Limited Range Of Species Research Articles

First Record of <i>Hemiphyllodactylus</i> Bleeker, 1860 (Squamata: Sauria: Gekkonidae) from the Eastern Himalayas

The gekkonid lizard genus Hemiphyllodactylus Bleeker, 1860 is represented by seven species in India, six of which are patchily distributed across montane habitats of peninsular India and one in Andaman and Nicobar islands. Here we report the occurrence of Hemiphyllodactylus sp. in Namdapha Tiger Reserve, Changlang district of Arunachal Pradesh in Northeast India. This is the first record of the genus from Eastern Himalayas and the larger Indian Himalayan Region. It is also the northern most distribution record of the genus for the country. The specimen collected is distinct from known Indian species and shows close affinity to Hemiphyllodactylus yunnanensis sensu lato with respect to morphological characters as well as geographic proximity of collection locality. However, considering the restricted montane distribution and limited range of species from mainland Southeast Asia and peninsular India, it most likely belongs to a hitherto undescribed species. The finding emphasizes the conservation significance of tropical evergreen forests of Eastern Himalayas and North east hills for herpetofaunal diversity and biodiversity in general.

Group-size preferences in a shoaling cichlid

Abstract Group size is an important criterion in social decisions. Accordingly, assessing quantities is common in many animals. In fishes, studies on numerical abilities focus on a limited range of species. Arguably, cichlids show the greatest variability of social patterns among vertebrates. Nevertheless, knowledge about their quantitative abilities is scarce. Here we use the Lake Tanganyika cichlid Lamprologus callipterus to scrutinize the quantitative abilities of fish in the context of shoaling. Females chose between different numbers of conspecifics, varying in absolute and relative number differences. In half of the trials both shoals were composed of familiar sisters, while all fish were unfamiliar non-kin in the other half. Test fish consistently preferred the larger of two shoals, irrespective of the ratios. Their activity differed significantly between familiarity/relatedness treatments, indicating recognition of this parameter. L. callipterus therefore has fine-tuned discrimination skills, adding to the evidence that quantitative abilities are widespread in fishes.

Pinoresinol-lariciresinol reductases, key to the lignan synthesis in plants.

This paper provides an overview on activity, stereospecificity, expression and regulation of pinoresinol-lariciresinol reductases in plants. These enzymes are shared by the pathways to all 8-8' lignans derived from pinoresinol. Pinoresinol-lariciresinol reductases (PLR) are enzymes involved in the lignan biosynthesis after the initial dimerization of two monolignols. They catalyze two successive reduction steps leading to the production of lariciresinol or secoisolariciresinol from pinoresinol. Two secoisolariciresinol enantiomers can be synthetized with different fates. Depending on the plant species, these enantiomers are either final products (e.g., in the flaxseed where it is stored after glycosylation) or are the starting point for the synthesis of a wide range of lignans, among which the aryltetralin type lignans are used to semisynthesize anticancer drugs such as Etoposide®. Thus, the regulation of the gene expression of PLRs as well as the possible specificities of these reductases for one reduction step or one enantiomer are key factors to fine-tune the lignan synthesis. Results published in the last decade have shed light on the presence of more than one PLR in each plant and revealed various modes of action. Nevertheless, there are not many results published on the PLRs and most of them were obtained in a limited range of species. Indeed, a number of them deal with wild and cultivated flax belonging to the genus Linum. Despite the occurrence of lignans in bryophytes, pteridophytes and monocots, data on PLRs in these taxa are still missing and indeed the whole diversity of PLRs is still unknown. This review summarizes the data, published mainly in the last decade, on the PLR gene expression, enzymatic activity and biological function.

Discrete call types referring to predation risk enhance the efficiency of the meerkat sentinel system

Sentinel behaviour, a form of coordinated vigilance, occurs in a limited range of species, mostly in cooperative breeders. In some species sentinels confirm their presence vocally by giving a single sentinel call type, whereby the rate and subtle acoustic changes provide graded information on the variation of perceived predation risk. In contrast, meerkat (Suricata suricatta) sentinels produce six different sentinel call types. Here we show that manipulation of perception of danger has different effects on the likelihood of emitting these different call types, and that these call types affect foraging individuals differently. Increasing the perceived predation risk by playing back alarm calls decreased the production rate of the common short note calls and increased the production rate of the rare long calls. Playbacks of short note calls increased foraging behaviour and decreased vigilance in the rest of the group, whereas the opposite was observed when playing long calls. This suggests that the common call types act as all-clear signals, while the rare call types have a warning function. Therefore, meerkats increase the efficiency of their sentinel system by producing several discrete call types that represent changes in predation risk and lead to adjustments of the group’s vigilance behaviour.

