The effects of three months of aerobic and strength training on selected performance- and fitness-related parameters in modern dance students

The purpose of the present study was to assess the effects of a 12-week aerobic and muscular strength training program on selected dance performance and fitness-related parameters in modern dance students. The sample consisted of 32 men and women (age 19 +/- 2.2 years) who were randomly assigned into exercise (n = 19) and control (n = 13) groups. Anthropometric and flexibility assessments, treadmill ergometry, strength measurements, and- on a separate day-a dance technique test were conducted pre- and postexercise training in both groups. After the end of the program, the exercise group revealed significant increases in dance (p < 0.02), VO(2)max (p < 0.04), flexibility (p < 0.01), and leg strength (p < 0.001) tests compared to controls. It is concluded that in modern dance students (a) a 3-month aerobic and strength training program has positive effects on selected dance performance and fitness-related parameters, (b) aerobic capacity and leg strength improvements do not hinder dance performance as studied herein, and (c) the dance-only approach does not provide enough scope for physical fitness enhancements.     

Effect of shrubs and seasonal variability of rainfall on the establishment of Aspidosperma quebracho‐blanco in two edaphically contrasting environments

Abstract Three experiments were conducted to verify if an increase in environmental stress level would affect the interactions between two species of nurse shrubs and seedlings of Aspidosperma quebracho‐blanco. This is a mesic species with a generalist distribution over an extensive environments gradient. The relationship between Larrea divaricata and seedlings of A. quebracho‐blanco was studied in two contrasting soils, a silty loam soil with higher surface clay content and a sandy loam soil. The effect of seasonal variability of rainfall on the initial establishment of seedlings under the shade of L. divaricata was evaluated in three consecutive years. The effect of nurse plant shade was tested comparing two shrub species with different types of leaf life span (sclerophyllous‐evergreen and leguminous‐deciduous). The natural establishment of A. quebracho‐blanco depended on shaded microsites, but not on the type of shade provided by different nurse shrubs. Emergence and initial establishment depended on interactions of soil type and seasonal rainfall variation with nurse plants. The importance of facilitation increased with clay soil (CS). Sandy soil was ‘less humid’ than CS under shrub shade. However, establishment success depends on opportune even rainfall distribution in interaction with nurse plant presence.     

Comparison of the blood redox status between long-distance and short-distance runners

Exercise increases the production of reactive oxygen species, which may damage a number of cell constituents. Organisms have developed a sophisticated antioxidant system for protection against reactive oxygen species. Our aim was to compare the adaptive responses of antioxidant mechanisms and the blood redox status of two groups of athletes, long-distance and short-distance runners. Thiobarbituric acid reactive substances, catalase activity and total antioxidant capacity was measured in the serum, while reduced and oxidized glutathione as well as their ratio were determined in blood hemolysates. Serum catalase activity (P<0.001) was found to be three times higher in long-distance compared to short-distance runners (25.4 vs. 8.9 micromol x min(-3) x ml(-1)), whereas the two groups did not differ in the other markers. Catalase activity also correlated significantly with maximal oxygen consumption in long-distance runners. In conclusion, we report here that long-distance and short-distance runners exhibit similar blood redox status judged by several oxidative stress indices, except for the much higher activity of catalase in long-distance runners. This different effect of the two training modules on catalase activity of long-distance runners might be partly due to the high oxygen load imposed during their repeated prolonged exercise bouts.     

Sex‐specific evolution of bite performance in Liolaemus lizards (Iguania: Liolaemidae): the battle of the sexes

Although differential selective pressures on males and females of the same species may result in sex‐specific evolutionary trajectories, comparative studies of adaptive radiations have largely neglected within‐species variation. In this study, we explore the potential effects of natural selection, sexual selection, or a combination of both, on bite performance in males and females of 19 species of Liolaemus lizards. More specifically, we study the evolution of bite performance, and compare evolutionary relationships between the variation in head morphology, bite performance, ecological variation and sexual dimorphism between males and females. Our results suggest that in male Liolaemus, the variation in bite force is at least partly explained by the variation in the degree of sexual dimorphism in head width (i.e. our estimate of the intensity of sexual selection), and neither bite force nor the morphological variables were correlated with diet (i.e. our proxy for natural selection). On the contrary, in females, the variation in bite force and head size can, to a certain extent, be explained by variation in diet. These results suggest that whereas in males, sexual selection seems to be operating on bite performance, in the case of females, natural selection seems to be the most likely and most important selective pressure driving the variation in head size. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 461–475.     

