A Review of Highway Agencies in the South Asia Region

Rohatgi, Rajesh; Bandyopadhyay, Arnab; Gupta, Deeksha

doi:10.1596/27403

Cited by 7 publications

(5 citation statements)

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“…We extracted data for responses to control and treatment levels of climate variables utilizing WebPlotDigitizer ver. 3.9 (Rohatgi 2011). In cases where use of WebPlotDigitizer might not be accurate, such as overlapping data points, raw data were requested from authors and included when available.…”

Section: Study Identification and Data Extractionmentioning

confidence: 99%

The weakest link: sensitivity to climate extremes across life stages of marine invertebrates

Pandori

Sorte

2018

Oikos

102

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Predicting the effects of climate change on Earth's biota becomes even more challenging when acknowledging that most species have life cycles consisting of multiple stages, each of which may respond differently to extreme environmental conditions. There is currently no clear consensus regarding which stages are most susceptible to increasing environmental stress, or ‘climate extremes’. We used a meta‐analytic approach to quantify variation in responses to environmental stress across multiple life stages of marine invertebrates. We identified 287 experiments in 29 papers which examined the lethal thresholds of multiple life stages (embryo, larva, juvenile and adult) of both holoplanktonic and meroplanktonic marine invertebrates subjected to the same experimental conditions of warming, acidification and hypoxia stress. Most studies considered short acute exposure to stressors. We calculated effect sizes (log response ratio) for each life stage (unpaired analysis) and the difference in effect sizes between stages of each species (paired analysis) included in each experiment. In the unpaired analysis, all significant responses were negative, indicating that warming, acidification and hypoxia tended to increase mortality. Furthermore, embryos, larvae and juveniles were more negatively affected by warming than adults. The paired analysis revealed that, when subjected to the same experimental conditions, younger life stages were more negatively affected by warming than older life stages, specifically among pairings of adults versus juveniles and larvae versus embryos. Although responses to warming are well documented, few studies of the effects of acidification and hypoxia met the criteria for inclusion in our analyses. Our results suggest that while most life stages will be negatively affected by climate change, younger stages of marine invertebrates are more sensitive to extreme heating events.

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Section: Study Identification and Data Extractionmentioning

confidence: 99%

The weakest link: sensitivity to climate extremes across life stages of marine invertebrates

Pandori

Sorte

2018

Oikos

102

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“…To obtain treatment means for response variables, we extracted numerical data from tables and text and used WebPlotDigitizer (Rohatgi 2011) to collect data from figures. When responses were given for >1 year of a study, we followed Gurevitch & Hedges (2001) and Borer et al (2005) in using only the final time point to allow the longest possible time for treatment effects to emerge.…”

Section: Quantifying Effect Sizesmentioning

confidence: 99%

Does primary productivity modulate the indirect effects of large herbivores? A global meta‐analysis

Daskin

Pringle

2016

Journal of Animal Ecology

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Summary1. Indirect effects of large mammalian herbivores (LMH), while much less studied than those of apex predators, are increasingly recognized to exert powerful influences on communities and ecosystems. The strength of these effects is spatiotemporally variable, and several sets of authors have suggested that they are governed in part by primary productivity. However, prior theoretical and field studies have generated conflicting results and predictions, underscoring the need for a synthetic global analysis. 2. We conducted a meta-analysis of the direction and magnitude of large mammalian herbivore-initiated indirect interactions using 67 published studies comprising 456 individual responses. We georeferenced 41 of these studies (comprising 253 responses from 33 locations on five continents) to a satellite-derived map of primary productivity. Because predator assemblages might also influence the impact of large herbivores, we conducted a similar analysis using a global map of large carnivore species richness. 3. In general, LMH reduced the abundance of other consumer species and also tended to reduce consumer richness, although the latter effect was only marginally significant. 4. There was a pronounced reduction in the strength of negative (i.e. suppressive, due e.g., to competition) indirect effects of LMH on consumer abundance in more productive ecosystems. In contrast, positive (facilitative) indirect effects were not significantly correlated with productivity, likely because these comprised a more heterogeneous array of mechanisms. We found no effect of carnivore species richness on herbivore-initiated indirect effect strength. 5. Our findings help to resolve the fundamental problem of ecological contingency as it pertains to the strength of an understudied class of multitrophic interactions. Moreover, these results will aid in predicting the indirect effects of anthropogenic wildlife declines and irruptions, and how these effects might be mediated by climatically driven shifts in resource availability. To the extent that intact ungulate guilds help to suppress populations of small animals that act as agricultural pests and disease reservoirs, the negative impacts of large mammal declines on human well-being may be relatively stronger in low-productivity areas.

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“…This research made use of Astropy, a community-developed core Python package for Astronomy (Astropy Collaboration et al 2013), and matplotlib, a Python library for publication quality graphics (Hunter 2007) and LMFIT, a nonlinear least-squares minimization and curvefitting package for Python (Newville et al 2014). Data from the literature was digitized using WebPlotDigitizer version 4.1 when not available in digital form (Rohatgi 2011). Analysis of CRRL observations was done using CRRLpy (Salas et al 2016).…”

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confidence: 99%

Carbon radio recombination lines from gigahertz to megahertz frequencies towards Orion A

Salas

Oonk

Emig

et al. 2019

A&A

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Context. The combined use of carbon radio recombination lines (CRRLs) and the 158 µm- [CII] line is a powerful tool for the study of the energetics and physical conditions (e.g., temperature and density) of photodissociation regions (PDRs). However, there are few observational studies that exploit this synergy. Aims. Here we explore the relation between CRRLs and the 158 µm-[CII] line in light of new observations and models. Methods. We present new and existing observations of CRRLs in the frequency range 0.15-230 GHz with ALMA, VLA, the GBT, Effelsberg 100m, and LOFAR towards Orion A (M42). We complement these observations with SOFIA observations of the 158 µm-[CII] line. We studied two PDRs: the foreground atomic gas, known as the Veil, and the dense PDR between the HII region and the background molecular cloud.Results. In the Veil we are able to determine the gas temperature and electron density, which we use to measure the ionization parameter and the photoelectric heating efficiency. In the dense PDR, we are able to identify a layered PDR structure at the surface of the molecular cloud to the south of the Trapezium cluster. There we find that the radio lines trace the colder portion of the ionized carbon layer, the C + /C/CO interface. By modeling the emission of the 158 µm-[CII] line and CRRLs as arising from a PDR we derive a thermal pressure > 5 × 10 7 K cm −3 and a radiation field G0 ≈ 10 5 close to the Trapezium. Conclusions. This work provides additional observational support for the use of CRRLs and the 158 µm-[CII] line as complementary tools to study dense and diffuse PDRs, and highlights the usefulness of CRRLs as probes of the C + /C/CO interface.

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A Review of Highway Agencies in the South Asia Region

Abstract: The task team would like to thank ECORYS Nederland B.V. and ICRA Management Consulting Services Limited (IMaCS), who were engaged for carrying out data collection, analysis, case studies and developing a major part of this study report. The task team highly appreciates support from Mssrs.

Cited by 7 publications

References 0 publications

The weakest link: sensitivity to climate extremes across life stages of marine invertebrates

The weakest link: sensitivity to climate extremes across life stages of marine invertebrates

Does primary productivity modulate the indirect effects of large herbivores? A global meta‐analysis

Carbon radio recombination lines from gigahertz to megahertz frequencies towards Orion A

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