Evidence for a Hard Ionizing Spectrum from a z=6.11 Stellar Population

We present the Magellan/FIRE detection of highly-ionized CIV 1550 and OIII] 1666 in a deep infrared spectrum of the z=6.11 gravitationally lensed low-mass galaxy RXC J2248.7-4431-ID3, which has previously-known Lyman-alpha. No corresponding emission is detected at the expected location of HeII 1640. The upper limit on HeII paired with detection of OIII] and CIV constrains possible ionization scenarios. Production of CIV and OIII] requires ionizing photons of 2.5-3.5 Ryd, but once in that state their multiplet emission is powered by collisional excitation at lower energies (~0.5 Ryd). As a pure recombination line, HeII emission is powered by 4 Ryd ionizing photons. The data therefore require a spectrum with significant power at 3.5 Ryd but a rapid drop toward 4.0 Ryd. This hard spectrum with a steep drop is characteristic of low-metallicity stellar populations, and less consistent with soft AGN excitation, which features more 4 Ryd photons and hence higher HeII flux. The conclusions based on ratios of metal line detections to Helium non-detection are strengthened if the gas metallicity is low. RXJ2248-ID3 adds to the growing handful of reionization-era galaxies with UV emission line ratios distinct from the general z=2-3 population, in a way that suggests hard ionizing spectra that do not necessarily originate in AGN.Comment: 7 pages, 4 figures, 1 table. Accepted for publication to ApJ

Agrobiodiversity and Its Conservation in Nepal

Nepal is a part of the world\u27s biodiversity hotspot and ranks the 49th in the world for biodiversity. Agrobiodiversity and its conservation status were studied through literature review, field survey, key informant survey and focus group discussion. Results of field implementation of some good practices and action research were also documented. Among 24,300 total species in the country, 28% are agricultural genetic resources (AGRs), termed as agrobiodiversity. Agrobiodiversity has six components (crops, forages, livestock, aquatic, insects and microorganisms) and four sub-components (domesticated, semi-domesticated, wild relatives and wild edible) in Nepal. Agrobiodiversity on each component exists at agroecosystem, species, variety/breed/biotype/race/strain, genotype and allele levels, within an altitude range from 60 to 5,000 masl. There are 12 agroecosystems supporting 1026 species under crop component, 510 under forage, 35 under livestock, 250 under the aquatic animal, 17 under aquatic plant, 3,500 under insect and 800 under microorganism. An estimated loss of agrobiodiversity is 40%, however, farmers have reported up to 100% loss of AGRs in some areas for a particular species. Conservation of agrobiodiversity has been initiated since 1986. Four strategies namely ex-situ, on-farm, in-situ and breeding have been adopted for conservation and sustainable utilization of AGRs. Eighty good practices including process, methods and actions for managing agrobiodiversity have been in practice and these practices come under five conservation components (sensitization, method and approach, accelerator, value and enabling environment). Within the country, 18,765 accessions of AGRs have been conserved in different kinds of banks. A total of 24,683 accessions of Nepalese crops, forages and microbes have been conserved in different International and foreign genebanks. Some collections are conserved as safety duplication and safety backup in different CGIARs\u27 banks and World Seed Vault, Korea. Two global databases (GENESYS and EURISCO) have maintained 19,200 Nepalese accessions. Geographical Information System, Climate Analog Tool and biotechnological tools have been applied for better managing AGRs. Many stakeholders need to further concentrate on the conservation and utilization of AGRs. Global marketing of some native AGRs is necessary for sustaining agriculture and attracting young generations as well as conserving them through use

Spectroscopy of CASSOWARY gravitationally-lensed galaxies in SDSS: characterisation of an extremely bright reionization-era analog at z=1.42z=1.42

We present new observations of sixteen bright ($r=19-21$) gravitationally lensed galaxies at $z\simeq 1-3$ selected from the CASSOWARY survey. Included in our sample is the $z=1.42$ galaxy CSWA-141, one of the brightest known reionization-era analogs at high redshift (g=20.5), with a large sSFR (31.2 Gyr$^{-1}$) and an [OIII]+H$\beta$ equivalent width (EW$_{\rm{[OIII]+H\beta}}$=730~\r{A}) that is nearly identical to the average value expected at $z\simeq 7-8$. In this paper, we investigate the rest-frame UV nebular line emission in our sample with the goal of understanding the factors that regulate strong CIII] emission. Whereas most of the sources in our sample show weak UV line emission, we find elevated CIII] in the spectrum of CSWA-141 (EW$_{\rm{CIII]}}$=4.6$\pm1.9$~\r{A}) together with detections of other prominent emission lines (OIII], Si III], Fe II$^\star$, Mg II). We compare the rest-optical line properties of high redshift galaxies with strong and weak CIII] emission, and find that systems with the strongest UV line emission tend to have young stellar populations and nebular gas that is moderately metal-poor and highly ionized, consistent with trends seen at low and high redshift. The brightness of CSWA-141 enables detailed investigation of the extreme emission line galaxies which become common at $z>6$. We find that gas traced by the CIII] doublet likely probes higher densities than that traced by [OII] and [SII]. Characterisation of the spectrally resolved Mg II emission line and several low ionization absorption lines suggests neutral gas around the young stars is likely optically thin, potentially facilitating the escape of ionizing radiation.Comment: 20 pages, 9 figures, Accepted for publication in MNRA

