Atmospheric dispersion and the implications for phase calibration

The success of any ALMA phase-calibration strategy, which incorporates phase transfer, depends on a good understanding of how the atmospheric path delay changes with frequency (e.g. Holdaway & Pardo 2001). We explore how the wet dispersive path delay varies for realistic atmospheric conditions at the ALMA site using the ATM transmission code. We find the wet dispersive path delay becomes a significant fraction (>5 per cent) of the non-dispersive delay for the high-frequency ALMA bands (>160 GHz, Bands 5 to 10). Additionally, the variation in dispersive path delay across ALMA's 4-GHz contiguous bandwidth is not significant except in Bands 9 and 10. The ratio of dispersive path delay to total column of water vapour does not vary significantly for typical amounts of water vapour, water vapour scale heights and ground pressures above Chajnantor. However, the temperature profile and particularly the ground-level temperature are more important. Given the likely constraints from ALMA's ancillary calibration devices, the uncertainty on the dispersive-path scaling will be around 2 per cent in the worst case and should contribute about 1 per cent overall to the wet path fluctuations at the highest frequencies.Comment: 13 pages, 10 figures, ALMA Memo 59

Drought-Tolerant Options for Southwest Agriculture: Grasses, Grains, and Legumes

The arid Southwest has been heavily impacted by drought and climate change. The Southwest states are some of the driest in the nation. Droughts damage pastures and crops, leading to economic losses in agriculture. This fact sheet is the first in a series of three that provide an overview of drought-tolerant crops, grasses, and native plants, which may assist in maintaining agricultural production for food and feed and sustain grasslands and rangelands in the arid Southwest. The following grasses, grains, and legumes used for forage, fodder, and human consumption, are all drought tolerant and, in many cases, tolerate salty soil conditions. Their drought-tolerant features are discussed in addition to soil preferences, preferred growing conditions, and market conditions and profitability

Drought-Tolerant Options for Southwest Agriculture: Edible Produce

The arid Southwest has been heavily impacted by drought and climate change. The Southwest states are some of the driest in the nation. From 2000 to 2020, 65% of the state of Utah experienced abnormally dry conditions, 78% of Arizona, 69% of New Mexico, and 71% of Nevada. Drought can damage pastures and crops, leading to economic losses in agriculture. Sustaining agricultural production (crops, food, livestock) on tribal lands will become progressively more challenging in the future due to decreased water availability, extended droughts, and changes in precipitation quantities and timing. This fact sheet is the second in a series of three that provide an overview of drought-tolerant crops, grasses, and native plants, which may assist in maintaining agricultural production for food and feed and sustain grasslands and rangelands in the arid Southwest. These plants possess unique characteristics that enable them to thrive under dry conditions and other stresses. Their drought-tolerant features are discussed in addition to soil preferences, preferred growing conditions, and market conditions and profitability

Drought-Tolerant Options for Southwest Agriculture: Ornamentals, Herbs, and Cosmetics

The arid Southwest has been heavily impacted by drought and climate change. The Southwest states are some of the driest in the nation. Water shortages are also common, especially in the late summer when water restrictions are often imposed. Drought can damage pastures and crops, leading to economic losses in agriculture. This fact sheet is the third in a series of three that provide an overview of drought-tolerant crops, grasses, and native plants, which may assist in maintaining agricultural production for food, feed, and cosmetics and sustain grasslands and rangelands in the arid Southwest. The following ornamental, herbs, and cosmetics are drought tolerant. Their drought-tolerant features are discussed in addition to soil preferences, preferred growing conditions, and market conditions and profitability

Function and evolution of the serotonin-synthetic bas-1 gene and other aromatic amino acid decarboxylase genes in Caenorhabditis

