Comment on "Turbulent heat transport near critical points: Non-Boussinesq effects" (cond-mat/0601398)

In a recent preprint (cond-mat/0601398), D. Funfschilling and G. Ahlers describe a new effect, that they interpret as non-Boussinesq, in a convection cell working with ethane, near its critical point. They argue that such an effect could have spoiled the Chavanne {\it et al.} (Phys. Rev. Lett. {\bf 79} 3648, 1997) results, and not the Niemela {\it et al.} (Nature, {\bf 404}, 837, 2000) ones, which would explain the differences between these two experiments. We show that:-i)Restricting the Chavanne's data to situations as far from the critical point than the Niemela's one, the same discrepancy remains.-ii)The helium data of Chavanne show no indication of the effect observed by D. Funfschilling and G. Ahlers.Comment: comment on cond-mat/060139

Identifikasi Nematoda Gastrointestinal Pada Katak Fejervarya Cancrivora Dan Limnonectes Macrodon Di Wilayah Kabupaten Bogor, Jawa Barat (Gastrointestinal Nematode Identification of Frogs Fejervarya Cancrivora and Limnonectes Macrodon in Bogor Residence)

A research was conducted to identify and to descript nematode worm genera as parasite from gastrointestinal tract of local consumption frogs. Fifty five adult Fejervarya cancrivora and seventy Limnonectes macrodon were collected from three subdistricts in Bogor Residence; Caringin, Cibatok, and Cimanggis. The research was also carried out to quantify prevalence nematode that infest both of frogs and to observe relationship between prevalence level and resource area also spesies of its. Nematode generas which found in F. cancrivora were identified as Amplicaecum, Camallanus, Aplectana, Cosmocerca, Cosmocercella,and Spinicauda. The same generas infested L. macrodon for exception Camallanus. Fejervarya cancrivora nematode prevalence level was higher than L. macrodon in all subdistricts. Its prevalence level weren't influenced by resource area. But, there was significant correlation between prevalence level and species of frogs (α=0,01 and α=0,05). The differences of gastrointestinal nematode infestation are related to differences in habitat and food type of frogs also life cycle of nematodes

Amplitude analysis of reactions pi(-)p->etapi(-)p and pi(-)p->etapi(0)n on polarized target and the exotic 1-+ meson

Recently several experimental groups analysed data on $\pi^- p \to \eta \pi^- p$ and $\pi^- p \to \eta \pi^0 n$ reactions with exotic $1^{-+}$ $P$-wave and found a conflicting evidence for an exotic meson $I=1 1^{-+} (1405)$. High statistics data on these reactions are presently analysed by BNL E852 Collaboration. All these analyses are based on the crucial assumption that the production amplitudes do not depend on nucleon spin. This assumption is in sharp conflict with the results of measurements of $\pi^- p \to \pi^- \pi^+ n$, $\pi^+ n \to \pi^+ \pi^- p$ and $K^+ n \to K^+ \pi^- p$ on polarized targets at CERN which find a strong dependence of production amplitudes on nucleon spin. To ascertain the existence of exotic meson $1^{-+} (1405)$, it is necessary to perform a model-independent amplitude analysis of reactions $\pi^- p \to \eta \pi^- p$ and $\pi^- p \to \eta\pi^0 n$. We demonstrate that measurements of these reactions on transversely polarized targets enable the required model independent amplitude analysis without the assumption that production amplitudes are independent on nucleon spin. We suggest that high statistics measurements of reactions $\pi^- p \to \eta\pi^- p$ and $\pi^- p \to\eta\pi^0 n$ be made on polarized targets at BNL and at Protvino IHEP, and that model-independent amplitude analyses of this polarized data be performed to advance hadron spectroscopy on the level of spin dependent production amplitudes.Comment: 23 page

Mass and width of sigma(750) scalar meson from measurements of pi(-)p->pi(-)pi(+)n on polarized target

Model independent amplitude analyses of $\pi^- p_\uparrow \to \pi^- \pi^+ n$ on polarized target at 17.2 GeV/c reveal resonant structure of S-wave transversity amplitudes $|\bar S|^2\Sigma$ and $|S|^2\Sigma$ near 750 MeV. Simultaneous fit to $|\bar S|^2\Sigma$ and $|S|^2\Sigma$ with a single $\sigma$ pole yields $m_\sigma = 775 \pm 17$ MeV and $\Gamma_\sigma = 147 \pm 33$ MeV. Simultaneous fit with two common $\sigma$ poles yields a lower $\chi^2/dpt$. Their resonance parameters are $m_\sigma = 786 \pm 24$ MeV, $\Gamma_\sigma = 130 \pm 47$ MeV and $m_{\sigma^\prime} = 670 \pm 30$ MeV, $\Gamma_{\sigma^\prime} = 59 \pm 58$ MeV.Comment: 4 pages, 3 figure

