Post‐capture survival of whale sharks encircled in tuna purse‐seine nets: tagging and safe release methods

1. Whale shark, the world's largest fish, is believed to be particularly vulnerable owing to its biological characteristics (slow growth, late maturation, great longevity) and is listed as Vulnerable by IUCN and included in Appendix II of CITES. 2. Whale sharks are occasionally encircled in tropical tuna purse‐seine nets, throughout this global fishery. Although apparent immediate survival rates following encirclement and release have recently been assessed through scientific onboard observer programmes, a more rigorous methodology is still required for studying post‐released survival. 3. This work provides a method for applying pop‐up satellite tags and reports an enhanced release procedure for whale sharks. The first assessment of survival after release from purse‐seine nets involved six whale sharks tagged between May and September 2014 in the eastern tropical Atlantic Ocean. Five tags transmitted data: three popped up as programmed (after 30 days), while two surfaced prematurely (one after 21 and the other after 71 days (programmed to pop off after 30 and 90 days, respectively)) but showed no sign of unusual behaviour. 4. Overall, whale sharks survived at least 21 days (one at least 71 days) after release from purse‐seine nets. These observations based on five large individuals (total length > 8 m), suggest that whale sharks have a good chance of survival when released with the proposed method. 5. Additional tagging in this and other oceans, especially of juveniles which may be more sensitive to encirclement and release operations, is essential to further assess whale shark post‐release survival rates in tuna purse‐seine fisheries. Copyright © 2016 John Wiley & Sons, Ltd.     

Comparative study on the antioxidant and biological activities of carvacrol, thymol, and eugenol derivatives

Four derivatives of thymol, carvacrol, and eugenol were synthesized: 4-(hydroxymethyl)-5-isopropyl-2-methylphenol, 4,4'-methylenebis(5-isopropyl-2-methyl)phenol, 4-allyl-6-(hydroxymethyl)-2-methoxyphenol, and 4-(hydroxymethyl)-2-isopropyl-5-methylphenol. The obtained derivatives showed remarkably better antioxidative properties according to 1,1-diphenyl-2-picrylhydrazyl assay (50% inhibitory concentrations = 4-156 microg/mL) and Rancimat assay (protection factors = 1.55-5.84) when compared with parent compounds and values similar to or better than those of butylated hydroxytoluene and vitamin C. At concentrations of 10 mM carvacrol derivatives had no toxic effect on viability of Escherichia coli K-12 (determined by minimum inhibitory concentrations). Other phenol derivatives showed reduced cytotoxic effect on E. coli K-12 at concentrations of 2-5 mM on the basis of 50% lethal dose measurements. In comparison with the parent compounds, phenol derivatives showed reduced cytotoxic effect for Saccharomyces cerevisiae cells (determined by yeast colony reduction). On the other hand, the majority of synthesized compounds had dose-dependent antiproliferative effects on human uterine carcinoma cells (HeLa), which makes them potentially interesting for the adjuvant experimental cancer treatments. The 4,4'-methylenebis(5-isopropyl-2-methyl)phenol derivative of carvacrol showed lower inhibiting capacity also for the HeLa cells, which makes this particular derivative attractive as an efficient antioxidant with negligible cytotoxic effects.     

Forage intake and nitrogen metabolism of beef cattle grazing palisadegrass-calopo mixed pasture managed using canopy light interception

To define the best grazing management strategy, it is important to assess animals' responses to variations in the structure and composition of tropical forages. This 2-year study evaluated animal response to Marandu palisadegrass (Urochloa brizantha)-calopo (Calopogonium mucunoides) mixed pastures managed under rotational grazing. Treatments consisted of three defoliation frequencies defined by rest periods interrupted at 90% (90LI), 95% (95LI) and 100% (100LI) of photosynthetically active radiation interception (LI). The stubble post-grazing height target was 15 cm. Statistical difference was declared at p < .10. The 100LI had lowest crude protein (CP) and in vitro dry matter digestibility (IVDDM) for the Marandu palisadegrass (p = <.001 both) and calopo (p = .003 and p = .067, respectively). Also, the OM digestibility decreased 7.0% in the 100LI condition than 90LI and 95LI treatment (p = .005). There was no difference in forage, grass, and legume intakes between the treatments (p > .10). The 100LI treatment decreased CP intake from grass in 33.3% (p = <.001) compared to other treatments. Greatest production of microbial N (p = .093) occurred with the 90LI treatment. The CP/digestible organic matter (DOM) ratio, urinary N excretion and retained N were lowest in the 100LI treatment (p = <.001, p = .007 and p = .014, respectively). The recommendation for grazing between 90 and 95% of LI is recommended because of greater CP intake and N utilization for the animals and improved the nutritive value of Marandu palisadegrass and calopo mixed pastures.     