Enhancement of Ethanol Production in Electrochemical Cell by Saccharomyces cerevisiae (CDBT2) and Wickerhamomyces anomalus (CDBT7)

Bioethanol (a renewable resource), blended with gasoline, is used as liquid transportation fuel worldwide and produced from either starch or lignocellulose. Local production and use of bioethanol supports local economies, decreases country's carbon footprint and promotes self-sufficiency. The latter is especially important for bio-resource-rich land-locked countries like Nepal that are seeking alternative transportation fuels and technologies to produce them. In that regard, in the present study, we have used two highly efficient ethanol producing yeast strains, viz., Saccharomyces cerevisiae (CDBT2) and Wickerhamomyces anomalous (CDBT7), in an electrochemical cell to enhance ethanol production. Ethanol production by CDBT2 (anodic chamber) and CDBT7 (cathodic chamber) control cultures, using 5% glucose as substrate, were 12.6 ± 0.42 and 10.1 ± 0.17 mg·mL−1 respectively. These cultures in the electrochemical cell, when externally supplied with 4V, the ethanol production was enhanced by 19.8 ± 0.50% and 23.7 ± 0.51%, respectively, as compared to the control cultures. On the other hand, co-culturing of those two yeast strains in both electrode compartments resulted only 3.96 ± 0.83% enhancement in ethanol production. Immobilization of CDBT7 in the graphite cathode resulted in lower enhancement of ethanol production (5.30 ± 0.82%), less than free cell culture of CDBT7. CDBT2 and CDBT7 when cultured in platinum nano particle coated platinum anode and neutral red-coated graphite cathode, respectively, ethanol production was substantially enhanced (52.8 ± 0.44%). The above experiments when repeated using lignocellulosic biomass hydrolysate (reducing sugar content was 3.3%) as substrate, resulted in even better enhancement in ethanol production (61.5 ± 0.12%) as compared to glucose. The results concluded that CDBT2 and CDBT7 yeast strains produced ethanol efficiently from both glucose and lignocellulosic biomass hydrolysate. Ethanol production was enhanced in the presence of low levels of externally applied voltage. Ethanol production was further enhanced with the better electron transport provision i.e., when neutral red was deposited on cathode and fine platinum nanoparticles were coated on the platinum anode

Lyα and C III] emission in z = 7–9 Galaxies: accelerated reionization around luminous star-forming systems?

We discuss new Keck/MOSFIRE spectroscopic observations of four luminous galaxies at z ≃ 7–9 selected to have intense optical line emission by Roberts-Borsani et al. Previous follow-up has revealed Lyα in two of the four galaxies. Our new MOSFIRE observations confirm that Lyα is present in the entire sample. We detect Lyα emission in the galaxy COS-zs7-1, confirming its redshift as zLyα = 7.154, and we detect Lyα in EGS-zs8-2 at zLyα = 7.477, verifying an earlier tentative detection. The ubiquity of Lyα in this sample is puzzling given that the IGM is expected to be significantly neutral over 7 7 is expected to be strongly luminosity-dependent, with transmission accelerated in systems with intense star formation

Spectroscopic constraints on UV metal line emission at z ≃ 6–9: the nature of Lyα emitting galaxies in the reionization era

Recent studies have revealed intense ultraviolet (UV) metal emission lines in a modest sample of z > 7 Lyman-α emitters, indicating a hard ionizing spectrum is present. If such high ionization features are shown to be common, it may indicate that extreme radiation fields play a role in regulating the visibility of Lyα in the reionization era. Here, we present deep near-infrared spectra of seven galaxies with Lyα emission at 5.4 7 have now been shown to have intense UV line emission, suggesting that extreme radiation fields are commonplace among the Lyα population. Future observations with JWST will eventually clarify the origin of these features and explain their role in the visibility of Lyα in the reionization era

Metal-poor star formation at z > 6 with JWST: new insight into hard radiation fields and nitrogen enrichment on 20 pc scales

