Impact of storage conditions on profilometry of eroded dental hard tissue

The aim of the present study was to analyze in how far drying of eroded dentin and enamel surfaces influence the results of profilometrical determinations with a stylus profilometer. Each five dentin and enamel samples were eroded with HCl (pH 2.6, 2 min). Surface profiles of the samples were recorded with a stylus profilometer in three series. In series 1, the samples were measured while stored in water and in series 2, under ambient conditions (21 degrees C, 35% humidity). In series 3, samples were completely desiccated and then rewetted. Profilometry was conducted at various time intervals for a period of up to 181 min (series 1 and 2) and 72 h (series 3). Only the dentin samples were affected by the storage conditions. Stable profilometrical readings for the eroded dentin samples were only feasible when the specimens were stored in water during the complete period of the experiment, including the profilometrical measurement. Thus, for erosion experiments using profilometrical analysis with a stylus profilometer, it is advised to store and measure dentin samples under wet conditions

Mitochondrial evidence for multiple radiations in the evolutionary history of small apes

Background: Gibbons or small apes inhabit tropical and subtropical rain forests in Southeast Asia and adjacent regions, and are, next to great apes, our closest living relatives. With up to 16 species, gibbons form the most diverse group of living hominoids, but the number of taxa, their phylogenetic relationships and their phylogeography is controversial. To further the discussion of these issues we analyzed the complete mitochondrial cytochrome b gene from 85 individuals representing all gibbon species, including most subspecies. Results: Based on phylogenetic tree reconstructions, several monophyletic clades were detected, corresponding to genera, species and subspecies. A significantly supported branching pattern was obtained for members of the genus Nomascus but not for the genus Hylobates. The phylogenetic relationships among the four genera were also not well resolved. Nevertheless, the new data permitted the estimation of divergence ages for all taxa for the first time and showed that most lineages emerged during four short time periods. In the first, between ~6.7 and ~8.3 mya, the four gibbon genera diverged from each other. In the second (~3.0 - ~3.9 mya) and in the third period (~1.3 - ~1.8 mya), Hylobates and Hoolock differentiated. Finally, between ~0.5 and ~1.1 mya, Hylobates lar diverged into subspecies. In contrast, differentiation of Nomascus into species and subspecies was a continuous and prolonged process lasting from ~4.2 until ~0.4 mya. Conclusions: Although relationships among gibbon taxa on various levels remain unresolved, the present study provides a more complete view of the evolutionary and biogeographic history of the hylobatid family, and a more solid genetic basis for the taxonomic classification of the surviving taxa. We also show that mtDNA constitutes a useful marker for the accurate identification of individual gibbons, a tool which is urgently required to locate hunting hotspots and select individuals for captive breeding programs. Further studies including nuclear sequence data are necessary to completely understand the phylogeny and phylogeography of gibbons

Epigenetic Anti-Cancer Treatment With a Stabilized Carbocyclic Decitabine Analogue

5-Aza-2'-deoxycytidine (Decitabine, AzadC) is a nucleoside analogue, which is in clinical use to treat patients with myelodysplastic syndrome or acute myeloid leukemia. Its mode of action is unusual because the compound is one of the few drugs that act at the epigenetic level of the genetic code. AzadC is incorporated as an antimetabolite into the genome and creates covalent, inhibitory links to DNA methyltransferases (DNMTs) that methylate 2'-deoxycytidine (dC) to 5-methyl-dC (mdC). Consequently, AzadC treatment leads to a global loss of mdC, which presumably results in a reactivation of silenced genes, among them tumor suppressor and DNA damage response genes. Because AzadC suffers from severe instability, which limits its use in the clinic, a more sophisticated AzadC derivative would be highly valuable. Here, we report that a recently developed carbocyclic AzadC analogue (cAzadC) blocks DNMT1 in the AML cell line MOLM-13 as efficient as AzadC. Moreover, cAzadC has a surprisingly strong anti-proliferative effect and leads to a significantly higher number of double strand breaks compared to AzadC, while showing less off-target toxicity. These results show that cAzadC triggers more deleterious repair and apoptotic pathways in cancer cells than AzadC, which makes cAzadC a promising next generation epigenetic drug

Knee complaints vary with age and gender in the adult population. Population-based reference data for the Knee injury and Osteoarthritis Outcome Score (KOOS)

BACKGROUND: Self-reported knee complaints may vary with age and gender. Reference data from the adult population would help to better interpret the outcome of interventions due to knee complaints. The objectives of the present study were to describe the variation of self-reported knee pain, function and quality of life with age and gender in the adult population and to establish population-based reference data for the Knee injury and Osteoarthritis Outcome Score (KOOS). METHODS: Population-based cohort retrieved from the national population register. The knee-specific Knee injury and Osteoarthritis Outcome Score (KOOS) was mailed to 840 subjects aged 18–84 yrs. RESULTS: 68% response rate. Women in the age group 55–74 reported more knee-related complaints in all the KOOS subscales than age-matched men. The differences were significant for the subscales Pain (p = 0.027), Symptoms (p = 0.003) and ADL function (p = 0.046). In men, worse ADL and Sport and Recreation function was seen in the oldest age group 75–84 years compared to the younger age groups (p < 0.030). In women, worse Pain (p < 0.007), ADL (p < 0.030), Sport and Recreation (p < 0.001) and QOL (p < 0.002) were seen already in the age group 55–74 compared to the younger age groups. CONCLUSION: We found pain and other symptoms, physical function, and knee-related quality of life to vary with age and gender implying the use of age- and gender matched reference values for improved understanding of the outcome after interventions due to knee injury and knee OA

