Shark ecotourism in Mexico: Scientific research, conservation, and contribution to a Blue Economy.

Shark ecotourism has the potential to contribute significantly to local and national economies and conservation, though this depends on a concerted effort to implement evidence-based management. Sharks are key attractions at some of the most important marine ecotourism sites throughout Mexico, focusing particularly on whale sharks, white sharks, hammerhead sharks, and several other reef-associated and pelagic species. This generates important employment opportunities and millions of USD in revenue, but truly implementing ecotourism requires that education and conservation be a part of activities and that these benefit local communities, so that the industry can be socially, economically and ecologically sustainable. In Mexico, this includes addressing potential negative impacts from vessel overcrowding, provisioning, inequitable distribution of ecotourism and conservation benefits and costs, and a broader lack of governance capacity to ensure that coastal development is environmentally sustainable and socially equitable. In the context of a Blue Economy centred on sustainability and local benefits, ecotourism provides a key incentive and opportunity to improve ocean management.

First record of the Pacific seahorse Hippocampus ingens in Guadalupe Island, Mexico.

This is the first record of the Pacific seahorse Hippocampus ingens at a northern oceanic island from the eastern Pacific Ocean. The photographic record of the juvenile female H. ingens was made in November 2015 during a cage diving trip at Guadalupe Island, Mexico. The presence of H. ingens in this area could be related to long distance dispersal mechanisms, as has been observed in other species of seahorses.

A novel icetexane diterpene, 5-epi-icetexone from Salvia gilliessi is active against Trypanosoma cruzi.

In this work the effect of a novel compound, 5-epi-icetexone (ICTX) obtained from Salvia gilliessi Benth. (Labiatae), is studied on cultured epimastigotes of Trypanosoma cruzi (Tulahuen). It was found that the compound exerts an antiproliferative effect on the parasites at concentrations between 2.8 and 4.2 microM, and similar sensitivity in other strains (Dm28c, CL-Brener and Y-strain). The compound was deleterious at concentrations higher than 4.2 microM, with an estimated IC50 of 6.5+/-0.75 microM, but with low cytotoxicity to mammalian cells. These effects were irreversible, even at short times of exposure to the drug. In solution, ICTX showed to be stable for at least 96 h at 29 degrees C. With cytostatic dose a little percentage of parasites was resistant to the action of ICTX, and they continued growing although with different kinetic. By electron transmission microscopy, at dose of 4.2 microM an external vesiculization was observed on the first day of exposure to the compound, but the parasite cytoplasm became plenty of vacuoles and exhibited nuclear disorganization from the second day of exposure. It was concluded that ICTX is active against T. cruzi and may act by multiple mechanisms. In future, this novel icetexane diterpene may be a good candidate for therapeutic use against Chagas' disease.

Determination of dysprosium and europium in sheep faeces by graphite furnace and tungsten coil electrothermal atomic absorption spectrometry.

Tungsten coil atomizer atomic absorption spectrometry (TCAAS) was used to determine Dy and Eu in acid-digested faeces of sheep. These elements were used as markers in animal nutrition studies. Samples were dried, ground and decomposed using a nitric-perchloric acid mixture. The accuracy of the developed method was evaluated by graphite furnace atomic absorption spectrometry (GFAAS). The results obtained for Eu were validated at a 95% confidence level using a paired t-test. The results for Dy were not validated owing to memory effects caused by carbide formation into the graphite tube. This effect did not occur for Eu. The detection limits for Dy and Eu were 6.9 and 2.1 mug l(-1) by TCAAS, and 2.2 and 5.2 mug l(-1) by GFAAS, respectively. Relative standard deviations (R.S.D.; n=5) were 0.7-3.8 and 0.8-5.6% for Dy and Eu by TCAAS and 0.8-5.4 and 0.3-3.8% for Dy and Eu by GFAAS, respectively. The lifetime of the tungsten coil was around 200 heating cycles, which is three-fold higher than graphite tube lifetime. The proposed method can be used to determine the passage rate of feed through animal digestive tract.

Icetexane and abietane diterpenoids from Salvia gilliessi.

One icetexane and two abietane diterpenes were isolated from the aerial parts of Salvia gilliesii, and characterized as 5-epi-icetexone; 12-hydroxy-11,14-diketo-6,8,12-abietatrien-19,20-olide and 6 alpha,12,19-trihydroxy-11,14-diketo-8,12-abietadien-20,7 beta-olide, respectively. The structures were established by analysis of their 1H and 13C NMR spectra with the aid of 2D experiments. The triterpene oleanolic acid was isolated from the same source.

