Luminosity functions of Lyman-alpha emitters at z=6.5, and z=5.7: evidence against reionization at z=6

Lyman-alpha emission from galaxies should be suppressed completely or partially at redshifts beyond reionization. Without knowing the instrinsic properties of galaxies at z = 6.5, this attenuation is hard to infer in any one source, but can be infered from a comparison of luminosity functions of lyman-alpha emitters at redshifts just before and after reionization. We combine published surveys of widely varying depths and areas to construct luminosity functions at z=6.5 and 5.7, where the characteristic luminosity L_star and density phi_star are well constrained while the faint-end slope of the luminosity function is essentially unconstrained. Excellent consistency is seen in all but one published result. We then calculate the likelihood of obtaining the z=6.5 observations given the z=5.7 luminosity function with (A) no evolution and (B) an attenuation of a factor of three. Hypothesis (A) gives an acceptable likelihood while (B) does not. This indicates that the z=6.5 lyman-alpha lines are not strongly suppressed by a neutral intergalactic medium and that reionization was largely complete at z = 6.5.Comment: Submitted to Astrophysical Journal Letter

Controlling Metamaterial Resonances with Light

We investigate the use of coherent optical fields as a means of dynamically controlling the resonant behaviour of a variety of composite metamaterials, wherein the metamaterial structures are embedded in a dispersive dielectric medium. Control and switching is implemented by coherently driving the resonant permittivity of the embedding medium by applied optical radiation. The effect of embedding Split ring resonators (SRR) in a frequency- dispersive medium with Lorentz-like dispersion or with dispersion engineered by electromagnetic induced transparency (EIT), is manifested in the splitting of the negative permeability band, the modified (frequency-dependent) filling fractions and dissipation factors. The modified material parameters are strongly linked to the resonant frequencies of the medium, while for an embedding medium exhibiting EIT, also to the strength and detuning of the control field. The robustness of control against the deleterious influence of dissipation associated with the metallic structures as well as the inhomogeneous broadening due to structural imperfections is demonstrated. Studies on plasmonic metamaterials that consist of metallic nanorods arranged in loops and exhibit a collective magnetic response at optical frequencies are presented. Control and switching in this class of plasmonic nanorod metamaterials is shown to be possible, for example, by embedding these arrays in a Raman active liquid like CS$_2$ and utilizing the Inverse Raman Effect.Comment: 9 pages, 9 figure

[OIII] Emission and Gas Kinematics in a Lyman-alpha Blob at z ~ 3.1

We present spectroscopic measurements of the [OIII] emission line from two subregions of strong Lyman-alpha emission in a radio-quiet Lyman-alpha blob (LAB). The blob under study is LAB1 (Steidel et al. 2000) at z ~ 3.1, and the [OIII] detections are from the two Lyman break galaxies embedded in the blob halo. The [OIII] measurements were made with LUCIFER on the 8.4m Large Binocular Telescope and NIRSPEC on 10m Keck Telescope. Comparing the redshift of the [OIII] measurements to Lyman-alpha redshifts from SAURON (Weijmans et al. 2010) allows us to take a step towards understanding the kinematics of the gas in the blob. Using both LUCIFER and NIRSPEC we find velocity offsets between the [OIII] and Lyman-alpha redshifts that are modestly negative or consistent with 0 km/s in both subregions studied (ranging from -72 +/- 42 -- +6 +/- 33 km/s). A negative offset means Lyman-alpha is blueshifted with respect to [OIII], a positive offset then implies Lyman-alpha is redshifted with respect to [OIII]. These results may imply that outflows are not primarily responsible for Lyman alpha escape in this LAB, since outflows are generally expected to produce a positive velocity offset (McLinden et al. 2011). In addition, we present an [OIII] line flux upper limit on a third region of LAB1, a region that is unassociated with any underlying galaxy. We find that the [OIII] upper limit from the galaxy-unassociated region of the blob is at least 1.4 -- 2.5 times fainter than the [OIII] flux from one of the LBG-associated regions and has an [OIII] to Lyman-alpha ratio measured at least 1.9 -- 3.4 times smaller than the same ratio measured from one of the LBGs.Comment: submitted to Ap

Studies on nematode parasites of fishes of Oinam lake Bishnupur district, Manipur, India

An extensive survey was done for fish nematode parasites of few economically important fishes of Oinam Lake, Bishnupur district, Manipur. 9 species of nematodes were encountered. They are Camallanus anabantis, Procamallanus (Procamallanus) saccobranchi, Paraquimperia manipurensis, Paragendria sp., juvenile stages of genus Syphacia, Haplonema, Spinitectus, Philometra and Parascarophis etc. Of these nematode species, Procamallanus (Procamallanus) saccobranchi, Paragendria sp and Haplonema sp. showed maximum abundance (14.28%) and Paraquimperia manipurensis, Parascarophis sp. showed minimum abundance (4.76%) of parasites. Among the fish species Anabas testudineus had highest percentage (50%) of parasites and Puntius sophore and Colisa labiosus had lowest percentage (1.25%) of parasites

The impact of insulin resistance, dyslipidemia and high sensitivity C-reactivity protein on carotid intima-media thickness in metabolic syndrome

Background: Carotid intima-media thickness (CIMT) is a strong predictor of cardiovascular events and associated with metabolic syndrome (MetS). The CIMT has been widely used as one of the parameters of atherosclerosis. The aim of the study was to evaluate the impact of insulin resistance, dyslipidemia and high sensitivity C-reactive protein on carotid intima-media thickness in metabolic syndrome patients of Western Maharashtra as very sparse data is available.Methods: It was a cross-sectional study of 400 adults (200 cases and 200 control), 18-50 years of age, both the sexes randomly selected from diabetes and obesity OPD at tertiary care hospital. Diagnosis of metabolic syndrome was done according to modified NCEP adult treatment panel III criteria. CIMT was measured by B mode ultrasound (Philips HT-11, Color Doppler), hs-CRP by ELISA method (Cal biotech). Insulin resistance by HOMA-IR (Homeostatic model assessment of insulin resistance). The predictors of CIMT with various variables were studied by multiple linear regression analysis.Results: We found significant increase in CIMT (0.7895±0.110, p<0.001) in MetS and a positive correlation of CIMT with age, waist to hip ratio, triglyceride levels and systolic blood pressure (p<0.001).Conclusions: Increased carotid intima-media thickness in metabolic syndrome may increase the risk of having a stroke and cardiovascular mortality. It was considered an early deterioration in the arterial intima and is a preclinical stage of atherosclerosis. Early diagnosis and prevention may help to reduce the risk of stroke and cardiovascular mortality.

Is There Any Potential in Service Trade of South Asia?

: Like many developing economies, services have emerged as crucial economic activities in South Asia, yet this cannot increase the rapid growth in the intra-trade in the region. To find out the service trade potential in the region, this paper uses revealed comparative advantage indices to assess the comparative advantage and the indicative trade potential of different South Asian countries in various services sub-sectors. The study reveals that there stands complementarities in the trade of services as Pakistan and Sri Lanka have a competitive advantage in Transport Services, while India has a competitive advantage in Computer and Information Services and Other Business Services. In travel services, Maldives and Nepal possess competitiveness while Bangladesh in Government Services. The study reveals that competitive services have not explored the potential yet. India being the most robust economy of the region must provide a pivotal role in making negotiations and commitments under SAARC Agreement on Trade in Services (SATIS) particularly in competitive services