BACKGROUND: Aromatic L-amino acid decarboxylase (AADC) enzymes catalyze the synthesis of biogenic amines, including the neurotransmitters serotonin and dopamine, throughout the animal kingdom. These neurotransmitters typically perform important functions in both the nervous system and other tissues, as illustrated by the debilitating conditions that arise from their deficiency. Studying the regulation and evolution of AADC genes is therefore desirable to further our understanding of how nervous systems function and evolve. RESULTS: In the nematode C. elegans, the bas-1 gene is required for both serotonin and dopamine synthesis, and maps genetically near two AADC-homologous sequences. We show by transformation rescue and sequencing of mutant alleles that bas-1 encodes an AADC enzyme. Expression of a reporter construct in transgenics suggests that the bas-1 gene is expressed, as expected, in identified serotonergic and dopaminergic neurons. The bas-1 gene is one of six AADC-like sequences in the C. elegans genome, including a duplicate that is immediately downstream of the bas-1 gene. Some of the six AADC genes are quite similar to known serotonin- and dopamine-synthetic AADC's from other organisms whereas others are divergent, suggesting previously unidentified functions. In comparing the AADC genes of C. elegans with those of the congeneric C. briggsae, we find only four orthologous AADC genes in C. briggsae. Two C. elegans AADC genes – those most similar to bas-1 – are missing from C. briggsae. Phylogenetic analysis indicates that one or both of these bas-1-like genes were present in the common ancestor of C. elegans and C. briggsae, and were retained in the C. elegans line, but lost in the C. briggsae line. Further analysis of the two bas-1-like genes in C. elegans suggests that they are unlikely to encode functional enzymes, and may be expressed pseudogenes. CONCLUSIONS: The bas-1 gene of C. elegans encodes a serotonin- and dopamine-synthetic AADC enzyme. Two C. elegans AADC-homologous genes that are closely related to bas-1 are missing from the congeneric C. briggsae; one or more these genes was present in the common ancestor of C. elegans and C. briggsae. Despite their persistence in C. elegans, evidence suggests the bas-1-like genes do not encode functional AADC proteins. The presence of the genes in C. elegans raises questions about how many 'predicted genes' in sequenced genomes are functional, and how duplicate genes are retained or lost during evolution. This is another example of unexpected retention of duplicate genes in eukaryotic genomes

Influential Article Review - How International Labor Organization Enables Food Sourcing on Board Liner Ships

This paper examines supply chain. We present insights from a highly influential paper. Here are the highlights from this paper: Food is important for liner shipping companies (LSCs) in their efforts to support daily lives and fulfil seafarer demand. Food issues are addressed in the International Labour Organization’s (ILO’s) Food and Catering (Ships’ Crews) Convention 1946 (No. 68), amended 2006. Moreover, the enforcement of the Maritime Labour Convention (MLC) Regulations and Code appears to have ensured that seafarers have hygienic conditions and that good quality food and drinking water are provided. The MLC aims to meet all current standards of international maritime labour conventions and recommendations, and comply with the fundamental principles found in other international labour conventions. Yet despite these efforts, food issues require greater attention, as maintaining the food supply chain is a dynamic and difficult task. To identify strategies for improving the procurement of food for ships, this paper illustrates how to facilitate the food supply for shipping lines and further evaluate the associated supply chain. Advanced technology, comprehensive procurement procedures, qualified personnel, extensive outbound logistics (i.e., distribution) networks and sound training programmes on food quality and safety are critical elements in the food supply chain, and will enhance the quality of food for seafarers. For our overseas readers, we then present the insights from this paper in Spanish, French, Portuguese, and German

Calibration of Computational Models with Categorical Parameters and Correlated Outputs via Bayesian Smoothing Spline ANOVA

It has become commonplace to use complex computer models to predict outcomes in regions where data does not exist. Typically these models need to be calibrated and validated using some experimental data, which often consists of multiple correlated outcomes. In addition, some of the model parameters may be categorical in nature, such as a pointer variable to alternate models (or submodels) for some of the physics of the system. Here we present a general approach for calibration in such situations where an emulator of the computationally demanding models and a discrepancy term from the model to reality are represented within a Bayesian Smoothing Spline (BSS) ANOVA framework. The BSS-ANOVA framework has several advantages over the traditional Gaussian Process, including ease of handling categorical inputs and correlated outputs, and improved computational efficiency. Finally this framework is then applied to the problem that motivated its design; a calibration of a computational fluid dynamics model of a bubbling fluidized which is used as an absorber in a CO2 capture system