Acaricidal activity of Metarhizium anisopliae isolated from paddocks in the Mexican tropics against two populations of the cattle tick Rhipicephalus microplus

The acaricidal effects of 55 strains of Metarhizium anisopliae (Metschnikoff) Sorokin, 1883 (Hypocreales: Clavicipitaceae) isolated from paddocks of cattle farms were evaluated in two Rhipicephalus microplus (Canestrini 1887) (Ixodida: Ixodidae) populations, of which one was multi‐resistant and one was susceptible to chemical acaricides. Percentage mortality and reproductive efficiency indices in R. microplus were evaluated by adult immersion tests at a dose of 1 × 10⁸ conidia/mL for each fungal strain. Some strains were selected to calculate lethal concentrations to kill 50% (LC₅₀) and 99% (LC₉₉) of engorged ticks. Strains MaV22, MaV26 and MaV55 induced 100% mortality in R. microplus on day 14. Strains MaV05, MaV09 and MaV22 caused mortality of >90% from day 12 onward in both tick populations. The most effective acaricidal fungal strain, MaV55, inhibited egg laying by 54.86 and 55.86% in acaricide‐resistant and ‐susceptible R. microplus populations, respectively. None of the fungal strains had statistically significant effects on larval hatching. In conclusion, nine strains of M. anisopliae demonstrated high acaricidal effects against R. microplus and reduced its egg laying. No differences in acaricidal effects were observed between the two populations of ticks tested.     

New hosts for the mite Ornithonyssus bursa in Argentina

The mite Ornithonyssus bursa (Berlese) (Mesostigmata: Macronyssidae) is considered a poultry pest causing important infestations in chickens and it is considered a potential vector of arbovirus. Despite being considered a common parasite in wild birds, there is scarce published information about its potential hosts and effects on them. Here we present new bird hosts for O. bursa, assess the presence of Alphavirus, Flavivirus and Bunyavirus in mites from three host species, and discuss its potential impact on wild bird populations. We found O. bursa infecting five raptor and six passerine wild bird species. For nine of these species, this is the first record of infection by O. bursa. Although all analysed mites were negative for the examined arboviruses, the small sample size of mites does not allow further conclusions at the present moment. Because of the general nature of this ectoparasite, its presence in migratory long dispersal and endangered bird species, and the seropositivity for arboviruses in some of the species studied here, we consider it critical to assess the role of O. bursa and other ectoparasites as vectors and reservoirs of pathogens and as potential deleterious agents in wild bird populations.     

Chloroplast protection in plum pox virus‐infected peach plants by L‐2‐oxo‐4‐thiazolidine‐carboxylic acid treatments: effect in the proteome

Sharka, a disease caused by plum pox virus (PPV), has a significant economic impact on fruit tree production. In this work, we analysed the effect of (2,1,3)‐benzothiadiazole (BTH) and L‐2‐oxo‐4‐thiazolidine‐carboxylic acid (OTC) on plant growth and virus content. OTC reduced sharka symptom, stimulated plant growth and alleviated PPV‐induced oxidative stress, indicated by a lack of changes in some oxidative stress parameters. PPV infection reduced chloroplast electron transport efficiency. However, in the presence of BTH or OTC, no changes in the chlorophyll fluorescence parameters were observed. PPV produced an alteration in chloroplast ultrastructure, giving rise to a decrease in starch contents that was less dramatic in OTC‐treated plants. Furthermore, PPV reduced the abundance of proteins associated with photosynthesis, carbohydrate and amino acid metabolism and photorespiration. These changes did not take place in OTC‐treated plants, and increases in the expression of proteins related with the aforementioned processes, including ADP‐glucose pyrophosphorylase, were produced, which correlated with the lower decrease in starch contents observed in PPV‐infected plants treated with OTC. The results suggested that OTC treatment provides protection to the photosynthetic machinery and/or the chloroplast metabolism in PPV‐infected peaches. Thus, OTC could have practical implications in agriculture in improving the vigour of different plant species as well as in immunizing plants against pathogens.     

First report of Stegomyia aegypti (= Aedes aegypti) in Mexico City,Mexico

Stegomyia aegypti (= Aedes aegypti) (Diptera: Culicidae) is a species of mosquito that is currently widespread in Mexico. Historically, the mosquito has been distributed across most tropical and subtropical areas lower than 1700 m a.s.l. Currently, populations that are found at higher altitudes in regions with cold and dry climates suggest that these conditions do not limit the colonization and population growth of S. aegypti. During a survey of mosquitoes in September 2015, larvae of S. aegypti mosquitoes were found in two different localities in Mexico City, which is located at about 2250 m a.s.l. Mexico City is the most populous city in Mexico and has inefficient drainage and water supply systems. These factors may result in the provision of numerous larval breeding sites. Mosquito monitoring and surveillance are now priorities for the city.     

Hypoderma actaeon: an emerging myiasis in roe deer (Capreolus capreolus)

Subcutaneous larvae of Hypoderma spp. (Diptera: Oestridae) were detected in the dorsal region in 10 roe deer, Capreolus capreolus (Artiodactyla: Cervidae), hunted in central Spain between January and March 2016. All larvae were found in the inner side of the hide during the skinning of the animals. The study of the morphological features of eight larvae of different stages collected from two animals allowed the identification of Hypoderma actaeon Brauer. The small size (4–5 mm) of some of the first instars suggests that the internal lifecycle of H. actaeon may be exclusively subcutaneous. This is the first confirmation of H. actaeon in roe deer; however, further studies to assess the spread of the parasite and to follow the evolution of this myiasis in roe deer are needed.