Process and molecular data of branched 1,3-β-D-glucans in comparison with Xanthan

Bioreactor cultivations were carried out with Schizophyllum commune and Xanthomonas campestris. Influence of process parameters and downstream processing on molecular data (molecular weight, intrinsic and shear viscosity) of the secreted exopolysaccharide are shown. Glucan formation of S. commune was enhanced by oxygen limitation. Depending on the type of agitator used, a maximum glucan formation rate of 0.12 kg/(m³ · h) was reached. During cultivation molecular weight and intrinsic viscosity went through a broad maximum with maximum data of 1.3 10⁷ g/mol and 15,400 cm³/g, respectively. After substrate consumption glucan degrading enzymes (glucananses) were released by S. commune. For washing out low molecular substances and concentrating cellfree glucan solutions cross-flow filtration technique with hollow fiber cartridges (molecular cut-off 100,000) were used. After this procedure the shear and intrinsic viscosity were decreased. In contrast to Xanthan, shear viscosity of glucan solutions was not affected by a change in pH from 2 to 12. The intrinsic viscosity of aqueous Xanthan and glucan solutions was opposingly altered by adding salt.List of Symbols A number of capillaries - C ^*g/(dm³ · h) formation rate - D ^–1 shear rate - k Pa/sⁿ consistency index - n flow behaviour index - MW g/mol molecular weight - R m radius - t h time - V dm³ volume - Y yield coefficient - mPas shear viscosity - [] cm³/g intrinsic viscosity - Pa shear stress Indices PS polysaccharide - X cell mass - S substrate - m maximum Dedicated to Prof. Dr. Fritz Wagner on his 60th birthday     

Do McKinnon lists provide reliable data in bird species frequency? A comparison with transect-based data

Although occurrence-based listing methods could provide reliable lists of species composition for a site, the effective reliability of this method to provide more detailed information about species frequency (and abundance) has been rarely tested. In this paper, we compared the species frequencies obtained for the same set of species-rich sites (wetlands of central Italy) from two different methods: McKinnon lists and line transects. In all sites we observed: (i) rapid cumulating curves of line transect abundance frequencies toward the asymptote represented by the maximum value in McKinnon occurrence frequency; (ii) a large amount of species having a low frequency with line transect method showing a high range of variation in frequency obtained by McKinnon lists; (iii) a set of species having a subdominant (>0.02-<0.05) and dominant species (>0.05) frequency with line transect showed all the highest value in McKinnon frequency. McKinnon lists provides only a coarse-grained proxy of species frequency of individuals distinguishing only between common species (having the highest values of McKinnon frequency) and rare species (all the other species). Although McKinnon lists have some points of strength, this method does not discriminate the frequencies inside the subset of common species (sub-dominant and dominant species). Therefore, we suggest a cautionary approach when McKinnon frequencies should be used to obtain complex univariate metrics of diversity.     

A morphological and molecular perspective of Trichoderma viride: is it one or two species?

Trichoderma (Ascomycetes, Hypocreales) strains that have warted conidia are traditionally identified as T. viride, the type species of Trichoderma. However, two morphologically distinct types of conidial warts (I and II) have been found. Because each type corresponds to a unique mitochondrial DNA pattern, it has been questioned whether T. viride comprises more than one species. Combined molecular data (sequences of the internal transcribed spacer 1 [ITS-1] and ITS-2 regions and of part of the 28S rRNA gene along with results of restriction fragment length polymorphism analysis of the endochitinase gene and PCR fingerprinting), morphology, physiology, and colony characteristics distinguish type I and type II as different species. Type I corresponds to "true" T. viride, the anamorph of Hypocrea rufa. Type II represents a new species, T. asperellum, which is, in terms of molecular characteristics, close to the neotype of T. hamatum.     