Depth distribution of roots of Eucalyptus dunnii and Corymbia citriodora subsp. variegata in different soil conditions

Understanding depth distribution of roots may help develop an understanding of plant productivity and the limits to productivity by indicating which parts of the soil profile are being accessed for water and nutrients. The subtropical east coast of Australia provides climatic and soil conditions that produce some of the highest plant productivity rates in the country. This has been recognised by the hardwood plantation industry and over the last decade a substantial estate of plantations has been established with plans for further expansion. However, two of the major species used, Eucalyptus dunnii and Corymbia citriodora subsp. variegata, have had little published research directly related to root depth distribution in the area. We examined root depth distribution in established plantations of E. dunnii and C. citriodora subsp. variegata under three contrasting soil types using the techniques of soil trench profile and coring. The results showed that the fine roots of C. citriodora subsp. variegata are at lower densities in poorly structured subsoils than the roots of E. dunnii. The root densities of both species in the subsoils of a Vertosol soil (with high levels of reactive, shrink–swell clays) were lower than for the other soil types. In native vegetation Vertosols are often colonised by grasses with few, scattered trees from a limited range of species. Our findings show lower levels of root growth in the Vertosols, particularly into the subsoil and this is likely to be the reason that productivity on these, otherwise fertile soils, is restricted.

Novel approaches and technologies in pollution assessment and monitoring: A UK perspective

For more than 50 years, the management of chemical pollution in the UK has relied on three major types of information. These are information about: (i) the potential toxicity of chemicals intentionally or unintentionally released into the environment; (ii) the concentration of particular chemicals in environmental samples; and (iii) the well-being of ecosystems or key species within ecosystems. Toxicity tests for lethal as well as sublethal effects are carried out in standard conditions, with a limited range of species. They provide data that are used, together with safety factors, to set “safe environmental limits” for specific chemicals. These limits are captured in regulations and enforced with the aid of monitoring programs. Sometimes, despite controlling contaminant levels in ecosystems, ecologists detect abnormalities or overt ecological damage. This may then lead to management actions to address each specific problem. In this paper, the limitations of the “chemical-based” approaches outlined above are highlighted. A range of contemporary methods that have been developed over the last 10–20 years and that are based on the identification of biological damage are also described. These are currently being deployed in the UK and the rest of the European Union. The relative merits of both approaches are compared and contrasted, with particular attention being paid to their practicality, cost-effectiveness and ecological relevance. Legal aspects of their use will also be briefly discussed.

N-Glycan Moieties in Neonatal Fc Receptor Determine Steady-state Membrane Distribution and Directional Transport of IgG

The neonatal Fc receptor (FcRn) is a major histocompatibility complex class I-related molecule known to protect IgG and albumin from catabolism and transport IgG across polarized epithelial cells in a bidirectional manner. Previous studies have shown species-specific differences in ligand binding, IgG transport direction, and steady-state membrane distribution when expressed in polarized epithelial cells. We hypothesized that these differences may be due to the additional N-glycans expressed on the rat FcRn, because N-glycans have been proposed to function as apical targeting signals, and that two of the N-glycan moieties have been shown to contribute to the IgG binding of rat FcRn. A panel of mutant human FcRn variants was generated to resemble the N-glycan expression of rat FcRn in various combinations and subsequently transfected into Madin-Darby canine kidney II cells together with human beta2-microglobulin. Mutant human FcRn clones that contained additional N-glycan side-chain modifications, including that which was fully rodentized, still exhibited specificity for human IgG and failed to bind to mouse IgG. At steady state, the mutant human FcRn with additional N-glycans redistributed to the apical cell surface similar to that of rat FcRn. Furthermore, the rodentized human FcRn exhibited a reversal of IgG transport with predominant transcytosis from an apical-to-basolateral direction, which resembled that of the rat FcRn isoform. These studies show that the N-glycans in FcRn contribute significantly to the steady-state membrane distribution and direction of IgG transport in polarized epithelia.

Diversity of vascular plant species in the montane boreal forest of western Canada in response to climatic changes during the last 25 ka, fire, and land use

Summary: This paper examines the biodiversity of vascular plants in the vast boreal forest area of the southern Cordillera of western Canada. It was glaciated until 11 ka, and since then, vascular plants have had difficulties colonizing the de glaciated areas from the surrounding refugia. Problems include the topography, the comparatively inhospitable climate, limited source areas, natural wildfires, and fluctuations in climate. As a result, the forest consists of up to 494 species of vascular plants at any one site compared to 871 species at Mount Rainier, Washington State. For comparison, 2,993 taxa have been reported from British Columbia indicating the limited colonization that has occurred. European Man has added to these problems by increasing fire frequency and by extensive, repeated logging of large areas. A limited amount of intensive irrigated agriculture also occurs near southern rivers and lakes. The end result is a limited range of species, of which 30% are regarded as rare or endangered. The consumers of the resulting biomass are therefore also limited in their food supply.

