Important Biological Parameter Research Articles

Vertical and Horizontal Variability of Chlorophyll-a and Its Relationship with Environmental Parameters in the Waters of Sangihe and Talaud Islands, North Sulawesi, Indonesia

The chlorophyll-a is an important biological parameter that could act as a proxy to indicate the abundance of phytoplankton and the primary productivity of an aquatic ecosystem. This paper investigates the vertical and horizontal variability of chlorophyll-a in the waters of Sangihe and Talaud Islands, Indonesia, and its correlation with water environmental parameters. In this study, the distribution of chlorophyll-a, temperature, salinity, and nutrients (NO3 and PO4) from the surface to a depth of 200 m (photic zone) was measured at 29 research stations. The results showed that the distribution of chlorophyll-a in the waters of the Sangihe-Talaud Islands was varied vertically and horizontally. The waters around the Sangihe Islands generally exhibited a higher chlorophyll-a distribution and shallower Deep Chlorophyll Maxima compared to the water around the Talaud Islands. The concentration of chlorophyll-a varied between 0.0017 and 1.2155 mg.m-3, with most of the water column in Sangihe-Talaud considered oligotrophic, although some stations or depths were mesotrophic or slightly eutrophic. The maximum chlorophyll-a concentration was found in the sub-surface layer at depths between 46 and 101 m. The low N:P ratio (<16) and N:Si ratio (<1) indicate that the water columns of Sangihe-Talaud, up to a depth of 200m, were N-limited. Based on the GAM analysis, chlorophyll-a concentration in Sangihe-Talaud waters was primarily regulated by temperature, salinity, and the N:P ratio, with weak influence from phosphate and the N:Si ratio. The analysis also suggests that primary productivity in Sangihe-Talaud is sensitive to temperature changes, indicating its vulnerability to future warming events.

Vimentin-positive invasive breast carcinoma of no special type: A breast carcinoma with lethal biological characteristics.

Vimentin is a stable mesenchymal immunohistochemical marker and is widely recognized as a major marker of mesenchymal tumors. The purpose of the present study was to investigate if the vimentin expression status might serve as a significant predictor of outcomes in patients with invasive breast carcinoma of no special type (IBC-NST) and to investigate, by comprehensive RNA sequencing analyses, the mechanisms involved in the heightened malignant potential of vimentin-positive IBC-NSTs. This study, conducted using the data of 855 patients with IBC-NST, clearly identified vimentin expression status as a very important independent biological parameter for accurately predicting the outcomes in patients with IBC-NST. RNA sequence analyses clearly demonstrated significant upregulation of coding RNAs known to be closely associated with cell proliferation or cellular senescence, and significant downregulation of coding RNAs known to be closely associated with transmembrane transport in vimentin-positive IBC-NSTs. We conclude that vimentin-positive IBC-NSTs show heightened malignant biological characteristics, possibly attributable to the upregulation of RNAs closely associated with proliferative activity and cellular senescence, and downregulation of RNAs closely associated with transmembrane transport in IBC-NSTs.

RDHCformer: Fusing ResDCN and Transformers for Fetal Head Circumference Automatic Measurement in 2D Ultrasound Images.

Fetal head circumference (HC) is an important biological parameter to monitor the healthy development of the fetus. Since there are some HC measurement errors that affected by the skill and experience of the sonographers, a rapid, accurate and automatic measurement for fetal HC in prenatal ultrasound is of great significance. We proposed a new one-stage network for rotating elliptic object detection based on anchor-free method, which is also an end-to-end network for fetal HC auto-measurement that no need for any post-processing. The network structure used simple transformer structure combined with convolutional neural network (CNN) for a lightweight design, meanwhile, made full use of powerful global feature extraction ability of transformer and local feature extraction ability of CNN to extract continuous and complete skull edge information. The two complement each other for promoting detection precision of fetal HC without significantly increasing the amount of computation. In order to reduce the large variation of intersection over union (IOU) in rotating elliptic object detection caused by slight angle deviation, we used soft stage-wise regression (SSR) strategy for angle regression and added KLD that is approximate to IOU loss into total loss function. The proposed method achieved good results on the HC18 dataset to prove its effectiveness. This study is expected to help less experienced sonographers, provide help for precision medicine, and relieve the shortage of sonographers for prenatal ultrasound in worldwide.