An Open-System Quantum Simulator with Trapped Ions

The control of quantum systems is of fundamental scientific interest and promises powerful applications and technologies. Impressive progress has been achieved in isolating the systems from the environment and coherently controlling their dynamics, as demonstrated by the creation and manipulation of entanglement in various physical systems. However, for open quantum systems, engineering the dynamics of many particles by a controlled coupling to an environment remains largely unexplored. Here we report the first realization of a toolbox for simulating an open quantum system with up to five qubits. Using a quantum computing architecture with trapped ions, we combine multi-qubit gates with optical pumping to implement coherent operations and dissipative processes. We illustrate this engineering by the dissipative preparation of entangled states, the simulation of coherent many-body spin interactions and the quantum non-demolition measurement of multi-qubit observables. By adding controlled dissipation to coherent operations, this work offers novel prospects for open-system quantum simulation and computation.Comment: Pre-review submission to Nature. For an updated and final version see publication. Manuscript + Supplementary Informatio

Komposisi dan Kemelimpahan Fitoplankton di Laguna Glagah Kabupaten Kulonprogo Provinsi Daerah Istimewa YOGYAKARTA

Penelitian bertujuan untuk: 1) mengidentifikasi jenis fitoplankton di laguna Glagah; 2) meng-identifikasi kemelimpahan fitoplankton di laguna Glagah; 3) mempelajari hubungan faktor fisiko-kimia lingkungan dengan kemelimpahan fitoplankton di laguna Glagah. Penelitian dilaksanakan pada tanggal 10 Desember 2012 di laguna Glagah desa Glagah kecamatan Temon Kabupaten Kulonprogo DIY. Pengambilan sampel dilakukan pada 3 stasiun pengamatan untuk mengidentifikasi faktor fisiko-kimia (pH, DO, dan alkalinitas) dan mengidentifikasi fitoplankton. Pengamatan dilakukan sebanyak 2 kali yaitu pada pukul 08.00 WIB (pagi) dan 13.00 WIB (siang). Pengujian faktor fisiko-kimia dan identifikasi fito-plankton dilakukan di laboratorium ekologi Fakultas Biologi UGM. Hasil penelitian menunjukkan bahwa fitoplankton yang ditemukan di laguna Glagah berjumlah 9 spesies dalam 3 fungsional grup dengan kemelimpahan rata-rata sebesar 1839.667 individu/L pada pagi hari dan 1640,333 pada siang hari. Fitoplankton yang paling melimpah adalah diatom. Berdasarkan analisis regresi korelasi antara kemelimpahan fitoplankton dan faktor fisiko-kimia perairan Laguna Glagah maka diperoleh kesimpulan bahwa terdapat hubungan antara faktor fisiko kimia meliputi pH, DO, dan alkalinitas dengan kemelimpahan fitoplankton

Island nucleation in the presence of step edge barriers: Theory and applications

We develop a theory of nucleation on top of two-dimensional islands bordered by steps with an additional energy barrier $\Delta E_S$ for descending atoms. The theory is based on the concept of the residence time of an adatom on the island,and yields an expression for the nucleation rate which becomes exact in the limit of strong step edge barriers. This expression differs qualitatively and quantitatively from that obtained using the conventional rate equation approach to nucleation [J. Tersoff et al., Phys. Rev. Lett.72, 266 (1994)]. We argue that rate equation theory fails because nucleation is dominated by the rare instances when two atoms are present on the island simultaneously. The theory is applied to two distinct problems: The onset of second layer nucleation in submonolayer growth, and the distribution of the sizes of top terraces of multilayer mounds under conditions of strong step edge barriers. Application to homoepitaxial growth on Pt(111) yields the estimate $\Delta E_S \geq 0.33$ eV for the additional energy barrier at CO-decorated steps.Comment: 13 pages, 3 figure

Long distance regularization in chiral perturbation theory with decuplet

We investigate the use of long distance regularization in SU(3) baryon chiral perturbation theory with decuplet fields. The one-loop decuplet contributions to the octet baryon masses, axial couplings, S-wave nonleptonic hyperon decays and magnetic moments are evaluated in a chirally consistent fashion by employing a cutoff to implement long distance regularization. The convergence of the chiral expansions of these quantities is improved compared to the dimensionally regularized version which indicates that the propagation of Goldstone bosons over distances smaller than a typical hadronic size, which is beyond the regime of chiral perturbation theory but included by dimensional regularization, is removed by use of a cutoff.Comment: 31 page

Correct quantum chemistry in a minimal basis from effective Hamiltonians

We describe how to create ab-initio effective Hamiltonians that qualitatively describe correct chemistry even when used with a minimal basis. The Hamiltonians are obtained by folding correlation down from a large parent basis into a small, or minimal, target basis, using the machinery of canonical transformations. We demonstrate the quality of these effective Hamiltonians to correctly capture a wide range of excited states in water, nitrogen, and ethylene, and to describe ground and excited state bond-breaking in nitrogen and the chromium dimer, all in small or minimal basis sets

Spatio-temporal variation in European starling reproductive success at multiple small spatial scales

Funding Information This work received funding from the Natural Environment Research Council, Fair Isle Bird Observatory Trust and the Royal Society. Acknowledgments We thank Jessica Walkup, Jeroen Minderman, and many volunteers for help with data collection; Deryk and Hollie Shaw and Fair Isle Bird Observatory staff for help and support; Xavier Lambin and Justin Travis for comments on the manuscript and NERC (DB); and Fair Isle Bird Observatory Trust (DB) and the Royal Society (JMR) for funding.Peer reviewedPublisher PD