Asymmetry and Fighting Performance in the Shore Crab Carcinus maenas

Fluctuating asymmetries (left–right differences in symmetric traits) can be negatively related to fitness parameters in a number of biological systems. Hence, it has been suggested that symmetric individuals should outcompete asymmetric individuals during intraspecific agonistic encounters. However, there is a lack of experimental evidence for such a relationship. We investigated the relationship between trait asymmetry (both directional and fluctuating asymmetry) and the outcome of agonistic encounters among size-matched male shore crabs. Our findings indicate that cheliped (‘weapon claw’) directional asymmetry is not related to the outcome of fights, whereas fluctuating asymmetry in the fifth pereiopod, but not the second pereiopod, is negatively related to the likelihood of winning conspecific aggressive encounters. This relationship is most readily explained by a biomechanical advantage in symmetric individuals, as the fifth pereiopod is likely to be mechanically important in maintaining stability and balance during fighting. There is no evidence that asymmetry (in traits that display fluctuating asymmetry) is related to an intrinsic individual quality factor. None the less, the relative mechanical advantage of low asymmetry may give rise to fitness benefits in symmetric crabs that may have evolutionary consequences

Chandra X-Ray Study of Galactic Supernova Remnant G299.2-2.9

We report on observations of the Galactic supernova remnant (SNR) G299.2$-$2.9 with the {\it Chandra X-Ray Observatory}. The high resolution images with {\it Chandra} resolve the X-ray-bright knots, shell, and diffuse emission extending beyond the bright shell. Interior to the X-ray shell is faint diffuse emission occupying the central regions of the SNR. Spatially-resolved spectroscopy indicates a large foreground absorption ($N_{\rm H}$ $\sim$ 3.5 $\times$ 10$^{21}$ cm$^{-2}$), which supports a relatively distant location ($d$ $\sim$ 5 kpc) for the SNR. The blast wave is encountering a highly inhomogeneous ambient medium with the densities ranging over more than an order of magnitude ($n_0$ $\sim$ 0.1 $-$ 4 cm$^{-3}$). Assuming the distance of $d$ $\sim$ 5 kpc, we derive a Sedov age of $\tau$ $\sim$ 4500 yr and an explosion energy of $E_0$ $\sim$ 1.6 $\times$ 10$^{50}$ ergs. The ambient density structure and the overall morphology suggest that G299.2$-$2.9 may be a limb-brightened partial shell extending to $\sim$7 pc radius surrounded by fainter emission extending beyond that to a radius of $\sim$9 pc. This suggests the SNR exploded in a region of space where there is a density gradient whose direction lies roughly along the line of sight. The faint central region shows strong line emission from heavy elements of Si and Fe, which is caused by the presence of the overabundant stellar ejecta there. We find no evidence for stellar ejecta enriched in light elements of O and Ne. The observed abundance structure of the metal-rich ejecta supports a Type Ia origin for G299.2$-$2.9.Comment: 16 pages (AASTex emulator style), 3 Tables, 10 Figures (including 1 color: Figure 1), Accepted by Ap

एकीकृत चावल-चिंगट-पख मछली पालन द्वारा परंपरागत पोक्काली चावल खेती का पुनर्नवीकरण

Rejuvenation of the traditional Pokkali farming system through integrated paddy – shrimp – Fin fish farmin

Submicron particles of Co, Ni and Co-Ni alloys

Magnetic sub-micron sized particles (with diameters in the range 100–600 nm) of Co, Ni and Co-Ni alloys, protected with polyvinylpyrrolidone have been prepared in gram quantities using the polyol process. Experiments carried out with different metal precursors and starting compositions have yielded reliable routes to produce particles of the desired diameters in the 100–600 nm range. The particles were characterized with X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, thermogravimetric analysis and magnetic measurements. The particles are found to be stable under ambient conditions indefinitely. The coercivity values of the Co and Ni particles are ∼50% higher compared to the corresponding bulk values. The alloy particles follow a trend similar to the bulk alloys

A comparison of the reproducibility of manual tracing and on-screen digitization for cephalometric profile variables

