City rats: From rat behaviour to human spatial cognition in urban environments

The structure and shape of an urban environment influence our ability to find our way about in the city^1-2^. Indeed, urban designers who face the challenge of planning environments that facilitate wayfinding^3^, have a consequent need to understand the relations between the urban environment and spatial cognition^4^. Previous studies have suggested that certain qualities of city elements, such as a distinct contrast with the background (e.g. The Eiffel Tower in Paris), or a clear morphology (e.g. the grid layout of Manhattan's streets) affect spatial behaviour and cognition^1,5-7^. However, only a few empirical studies have examined the relations between the urban environment and spatial cognition. Here we suggest that testing rats in experimental environments that simulate certain facets of urban environment can provide an insight into human spatial behaviour in urban environments with a similar layout. Specifically, we simulated two city layouts: (1) a grid street layout such as that of Manhattan; and (2) an irregular street layout such as that of Jerusalem. We found that the rats that were tested in the grid layout covered more ground and visited more locations, compared with the restricted movement demonstrated by the rats tested in the irregular layout. This finding in rats is in accordance with previous findings that urban grids conduce to high movement flow throughout the city, compared to low movement flow in irregular urban layouts^8-9^. Previous studies revealed that the spatial behaviour of rats and humans is controlled by the same underlying mechanisms^10-11^. In the same vein, we show that rats demonstrate spatial movement patterns that recall those of humans in similar urban environments. Rat behaviour may thus offer an in-vivo means for testing and analyzing the spatial cognitive principles of specific urban designs and for inferring how humans may perceive a particular urban environment and orient in it

Enhancement of CP Violation in B^+- to K_i^+- D^0 By Resonant Effects

Resonance width effects in charged $B$ decays to neutral $D$ mesons and excited kaon states $K_i$ around 1400 MeV are shown to lead to large calculable final state phases. $CP$ asymmetries are defined for any charged $B$ decay to three pseudoscalar mesons involving intermediate overlapping resonance states. Asymmetries up to about 10$\%$ are found in $B^+\to K^+_i D^0\to (K\pi)^+ D^0$. Decay distributions can be used to determine the weak phase $\gamma$ of the Cabibbo-Kobayashi-Maskawa (CKM) matrix. No separation of the contributions from individual resonances is required.Comment: 11 page

Akibat Hukum Penanggalan Kekebalan (Immunity Waiver) Kepada Pejabat Diplomatik Ditinjau dari Konvensi Wina 1961 (Studi Kasus Penanggalan Kekebalan terhadap Asisten Atase Militer Malaysia di Selandia Baru Tahun 2014)

Asisten atase militer sebagai pejabat diplomatik dalam menjalankan misi diplomatiknya diberikan hak istimewa dan kekebalan dengan harapan bisa melangsungkan misi tersebut tanpa hambatan. Dalam prakteknya banyak pejabat diplomatik yang menyalahi aturan dari negara penerima dan menggunakan hak kekebalan serta keistimewaan tersebut sebagai suatu perlindungan untuk terbebas dari proses hukum. Pada Kenyataanya juga diatur bahwa kekebalan tidak bersifat mutlak dan bisa ditanggalkan. Permasalahan yang diteliti adalah bagaimana pengaturan mengenai penanggalan kekebalan menurut Konvensi Wina 1961 dan akibat hukum yang timbul dengan adanya penanggalan kekebalan terhadap asisten atase militer suatu negara. Metode pendekatan yang digunakan dalam penulisan hukum ini adalah yuridis normatif. Spesifikasi penelitian yang digunakan adalah deskriptif analisis. Metode analisis data dalam penlitian ini adalah normatif kualitatif. Metode pengumpulan data dilakukan penulis melalui studi kepustakaan. Berdasarkan hasil penelitian disimpulkan bahwa suatu hak kekebalan yang dimiliki oleh pejabat diplomatik bisa ditanggalkan oleh negara pengirim menurut Konvensi Wina 1961. Malaysia selaku negara pengirim menanggalkan kekebalan asisten atase militernya untuk berlangsungnya proses hukum di Selandia Baru sebagai negara penerima. Asisten atase militer Malaysia resmi dijatuhi hukuman oleh negara penerima dan setelah selesai menuntaskannya ia dideportasi kembali ke Malaysia.Abstrak ditulis dalam bahasa Indonesia dan bahasa Inggris. Merupakan uraian singkat yang memuat tujuan, hasil penelitian, kesimpulan, serta implikasinya

Animals do not commit suicide but do display behaviors that are precursors of suicide in humans

Although my commentary begins with a report about a monkey committing suicide, I agree with the target article\u27s concluding statement that we cannot currently prove that any animal has committed suicide. The author’s proposed continuist approach is based on animal behaviors reminiscent of symptoms preceding suicide in humans (e.g., deep depression and grief). However, in both humans and nonhuman animals, these are just potential precursors of suicide, and dying as a result of grief is not necessarily suicide. In the absence of supporting evidence, the continuist hypothesis of animal suicide is not sustained

