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Scheduling is a critical function that is present throughout many industries and applications. A great need exists for developing scheduling approaches that can be applied to a number of different scheduling problems with significant impact on performance of business organizations. A challenge is emerging in the design of scheduling support systems for manufacturing environments where dynamic adaptation and optimization become increasingly important. At this scenario, self-optimizing arise as the ability of the agent to monitor its state and performance and proactively tune itself to respond to environmental stimuli.

Streamflow in south-central Chile (SCC, ∼ 37–42∘ S) is vital for agriculture, forestry production, hydroelectricity, and human consumption. Recent drought episodes have generated hydrological deficits with damaging effects on these activities. This region is projected to undergo major reductions in water availability, concomitant with projected increases in water demand. However, the lack of long-term records hampers the development of accurate estimations of natural variability and trends. In order to provide more information on long-term streamflow variability and trends in SCC, here we report findings of an analysis of instrumental records and a tree-ring reconstruction of the summer streamflow of the Río Imperial (∼ 37∘ 40′ S–38∘ 50′ S). This is the first reconstruction in Chile targeted at this season. Results from the instrumental streamflow record (∼ 1940 onwards) indicated that the hydrological regime is fundamentally pluvial with a small snowmelt contribution during spring, and evidenced a decreasing trend, both for the summer and the full annual record. The reconstruction showed that streamflow below the average characterized the post-1980 period, with more frequent, but not more intense, drought episodes. We additionally found that the recent positive phase of the Southern Annular Mode has significantly influenced streamflow. These findings agree with previous studies, suggesting a robust regional signal and a shift to a new hydrological scenario. In this paper, we also discuss implications of these results for water managers and stakeholders; we provide rationale and examples that support the need for the incorporation of tree-ring reconstructions into water resources management.

https://viurrspace.ca/bitstream/handle/10613/13435/Mar06-1920.pdf?sequence=2&isAllowed=y

https://viurrspace.ca/bitstream/handle/10613/22731/Nov19-1884.pdf?sequence=2&isAllowed=y

Despite the abundance of detached seed-fern ovules (Euramerican and Cathaysian floral provinces, Pennsylvanian - Permian) as compression / impression, their palaeobiochemistry remains unknown. The Late Pennsylvanian strata of the Sydney Coalfield, Canada, have yielded numerous ovulate trigonocarpalean compressions, 6-8cm long, with preserved cuticles assigned to Trigonocarpus grandis (Lesquereux) Cleal et Zodrow. The macerated cuticles are analyzed by Fourier Transform Infrared spectroscopy (FTIR), Carbon-13 Nuclear Magnetic Resonance (13C NMR), and Pyrolysis Gas Chromatography-mass spectrometry (Py-GC-MS). FTIR and 13C NMR data reveal a predominantly aliphatic structure including C-H groups (with or without hetero-substitution such as in alkyl and aryl alcohols, ethers, esters, and ketones). Larger CH2/CH3 ratios (above 20) suggest the presence of long and straight aliphatic side chains linked to the main macromolecular structure. Other groups present include C-O (in phenols and phenoxy structures, and aryl and alkyl ethers and alcohols), C=O carbonyl groups (in carboxylic acids and conjugated and highly conjugated structures such as ketones), C=C (in aromatic carbon structures with and without bridging to other carbon groups), and O-H (in aliphatic or aromatic alcohols). In addition, 13C NMR shows, compared to other cuticles in related seed ferns, a high amount of acetal groups as they occur in di- and polysaccharides. In agreement with FTIR and NMR results, Py-GC-MS data show the presence of highly aliphatic molecules (alkanes/alkenes) with carbons between C4 and C8 (including a complex mixture of mono and di unsaturated hydrocarbon isomers up to C8). Other compounds detected include benzene and toluene. However, the most striking chemical feature of the pyrolysates markers is the presence of 5 isomers of C5H8 including isoprene (0.5 - 1.0 % abundance). The latter could be derived from some tocopherol precursor (vitamin E-like compound). If confirmed, this is the earliest chemical evidence for the presence of isoprenoids in vascular plants. Facultad de Ciencias Naturales y Museo Sesiones libres