Pre-analytical phase impact in the differences in natremia obtained by direct and indirect ion selective electrodes methods

Natremia is an important biological parameter providing information on the hydration state of patient's intracellular sector. Its measurement can be carried out either by multiparametric laboratory analyser (indirect potentiometry) or delocalized biology analyser (direct potentiometry). The main problem is that for a same patient, these two analysers can give quite different results, hence inducing interpretation problems for clinician. Two one-week study periods comparing the variations in blood sodium levels produced by these automatic analysers were carried out in two intensive care units of Clermont-Ferrand University Hospital. During the second study period, a protocol for collecting blood samples was applied in order to improve the pre-analytical conditions. Between the two weeks of studies, the median of the differences in natremia was significantly reduced, going from 4mmol/L to 2mmol/L (p <0.001), as was the proportion of patients with large differences in sodium levels (strictly higher than 3mmol/L) going from 51% to 24.8% (p <0.001). The patients still presenting large variations in sodium had a median of proteins significantly lower than patients with deviations less than or equal to 3mmol/L: 58.1g/L against 62.25g/L respectively (p <0.001) leading to pseudo-hypernatremia (indirect potentiometry). Despite a significant reduction in differences linked to the application of good preanalytical practices, some patients nonetheless presented a major difference in natremia due to the difference of technique (variations in the lipidoprotein phase of the plasma of intensive care patients) and to the measurement uncertainties.

Derivation of Regression Equation for Estimation of Height from the Length of Clavicles

Background: The various features of clavicle help to decide the gender and height of the individual.Stature is an important biological parameter in medico-legal forensic examination. The length of clavicleis considered as an important anthropological parameter. The present study was undertaken with the aim ofderiving of regression equation for estimation of height from the lengths of clavicle.Methodology: This cross sectional, observational study was conducted from October 2019 to February2020 after getting approval from IEC. 489 healthy subjects (290 males and 199 females) were included inthe study after getting the informed consent. Length of clavicle and height of individual were measured andmean was calculated. Regression equations were derived after statistical analysis.Results: The values obtained by statistical analysis were found statistically significant. Equation werederived for estimation of height from right and left clavicles in males as well as females. The mean lengthsof right sided clavicles are more than that of left sided clavicles in both the genders.Discussion: Stature estimation is key parameter in the identification process of unknown individuals inwhich human remains are found in mutilated form or as skeletal remains. In the present study, we attemptedto correlate the lengths of clavicle with stature of individual. The present study also proved that lengths ofclavicles are more in males than in females which can be attributed to heavy built in males.

Research on volume prediction of single tree canopy based on three-dimensional (3D) LiDAR and clustering segmentation

ABSTRACT Canopy volume information of fruit trees is a very important biological parameter, which is of great significance to predict the yield of fruit trees, estimate the application amount of pesticides and fertilizers. This study proposes a novel volume prediction method of single tree canopy based on the three-dimensional (3D) Light Detection and Ranging (LiDAR) point cloud. The method involves several steps, mainly including point cloud pre-processing, spatial clustering segmentation based on K-dimensional tree (KD tree), acquisition of single tree structural parameters, calculation of tree canopy volume based on multiple regression analysis. This study tests the performance of the proposed method with a collected data set of Begonia forest. The average error and standard deviation between the predicted and manually measured heights to the canopy are 0.038 m and 0.030 m, respectively. As to the diameter of the trunk, the average error and standard deviation are 0.013 m and 0.008 m, respectively. The coefficient of determination (R 2) of the proposed canopy volume prediction method is 0.8610, and the F test result is significant. High correlation is found between the predicted canopy volumes and the R 2 value is 0.8223. The experimental results verify the validity of the proposed method. The research can provide a stable and accurate technical reference for the statistics on forest biomass.

