Effects of increased atmospheric CO2 on nutritional contents in poplar (Populus pseudo-simonii [Kitag.]) tissues and larval growth of gypsy moth (Lymantria dispar)

Changes in the concentrations of phytochemical compounds usually occur when plants are grown under elevated atmospheric CO₂. CO₂-induced changes in foliar chemistry tend to reduce leaf quality and may further affect insect herbivores. Increased atmospheric CO₂ also has a potential influence on decomposition because it causes variations in chemical components of plant tissues. To investigate the effects of increased atmospheric CO₂ on the nutritional contents of tree tissues and the activities of leaf-chewing forest insects, samples of Populus pseudo-simonii [Kitag.] grown in open-top chambers under ambient and elevated CO₂ (650 μmol mol^-1) conditions were collected for measuring concentrations of carbon, nitrogen, C : N ratio, soluble sugar and starch in leaves, barks, coarse roots (>2 mm in diameter) and fine roots (<2 mm in diameter). Gypsy moth (Lymantria dispar) larvae were reared on a single branch of experimental trees in a nylon bag with 1 mm 1 mm grid. The response of larval growth was observed in situ. Elevated CO₂ resulted in significant reduction in nitrogen concentration and increase in C : N ratio of all poplar tissues. In all tissues, total carbon contents were not affected by CO₂ treatments. Soluble sugar and nonstructural carbohydrate (TNC) in the poplar leaves significantly increased with CO₂ enrichment, whereas starch concentration increased only on partial sampling dates. Carbohydrate concentration in roots and barks was generally not affected by elevated CO₂, whereas soluble sugar contents in fine roots decreased in response to elevated CO₂. When second instar gypsy moth larvae consuming poplars grew under elevated CO₂ for the first 13 days, their body weight was 30.95% lower than that of larvae grown at ambient CO₂, but no significant difference was found when larvae were fed in the same treatment for the next 11 days. Elevated atmospheric CO₂ had adverse effects on the nutritional quality of Populus pseudo-simonii [Kitag.] tissues and the resultant variations in foliar chemical components had a significant but negative effect on the growth of early instar gypsy moth larvae.     

Lysine and threonine biosynthesis in sorghum seeds: characterisation of aspartate kinase and homoserine dehydrogenase isoenzymes

Aspartate kinase (AK, EC 2.7.2.4) and homoserine dehydrogenase (HSDH, EC 1.1.1.3) have been partially purified and characterised from immature sorghum seeds. Two peaks of AK activity were eluted by anion‐exchange chromatography [diethylaminoethyl (DEAE)‐Sephacel] with 183 and 262 mM KCl, and both activities were inhibited by lysine. Similarly, two peaks of HSDH activity were eluted with 145 and 183 mM KCl; the enzyme activity in the first peak in elution order was shown to be resistant to threonine inhibition, whereas the second was sensitive to threonine inhibition. However, following gel filtration chromatography (Sephacryl S‐200), one peak of AK activity co‐eluted with HSDH and both activities were sensitive to threonine inhibition, suggesting the presence of a bifunctional threonine‐sensitive AK–HSDH isoenzyme with a molecular mass estimated as 167 kDa. The activities of AK and HSDH were studied in the presence of lysine, threonine, methionine, valine, calcium, ethylene glycol bis(2‐aminoethylether)‐N,N,N′N′‐tetraacetic acid, calmodulin, S‐adenosylmethionine (SAM), S‐2‐aminoethyl‐l ‐cysteine (AEC) and increasing concentrations of KCl. AK was shown to be inhibited by threonine and lysine, confirming the existence of two isoenzymes, one sensitive to threonine and the other sensitive to lysine, the latter being predominant in sorghum seeds. Methionine, SAM plus lysine and AEC also inhibited AK activity; however, increasing KCl concentrations and calcium did not produce any significant effect on AK activity, indicating that calcium does not play a role in AK regulation in sorghum seeds. HSDH also exhibited some inhibition by threonine, but the majority of the activity was not inhibited, thus indicating the existence of a threonine‐sensitive isoenzyme and a second predominant threonine‐insensitive isoenzyme. Valine and SAM plus threonine also inhibited HSDH; however, increasing concentrations of KCl and calcium had no inhibitory effect.     

