Stable isotopes of soil collected from feet of two species of migratory Acrocephalus give clues to stopover sites

Soil samples were collected from the feet of Marsh Warblers Acrocephalus palustris and Reed Warblers Acrocephalus scirpaceus caught soon after crossing the Sudan Red Sea coast of Africa. We measured carbon  (δ13Csoil_feet) and deuterium (δDsoil_feet) isotope ratios in these soils with the objective of identifying possible take-off sites of these birds. We collected soils from three sites in the Caucasus region, a potential refuelingarea for the flight to Sudan, and from the Sudan Red sea coast, and compared their deuterium (δDsoil) with δDsoil_feet. There was a strong relationship between the arrival date of the birds and the isotope  signatures (δ13soil_feet and δDsoil_feet) of the soil they carried. Results suggest that warblers from different geographical regions or of differentage groups might use different staging sites before reaching the Sudan. Data for precipitation deuterium (äDprec) together with äDsoil and δDsoil_feet suggest that while early arriving birds had taken off from southeast Europe (picking up soil from this region), those arriving later had stopped off in Arabia. This indicates an intrinsic difference in strategy  between birds migrating at different times of the season. The isotopic compositions of biological tissues such as feathers have commonly been applied to track animal movement. But this is the first report of analysis of soil from birds’ feet: a novel approach to isotopic study based on material picked up and carried by an animal externally

Differential maternal testosterone allocation among siblings benefits both mother and offspring in the Zebra finch <i>Taeniopygia guttata</i>

Parents are selected to preferentially invest in the offspring with highest reproductive value. One mechanism for achieving this is the modification of competitive asymmetries between siblings by maternal hormones. In many organisms, offspring value varies according to birth position in the brood, which determines survival chances and competitive advantage over access to resources. In birds, variation in yolk androgen allocation over the laying sequence is thought to modulate dominance of senior chicks over junior brood mates. We tested this hypothesis in zebra finches, which show a naturally decreasing pattern of within-clutch testosterone allocation. We abolished these within-clutch differences by experimentally elevating yolk testosterone levels in eggs 2-6 to the level of egg 1, and we assessed fitness measures for junior offspring (eggs 2-6), senior offspring (egg 1), and their mothers. Testosterone-injected eggs hatched later than control eggs. Junior, but not senior, chicks in testosterone-treated broods attained poorer phenotypic quality compared to control broods, which was not compensated for by positive effects on seniors. Mothers were generally unaffected by clutch treatment. Thus, naturally decreasing within-clutch yolk testosterone allocation appears to benefit all family members and does not generally enhance brood reduction by favoring senior chicks, in contrast to the widely held assumption

The nonrelativistic limit of the relativistic point coupling model

We relate the relativistic finite range mean-field model (RMF-FR) to the point-coupling variant and compare the nonlinear density dependence. From this, the effective Hamiltonian of the nonlinear point-coupling model in the nonrelativistic limit is derived. Different from the nonrelativistic models, the nonlinearity in the relativistic models automatically yields contributions in the form of a weak density dependence not only in the central potential but also in the spin-orbit potential. The central potential affects the bulk and surface properties while the spin-orbit potential is crucial for the shell structure of finite nuclei. A modification in the Skyrme-Hartree-Fock model with a density-dependent spin-orbit potential inspired by the point-coupling model is suggested.Comment: 21 pages, latex, 1 eps figure. accepted for publication in annals of physic

Spring weights of some Palaearctic passerines in Ethiopia and Kenya: evidence for important migration staging areas in eastern Ethiopia

Palaearctic migrants were trapped in late April and early May at a passage site near Jijiga in eastern Ethiopia. Willow Warblers Phylloscopus trochilus and Spotted Flycatchers Muscicapa striata were predominant, while Red-backed Shrikes Lanius collurio, Sedge Warblers Acrocephalus schoenobaenus, Reed Warblers A. scirpaceus, Garden Warblers Sylvia borin and Common Whitethroats S. communis also featured prominently. Weights were high in all species, and over 70% of the birds caught were extremely fat. Spring weights and fat scores at Jijiga were compared with those found in the same species in Kenya, and the difference was striking. In Kenya, most species had mean spring weights 10–20% above lean weight; at Jijiga, species’ mean weights ranged from 30% to 55% above lean weight. Whereas the reserves of most migrants departing from Kenya would have supported flights only as far as Ethiopia, the fat loads of birds at Jijiga indicated a potential for crossing Arabia with little need to feed. This suggests important staging and fattening grounds between these two areas, perhaps in the Acacia–Commiphora bushlands drained by the upper Juba and Shebelle rivers and their tributaries

Rabin’s calibration theorem revisited

We simplify and refine the theoretical results behind Rabin’s famous calibration theorem for expected utility preferences and present the resulting tightened versions of his numerical illustrations

Optical trapping with "on-demand" two-photon luminescence using Cr:LiSAF laser with optically addressed saturable Bragg reflector

We demonstrate a diode-pumped Cr:LiSAF laser with controllable and reliable fast switching between its continuous-wave and mode-locked states of operation using an optically-addressed semiconductor Bragg reflector, permitting dyed microspheres to be continuously trapped and monitored using a standard microscope imaging and on-demand two-photon-excited luminescence techniques

Buku Foto "Menganyam" Naskah Akademik Skripsi Berbasis Karya

Anyaman pandan, merupakan salah satu kekayaan bangsa Indonesia dalam bentuk kerajinan tangan. Banyak nilai-nilai positif yang terkandung dalam kerajinan tangan ini, mulai dari kreatifitas, keunikan, nilai-nilai budayanya, bahkan mengenai lingkungan hidup. Ada banyak jenis dan variasi anyaman pandan, salah satunya berasal dari Kabupaten Bantul, Daerah Istimewa Yogyakarta. Tepatnya di sebuah dusun bernama Soropadan. Anyaman pandan ini adalah peninggalan leluhur yang sudah diwariskan secara turun temurun. Meski merupakan warisan leluhur, di zaman ini warisan tersebut mulai ditinggalkan generasi muda. Yang tersisa sebagai perajin anyaman pandan adalah wanita-wanita lanjut usia. Ada beberapa faktor dari ditinggalkannya seni anyaman ini, salah satunya adalah faktor ekonomi. Barang kerajinan anyaman ini dihargai sangat murah, juga kurang apresiasi dari masyarakat dan pemerintah. Padahal, sebagai salah satu kekayaan bangsa Indonesia, kerajinan ini juga dapat membantu menjawab isu lingkungan mengenai limbah plastik. Maka dari itu, cerita mengenai para perajin anyaman pandan dan barang kerajinannya dijadikan tema utama dalam photobook

A rapid-screening approach to detect and quantify microplastics based on fluorescent tagging with Nile Red

A new approach is presented for analysis of microplastics in environmental samples, based on selective fluorescent staining using Nile Red (NR), followed by density-based extraction and filtration. The dye adsorbs onto plastic surfaces and renders them fluorescent when irradiated with blue light. Fluorescence emission is detected using simple photography through an orange filter. Image-analysis allows fluorescent particles to be identified and counted. Magnified images can be recorded and tiled to cover the whole filter area, allowing particles down to a few micrometres to be detected. The solvatochromic nature of Nile Red also offers the possibility of plastic categorisation based on surface polarity characteristics of identified particles. This article details the development of this staining method and its initial cross-validation by comparison with infrared (IR) microscopy. Microplastics of different sizes could be detected and counted in marine sediment samples. The fluorescence staining identified the same particles as those found by scanning a filter area with IR-microscopy