Genomic and microarray approaches to coral reef conservation biology

New technologies based on DNA microarrays and comparative genomics hold great promise for providing the background biological information necessary for effective coral reef conservation and management. Microarray analysis has been used in a wide range of applications across the biological sciences, most frequently to examine simultaneous changes in the expression of large numbers of genes in response to experimental manipulation or environmental variation. Other applications of microarray methods include the assessment of divergence in gene sequences between species and the identification of fast-evolving genes. Arrays are presently available for only a limited range of species, but with appropriate controls they can be used for related species, thus avoiding the considerable costs associated with development of a system de novo. Arrays are in use or preparation to study stress responses, early development, and symbiosis in Acropora and Montastraea. Ongoing projects on several corals are making available large numbers of expressed gene sequences, enabling the identification of candidate genes for studies on gamete specificity, allorecognition and symbiont interactions. Over the next few years, microarray and comparative genomic approaches are likely to assume increasingly important and widespread use to study many aspects of the biology of coral reef organisms. Application of these genomic approaches to enhance our understanding of genetic and physiological correlates during stress, environmental disturbance and disease bears direct relevance to the conservation of coral reef ecosystems.

The Development of a Computer Code for the Estimation of Combustor Exhaust Temperature Using Simple Gas Analysis Measurements

Advances in gas turbine technology have led to levels of turbine inlet temperature that preclude the use of thermocouple and simple gas analysis techniques for gas temperature determination. Simple gas analysis schemes rely on the measurement of a very limited range of species in the gas sample: typically, CO2, CO, and hydrocarbons (UHC). A method of estimating the other important species is required. Simple gas analysis schemes that rely only on elemental mass balance equations to determine the concentration of species are inadequate where high temperature results in significant dissociation. A method has been developed to enable temperature determination at levels that render simple schemes inaccurate. The procedure is based on the measurement of CO2, CO, UHC, and oxides of nitrogen in the exhaust gas. Other species concentrations are calculated using an assumption of partial thermodynamic equilibrium. This allows the calculation of many important combustion parameters. The method has been implemented as a computer code, with an object orientated design approach using the C++ language. The paper details the theory behind the approach and its implementation. The expected errors for practical applications are discussed and quantified. The method is illustrated by an exhaust temperature pattern factor investigation of an annular combustor. Temperatures determined by thermocouples are compared with those calculated from gas samples.

Glycinebetaine is a major nitrogen-containing solute in the malvaceae

The zwitterionic quaternary ammonium compound glycinebetaine was detected in all but three of over 100 species of various genera in the family Malvaceae. In a more limited range of species, particularly of Gossypium, glycinebetaine accumulated to concentrations sometimes in excess of 100 mM water in response to water deficit or salinity stress. Glycinebetaine concentrations were highest in young tissues and accounted for about 10% of the total nitrogen.

Occurrence and diversity of plasmids in ovine isolates of Pasteurella haemolytica

160 ovine isolates of Pasteurella heamolytica, representing each of the 16 serotypes and also untypable strains, were examined for plasmid content. Plasmid DNA was identified in, and prepared from, strains of serotypes A2, T3, A14 and A16 and also from an untypable strain. The relationship between the plasmids present in the different strains was examined both by restriction fragment profile analysis and by DNA/DNA hybridisation. Both methods gave broadly similar results and showed that each serotype tended to contain either a single plasmid species, or a limited range of species, and that structural similarities could traverse serotype boundaries. None of the plasmidbearing strains showed any significant level of resistance to a range of antibiotics.

Isolation and partial characterization of a type IV bacterial immunoglobulin binding protein

A series of bovine G streptococcal isolates were screened for expression of type IV Fc binding proteins. An isolate expressing high levels of type IV binding proteins was selected and expanded by use of a colony selection technique. A variety of different extraction procedures were compared and the optimal solubilization procedure was found to be hot acid extraction of the bacteria. The extracted protein could be affinity purified on a column of immobilized rabbit IgG. The type IV Fc binding protein was found to be antigenically unrelated to the type I, II or III bacterial Fc binding proteins and displayed the lowest affinity and most limited range of species and subclass reactivity of any bacterial Fc binding protein thus far characterized.

Passage of duck hepatitis virus in cell cultures derived from avian embryos of different species

An egg-attenuated strain of duck hepatitis virus was successfully passaged through cell cultures of avian embryos derived from goose, turkey, guinea fowl, Japanese quail, pheasant and chicken. Two field strains of the virus were passaged in a more limited range of species.

Micro-organisms of the Leaf Surface: Estimation of the Mycoflora of the Barley Phyllosphere

SUMMARY: During a 17-day period the mycoflora of the barley phyllosphere was assessed by microscopic observation of leaf impressions. The frequency of fungal colonies detected was 0.1 to 17.2 per cm2 of leaf. In favourable conditions the leaf area occupied by each colony was about 0.05 mm2. The total surface of colonization could thus reach 2 mm2/cm2, but generally varied between 0.002 and 0.774 mm2. Only a limited range of species was observed, predominantly Cladosporium spp. The highest active populations coincided with a period of massive emission of pollen. The quantitative results obtained bore little relation to those from leaf-washing counts: the reasons for this are discussed.