Humpback whales in Banderas Bay, Mexico: relative abundance and temporal patterns between 2004 and 2017

Banderas Bay, Mexico is an important breeding and transit area for the North Pacific humpback whale (Megaptera novaeangliae) population. In this paper we estimated relative abundance (RA = number of whales/hours of navigation) as a proxy to assess population temporary patterns in the area. We analyzed data from 14 breeding seasons (2004-2017), collected between December and March each winter. A total of 8,013 whales were observed in 1,394.6 navigation hours. Average seasonal RA was 5.7 whales per hour with a maximum of 7.5 (2013) and a minimum of 4.0 (2016). Sea surface temperature (SST) averaged 25.1°C and remained within the range considered optimal for humpback whale reproduction areas. SST showed no significant correlation with RA (r = 0.183). Inter-seasonal RA values suggested an increase throughout the study period, although the increase was not statistically significant (R = 0.32; R2 = 0.10; t = 1.15, p > 0.05). Intra-seasonal analyses showed that RA in December and January were significantly higher (U = 150, p < 0.05) than in February and March; this pattern was consistent throughout the seasons of study. These results represent a shift in the intra-seasonal abundance peak relative to previous studies when most whales were observed between January and February. It is important to recognize changes in population parameters of humpback whales in breeding areas to improve management practices. This study also highlights the potential of opportunistic platforms, such as whale watching tour boats, as viable sources of quality information, particularly in contexts when funding is limited.

Nocturnal variation of the zooplankton community in coral reef substrates at Isla del Coco National Park (Eastern Tropical Pacific)

Introduction: Zooplankton is a major link in coral reef food webs and a source of nutrients for corals. Demersal zooplankton in coral reefs makes diel migrations at night to avoid predation by fish and corals, increasing abundance and biomass at night. Objectives: To study the composition and variation of the demersal and pelagic zooplankton community at night and to increase the taxonomic knowledge of the benthic copepod fauna over different substrates of a coral reef. Methods: Traps made of plastic, with a 100 μm mesh size collector cup attached, were placed for 12 hours between 5-10 m depth over four substrates: (1) sand, (2) small and (3) big colonies of Porites lobata, and (4) dead and alive corals. Sampling started at dusk (1800 h), and the collector cups were collected and replaced at 2100 and 0000, and the last samples removed at down (0600 h). Results: The highest abundance of zooplankton was capture over P. lobata colonies between 0000 to 0600 h. Copepods (adults, copepodites, and nauplii) dominated the community structure and were more abundant during all the time intervals and substrates. Pelagic copepods were more abundant than the benthic, however, not more diverse. Among the benthic copepods, 20 new records of harpacticoids and calanoids were registered for Isla del Coco and Costa Rican waters. Appendicularians and decapod larvae were also abundant. Changes in coral reef community structure were related with time and not with the kind of substrate, although some taxa were found only in a specific time interval or substrate. Conclusions: Community structure and abundance of demersal and pelagic coral reef zooplankton in Chatham Bay were dominated by copepods, larvaceans and decapod larvae, similar to other coral reefs around the world. The highest abundance peak of organisms in the water column between 0000 to 0600 h could be related to diel migration.

Advances at TRIUMF-ISAC and decay of neutron-rich Cd studied with GRIFFIN

The β-decay half lives of nuclei near the r-process path are critical information required for abundance calculations, especially those near neutron number N = 82. Specifically, the nuclei below doubly-magic 132Sn are key, and play an important role in the formation and shape of the second r-process abundance peak. The half lives in this region are challenging to measure due to the significant β-delayed neutron decay branches and the population of isomeric states with half lives comparable to the ground states. However, by measuring the time distribution of γ rays, these complications can be eliminated. This requires, however, a very effcient γ-ray spectrometer since the production of isotopes in this region is very limited. The new GRIFFIN array at TRIUMF-ISAC provides the high effciency required for these measurements. Recent improvements in the quality of the beams produced at TRIUMF, employing the IG-LIS device, are outlined, as well as the current status of the ARIEL facility. The GRIFFIN spectrometer and its use are briefly described. The experiment to measure the half lives of 128-130Cd is outlined and the results given, and some examples of the power of GRIFFIN to expand decay schemes, specifically for the decay of 128Cd to 128In, are given.

THE DIVERSITY OF THE PARASITIC SYSTEM IS THE BASE OF THE STABILITY OF THE FUNCTIONING OF NATURAL FOCUS OF THE INFECTION

This paper presents the authors’ opinion concerning such understudied issue of epizootology as the cause of the stability of the functioning of the natural focus of infection. The diversity of the biocenotic complex including main, secondary and casual carriers; numerous, small in number and rare vectors; strains with high virulence, low virulence and altered strains of the causative agent of infection, as well as population nonuniformity of biocenosis constituents contribute to the stability of the functioning of the natural focus in certain landscape-geographic conditions. The heterogeneity during the achievement of the abundance peak by various carrier and vector species also promotes to the stability. Universality of the principle of the proposition offered here for three- and two-component constituents of a natural focus of infection, as well as for infections caused by sapronotic pathogens, allows consider it as a biological law of the stable functioning of a natural focus of infection.

FeCl3-catalyzed Synthesis of Dehydrodiisoeugenol

Dehydrodiisoeugenol (DDIE) synthesis has been performed by modifying a method recommended by Leopold with a different ratio of isoeugenol and FeCl₃ (1.9:1). FeCl₃ was chosen as catalyst due to its efficiency and environment-friendly property. This modification yielded 22.93 % of product. The product, a white crystalline form, was characterized using thin layer chromatography, melting point, UV, IR, HRMS, and NMR spectroscopy, as well as HPLC, employing pure DDIE as the standard. TLC chromatogram showed Rf 0.32 using n-hexane/ethyl acetate (8:2). The crystals melted at 138-139 ^oC, while its UV maximum was detected at l 273 nm. IR spectrum showed a specific broad O-H stretch at 3437.15 cm^-1, C-H aromatic and C-H alkene at 3163.26 and 3024.38 cm^-1, C-H alkyl stretch at 2951.09 and 2927.94 cm^-1. An overtone peak of aromatic was detected at 2100 to 1700 cm^-1. C-O peak was detected at 1126.43 cm^-1. HPLC showed that this compound was eluted at 11.886 minutes after it was injected to a C18 column 250 x 4 mm using a mixture of methanol and double distilled water (73:27) for mobile phase. HRMS spectra predicted that the molecular structure is C₂₀H₂₂O₄ as showed by abundance peak at <em>m/z </em>327.1595 of [M+H]⁺. ¹H-NMR and ¹³C-NMR indicated that the synthesized compound contains 13 types of proton and 20 types of carbon. Herein we reported that white needle-like crystals of DDIE using FeCl₃ as catalyst had been synthesized, moreover the decreasing of the catalyst reduced the yield of the product.

Updated calculations of the ionization equilibrium for the non-Maxwellian electron n-distributions in solar flares

The assumption of an equilibrium (Maxwellian) distribution of electron energies cannot explain observed high intensities of the Si XIId satellite lines relative to the Si XIII allowed lines during the flares. However, the presence of n-distribution with a higher and narrower shape than the Maxwellian one is able to explain this behavior. We calculated the ionization equilibrium for the non-thermal n-distributions using the latest atomic data for each element up to the proton number of 30. Significant changes in the shape and maxima of the ion abundance peak occur and can strongly influence the temperature diagnostics.