. Compared to the other two transects, Transect 2 had lower individual abundance and density, but also the poorest species richness. In terms of biodiversity, Transect 1 is the highest. With a composition of 15 species, Transect 1 has a higher H' index value than in Transect 2 and Transect 3. Between Transect 2 and Transect 3 there is no significant difference in the Shannon index value. The three transects showed a low dominance index value and a relatively high evenness index value.Keywords: Gastropod; Community; Mangrove; Bahowo AbstrakArtikel ini menggambarkan struktur komunitas Gastropoda di Kawasan Ekowisata Mangrove Bahowo, Manado. Dari 30 unit sampel (kuadrat) yang dianalisis, diperoleh 185 individu gastropoda yang termasuk dalam 27 spesies dengan rata-rata kepadatan 6,17 individu/m2. Diperoleh nilai indeks Shannon (H’) cukup tinggi yakni 3,038, indeks kemerataan (E) juga tinggi yakni 0,922, dan indeks dominansi (D) yang rendah yakni 0,078. Variasi stuktur komunitas Gastropoda ini terjadi antar transek. Pada Transek 1 terdapat 15 spesies dengan kepadatan rata-rata 7,6 individu/m2. Spesies paling dominan di transek ini  adalah Tectus fenestratus dengan kepadatan 1,6 individu/m2 dan kelimpahan relatif 21,05%. Pada Transek 2 terdapat 7 spesies dengan kepadatan rata-rata 2,6 individu/m2. Spesies paling dominan di transek ini adalah Angaria delphinus dengan kepadatan 0,6 individu/m2 dan kelimpahan relatif 23,08%. Pada Transek 3 terdapat 9 spesies dengan kepadatan rata-rata 8,3 individu/m2. Spesies paling dominan di transek ini  adalah Terebralia sulcata dengan kepadatan 2,7 individu/m2 dan kelimpahan relatif 32,53% Dibandingkan dengan dua transek lainnya, Transek 2 memiliki kelimpahan dan kepadatan individu lebih rendah, tapi juga paling miskin kekayaan spesies. Dari segi keanekaagaman hayati, Transek 1 adalah yang tertinggi. dengan komposisi 15 spesies, Transek 1 memiliki nilai indeks H’ lebih tinggi dibandingkan dengan di Transek 2 dan di Transek 3. Antara Transek 2 dan Transek 3 tidak menunjukkan perbedaan yang nyata nilai indeks Shannonnya. Pada ketiga transek menunjukkan nilai indeks dominansi yang rendah dan nilai indeks kemerataan yang relatif tinggi.Kata Kunci: Komunitas; Gastropoda; Mangrove; Bahow

A typical reconstruction limit of compressed sensing based on Lp-norm minimization

We consider the problem of reconstructing an $N$-dimensional continuous vector \bx from $P$ constraints which are generated by its linear transformation under the assumption that the number of non-zero elements of \bx is typically limited to $\rho N$ ($0\le \rho \le 1$). Problems of this type can be solved by minimizing a cost function with respect to the $L_p$-norm ||\bx||_p=\lim_{\epsilon \to +0}\sum_{i=1}^N |x_i|^{p+\epsilon}, subject to the constraints under an appropriate condition. For several $p$, we assess a typical case limit $\alpha_c(\rho)$, which represents a critical relation between $\alpha=P/N$ and $\rho$ for successfully reconstructing the original vector by minimization for typical situations in the limit $N,P \to \infty$ with keeping $\alpha$ finite, utilizing the replica method. For $p=1$, $\alpha_c(\rho)$ is considerably smaller than its worst case counterpart, which has been rigorously derived by existing literature of information theory.Comment: 12 pages, 2 figure

Ecological Study Of Lokan Mussels (Geloina spp) In Mangrove Likupang Village, Ambong Village, North Minahasa