The aim of this investigation was to analyse and compare the reproducibility of manual cephalometric tracings with on-screen digitization using a soft tissue analysis. A random sample of 20 lateral cephalometric radiographs, in the natural head posture, was selected. On-screen digitization using Viewbox (R) 3.1.1.9 cephalometric software and manual tracing on a 1:1 printout of the image was carried out twice in different sessions 1 week apart. Differences were analysed using a repeated measurement analysis of variance with method, session, and method-session interaction as explaining variables. The differences were expressed as an absolute percentage of the overall mean. The findings of the present study indicate that the two measurement methods differ significantly for 11 variables (P = 0.001 to P = 0.042). The area around stomion was the least reproducible. Except for s-n(s)-unt, nasal protrusion, with the manual technique, all mean differences between sessions and between methods were less than 1 degree or 1 mm and were, on-screen, smaller for 13 variables compared with those traced manually. Absolute percentage differences of the overall mean were smaller for seven variables with the digital technique and three variables in the manual technique, while four manual variables and one on-screen variable exceeded 2 per cent of the overall mean. Although small significant differences were found, the clinical relevance remains questionable

Ariel - Volume 9 Number 6

Executive Editor Seth B. Paul Associate Editor Warren J. Ventriglia Business Manager Fredric Jay Matlin University News John Patrick Welch World News George Robert Coar Editorials Editor Steve Levine Features Mark Rubin Sports Editor Eli Saleeby Photo Editor Ken Buckwalter Circulation Victor Onufreiczuk Lee Wugofski Graphics and Art Steve Hulkower Commons Editor Brenda Peterso

Effect of size on the Coulomb staircase phenomenon in metal nanocrystals

The Coulomb staircase in polymer-covered Pd and Au nanocrystals of varying diameters in the 1.7-6.4 nm has been investigated by employing tunneling conductance measurements. Charging up to several electrons is observed at room temperature in the I-V data. Small nanocrystals show charging steps exceeding 200 mV while the larger ones exhibit smaller steps. Significantly, the charging energies follow a scaling law of the form, U=A+B/d, where d is the diameter of the nanocrystal. Furthermore, the line widths in the derivative spectra also vary inversely with the diameter

Self-assembling bilayers of palladiumthiolates in organic media

Alkylthiolates of palladium forming a homologous series (butyl to octadecyl) have been prepared and characterized using X-ray diffraction and STM. The thiolates adopt an unusual bilayered lamellar structure, whose thickness is governed by the length of the alkyl chain. These mesophases melt in the temperature range, 60° to 100°C, with the melting point increasing linearly with the thiol chain length. There is evidence to suggest that the alkyl chains are orientationally disordered especially prior to melting

Sustainability Capacity of HIV Programs in National Capital Region, Philippines

Across all the regions in the Philippines, the National Capital Region (NCR) got the highest percentage (37%) for HIV newly diagnosed cases based from  the July-August 2017 HIV/AIDS and ART Registry of the Philippines’ report. The National HIV, AIDS, and STI Prevention and Control Program (NASPCP) of the Department of Health (DOH) lead the different health services in the prevention of HIV transmission. Anchored with the NASPCP, different HIV programs of DOH’s selected partner institutions and organizations within NCR continuously exist. However, due to the increase on the number of newly diagnosed HIV cases in the country, ensuring its sustainability through assessing the different domains of their program was in need to be studied. This article was based from an undergraduate thesis study which aimed to assess the sustainability capacity of HIV programs among DOH’s selected partner institutions and organizations within NCR, Philippines, scoping the eight domains specifically the environmental support, funding stability, partnerships, organizational capacity, program evaluation, program adaptation, communications, and strategic planning. The study used a quantitative approach; 17 government institutions specifically city health offices and 13 non-government HIV-related organizations for a total of 30 respondents. Survey method was utilized using the standardized Program Sustainability Assessment Tool adapted from the Washington University in St. Louis. Based from the results and findings of the study, generally, all the domains were leaning either in great and greater extent as verbally interpreted. From the conclusion, all the domains of the HIV programs of the respondents were sustainable. However, the study recommended to the DOH and all the HIV program implementers the developed and proposed narrative-type action plan. By that means, future researchers can assess again and see if the NCR achieved the vision of the Health Sector Plan for HIV and STI for the year 2015-2020 to have zero new infections, zero discrimination, and zero AIDS-related deaths