Nearly a decade ago, we began to see indications that reionization-era galaxies power hard radiation fields rarely seen at lower redshift. Most striking were detections of nebular C IV emission in what appeared to be typical low-mass galaxies, requiring an ample supply of 48 eV photons to triply ionize carbon. We have obtained deep JWST/NIRSpec R = 1000 spectroscopy of the two z > 6 C IV-emitting galaxies known prior to JWST. Here, we present a rest-UV to optical spectrum of one of these two systems, the multiply-imaged z = 6.1 lensed galaxy RXCJ2248-ID. NIRCam imaging reveals two compact (10 400 M☉ yr−1 kpc−2) formed in a recent burst. We stack spectra of 3 images of the galaxy (J = 24.8–25.9), yielding a very deep spectrum providing a high-S/N template of strong emission line sources at z > 6. The spectrum reveals narrow high-ionization lines (He II, C IV, N IV]) with line ratios consistent with powering by massive stars. The rest-optical spectrum is dominated by very strong emission lines ([O III] EW = 2800 Å), albeit with weak emission from low-ionization transitions ([O III]/[O II] = 184). The electron density is found to be very high (6.4–31.0 × 104 cm−3) based on three UV transitions. The ionized gas is metal poor (12 + log(O/H) = 7.43+−00.0917), yet highly enriched in nitrogen (log(N/O) = −0.39+−00.1011). The spectrum appears broadly similar to that of GNz11 at z = 10.6, without showing the same AGN signatures. We suggest that the hard radiation field and rapid nitrogen enrichment may be a short-lived phase that many z > 6 galaxies go through as they undergo strong bursts of star formation. We comment on the potential link of such spectra to globular cluster formation

The glycoprotein-hormones activin A and inhibin A interfere with dendritic cell maturation

<p>Abstract</p> <p>Background</p> <p>Pregnancy represents an exclusive situation in which the immune and the endocrine system cooperate to prevent rejection of the embryo by the maternal immune system. While immature dendritic cells (iDC) in the early pregnancy decidua presumably contribute to the establishment of peripheral tolerance, glycoprotein-hormones of the transforming growth factor beta (TGF-beta) family including activin A (ActA) and inhibin A (InA) are candidates that could direct the differentiation of DCs into a tolerance-inducing phenotype.</p> <p>Methods</p> <p>To test this hypothesis we generated iDCs from peripheral-blood-monocytes and exposed them to TGF-beta1, ActA, as well as InA and Dexamethasone (Dex) as controls.</p> <p>Results</p> <p>Both glycoprotein-hormones prevented up-regulation of HLA-DR during cytokine-induced DC maturation similar to Dex but did not influence the expression of CD 40, CD 83 and CD 86. Visualization of the F-actin cytoskeleton confirmed that the DCs retained a partially immature phenotype under these conditions. The T-cell stimulatory capacity of DCs was reduced after ActA and InA exposure while the secretion of cytokines and chemokines was unaffected.</p> <p>Conclusion</p> <p>These findings suggest that ActA and InA interfere with selected aspects of DC maturation and may thereby help preventing activation of allogenic T-cells by the embryo. Thus, we have identified two novel members of the TGF-beta superfamily that could promote the generation of tolerance-inducing DCs.</p

Meeting Future Energy Needs in the Hindu Kush Himalaya

As mentioned in earlier chapters, the HKH regions form the entirety of some countries, a major part of other countries, and a small percentage of yet others. Because of this, when we speak about meeting the energy needs of the HKH region we need to be clear that we are not necessarily talking about the countries that host the HKH, but the clearly delineated mountainous regions that form the HKH within these countries. It then immediately becomes clear that energy provisioning has to be done in a mountain context characterized by low densities of population, low incomes, dispersed populations, grossly underdeveloped markets, low capabilities, and poor economies of scale. In other words, the energy policies and strategies for the HKH region have to be specific to these mountain contexts

Predicting global invasion risks: a management tool to prevent future introductions

Predicting regions at risk from introductions of non-native species and the subsequent invasions is a fundamental aspect of horizon scanning activities that enable the development of more effective preventative actions and planning of management measures. The Asian cyprinid fish topmouth gudgeon Pseudorasbora parva has proved highly invasive across Europe since its introduction in the 1960s. In addition to direct negative impacts on native fish populations, P. parva has potential for further damage through transmission of an emergent infectious disease, known to cause mortality in other species. To quantify its invasion risk, in regions where it has yet to be introduced, we trained 900 ecological niche models and constructed an Ensemble Model predicting suitability, then integrated a proxy for introduction likelihood. This revealed high potential for P. parva to invade regions well beyond its current invasive range. These included areas in all modelled continents, with several hotspots of climatic suitability and risk of introduction. We believe that these methods are easily adapted for a variety of other invasive species and that such risk maps could be used by policy-makers and managers in hotspots to formulate increased surveillance and early-warning systems that aim to prevent introductions and subsequent invasions