Model versus model or model versus data? A commentary on Berg and McDowell's "Quantitative, steady-state properties of Catania's computational model of the operant reserve"

Berg and McDowell's (2011) systematic exploration of some parameters of Catania's (2005) operant reserve model generated significant departures from the data predicted by matching models, especially in the form of an inflection point at the low end of the input-output function. The models need to be compared not only with each other but also with data. Much of the data to which both models have been fitted was obtained decades ago using equipment that constrained procedures and created unanalyzed contingencies. For example, in those days scheduled but unobtained reinforcers could not accumulate. To do justice to the sophistication of contemporary models, we need new data sets based on schedules that do not include such artifacts. Without such data, it is impossible to say whether the Berg/McDowell inflections are properties of behavior revealed by the model or are instead deviations of the model from real behavior and from other models.     

Is the polymorphism of protein amounts related to phenotypic variability? A comparison of two-dimensional electrophoresis data with morphological traits in maize

Summary The hypothesis that the quantitative variations in gene product levels could be a more important basis for morphological and adaptative change than the classical qualitative variability revealed by electrophoretic techniques was studied by comparing five maize lines from three sets of variables: (i) qualitative variations of proteins (presence/absence) revealed by two-dimensional polyacrylamide gel electrophoresis (2D PAGE), at a physiological seedling stage; (ii) quantitative variations in proteins (spots more or less intense) revealed by 2D PAGE, at the same physiological stage; (iii) general combining abilities of fourteen heritable, morphological or agronomical characters measured at various juvenile and adult stages. Distances between lines were defined, based on qualitative and quantitative variations of proteins. These distances do not appear to be correlated and do not give the same patterns of divergence between lines, as shown by principal coordinate analyses. Mahalanobis distances computed from the general combining abilities of the morphological characters are significantly correlated (r=0.75) to quantitative but not to qualitative distances. The comparison of the first planes of the principal coordinate analyses performed on the three kinds of distances clearly confirms this finding. Our results are discussed in connection with the possible genetic meaning of the two molecular distances and with the hypothesis that regulatory processes are primarily implicated in morphological variation.     

A comparison of two subarachnoid α2-agonists,xylazine and clonidine,with respect to duration of antinociception,and hemodynamic effects in goats

Subarachnoid administration of clonidine and xylazine produces antinociception in several species and in humans. The present study compares these two drugs administered by the subarachnoid route to goats. Goats (n=6) were randomly assigned to three treatment groups. All animals of each group received 0.06 mg kg⁻¹ clonidine (CLO), 0.1 mg kg⁻¹ xylazine (XIL) and 0.9% saline solution (SS), with a minimum interval of 1 week between treatments. All injections were made into the subarachnoid space between the last lumbar vertebra and the first sacral vertebra. Analgesia, ataxia, sedation, cardiovascular and respiratory effects, and rectal temperature were evaluated at predefined regular time intervals before drug administration (baseline) and after administration. The onset of analgesia by clonidine and xylazine was observed in 6.8±1.8 and 9.5±2.6 min (mean±S.D.), respectively. Both α₂-agonists produced analgesia of dorsocaudal rib areas, flanks, hind limbs, perineum and tail, sedation and ataxia. The duration of antinociception after clonidine administration was 118.8±24 min and after xylazine 88.3±15 min (mean±S.D.). Clonidine and xylazine subarachnoidally administered induced a significant (P<0.05) decrease in heart and respiratory rates and hypothermia in relation to the basal value. Neither drug significantly altered blood pressure. Both α₂-agonist drugs induced frequent diuresis and an increase in salivation. We conclude that subarachnoid clonidine produces longer antinociception with less ataxia than xylazine in goats. However, the drug induced bradycardia, a decrease in the respiratory rate and hypothermia, with a small compromise in the blood pressures at the doses studied. Further studies should be done to determine whether this analgesia is sufficient for surgical procedures.     