Helium Cryostat for Experimental Study of Natural Turbulent Convection

V disertační práci je popsán heliový kryostat s experimentální válcovou konvekční celou pro studium proudění při přirozené konvekci za velmi vysokých Rayleigho čísel Ra (až do řádu 10^15) a Nusseltových čísel Nu (až do řádu 10^4). Pracovní látkou je studené 4He, které umožňuje díky výhodným fyzikálním vlastnostem dosažení velmi vysokých hodnot čísel Ra. Návrh kryostatu je založen na koncepci lázňových NMR kryostatů s nízkým odparem kryokapalin. Ve středu kryostatu je umístěna konvekční cela o průměru 300 mm a výšce 300 mm. Celu tvoří horní a spodní dno a výměnná střední část. Tyto díly jsou spojeny rozebíratelnými přírubami těsněnými indiovým drátem. Výměnná část umožňuje snadnou modifikaci geometrie cely. Hlavní přednost kryostatu spočívá v minimálním vlivu konstrukce cely a použitých materiálů na studovanou konvekci. Cela kryostatu je navržena pro pracovní tlaky do 250 kPa.The thesis focuses on the design of a helium cryostat with an experimental convection cell for the study of natural turbulent convection in the range of Rayleigh numbers Ra up to 1015 and Nusselt numbers Nu up to 104. Cryogenic 4He gas is used as a working fluid for experimental studies due to its advantageous properties that allow reaching very high Ra numbers. The cryostat design is based on the conception of low-loss NMR magnet cryostats. In the centre of the cryostat a cylindrical convection cell of 300 mm in diameter and 300 mm in height is placed. The cell is made of middle, top and bottom parts. These are jointed together by flanges sealed by indium wires. The middle part is exchangeable and allows the geometry of the cell to be modified. The cell is designed for measurements at pressures up to 250 kPa. The main advantage of this cryostat is the minimal influence of the cell design and materials on the studied convection.

Native species Maxvachonia chabaudi Mawson, 1972 (Nematoda: Cosmocercoidea) found in the invasive marine toad Rhinella marina (Linnaeus) (Anura: Bufonidae) in Australia

The genus Maxvachonia Chabaud et Brygoo, 1960 (Ascaridomorpha: Cosmocercidae) is a poorly known group of parasitic nematodes. Species of Maxvachonia are native to Madagascar-Australo-Papuan Region, where they are known to parasitise frogs, snakes and skinks. Unfortunately, most of Maxvachonia species have been inadequately described. In the present study, we report the native species Maxvachonia chabaudi Mawson, 1972 from the intestine of the invasive marine toad Rhinella marina (Linnaeus) in Australia for the first time. We speculate that the marine toads infected with M. chabaudi are likely related to their eating skinks or the similarity in diet/habitat/ecology between the toad and the skinks. The detailed morphology of M. chabaudi was studied using light microscopy and, for the first time, scanning electron microscopy, based on the newly collected specimens. Some characters important for the specific diagnosis of M. chabaudi are reported for the first time, including each lip with distinct inner flanges, the location of vulva varying from anterior to posterior of the oesophageal bulb and the presence of single medio-ventral precloacal papilla. An identification key to the species of Maxvachonia is provided

Pathological findings on natural infection with Physaloptera praeputialis in cats

To study the pathological changes in the stomach of cat caused by Physaloptera praeputialis, 22 stray cats were euthanized. At necropsies, seven cats were found to be infected with this nematode. Thickening of the stomach wall, congestion and oedema, along with tiny erosions, were observed in gross pathology. Histopathology observations indicated congestion, oedema, leukocytic infiltration, necrosis, hyperplasia and cystic changes of glands and hyperplasia of muscular coat. These changes were indicative of inflammatory and degenerative reaction brought about by parasitic infection with P. praeputialis and its consequent irritating effects on the stomach. This is the second report of pathological observations of P. praeputialis infection in domestic cats

Silver Staining for Elucidation of the Synlophe in Trichostrongyle Nematodes

Staining techniques are relatively rare in the study of parasitic nematodes. A novel silver-staining method is described for elucidation of the synlophe (a system of longitudinal cuticular ridges), a character of great systematic importance among the trichostrongyloid nematodes. Ridges are stained optically black and appear in great contrast to the body of the nematode. This method augments current use of interference contrast for examination of the synlophe. Detailed studies of the configuration of the synlophe in entire specimens are possible with standard light microscopy for the first time