Relationship between nutritional status and tooth loss in an older population from Sri Lanka

doi: 10.1111/j.1741‐2358.2011.00518.x Relationship between nutritional status and tooth loss in an older population from Sri Lanka Objective: To determine the relationship between tooth loss and nutritional status in older individuals in Sri Lanka. Background: In developing countries, both the prevalence of malnutrition and oral disease are high among older individuals. Materials and methods: Four hundred and eighty subjects aged 60 years and above were selected to be included in the sample, of which 437 responded giving an overall response rate of 91%. Data were collected by means of an interviewer administered questionnaire, an oral examination and a physical examination to determine height and weight to calculate the body mass index (BMI). Results: Based on the WHO cut‐offs for BMI, 62, 20 and 18% of the sample were normal, under‐ and over‐weight, respectively. A multinomial logistic regression analysis with normal weight as the reference category revealed that missing teeth and denture status were associated with being underweight but not with being overweight. Conclusion: In older individuals, tooth loss is significantly associated with being underweight.     

Nutritional and Morphological Traits of Invasive and Exotic Fleshy‐fruits in South Africa

While fleshy‐fruited invasive alien plants are recognized as some of the worst invaders on a global scale, until recently, little consideration has been given to the frugivores that feed on these fruits and, more specifically, the fruit traits, which may influence this. We investigated a series of morphological and nutritive fruit traits for ca 30 species of fleshy‐fruited invasive alien and exotic species in South Africa. Invasive alien fruit traits were compared with comparable traits of a similar sample size of indigenous fleshy fruits, which occur in the same area. Finally, the similarity of traits for the same invasive alien species was compared with those fruits in Australia. Invasive alien fleshy fruits were similar in morphology, but greater in some nutritive aspects when compared with indigenous fruits. Furthermore, they were very similar in all aspects to their counterparts in Australia. Most seeds of invasive fleshy fruits were small and light, which may explain some of their invasive success, as benefits associated with small seededness may promote invasive potential. Nutritionally, most invasive alien fleshy‐fruits were hexose‐dominant, containing low lipid and nitrogen content. While frugivore preference trends remain to be formally investigated, this study provides insights into fruit traits, which may tentatively outline why invasive fruits are universally fed on and thus successfully spread.     

Effect of undernutrition on deciduous tooth emergence among Rajput children of Shimla District of Himachal Pradesh, India

This article examines the influence of nutritional status on the emergence of deciduous dentition in a cross-sectional sample of 510 rural Rajput children from the Jubbal and Kotkhai Tehsils, Shimla District, Himachal Pradesh, India. The nutritional status of each child was evaluated using Z-scores of height/supine length-for-age (HAZ), weight-for-age (WAZ), and weight-for-height (WHZ). The effects of sex and side on deciduous dental emergence were not statistically significant. Partial correlation indicates that the number of emerged teeth (T) was more strongly correlated with height than with other anthropometric variables. In most age groups, the stunted boys and girls (HAZ <-2) had fewer emerged teeth than nonstunted age peers (HAZ >-2). The mean T in underweight children was also less than that of the normal children, with a few exceptions. The stunted children have a significantly greater likelihood of delayed emergence of deciduous dentition. Measures of linear growth status are more closely related to dental development than measures of growth in mass. The findings indicate that even moderate undernutrition can delay deciduous tooth emergence.     

A case of adult cannibalism in the gray mouse lemur, Microcebus murinus

Cannibalism, defined as the eating of conspecific flesh, has been observed in a number of primate species, although it is still a relatively rare phenomenon. In cases where primates were seen feeding on an individual of the same species, the victims have exclusively been infants or juveniles. Here, I report an event of a free-living, adult male gray mouse lemur, Microcebus murinus, cannibalizing an adult conspecific female that died of an unknown cause. This observation has implications for the basic ecology of the species and highlights the potential for great flexibility in diet and behavior by a primate. This is, to my knowledge, the first communication of cannibalistic behavior in this species, as well as the first reported case of a nonhuman primate cannibalizing an adult conspecific.     