Determination of Condition Factor (CF) and Hepatosomatic Index (HSI) of Barbonymus schwanenfeldii from Galas River, Kelantan

The rapid growth of agriculture and industrial activities has resulted in decreasing of water quality in the aquatic ecosystem, which is significantly hazardous for fish health. Fish are commonly situated at the top of aquatic food chain is known to be nutritious with essential proteins. The purpose of this study is to determine the condition factor and hepatosomatic index of Barbonymus schwanenfeldii from Galas River, Kelantan. The sizes of slaughtered fish ranging from 319 ± 0.05 to 456 ± 1.32 g in weight while 28 ± 0.34 to 36 ± 1.42 cm in total length. From a sample size of 40 specimens, the average of K value was 1.15 ± 0.21 and 2.31 ± 0.13 of HSI value. Thus, the results revealed that the fish species was in a poor condition. Refer to the matter; the condition of study area is not suitable for fish habitat. Condition factor of fishes is important biological parameter which can provides information on fish well-being. The condition factor and hepatosomatic index compares the well-being of a fish is based on the hypothesis that heavier fish of a given length are in a better condition.

Characteristics of canopy stomatal conductance of Platycladus orientalis and its responses to environmental factors in the mountainous area of North China

Canopy stomatal conductance (gs) is an important biological parameter to measure water vapor flux in canopy atmosphere interface. Exploring characteristics of canopy stomatal conductance and its responses to environmental factors can offer theoretical evidence for conducting mechanism based study of vapor exchange process in forest canopy. SF-L thermal dissipation probe was adopted to measure sap flow density (Js) of Platycladus orientalis in 2014. The environmental factors including photosynthetically active radiation (PAR), vapor pressure deficit (VPD) and air temperature (T) were simultaneously observed. The canopy stomatal conductance was calculated, and the responses of gs to environmental factors were analyzed. The results showed that the daily variation of sap flow density was of two peak pattern curve, and the Js in growing season was higher than in non-growing season. And the bigger DBH was, the higher Js would be. The daily variation of canopy stomatal conductance was similar to the canopy transpiration of per leaf area (EL), which was of two peak pattern curve. The gs and EL in growing season were higher than those in non growing season. The canopy stomatal conductance and air temperature presented parabolic relation, and gs reached peak valley at around 10 ℃. Taking the value of 400 μmol·m-2·s-1 as the PAR thre shold, when PAR was under this threshold, gs was positively correlated with PAR. When PAR was beyond this threshold, the correlation between gs and PAR would be small. The relationship between canopy stomatal conductance and vapor pressure deficit was negative logarithmic function. As VPD increasing, gs decreased gradually. Higher air temperature and photosynthetically active radiation, and lower vapor pressure deficit contributed to higher canopy stomatal conductance of P. orientalis and could promote greater canopy transpiration.

Pore size estimation from double diffusion encoding

Abstract Double diffusion encoding is a magnetic resonance technique with applications in measuring microstructure. In many tissues, cell size (which is of a few micrometers) is an important biological parameter. Estimating an arbitrary pore size distribution from a diffusion attenuated signal usually relies on varying a single experimental setting. This inversion process is numerically unstable. Numerical simulations are presented, where multiple experimental settings are varied concomitantly. The inversion’s results show good agreement with ground truth.

Assimilating leaf area index of three typical types of subtropical forest in China from MODIS time series data based on the integrated ensemble Kalman filter and PROSAIL model

Subtropical forest ecosystems play essential roles in the global carbon cycle and in carbon sequestration functions, which challenge the traditional understanding of the main functional areas of carbon sequestration in the temperate forests of Europe and America. The leaf area index (LAI) is an important biological parameter in the spatiotemporal simulation of the carbon cycle, and it has considerable significance in carbon cycle research. Dynamic retrieval based on remote sensing data is an important method with which to obtain large-scale high-accuracy assessments of LAI. This study developed an algorithm for assimilating LAI dynamics based on an integrated ensemble Kalman filter using MODIS LAI data, MODIS reflectance data, and canopy reflectance data modeled by PROSAIL, for three typical types of subtropical forest (Moso bamboo forest, Lei bamboo forest, and evergreen and deciduous broadleaf forest) in China during 2014–2015. There were some errors of assimilation in winter, because of the bad data quality of the MODIS product. Overall, the assimilated LAI well matched the observed LAI, with R2 of 0.82, 0.93, and 0.87, RMSE of 0.73, 0.49, and 0.42, and aBIAS of 0.50, 0.23, and 0.03 for Moso bamboo forest, Lei bamboo forest, and evergreen and deciduous broadleaf forest, respectively. The algorithm greatly decreased the uncertainty of the MODIS LAI in the growing season and it improved the accuracy of the MODIS LAI. The advantage of the algorithm is its use of biophysical parameters (e.g., measured LAI) in the LAI assimilation, which makes it possible to assimilate long-term MODIS LAI time series data, and to provide high-accuracy LAI data for the study of carbon cycle characteristics in subtropical forest ecosystems.

