Instability Heating of Sympathetically-Cooled Ions in a Linear Paul Trap

Sympathetic laser cooling of ions stored within a linear-geometry, radio frequency, electric-quadrupole trap has been investigated using computational and theoretical techniques. The simulation, which allows 5 sample ions to interact with 35 laser-cooled atomic ions, revealed an instability heating mechanism, which can prevent ions below a certain critical mass from being sympathetically cooled. This critical mass can however be varied by changing the trapping field parameters thus allowing ions with a very large range of masses to be sympathetically cooled using a single ion species. A theoretical explanation of this instability heating mechanism is presented which predicts that the cooling-heating boundary in trapping parameter space is a line of constant $q_u$ (ion trap stability coefficient), a result supported by the computational results. The threshold value of $q_u$ depends on the masses of the interacting ions. A functional form of this dependence is given

Molecular Dynamics Simulation of Sympathetic Crystallization of Molecular Ions

It is shown that the translational degrees of freedom of a large variety of molecules, from light diatomic to heavy organic ones, can be cooled sympathetically and brought to rest (crystallized) in a linear Paul trap. The method relies on endowing the molecules with an appropriate positive charge, storage in a linear radiofrequency trap, and sympathetic cooling. Two well--known atomic coolant species, ${}^9{\hbox{Be}}^+$ and ${}^{137}{\hbox{Ba}}^+$, are sufficient for cooling the molecular mass range from 2 to 20,000 amu. The large molecular charge required for simultaneous trapping of heavy molecules and of the coolant ions can easily be produced using electrospray ionization. Crystallized molecular ions offer vast opportunities for novel studies.Comment: Accepted for publication in Phys. Rev.

Heavy metals bioaccumulation in tissues of Tilapia zilli as indicators of water pollution in kafinchiri reservoir, Kano - Nigeria

This study assessed the levels of heavy metals accumulation in water, gills and liver of Tilapia zilli fish collected from Kafinchiri water Reservoir for a period of four months with the aim of predicting health risk effect on consumers. Water and Tilapia zilli samples were collected from three different sites along the course of the dam; upstream, midstream and downstream. The concentration of copper, lead, chromium and cadmium in water and their accumulation in the liver and gills of the sampled fishes were determined using atomic absorption spectrophotometer. The results revealed that concentration of dissolved heavy metals in the water ranges from Cu (0.4mg/L- 0.6mg/L), Pb (0.9 mg/L – 1.4mg/L), Cr (undetected - 0.1mg/L) and Cd (0.01mg/L – 0.02mg/L). Accumulation in the gills of tilapia fish ranges from Cu (0.8μg/g – 0.85μg/g), Pb (0.3μg/g -0.9μg/g), Cr (≤0.1μg/g) and Cd was not detected. The accumulation of heavy metals in the liver were Cu (3.0μg/g – 5.4μg/g), Pb (2.7μg/g – 9.6μg/g) and Cr (0.1μg/g – 0.15μg/g) and Cd not detected. Water content chemical analysis indicated that; sampling point B (midstream) had the highest concentration of the heavy metals in which Pb recorded had the highest Bioaccumulation factor (BAF) of 5.76. The mean range of physicochemical parameters studied were temperature (25.90 – 27.37 °C), pH (7.60 – 8.52), DO (6.27 – 7.47mg/L), BOD (2.02 – 3.02mg/L), turbidity (28.05 - 34.00 NTU), electrical conductivity(187.60 – 361.17μS/cm), TDS (211 - 363mg/L), Total dissolved solids, electrical conductivity, turbidity and nitrate recorded significant difference between sites (P<0.05). It was believed that domestic activities around the reservoir is the major contributing factor to the accumulation of toxic heavy metals in fish examined. It is recommended that intervention by relevant authorities is needed curtail potential long term effect of this pollutants in the reservoir.Key words: Heavy metals Pollution, Tilapia zilli, Bioaccumulation, Kafinchiri Reservoi

Structurally-related (−)-epicatechin metabolites in humans: assessment using de novo chemically synthesized authentic standards

Accumulating data suggest that diets rich in flavanols and procyanidins are beneficial for human health. In this context, there has been a great interest in elucidating the systemic levels and metabolic profiles at which these compounds occur in humans. While recent progress has been made, there still exist considerable differences and various disagreements with regard to the mammalian metabolites of these compounds, which in turn is largely a consequence of the lack of availability of authentic standards that would allow for the directed development and validation of expedient analytical methodologies. In the present study, we developed a method for the analysis of structurally-related flavanol metabolites using a wide range of authentic standards. Applying this method in the context of a human dietary intervention study using comprehensively characterized and standardized flavanol- and procyanidin-containing cocoa, we were able to identify the structurally-related (−)-epicatechin metabolites (SREM) postprandially extant in the systemic circulation of humans. Our results demonstrate that (−)-epicatechin-3′-β-D-glucuronide, (−)-epicatechin-3′-sulfate, and a 3′-O-methyl(−)-epicatechin-5/7-sulfate are the predominant SREM in humans, and further confirm the relevance of the stereochemical configuration in the context of flavanol metabolism. In addition, we also identified plausible causes for the previously reported discrepancies regarding flavanol metabolism, consisting to a significant extent of inter-laboratory differences in sample preparation (enzymatic treatment and sample conditioning for HPLC analysis) and detection systems. Thus, these findings may also aid in the establishment of consensus on this topic

Pendidikan Kesehatan Deteksi Dini Tumbuh Kembang pada Anak di Paud Lab School UNPGRI Kediri

Perkembangan anak usia dini memegang peranan yang sangat penting dalam perkembangan seorang individu. Agar seorang anak memiliki perkembangan yang baik, maka perlu ada deteksi dini tumbuh kembang anak yang memiliki tujuan tercapainya optimalisasi perkembangan seorang anak. Sangat disayangkan masih sedikit orang tua yang memiliki kesadaran untuk melakukan deteksi dini tumbuh kembang anak ini. Melalui metode penyuluhan tentang deteksi dini tumbuh kembang anak orang tua diharapkan memiliki kesadaran dan keahlian dalam melakukan deteksi dini tumbuh kembang anak. Hasil dari kegiatan ini menunjukkan pertumbuhan status gizi ( 87,5 % ), lingkar kepala ( 100 % ), perkembangan menggunakan  KPSP dengan hasil ( 100 %), perkembangan mental emosional ( 77,8 % ), tes daya dengar ( 100% ), tes daya lihat ( 100 % ) bahwa pasca penyuluhan, orang tua  dan guru memiliki kesadaran yang lebih baik tentang pentingya melakukan deteksi dini tumbuh kembang anak sebagai upaya optimalisasi perkembangan anak

On open-closed extension of boundary string field theory

We investigate a classical open-closed string field theory whose open string sector is given by boundary string field theory. The open-closed interaction is introduced by the overlap of a boundary state with a closed string field. With the help of the Batalin-Vilkovisky formalism, the closed string sector is determined to be the HIKKO closed string field theory. We also discuss the gauge invariance of this theory in both open and closed string sides.Comment: 25 pages, 2 figures, comments and a reference added, typos correcte