58 research outputs found

    Dusty star forming galaxies at high redshift

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    The global star formation rate in high redshift galaxies, based on optical surveys, shows a strong peak at a redshift of z=1.5, which implies that we have already seen most of the formation. High redshift galaxies may, however, emit most of their energy at submillimeter wavelengths if they contain substantial amounts of dust. The dust would absorb the starlight and reradiate it as far-infrared light, which would be redshifted to the submillimeter range. Here we report a deep survey of two blank regions of sky performed at submillimeter wavelengths (450 and 850-micron). If the sources we detect in the 850-micron band are powered by star formation, then each must be converting more than 100 solar masses of gas per year into stars, which is larger than the maximum star formation rates inferred for most optically-selected galaxies. The total amount of high redshift star formation is essentially fixed by the level of background light, but where the peak occurs in redshift for the submillimeter is not yet established. However, the background light contribution from only the sources detected at 850-micron is already comparable to that from the optically-selected sources. Establishing the main epoch of star formation will therefore require a combination of optical and submillimeter studies.Comment: 10 pages + 2 Postscript figures, under embargo at Natur

    Wide Crossing Technology for Pigeonpea Improvement

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    Pigeonpea (Cajanus cajan Millsp,) has ample genetic and genomic information now. It is endowed with rich germplasm in different gene pools. One of the easiest material to use in those are in the primary gene pool, which are closely related to cultivated pigeonpea. It is observed that species placed beyond the primary gene pool are a rich source of genetic variation. They contribute beneficial traits to pigeonpea such as pest or disease resistance, resistance to abiotic stresses, cytoplasmic male sterile systems (CMS) leading to yield improvement, and some novel traits such as homozygous pigeonpea lines. To effectively utilize the immense variation present in the secondary, tertiary, and quaternary gene pool of pigeonpea, a thorough knowledge of crossability and concerted effort is essential

    Shedding Light on the Galaxy Luminosity Function

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    From as early as the 1930s, astronomers have tried to quantify the statistical nature of the evolution and large-scale structure of galaxies by studying their luminosity distribution as a function of redshift - known as the galaxy luminosity function (LF). Accurately constructing the LF remains a popular and yet tricky pursuit in modern observational cosmology where the presence of observational selection effects due to e.g. detection thresholds in apparent magnitude, colour, surface brightness or some combination thereof can render any given galaxy survey incomplete and thus introduce bias into the LF. Over the last seventy years there have been numerous sophisticated statistical approaches devised to tackle these issues; all have advantages -- but not one is perfect. This review takes a broad historical look at the key statistical tools that have been developed over this period, discussing their relative merits and highlighting any significant extensions and modifications. In addition, the more generalised methods that have emerged within the last few years are examined. These methods propose a more rigorous statistical framework within which to determine the LF compared to some of the more traditional methods. I also look at how photometric redshift estimations are being incorporated into the LF methodology as well as considering the construction of bivariate LFs. Finally, I review the ongoing development of completeness estimators which test some of the fundamental assumptions going into LF estimators and can be powerful probes of any residual systematic effects inherent magnitude-redshift data.Comment: 95 pages, 23 figures, 3 tables. Now published in The Astronomy & Astrophysics Review. This version: bring in line with A&AR format requirements, also minor typo corrections made, additional citations and higher rez images adde

    Pigeonpea

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    Pigeonpea was labeled as an orphan crop but is now a trendy and pacesetter, with ample genetic and genomic information becoming available in recent times. It is now possible to cross wild relatives not only from the Cajanus group placed in the secondary and tertiary gene pool but also the related genera placed in the quaternary gene pool. This is no small achievement for a legume which is an important crop of Asia and Africa and plays a major role in the diet of majority of the people of this region. The need of the hour is further committed research on wide crosses in pigeonpea

    5-HT modulation of pain perception in humans

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    © 2017, The Author(s). Introduction: Although there is clear evidence for the serotonergic regulation of descending control of pain in animals, little direct evidence exists in humans. The majority of our knowledge comes from the use of serotonin (5-HT)-modulating antidepressants as analgesics in the clinical management of chronic pain. Objectives: Here, we have used an acute tryptophan depletion (ATD) to manipulate 5-HT function and examine its effects of ATD on heat pain threshold and tolerance, attentional manipulation of nociceptive processing and mood in human volunteers. Methods: Fifteen healthy participants received both ATD and balanced amino acid (BAL) drinks on two separate sessions in a double-blind cross-over design. Pain threshold and tolerance were determined 4 h post-drink via a heat thermode. Additional attention, distraction and temperature discrimination paradigms were completed using a laser-induced heat pain stimulus. Mood was assessed prior and throughout each session. Results: Our investigation reported that the ATD lowered plasma TRP levels by 65.05 ± 7.29% and significantly reduced pain threshold and tolerance in response to the heat thermode. There was a direct correlation between the reduction in total plasma TRP levels and reduction in thermode temperature. In contrast, ATD showed no effect on laser-induced pain nor significant impact of the distraction-induced analgesia on pain perception but did reduce performance of the painful temperature discrimination task. Importantly, all findings were independent of any effects of ATD on mood. Conclusion: As far as we are aware, it is the first demonstration of 5-HT effects on pain perception which are not confounded by mood changes

    Does corporate reputation matter? Role of social media in consumer intention to purchase innovative food product

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    The exponential growth of the corporate reputation in food industry has resulted in innovations in every link of its supply chain. There have been studies that have characterized innovation in various industries from the perspective of technology, but far fewer in the area of corporate reputation, consumer perception, and intention towards innovations in food products. This research analyses the innovations in the food industry from the perspective of the consumer and provides a conceptual framework of food innovation stages. The study also investigates the relationship between corporate reputation and intention towards food innovation along with the other components of TPB model with an extension of social media engagement. The results from India and US samples confirm that social media engagement have a significant role to play in creating intention to purchase innovative food products. The study compares the US and Indian samples and identifies differences in subjective norms and perceived behavioural control

    Protein Quality Of Autoclaved Cowpea Varieties As Influenced By Anti-Nutritional Factors

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    One hundred and ten (110) weanling male winstar strain rats were used to determine the protein efficiency ration (PER) and net protein ration (NPR) of five cowpea samples. PER ranged from 1.06 in IT 8JD-1137 to 1.91 in IT84E-1-108 while values in autoclaved samples ranged from 1.55 in IT8ID-1137 to 2.78 in IT84E-1-108. for NPR, raw samples gave values that ranged between 2.44 and 3.57 in IT81D-1137 and IT84E-1-108 respectively. Autoclaved samples gave NPR values that ranged from 2.72 to 4.47 in IT 81D-1137 and IT84E-1-108 respectively. In the raw and autoclaved cowpea diets, trypsin inhibitor, lectin and tannic acid were negatively correlated with PER and NPR while HCN and phytic acid had positive relationship with these indicators of protein quality. In autoclaved samples cowpea variety IT84E-1 1-108 had the highest PER and NPR values showing that it would support growth to a reasonable extent.Keywords: Protein efficiency ratio, net protein ratio, autoclaving, antinutritional factors, cowpea varietie
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