Phenotypic changes associated with the fitness cost in antibiotic resistant Escherichia coli strains.

the acquisition of antibiotic resistance in bacterial cells is often accompanied with a reduction of fitness in the absence of antibiotics, known as the "fitness cost". The magnitude of this fitness cost is an important biological parameter that influences the degree to which antibiotic resistant strains become widespread. However, the relationship between the fitness cost and comprehensive phenotypic and genotypic changes remains unclear. Here, we quantified the fitness cost of resistant strains obtained by experimental evolution in the presence of various antibiotics, and analyzed how the cost correlated to phenotypic and genotypic changes in the resistant strains. we measured the specific growth rate of the resistant strains in the presence of various concentrations of drugs or in their absence. In the absence of drugs, the resistant strains showed reductions of approximately 20% to 50% in growth rate compared with the parent strain, which corresponded to the fitness cost. We found that the decrease of the specific growth rate was correlated with overall expression changes between the parent and resistant strains, measured by the Euclid distance between expression profiles. We also found that there are a number of genes whose changes in expression levels were significantly correlated with the growth rate, which may account for the observed correlation between the fitness cost and overall expression changes. our analysis provides a basis for quantitative understanding of the mechanism of the fitness cost. This understanding may provide clues on how to influence the fitness cost that accompanies resistance acquisition and consequently how to limit the spread of antibiotic resistant strains.

The Frequency of Granulocytes with Spontaneous Somatic Mutations: A Wide Distribution in a Normal Human Population

Germ-line mutation rate has been regarded classically as a fundamental biological parameter, as it affects the prevalence of genetic disorders and the rate of evolution. Somatic mutation rate is also an important biological parameter, as it may influence the development and/or the course of acquired diseases, particularly of cancer. Estimates of this parameter have been previously obtained in few instances from dermal fibroblasts and lymphoblastoid cells. However, the methodology required has been laborious and did not lend itself to the analysis of large numbers of samples. We have previously shown that the X-linked gene PIG-A, since its product is required for glycosyl-phosphatidylinositol-anchored proteins to become surface bound, is a good sentinel gene for studying somatic mutations. We now show that by this approach we can accurately measure the proportion of PIG-A mutant peripheral blood granulocytes, which we call mutant frequency, ƒ. We found that the results are reproducible, with a variation coefficient (CV) of 45%. Repeat samples from 32 subjects also had a CV of 44%, indicating that ƒ is a relatively stable individual characteristic. From a study of 142 normal subjects we found that log ƒ is a normally distributed variable; ƒ variability spans a 80-fold range, from less than 1×10−6 to 37.5×10−6, with a median of 4.9×10−6. Unlike other techniques commonly employed in population studies, such as comet assay, this method can detect any kind of mutation, including point mutation, as long as it causes functional inactivation of PIG-A gene. Since the test is rapid and requires only a small sample of peripheral blood, this methodology will lend itself to investigating genetic factors that underlie the variation in the somatic mutation rate, as well as environmental factors that may affect it. It will be also possible to test whether ƒ is a determinant of the risk of cancer.