Based on the observations of 48 individuals and 2 species, the results of analysis of the Density of Lokan Mussels (Geloina spp) at the 3 stations showed that the highest density was at station II of 6.8 Ind/m2 and followed by station III of 6.4 Ind/m2 and the lowest was at station I of 6 Ind/m2, with a total density of 19.2 ind/m2.Equation The long-weight relationship at station I of the Geloina erosa species is W = -2.0299 + 2.3331L with a value of b <3 meaning (negative allometric), the species of Geloina expansa is W = -4.5186 + 3.6111L with a value of b> 3 means (positive allometric). The long-weight relationship at station II of the Geloina erosa species is W = -7.9857 + 5.4459L with a value of b > 3 meaning (positive allometric), the species of Geloina expansa is W = -5.6998 + 4.2558L with a value of b > 3 means (positive allometric ). The long-weight relationship at station III of the Geloina erosa species was W = -4.8901 + 3.832L with a value of b > 3 meaning (positive allometric), Geloina expansa species was W = -4.4782 + 3.5928L with a value of b > 3 meaning (positive allometric). Keywords: ecological studies; Density, weight length relationships, dispersal patterns Abstrak Berdasarkan hasil pengamatan jumlah individu 48 dan terdapat 2 spesies, hasil analisisKepadatan Kerang Lokan (Geloina spp) pada ke 3 stasiun  menunjukan kepadatan tertinggi terdapat pada stasiun II sebesar 6,8 Ind/m2 dan di ikuti stasiun III sebesar 6,4 Ind/m2 dan terendah pada stasiun I sebesar 6 Ind/m2 ,  dengan kepadatan total 19,2 ind/m2. Persamaan Hubungan panjang berat pada stasiun I spesies Geloina erosa adalah W =  - 2,0299+2,3331L dengan nilai b < 3 artinya (allometrik negatif ), spesies Geloina expansa adalah W =  - 4,5186 + 3,6111L  dengan nilai b > 3 artinya (allometrik positif). Hubungan panjang berat pada stasiun II spesies Geloina erosa adalah W = - 7,9857 + 5,4459L dengan nilai b > 3 artinya (allometrik positif), spesies Geloina expansa adalah W =  - 5,6998 + 4,2558L  dengan nilai b > 3 artinya (allometrik positif ). Hubungan panjang berat pada stasiun III spesies Geloina erosa adalah W = - 4,8901 + 3,832L dengan nilai b > 3 artinya (allometrik positif), spesies Geloina expansa adalah W = - 4,4782 + 3,5928L dengan nilai b > 3 artinya ( allometrik positif). Kata kunci : studi ekologi ; Kepadatan, hubungan panjang berat, pola penyebara

Are Steadily Moving Crystals Unstable?

We study the dynamics of small fluctuations about the uniform state of a crystal moving through a dissipative medium, e.g. a sedimenting colloidal crystal or a moving flux lattice, using a set of continuum equations for the displacement fields, and a one-dimensional driven lattice-gas model for the coupled concentration and tilt fields. For the colloidal crystal we predict a continuous nonequilibrium phase transition to a clumped state above a critical Peclet number.Comment: 4 pages, revtex, 2 .eps figures, uses epsf.sty; To be published in Phys. Rev. Lett. This version is substantially rewritten but the essential content is the same as befor

To stop or not to stop: what should we be doing with biologic DMARDs when patients undergo orthopaedic surgery?

Management of biologic DMARDs in patients undergoing orthopaedic surgery is variable; flare avoidance is a priority

Probabilistic Reconstruction in Compressed Sensing: Algorithms, Phase Diagrams, and Threshold Achieving Matrices

Compressed sensing is a signal processing method that acquires data directly in a compressed form. This allows one to make less measurements than what was considered necessary to record a signal, enabling faster or more precise measurement protocols in a wide range of applications. Using an interdisciplinary approach, we have recently proposed in [arXiv:1109.4424] a strategy that allows compressed sensing to be performed at acquisition rates approaching to the theoretical optimal limits. In this paper, we give a more thorough presentation of our approach, and introduce many new results. We present the probabilistic approach to reconstruction and discuss its optimality and robustness. We detail the derivation of the message passing algorithm for reconstruction and expectation max- imization learning of signal-model parameters. We further develop the asymptotic analysis of the corresponding phase diagrams with and without measurement noise, for different distribution of signals, and discuss the best possible reconstruction performances regardless of the algorithm. We also present new efficient seeding matrices, test them on synthetic data and analyze their performance asymptotically.Comment: 42 pages, 37 figures, 3 appendixe