Application and comparison of remote sensing GPP models with multi-site data in China北大核心CSCD

Aims Estimation of gross primary productivity (GPP) of vegetation at the global and regional scales is important for understanding the carbon cycle of terrestrial ecosystems. Due to the heterogeneous nature of land surface, measurements at the site level cannot be directly up-scaled to the regional scale. Remote sensing has been widely used as a tool for up-saling GPP by integrating the land surface observations with spatial vegetation patterns. Although there have been many models based on light use efficiency and remote sensing data for simulating terrestrial ecosystem GPP, those models depend much on meteorological data; use of different sources of meteorological datasets often results in divergent outputs, leading to uncertainties in the simulation results. In this study, we examines the feasibility of using two GPP models driven by remote sensing data for estimating regional GPP across different vegetation types. Methods Two GPP models were tested in this study, including the Temperature and Greenness Model (TG) and the Vegetation Index Model (VI), based on remote sensing data and flux data from the China flux network (ChinaFLUX) for different vegatation types for the period 2003-2005. The study sites consist of eight ecological stations located in Xilingol (grassland), Changbaishan (mixed broadleaf-conifer forest), Haibei (shrubland), Yucheng (cropland), Damxung (alpine meadow), Qianyanzhou (evergreen needle-leaved forest), Dinghushan (evergreen broad-leaved forest), and Xishuangbanna (evergreen broad-leaved forest), respectively. Important findings All the remote sensing parameters employed by the TG and VI models had good relationships with the observed GPP, with the values of coefficient of determination, R2, exceeding 0.67 for majority of the study sites. However, the root mean square errors (RMSEs) varied greatly among the study sites: the RMSE of TG ranged from 0.29 to 6.40 g·m-2·d-1, and that of VI ranged from 0.31 to 7.09 g·m-2·d-1, respectively. The photosynthetic conversion coefficients m and a can be up-scaled to a regional scale based on their relationships with the annual average nighttime land surface temperature (LST), with 79% variations in m and 58% of variations in a being explainable in the up-scaling. The correlations between the simulated outputs of both TG and VI and the measured values were mostly high, with the values of correlation coefficient, r, ranging from 0.06 in the TG model and 0.13 in the VI model at the Xishuangbanna site, to 0.94 in the TG model and 0.89 in the VI model at the Haibei site. In general, the TG model performed better than the VI model, especially at sites with high elevation and that are mainly limited by temperature. Both models had potential to be applied at a regional scale in China.     

Weak or strong invaders? A comparison of impact between the native and invaded ranges of mammals and birds alien to Europe

Aim Species introduced to an area outside of their native range are often thought to have higher impact in this new area. We examined whether this is really the case in mammals and birds and to what extent. In particular, we explored how impacts of alien species vary in relationship to invader identity and type of impact. Location Global. Methods We conducted a thorough review of the literature to compare the impact of alien European mammals and birds in their native and invaded ranges. Based on a series of environmental and economic impact scores, we ordered species along a continuum from weak invaders, which have lower impact in the invaded range, to strong invaders, which have higher impact in the invaded range. Results We found that nearly 80% of the mammals are strong invaders, but only half of the birds. Members of these two classes also affect their communities in different ways; birds more often have an impact via hybridization, whereas mammals have stronger impacts via herbivory, transmission of diseases to wildlife and their effects on agriculture, livestock and forestry. Main conclusions Generally, mammals and birds have different impacts when invading new regions. Although there are some bird species that are strong invaders, these remain the exception among birds, whereas most mammals increase their impact in the invaded range. This study provides a deeper insight into patterns of impact in the invaded range.     

Are tree trunks habitats or highways? A comparison of oribatid mite assemblages from hoop-pine bark and litter