Biologic importance and prognostic significance of selected clinicopathological parameters in patients with oral and oropharyngeal squamous cell carcinoma, with emphasis on smoking, protein p16INK4a expression, and HPV status

The aim of this study is to evaluate the biologic importance and prognostic significance of selected clinicopathological parameters in patients with oral (OSCC) and oropharyngeal (OPSCC) squamous cell carcinoma, with emphasis on smoking, protein p16(INK4a) (p16) expression, and human papillomavirus (HPV) status.The study sample consisted of 48 patients with OSCC and 44 patients with OPSCC. Half of the patients were nonsmokers and the other half were gender-, age- and tumor localization-matched smokers. p16 expression was detected in 17/48 (35 %) OSCCs and in 36/44 (82 %) OPSCCs and HPV DNA was present in 7/48 (15 %) OSCCs and in 35/44 (80 %) OPSCCs. The sensitivity and specificity of p16 expression for HPV DNA presence were 0.74 and 0.88, respectively. The OPSCCs were more frequently basaloid (p < 0.001) while the OSCCs were more frequently conventional (p < 0.000001). The OSCCs were more likely to recur locally and to be the cause of death (p = 0.009 in both parameters).The HPV-positive tumors were more frequently localized in oropharynx, were basaloid SCCs and were p16- and HPV-positive (p < 0.000001 in all 4 parameters). The HPV-negative tumors were more frequently localized in oral cavity (p < 0.000001), more frequently asociated with local, regional and locoregional recurence (p = 0.011, p = 0.019 and p = 0.030, respectively) and with tumor-related death (p = 0.003). There was no significant difference with regard to smoking history (p > 0.05). The survival of patients with HPV-positive tumors was significantly longer (median 112 months; 95% CI 54 - 112 months) than that of patients with HPV-negative tumors (median 17 months; 95% CI 12 - 39 months) (p < 0.001). The HPV status of OSCC/OPSCC is an important biological and prognostic parameter and should be examined in all cases, using PCR or immunohistochemical detection of surrogate marker p16. Smoking itself does not seem to be an important prognostic factor.

Auricular surface aging: A blind test of the revised method on historic Italians from Sardinia

Age determination from human skeletal remains is an important biological parameter in both forensic and bioarchaeological contexts. This study presents the results of a blind test of the revised auricular surface age estimation method proposed by Buckberry and Chamberlain (Am. J. Phys. Anthropol. 119 (2002) 321-329) on a large sample (n=404) of known sex and age from the Sassari collection, housed at the Museum of Anthropology, University of Bologna, Italy. Ilia were scored for five features: transverse organization, surface texture, microporosity, macroporosity, and apical changes, which combined for a composite score. The results indicated that all features and the composite score were positively correlated with known age. Composite scores were significantly different between the sexes, suggesting that males and females should be treated separately. Bias and inaccuracy varied across age intervals. Age tended to be overestimated in individuals under age 59 and underestimated for those over age 60 years. However, the revised method showed improvement over the original auricular surface method (Lovejoy et al., Am. J. Phys. Anthropol. 68 (1985) 15-28), especially for aging older individuals. Considerable variation exists in the age ranges derived from composite scores and few significant differences were found between age stages, suggesting that fewer stages with wider age ranges may be necessary. The independent, quantitative scoring of the surface features makes the revised method substantially easier to apply and the method shows significant improvement for aging older individuals.

Modelling river-floodplain interaction during flood propagation

The (re)integration of flood storage areas in the river system is considered and proved as an effective flood protection measure. By their (controlled) filling and emptying, inundation risks for downstream areas with higher vulnerability can be reduced. They have an influence not only on the flood level, but also on the residence time of the water in the river ecosystem, which is an important biological parameter. A good prediction of storage flow is therefore necessary in an integrated ecosystem model. In such a model, which is being developed by the universities of Ghent and Antwerp, hydraulic, biological and biogeochemical processes are coupled. In this paper, a one-dimensional hydrodynamic module of the integrated STRIVE (STReam RIVer Ecosystem) model, which is based on the de Saint–Venant equations and solved by the Preissmann scheme, is adapted to be able to include flow exchange with storage cells. This model is validated with experimental laboratory measurements on a small scale. The flow between the storage cells and the river is controlled by weirs (flooded river banks). Model simulations with STRIVE are also compared with HEC-RAS simulations. Good agreement between simulations of both models and between the STRIVE simulations and the measurements is found.

The Presence of Multilineage Dysplasia (MLD) Has No Significant Impact On Biological, Clinico-Pathological, and Prognostic Features in AML with Mutated Nucleophosmin (NPM1).