Locomotor activity in common spiny mice (Acomys cahirinuse): The effect of light and environmental complexity

BACKGROUND: Rodents typically avoid illuminated and open areas, favoring dark or sheltered environments for activity. While previous studies focused on the effect of these environmental attributes on the level of activity, the present study tested whether the spatio-temporal structure of activity was also modified in illuminated compared with dark and complex compared with open arenas. For this, we tested common spiny mice (Acomys cahirinus) in empty or stone-containing arenas with lights on or lights off. RESULTS: In an illuminated or open arena, spiny mice moved in less frequent but longer trips with relatively long distances between consecutive stops. In contrast, in either a dark arena or an arena with stones, the animals took shorter and more frequent trips, with more stops per trip and shorter inter-stop distances. In illuminated arenas spiny mice remained mainly along the walls, whereas locomotion in the center was more prevalent in dark empty arenas, and was carried out along convoluted paths. Increasing environmental complexity by adding stones to either illuminated or dark arenas increased locomotion along straight trajectories and away from walls. CONCLUSIONS: Earlier findings of reduced activity in illuminated or open areas have been extended in the present study by demonstrating changes in the spatio-temporal structure of locomotor behavior. In the more complex arenas (with stones) spiny mice traveled along short straight segments whereas in the open their trips were longer and took the shape of a zigzag path which is more effective against fast or nearby predators. Alternatively, the zigzag path may reflect a difficulty in navigation

CP Nonconservation in ppˉ→tbˉXp\bar p\to t\bar b X at the Tevatron

The reaction $p\bar p\to t\bar bX$ is found to be rather rich in exhibiting several different types of CP asymmetries. The spin of the top quark plays an important role. Asymmetries are related to form factors arising from radiative corrections of the $tbW$ production vertex due to non-standard physics. As illustrations, effects are studied in two Higgs Doublet Models and in Supersymmetric Models; asymmetries up to a few percent may be possible.Comment: 14 pages, 3 figures. Note: replaced due to minor problems that appeared on some postscript previewers. No change in conten

Laser optical separation of chiral molecules

The optical trapping of molecules with an off-resonant laser beam involves a forward-Rayleigh scattering mechanism. It is shown that discriminatory effects arise on irradiating chiral molecules with circularly polarized light; the complete representation requires ensemble-weighted averaging to account for the influence of the trapping beam on the distribution of molecular orientations. Results of general application enable comparisons to be drawn between the results for two limits of the input laser intensity. It emerges that, in a racemic mixture, there is a differential driving force whose effect, at high laser intensities, is to produce differing local concentrations of the two enantiomers

FCNC-induced heavy-quark events at the LHC from Supersymmetry

We analyze the production and subsequent decay of the neutral Higgs bosons of the MSSM into electrically neutral quark pairs qq'=bs,tc of different flavors at the LHC and compare with the direct FCNC production mechanisms. The cross-sections are computed in the unconstrained MSSM with minimal flavor-mixing sources and taking into account the stringent bounds from radiative B-meson decays. We extend the results previously found for these FCNC processes, which are singularly uncommon in the SM. Specifically, we report here on the SUSY-EW contribution of the Higgs-mediated FCNC cross-section into bs and tc final states and the SUSY-QCD and SUSY-EW contributions to bs-production. In this way, the complete map of MSSM predictions for the qq'-pairs produced at the LHC becomes available. The upshot is that the most favorable channels are: 1) the Higgs boson FCNC decays into bs, and 2) the direct production of tc pairs, both of them at the 1 pb level and mediated by SUSY-QCD effects. If, however, the latter are suppressed, we find a small SUSY-EW yield for the tc-production through Higgs decays but, at the same time, a cross-section of 0.1-1 pb for bs-production, which implies a significant number (10^4-10^5) of bs-pairs per 100 inverse femtobarn of integrated luminosity.Comment: LaTeX, 17 pages, 4 figures, 4 tables. Extended discussion. Accepted in Phys. Lett.

Indirect Bounds on Z-> mu e and Lepton Flavor Violation at Future Colliders

Motivated by the interest in lepton number violating processes, we study the connection between the rate of Z -> mu e decay and those of the low-energy processes mu ->3 e, and mu -> e conversion in nuclear field. We show that if the vector or axial Z form factors are dominant, Br(Z->mu e) is not observable, while if the Z dipole form factors are dominant, the relatively weak indirect bound Br(Z->mu e)<7 10^{-9} does not fully preclude a signal at future colliders, as TESLA. We finally comment on the relation of Z->mu e with Z->tau e and Z->tau mu decays, and suggest a simple scaling law for these three processes.Comment: 10 pages, references adde