Gustav Mahler's choice. A note on adolescence, genius, and psychosomatics.

At a time of crisis in his marital life, Gustav Mahler met with Freud. After the meeting with Freud, Mahler's spirits and sexual potency were restored, and his attitude toward his wife changed remarkably. However, these changes were accompanied by an apparent loss of the ability to compose: there is no evidence that Mahler wrote any new music between the summer of 1910, when he saw Freud, and May of 1911, when he died from complications of streptococcal endocarditis. Mahler in effect had chosen human love over artistic creativity. An analysis of the encounter and its effects on the composer's artistic capabilities raises questions about the psychology of genius, adolescent trauma, and psychosomatics.

Removable partial dentures: the altered-cast technique.

The altered-cast technique, also known as the corrected-cast technique, for distal extension removable partial dentures (RPD), is not routinely utilized by dentists. Although the technique requires an additional step for both the dentist and dental technician, it offers several advantages--maximum stability, minimal stress on abutment teeth, and more predictable occlusion. The following article describes the altered-cast technique, as well as some advantages and disadvantages of the technique. A quick and easy procedure for constructing an altered-cast is also presented.

Schistosome circulating anodic antigen in serum of individuals infected with Schistosoma japonicum from the Philippines before and after chemotherapy with praziquantel.

The presence of the schistosome circulating anodic antigen (CAA) in serum of patients infected with Schistosoma japonicum from The Philippines has been investigated using an enzyme-linked immunosorbent assay (ELISA). Serum samples were tested from 48 patients who excreted S. japonicum eggs, 9 individuals with a negative stool examination, and 20 controls with both a negative stool and a negative circumoval precipitin test. No false positive result was detected for the unequivocally negative controls. CAA could be demonstrated in 72.9% of the egg-excreting patients. A positive correlation between parasite burden (eggs per gram of faeces) and antigen level (CAA titre) was found (Spearman's rho = 0.48, P < 0.001, n = 48). Four of 18 sera from the egg-negative individuals were positive in the ELISA. In view of the fact that anti-worm antibodies were also detected in these 4 sera, those reactions suggest active infection not detected by stool examination. In serum from patients treated with praziquantel, a significant drop in CAA titre was seen within 5 d after treatment (Wilcoxon's chi T = -2.23, P = 0.0258, n = 21). In conclusion, the detection of CAA by ELISA in S. japonicum infection can give valuable information in both individual diagnosis and therapeutic drug monitoring, as well as in epidemiological studies or disease control programmes.

Special symbols in early female oedipal development: fantasies of folds and spaces, protuberances and concavities.

The authors present three examples, from the observation of pre-latency girls, of the use of anatomic regions for symbolic purposes. In the two cases, the first interdigital fold became the locus for castration anxiety; and in the other, the laryngeal prominence and jugular notch served as the focus for symbolic displacement of psychosexual concerns. The employment of these particular symbols, to the best of the authors' knowledge, has not been reported previously in the literature. The authors conclude by calling for further investigation into the relationship between the processes involved in such symbol-formation and those that occur in neurosogenesis.

Generalizing articulation training with trainable mentally retarded subjects.

A multiple-baseline technique was used to evaluate generalization effects during articulation training with trainable mentally retarded subjects. Four target words were selected for each subject on the basis of whether the subject could articulate the word correctly when it was modelled but could not articulate the word correctly in response to a picture of it. Five different settings were selected for generalization probing and training for each subject. In Setting 1, Experimenter 1 initiated training sequentially on all four target words for each subject. Other experimenters probed for correct articulation generalization in four other settings. Training was initiated in these four other settings sequentially only if correct responding failed to generalize to a setting. Results indicated that it was necessary to initiate training on at least three of the four selected target words in at least one additional setting with an additional trainer before correct responding generalized to untrained settings.

An experimental analysis of response acquisition and elimination with positive reinforcers.

An 11 year old retarded child with a history of deviant behaviors underwent an extensive experimental-therapeutic program. This habilitation program was an extensive effort to decrease deviant behavior and to increase appropriate behavior. The program provided an experimental analysis of omission procedures for the reduction of deviant behaviors, and positive reinforcement for the acquisition and maintenance of appropriate play behavior. Response covariation of deviant behaviors was demonstrated. The study included a time period when the child was physically ill and under medical isolation. At the end of a two year follow-up, the child had significantly advanced her overall behavioral repertoire thus improving her physical health and living conditions.