Abstract 2618▪▪This icon denotes an abstract that is clinically relevant.Poster Board II-594AML with mutated nucleophosmin (NPM1) is a provisional entity in the WHO-2008 classification of myeloid neoplasms. A yet unresolved issue concerning NPM1-mutated AML is the biological and clinical significance of concomitant multilineage dysplasia (MLD). So far, NPM1+ AML with MLD is classified as AML with myelodysplasia-related changes in the new WHO classification. Therefore, we addressed the impact of MLD in 378 de novo AML patients with mutated/cytoplasmic NPM1 and performed comparison of cytomorphological features, cytogenetics, the FLT3 mutation status, and gene expression profiles in patients with and without MLD. MLD - as defined by dysplastic features in at least two hematopoietic lineages by cytomorphology - was present in 95/378 (25.1%) cases. Mean age (±standard deviation) was 52.1±14.0 years in the group with MLD and 54.8±14.5 in the group without MLD (p=0.11). Males comprised 50/95 (52.6%) in the group with MLD vs. 119/283 (42%) in the group without MLD (p=0.075). Morphological subtypes according to FAB/WHO were available in 365 cases (96.5%) and did not differ significantly between both groups. The median WBC was 17.1 G/l (range: 0.9–211.0 G/l) in the group with MLD and 35.6 G/l (range: 0.5–600.0 G/l) in the group without MLD (p=0.0027). Absence of CD34 expression was observed in 60/74 (81.1%) and 172/212 (81.1%) cases of the groups with and without MLD, respectively (p=1.0). Cytogenetic data was available in all 378 cases: An abnormal karyotype was present in 15/95 (15.8%) cases with MLD and in 37/283 (13.1%) cases without MLD (p=0.49). Molecular analyses detected the FLT3-ITD in 16/91 (17.6%) cases tested with MLD and in 110/276 (39.9%) cases without MLD (p<0.001). FLT3-TKD mutations were found in 7/80 (8.8%) patients within the group with MLD and in 21/221 (9.5%) patients within the group without MLD, respectively (p=1.0). Moreover, NPM1-mutated AML with or without MLD demonstrated non-discriminative microarray gene expression profiles (Affymetrix HG-U133 Plus 2.0). The gene expression profiles, however, clearly differed between NPM1-mutated AML and NPM1-wildtype cases as control group, e.g. by detectable downregulation of CD34 and upregulation of the characteristic HOX gene signature. This indicates that NPM1 mutations rather than MLD dictate the distinctive features of this AML subtype. With respect to clinical relevance, presence of MLD had no significant influence on overall survival (OS), however, it was related to a better event-free survival (EFS, median 33.3 vs. 13.9 months, p=0.0412), which is likely due to the fact that FLT3-ITD were less common in the MLD+ group (p=0.001). In addition also in our cohort the presence of an FLT3-ITD was associated with a significantly shorter EFS (median 11.2 vs. 22.3 months, p=0.0002) and a significantly shorter OS (median 12.5 months vs. not reached, p<0.0001). MLD also had no impact on outcome if analyzed within the groups with or without FLT3-ITD, respectively. Multivariate analysis revealed FLT3-ITD as the only parameter independently related to EFS (p=0.0051) and OS (p=0.0024). In conclusion, the discrimination of AML with MLD from AML without MLD in NPM1-mutated AML does not lead to distinct entities of AML since biologic features and outcome are largely similar. The FLT3-ITD mutation, however, again was confirmed to be an important biological parameter in AML with NPM1 mutations as demonstrated by a significantly worse outcome. Thus, our data underlines that NPM1+ AML is a distinct entity and further suggests that NPM1+ AML should be considered as one group irrespective of the presence or absence of MLD. Disclosures:Haferlach:MLL Munich Leukemia Laboratory: Equity Ownership. Macijewski:MLL Munich Leukemia Laboratory: Employment. Weiss:MLL Munich Leukemia Laboratory: Employment. Schnittger:MLL Munich Leukemia Laboratory: Equity Ownership. Kern:MLL Munich Leukemia Laboratory: Equity Ownership. Kohlmann:MLL Munich Leukemia Laboratory: Employment. Miesner:MLL Munich Leukemia Laboratory: Employment. Haferlach:MLL Munich Leukemia Laboratory: Equity Ownership. Falini:Xenomics: Patents & Royalties.