Abstract Oribatid mites (Acari: Oribatida) are among the most diverse and abundant inhabitants of forest soil and litter, but also have species-rich assemblages on bark and in the canopies of trees. It is unclear whether the trunk of a tree acts simply as a 'highway' for movement of mites into and out of the canopy, or whether the trunk has a distinctive acarofauna. We compare oribatid assemblages from the trunk bark of hoop pine ( Araucaria cunninghamii ) with those from litter collected beneath the same trees. A 1.0 by 0.5 m area of bark was sampled from three trees at each of five sites using a knockdown insecticide. A 1-L sample of leaf litter was collected as close as possible to the base of each sampled tree. Mites were extracted using Tullgren funnels, identified to genus and morphospecies, and counted. Assemblages were almost 100% distinct, with only one oribatid morphospecies ( Pseudotocepheus sp.) collected from both litter and bark. Litter had a higher taxon richness than bark in total and per sample, but oribatids made up a greater percentage of the acarofauna in the bark samples. We had expected that the more consistent physical substrate of bark would be reflected in greater similarity of oribatid faunas on trunks than in litter; however, the opposite proved to be the case. We conclude that hoop-pine trunks are habitats rather than highways for oribatid mites. Based on the observed higher turnover among bark faunas, tree trunks may represent habitat islands whose colonisation by particular oribatid species is more stochastic than that of the more continuous 'sea' of litter.     

To catch or to sight? A comparison of demographic parameter estimates obtained from mark-recapture and mark-resight models

Accurate assessments of population parameters, such as survival and abundance, are critical for effective wildlife conservation. In order for wildlife managers to undertake long-term monitoring of populations, the data collection must be as cost-effective as possible. Two demographic modelling techniques commonly used are mark-recapture and mark-resight. Mark-resight can be used in conjunction with biotelemetry methods and offers a more cost effective alternative to the traditional mark-recapture models. However, there has been no empirical comparison of the demographic parameters obtained from the two modelling techniques. This study used photographs of natural markings to individually identify wobbegong sharks (Orectolobus maculatus) sighted during underwater surveys over a 2 year period, during eight distinct sampling periods, and analysed with Pollock’s robust design mark-recapture models. These estimates were then compared, using z tests, with Poisson-lognormal mark-resight models that used resightings of sharks previously tagged with telemetry transmitters, and the telemetry data to calculate the number of marked animals present in each sampling period. Sharks were categorised into four groups according to their sex and age-class (adult/juvenile). The results indicated that there was a high degree of transience in the population, with 62 % of sharks only being sighted in one sampling period. Based on normalized Akaike weights, there was no single ‘best’ model for either type of modelling technique and model averaging was used to determine the demographic estimates. Both models showed higher abundance of wobbegongs in the austral spring and summer seasons, however, the models produced statistically different results for five of the eight sampling periods. The mark-recapture model estimated apparent survival between 78 and 95 %, whereas the mark-resight models estimated it between 48 and 97 %. Crucially, there was no statistical difference between the survival estimates from corresponding sex/age-class. The temporary emigration parameters differed substantially between the model types. The mark-recapture model showed support for Markovian movement, whereas the mark-resight supported random emigration. The timing of the tagging events likely biased the abundance and temporary emigration parameters estimated by mark-resight models and must be taken into consideration when designing a mark-resight study. Despite this, this study shows that robust demographic estimates, that are comparable to labour intensive mark-recapture estimates, can still be obtained using mark-resight methods. Given the substantial increase in biotelemetry studies of medium and large sized vertebrates, mark-resight models may play an important future role in estimating demographic parameters.     

Is health status of elderly worsening in India? A comparison of successive rounds of national sample survey data

The increasing greying of India's population raises concerns about the welfare and health status of the aged. One important source of information of health status of the elderly is the National Sample Survey Rounds on Morbidity and Health Care Expenditure. Using unit-level data for 1995-96 and 2004, this paper examines changes in reported health status of the elderly in India and analyses their relationship with living arrangements and extent of economic dependency. It appears that even after controlling for factors like caste, education, age, economic status and place of residence, there has been a deterioration in self-perceived current health status of the elderly. The paper argues that, although there have been changes in the economic condition and traditional living arrangements--with a decline in co-residential arrangements--this is not enough to explain the decline in reported health status and calls for a closer look at narratives of neglect being voiced in developing countries.     