Accuracy of four ultrasonography techniques in predicting histopathological classification of canine mammary carcinomas

Due to the importance of presurgical, noninvasive, and accurate diagnostic tools in mammary carcinoma characterization, this prospective secondary observational cohort study was designed to evaluate and compare the diagnostic accuracy of B‐mode, Doppler, contrast enhancement ultrasonography, or acoustic radiation force impulse–elastography in identifying mammary carcinomas types with high degree of malignancy. A total of 246 mammary carcinomas from 141 female dogs were analyzed using B‐mode, Doppler, contrast enhancement ultrasonography, and acoustic radiation force impulse ultrasonography prior to their histopathological classification according to types (simple, complex, or special) and grade (I, II, or III). Qualitative and quantitative variables were compared between carcinoma types and grades by Fisher's or analysis of variance. Diagnostic performance was estimated by receiver‐operating characteristic analysis, using histopathological classification as a reference. Deformability (acoustic radiation force impulse) had a diagnostic specificity of 100% and sensitivity of 12% in identifying special carcinomas. A width:length ratio greater than 0.53 can be suggestive of special carcinoma, with 80% sensitivity and 76% specificity. Contrast wash‐in and peak enhancement times lower than 7.5 and 13.5 s, respectively, were indicative of complex carcinoma at 62% sensitivity and 60% specificity. Contrast wash‐in, peak enhancement, and wash‐out times greater than 6.5, 12.5, and 64.5 s, respectively; were indicative of grade II and III carcinoma at 68% sensitivity and 62% specificity. In conclusion, B‐mode ultrasonography, contrast enhancement ultrasonography, and acoustic radiation force impulse–elastography enabled the identification of some of the characteristics of high‐grade mammary carcinoma types and grades in female dogs with limited accuracy. The findings from this study may contribute to oncology research and clinical management canine patients.     

Marine Natural Products Acting on the Acetylcholine-Binding Protein and Nicotinic Receptors: From Computer Modeling to Binding Studies and Electrophysiology

For a small library of natural products from marine sponges and ascidians, in silico docking to the Lymnaea stagnalis acetylcholine-binding protein (AChBP), a model for the ligand-binding domains of nicotinic acetylcholine receptors (nAChRs), was carried out and the possibility of complex formation was revealed. It was further experimentally confirmed via competition with radioiodinated α-bungarotoxin ([¹²⁵I]-αBgt) for binding to AChBP of the majority of analyzed compounds. Alkaloids pibocin, varacin and makaluvamines С and G had relatively high affinities (K_i 0.5–1.3 μM). With the muscle-type nAChR from Torpedo californica ray and human neuronal α7 nAChR, heterologously expressed in the GH₄C₁ cell line, no competition with [¹²⁵I]-αBgt was detected in four compounds, while the rest showed an inhibition. Makaluvamines (K_i ~ 1.5 μM) were the most active compounds, but only makaluvamine G and crambescidine 359 revealed a weak selectivity towards muscle-type nAChR. Rhizochalin, aglycone of rhizochalin, pibocin, makaluvamine G, monanchocidin, crambescidine 359 and aaptamine showed inhibitory activities in electrophysiology experiments on the mouse muscle and human α7 nAChRs, expressed in Xenopus laevis oocytes. Thus, our results confirm the utility of the modeling studies on AChBPs in a search for natural compounds with cholinergic activity and demonstrate the presence of the latter in the analyzed marine biological sources.     

A novel Streptococcus species causing clinical mastitis in a pregnant donkey

An 8-y-old jenny was presented because of anorexia and mild depression. The jenny had weaned her colt 10 d before the admission. Upon arrival at the University of Illinois Veterinary Teaching Hospital, the heart rate was elevated, and the right udder was painful and swollen on palpation. Milk stripping of the affected side revealed purulent content; the contralateral udder had normal-appearing milk. Cytology of mammary gland secretions from the affected side revealed a large number of hypersegmented reactive neutrophils with phagocytized bacteria. Complete blood count, serum chemistry, and fibrinogen were within normal limits. A diagnosis of clinical mastitis was made, and the jenny was started on a 5-d course of broad-spectrum antibiotics, a non-steroidal anti-inflammatory, hydrotherapy, and milk stripping. Clinical signs reduced over time, and the cure was attained by 96 h post-admission. Aerobic culture and subsequent MALDI-TOF MS analysis identified a bacterium of the Streptococcus genus but not the species. Whole-genome analysis was performed, and 16S rDNA sequencing and analysis determined that our isolate 20-37394 clustered with 2 other Streptococcus strains (27284-01 and 28462). Single-nucleotide variations and phylogenetic tree analysis revealed that Streptococcus 20-37394 had 96.8% and 94.9% identities to Streptococcus strains 27284-01 and 28462, respectively; therefore, the bacteria isolated in our case was deemed as a new Streptococcus species.     

182W evidence for long-term preservation of early mantle differentiation products

Late accretion, early mantle differentiation, and core-mantle interaction are processes that could have created subtle (182)W isotopic heterogeneities within Earth's mantle. Tungsten isotopic data for Kostomuksha komatiites dated at 2.8 billion years ago show a well-resolved (182)W excess relative to modern terrestrial samples, whereas data for Komati komatiites dated at 3.5 billion years ago show no such excess. Combined (182)W, (186,187)Os, and (142,143)Nd isotopic data indicate that the mantle source of the Kostomuksha komatiites included material from a primordial reservoir that represents either a deep mantle region that underwent metal-silicate equilibration or a product of large-scale magmatic differentiation of the mantle. The preservation, until at least 2.8 billion years ago, of this reservoir-which likely formed within the first 30 million years of solar system history-indicates that the mantle may have never been well mixed.