Evaluation of the minimal replication time of Cauliflower mosaic virus in different hosts

Though the duration of a single round of replication is an important biological parameter, it has been determined for only few viruses. Here, this parameter was determined for Cauliflower mosaic virus (CaMV) in transfected protoplasts from different hosts: the highly susceptible Arabidopsis and turnip, and Nicotiana benthamiana, where CaMV accumulates only slowly. Four methods of differing sensitivity were employed: labelling of (1) progeny DNA and (2) capsid protein, (3) immunocapture PCR,, and (4) progeny-specific PCR. The first progeny virus was detected about 21 h after transfection. This value was confirmed by all methods, indicating that our estimate was not biased by the sensitivity of the detection method, and approximated the actual time required for one round of CaMV replication. Unexpectedly, the replication kinetics were similar in the three hosts; suggesting that slow accumulation of CaMV in Nicotiana plants is determined by non-optimal interactions in other steps of the infection cycle.

Surface Charge Tunability and Size Dependent Luminescence Anisotropy of Aqueous Synthesized ZnS/Dendrimer Nanocomposites

Highly water-soluble, biocompatible, fluorescent, ZnS/Dendrimer nanocomposites have been synthesized, for the first time, with amino-, carboxyl- or hydroxyl-terminated Polyamidoamine dendrimer. Average size of ZnS nanoparticles within the dendrimer matrix was found to be in the range of 2.2-3.1 nm. ZnS nanoparticles with high monodispersity and photoluminescence efficiency was obtained by tuning various experimental parameters. An eight-fold increase in super-saturation of initial reactants caused a sharp focusing of size distribution by 38% and photoluminescence quantum efficiency also increased from 1.3% to 4.2%. ZnS/Dendrimer nanocomposites display constant positive polarized emission with the anisotropy value of 0.2, which makes it a promising candidate for biophysical probe. The anisotropy value was found to increase with increasing particle size of ZnS nanoparticles and also to depend on nature of surface end groups of the dendrimer molecule. Surface charge being an important biological parameter was tuned by varying pH of the reaction medium. Further, it is demonstrated that photoluminescence and surface charge of these nanocomposites are governed by the surface functionality of the dendrimer molecule.

Pretty Good Yield and exploited fishes

Abstract While much of traditional fisheries theory has concentrated on maximum or optimum yield, the reality of fisheries management is that biomass yield is only one of the several indicators of fisheries performance, and desired outcomes generally only need to provide something near the maximum possible yield. A range of policies are explored to find those that produce “Pretty Good Yield” defined as sustainable yield at least 80% of the maximum sustainable yield. Such yields are generally obtained over a broad range of stock sizes (20–50% of unfished stock abundance), and this range is not sensitive to the population's basic life history parameters such as natural mortality rate, somatic growth rate, or age at maturity. The most important biological parameter determining this range is the intensity of recruitment compensation. Meta-analysis shows compensation is usually strong and there is reasonably little yield lost at what are now widely accepted definitions of overfishing or risk for most stocks. Similarly, maintaining stocks at 50% of unfished stock abundance for ecological or economic reasons results in little expected loss of yield.

An angiosperm quality index (AQI) for Cantabrian estuaries

Angiosperms are an important biological parameter for establishing the status in transitional waters. Angiosperms grow from subtidal to upper intertidal zones and are sensitive to the most important pressures present in estuaries. A multi-metric for determining the status of Cantabrian estuaries has been developed by taking into account the angiosperms that live in these environments. This metric integrates two important directives: the Water Framework Directive (WFD) and the Habitats Directive. To be precise, the diversity of the existing habitats, the coverage in relative terms with respect to the optimal situation, and the loss of extension are considered in the metric. The application of the method to three Cantabrian estuaries subjected to different pressures demonstrates that the metric captures the degree of pressures of each estuary. The multi-metric method allows us to identify the type of problems to be tackled by the relevant authorities in the programme of measures of the river basin management plan.