Preparation,properties and crystal structures of nickel(II) complexes with acyclic schiff bases derived from 2,6-diformyl-4-chlorophenol and 1,5-diamino-3-thiapentane or 3,3′-diamino-N-methyl-dipropylamine

Nickel(II) complexes with the compartmental Schiff bases derived from 2,6-diformyl-4-chlorophenol and 1,5-diamino-3-thiapentane (H₂L¹) or 3,3′-diamino-N-methyl-dipropylamine (H₂L²) were synthesized, and the crystal structures of [Ni(L¹)- (py)₂] and [Ni(L²)(dmf)]·H₂0 were determined by X-ray crystallography.Ni(L¹)(py)₂ is monoclinic, space group C2/c, with a= 18.457(6), b = 11.116(7), c= 16.098(6) Å, and β = 115.79(5)°; D_c = 1.49 g cm⁻³ for Z = 4. The structure was refined to the final R of 6.9%. The molecule has C₂ symmetry. The nickel atom is six-coordinated octahedral. Selected bond lengths are: NiO 2.04(1) Å, NiN (L¹) 2.08(1) Å, NiN(py) 2.17(1) Å.[Ni(L²)(dmf)]·H₂O is monoclinic, space group P2₁/n, with a = 17.329(6), b = 13.322(7), c = 12.476(7) Å and β = 95.43(5)°; D_c = 1.45 g cm⁻³ for Z = 4. The structure was refined to the final R of 5.1%. The nickel atom is bonded in the octahedral geometry to the bianionic pentadentate ligand L² and to one molecule of dimethylformamide. Selected bond lengths are: NiO (charged) 2.063(3) Å (mean value), NiO (neutral) 2.120(3) Å, NiN (planar) 2.050(3) Å (mean value), NiN (tetrahedral) 2.177(3) Å.     

Introduced delicacy or native species? A natural origin of Bermudian terrapins supported by fossil and genetic data

Humans have greatly altered the natural distribution of species, making it difficult to distinguish between natural and introduced populations. This is a problem for conservation efforts because native or introduced status can determine whether a species is afforded protection or persecuted as an invasive pest. Holocene colonization events are especially difficult to discern, particularly when the species in question is a naturally good disperser and widely transported by people. In this study, we test the origin of such a species, the diamondback terrapin (Malaclemys terrapin), on Bermuda using a combination of palaeontologic (fossil, radiometric and palaeoenvironmental) and genetic data. These lines of evidence support the hypothesis that terrapins are relatively recent (between 3000 and 400 years ago) natural colonizers of Bermuda. The tiny population of Bermudian terrapins represents the second naturally occurring non-marine reptile that still survives on one of the most densely populated and heavily developed oceanic islands in the world. We recommend that they should be given protection as a native species.     

Rep-PCR - a variant to RAPD or an independent technique of bacteria genotyping? A comparison of the typing properties of rep-PCR with other recognised methods of genotyping of microorganisms

The paper presents technical aspects of rep-PCR fingerprinting technique and compares its typing abilities, differentiation power and reproducibility with other recognised and recommended genotyping methods. Although rep-PCR fingerprinting is similar to MAAP techniques, it demonstrates some essentially different elements. The data presented in this review, indicate a rep-PCR genomic fingerprinting technique as a highly discriminating, independent screening method for determining the taxonomical diversity of bacterial population.     

Pathogenicity and transmissibility of 2019-nCoV—A quick overview and comparison with other emerging viruses

A zoonotic coronavirus, tentatively labeled as 2019-nCoV by the World Health Organization (WHO), has been identified as the causative agent of the viral pneumonia outbreak in Wuhan, China, at the end of 2019. Although 2019-nCoV can cause a severe respiratory illness like SARS and MERS, evidence from clinics suggested that 2019-nCoV is generally less pathogenic than SARS-CoV, and much less than MERS-CoV. The transmissibility of 2019-nCoV is still debated and needs to be further assessed. To avoid the 2019-nCoV outbreak turning into an epidemic or even a pandemic and to minimize the mortality rate, China activated emergency response procedures, but much remains to be learned about the features of the virus to refine the risk assessment and response. Here, the current knowledge in 2019-nCoV pathogenicity and transmissibility is summarized in comparison with several commonly known emerging viruses, and information urgently needed for a better control of the disease is highlighted.     