Rib lesions in skeletons from early neolithic sites in Central Germany: On the trail of tuberculosis at the onset of agriculture

As an infectious disease, tuberculosis (TB) is one of the major causes of death worldwide. Paleopathological and paleomicrobiological studies indicate a long standing association of the causative agent Mycobacterium tuberculosis and its human host. Since the occurrence and the epidemic spread of this pathogen seem to be closely linked to social and biological factors, it is of particular interest to understand better the role of TB during periods of social and nutritional change such as the Neolithic. In this study, 118 individuals from three sites in Saxony‐Anhalt (Germany) dating to the Linear Pottery Culture (5400–4800 BC) were examined macroscopically to identify TB related bone lesions. In two individuals, Pott's disease was detected. In addition, periosteal reactions of varying degrees and frequency were observed mainly along the neck of the ribs in 6.5% (2/31) of subadults and 35.1% (20/57) of adults, with one site standing out markedly. Rib lesions, however, are not specific indicators of TB as they can also be caused by other diseases; so additional investigations were undertaken using histology and micro‐CT scans to say more about the disease process. Supplementary molecular analyses indicate the presence of pathogens belonging to the Mycobacterium tuberculosis complex in individuals of all sites. Furthermore, we discuss the occurrence and spread of TB during the Neolithic with regard to nutritional aspects and possible risks of infection. The data presented provide important insights into the health status of Early Neolithic populations in Central Germany. Am J Phys Anthropol, 2012. © 2012 Wiley Periodicals, Inc.     

Plant-ants use symbiotic fungi as a food source: new insight into the nutritional ecology of ant-plant interactions

Usually studied as pairwise interactions, mutualisms often involve networks of interacting species. Numerous tropical arboreal ants are specialist inhabitants of myrmecophytes (plants bearing domatia, i.e. hollow structures specialized to host ants) and are thought to rely almost exclusively on resources derived from the host plant. Recent studies, following up on century-old reports, have shown that fungi of the ascomycete order Chaetothyriales live in symbiosis with plant-ants within domatia. We tested the hypothesis that ants use domatia-inhabiting fungi as food in three ant-plant symbioses: Petalomyrmex phylax/Leonardoxa africana, Tetraponera aethiops/Barteria fistulosa and Pseudomyrmex penetrator/Tachigali sp. Labelling domatia fungal patches in the field with either a fluorescent dye or (15)N showed that larvae ingested domatia fungi. Furthermore, when the natural fungal patch was replaced with a piece of a (15)N-labelled pure culture of either of two Chaetothyriales strains isolated from T. aethiops colonies, these fungi were also consumed. These two fungi often co-occur in the same ant colony. Interestingly, T. aethiops workers and larvae ingested preferentially one of the two strains. Our results add a new piece in the puzzle of the nutritional ecology of plant-ants.     

Supplementing Seed Banks to Rehabilitate Disturbed Mojave Desert Shrublands: Where Do All the Seeds Go?

Revegetation of degraded arid lands often involves supplementing impoverished seed banks and improving the seedbed, yet these approaches frequently fail. To understand these failures, we tracked the fates of seeds for six shrub species that were broadcast across two contrasting surface disturbances common to the Mojave Desert—sites compacted by concentrated vehicle use and trenched sites where topsoil and subsurface soils were mixed. We evaluated seedbed treatments that enhance soil‐seed contact (tackifier) and create surface roughness while reducing soil bulk density (harrowing). We also explored whether seed harvesting by granivores and seedling suppression by non‐native annuals influence the success of broadcast seeding in revegetating degraded shrublands. Ten weeks after treatments, seeds readily moved off of experimental plots in untreated compacted sites, but seed movements were reduced 32% by tackifier and 55% through harrowing. Harrowing promoted seedling emergence in compacted sites, particularly for the early‐colonizing species Encelia farinosa, but tackifier was largely ineffective. The inherent surface roughness of trenched sites retained three times the number of seeds than compacted sites, but soil mixing during trench development likely altered the suitability of the seedbed thus resulting in poor seedling emergence. Non‐native annuals had little influence on seed fates during our study. In contrast, the prevalence of harvester ants increased seed removal on compacted sites, whereas rodent activity influenced removal on trenched sites. Future success of broadcast seeding in arid lands depends on evaluating disturbance characteristics prior to seeding and selecting appropriate species and seasons for application.