The polarized UV-absorption spectra and the crystal structure of two different monoclinic crystal forms of the retinal homologue β-8′-apocarotenal

During the visual process, light absorption in the 11-cis retinylidene chromophore leads to a rapid cis-trans-isomerization which initiates the phototransduction step. Important spectroscopic properties of this chromophore can be derived from polarized UV-absorption spectra of crystalline 11-cis-retinal if a parallel X-ray structure analysis is performed. Several questions about the relation between molecular geometry and spectroscopic behavior could not be answered from these spectra. All crystal forms of 11-cis-retinal contain this molecule in its 6-s-cis-ring conformation. For the retinal homologue, -8-apocarotenal (APC), however, two crystal forms with different ring conformation can be grown. The spectrum of -APC (6-s-cis) shows a vibronic structure whereas that of -APC (6-s-trans) is diffuse but has a distinct shoulder on the low energy side of the main band. This S-band is typical for retinal spectra and has been ascribed to a transition into a ¹A _g ^-* -state. The appearance of the S-band is not correlated with a 6-s-cis-conformation as suggested by the retinal spectra but is due to intermolecular interactions: -APC has a dense dimer packing and a strong electrostatic interaction between the -electron systems. This might cause the forbidden ¹A _g ^-* -transition. On the other hand, this interaction is missing in the loose and polar packing of -APC which favors vibration in the polyene chain. This finding is remarkable in view of the photodynamic behavior of the visual chromophore for which strong electrostatic interactions with the protein helices of its binding site have to be postulated.Abbreviations APC 8--Apocarotenal - -APC/-APC /-form of crystallized APC - -CIS/-CIS /-form of crystallized 11-cis-retinal - ATR all-trans retinal - UV ultraviolet light - CI quantum-mechanical calculation employing configuration interaction - PPP-MRD quantum-mechanical calculations after Pariser, Parr, Pople employing multireference determinants - S-bands shoulder on main absorption band - R, S right, left enantiomer - EtOH ethyl alcohol - PE petroleum ether - E direction of electric vector of incident light - b crystallographic b-axis     

A comparison of the crosslinking abilities of glutaraldehyde,formaldehyde and α-hydroxyadipaldehyde with bovine serum albumin and casein

Summary The crosslinking effects of formaldehyde, -hydroxyadipaldehyde and glutaraldehyde have been compared by various techniques. Using a micro-Ouchterlony technique with an aldehyde treated bovine serum albumin-rabbit anti-bovine serum albumin system it was found that glutaraldehyde prevented precipitin line formation except at very high titres of antibody. The effects of formaldehyde and -hydroxyadipaldehyde were less marked. Cellulose acetate electrophoresis of aldehyde treated bovine serum albumin showed an increase in mobility compared with the untreated protein. Starch gel electrophoresis of aldehyde fixed liver slices showed no protein loss after glutaraldehyde fixation whereas the other aldehydes permitted proteins to be extracted. Polyacrylamide gel electrophoresis of the aldehyde treated bovine serum albumin showed a little change in mobility after formaldehyde and -hydroxyadipaldehyde treatment and a little polymer formation. Glutaraldehyde on the other hand produced much polymer. These findings were confirmed by gel filtration with Sephadex G-200. Intermolecular crosslinking with glutaraldehyde was dependant on the aldehyde concentration.     

Synthesis and evaluation of two series of 4′-aza-carbocyclic nucleosides as adenosine A2A receptor agonists

The synthesis of two series of 4′-aza-carbocyclic nucleosides are described in which the 4′-substituent is either a reversed amide, relative to the carboxamide of NECA, or an N-bonded heterocycle. Using established purine substitution patterns, potent and selective examples of agonists of the human adenosine A_2A receptor have been identified from both series. The propionamides 14–18 and the 4-hydroxymethylpyrazole 32 were determined to be the most potent and selective examples from the 4′-reversed amide and 4′-N-bonded heterocyclic series, respectively.