Microwave initiated synthesis of polyacrylamide grafted Psyllium and its application as a flocculant

This paper reports a novel microwave initiated method for synthesis of polyacrylamide grafted Psyllium (Psy-g-PAM). Psyllium was modified through grafting of polyacrylamide (PAM) chains on it using microwave radiations only, in absence of any other free radical initiator. The grafting was confirmed by intrinsic viscosity study and characterization techniques like FTIR spectroscopy, elemental analysis (C, H, N, O and S) and SEM morphology study. Further, the flocculation efficacy of the synthesized graft copolymers was studied in kaolin and coal fine suspension through standard 'Jar test' procedure.     

Microwave initiated synthesis of polymethylmethacrylate grafted guar (GG-g-PMMA), characterizations and applications

Guar gum was grafted with polymethylmethacrylate (PMMA) by microwave initiated method. The synthesis was optimized for highest percentage grafting, by varying the microwave irradiation time and monomer (methyl methacrylate) concentration. The various grades of grafted product (GG-g-PMMA) were characterized through standard physicochemical characterization techniques (intrinsic viscosity measurement, elemental analysis, FTIR spectroscopy & SEM morphology study). Further, flocculation efficacy of this grafted polysaccharide was studied by standard 'Jar test' procedure in 0.5% kaolin suspension, to assess its application as flocculating agent for wastewater treatment and mineral ore beneficiation. Correlation between percentage grafting and intrinsic viscosity was also studied for the possibility of using it as a tool to control the intrinsic viscosity in the final product. This leads to the possibility of application of the grafted product as superior viscosifier than guar gum.     

Polyacrylamide grafted Agar: Synthesis and applications of conventional and microwave assisted technique

Polyacrylamide grafted Agar (Ag-g-PAM) has been successfully synthesized by conventional method and microwave assisted method. The former method employs ceric ammonium nitrate (CAN) as the free radical initiator while the latter uses the combination of ceric ammonium nitrate (CAN) and microwave irradiation. The synthesized graft copolymers have been characterized by elemental analysis (C, H, N, O and S), FTIR spectroscopy, intrinsic viscosity measurement and scanning electron micrograph (SEM); taking agar as a reference. Flocculation efficacy of synthesized graft copolymers was studied in kaolin suspension and in waste water through 'Jar test' procedure. In the present investigation, we have observed that polyacrylamide grafted agar synthesized by microwave assisted technique shows superior properties than conventional technique. These properties are reported in terms of intrinsic viscosity, flocculation efficacy and pollutant load reduction of waste water.     

Plant and invertebrate assemblages on waste rock at Wangaloa coal mine, Otago, New Zealand

Natural regeneration on waste rock was investigated at the old Wangaloa coal mine, south-east Otago. A 450-m long waste rock stack had been created 40–50 years ago, and has had little anthropogenic intervention since. The stack is made up of a gradient of three main waste rock types, defined as ‘silt-rich’, ‘mixed’, and ‘quartz-rich’, which reflect different proportions of loess siltstone and quartz gravel conglomerate. Plant species assemblages were quantified in four 5-m² quadrats in each waste rock type. Invertebrates were heat extracted from substrate cores (7 cm diameter; depth 5 cm) collected from quadrats over an eight-week period in spring 2003. Ordination analysis showed statistically distinct plant and invertebrate assemblages had arisen on each waste rock type. Revegetation patterns were dominated by native, woody individuals on all waste rock types, particularly manuka (Leptospermum scoparium) and kanuka (Kunzea ericoides). Plant cover on ‘silt-rich’ waste rock was four-fold that on ‘quartz-rich’ waste rock. Total numbers of invertebrates were highest on ‘quartz-rich’ waste rock, but richness greatest on ‘silt-rich’ waste rock. Collembola dominated the fauna but their numbers were proportionally greatest in poorly vegetated areas. Further work is required to explain the absence of plants and invertebrates from local areas of waste rock.     

Assimilate translocation and expression of sucrose transporter,OsSUT1, contribute to high-performance ripening under heat stress in the heat-tolerant rice cultivar Genkitsukushi

High temperature reduces the grain quality of rice, a situation likely to become more frequent because of global warming. We studied the effects of high-temperature stress on grain quality of heat-tolerant cultivar ‘Genkitsukushi’ and heat-sensitive cultivar ‘Tsukushiroman’. When day/night temperatures were 31/26 °C from heading until maturity, the grain quality of ‘Genkitsukushi’ was rated at the first inspection grade (high quality), whereas ‘Tsukushiroman’ showed a remarkable increase in the percentage of white immature kernels (low quality). Nonstructural carbohydrate content in the stem of ‘Genkitsukushi’ the early maturation was significantly higher than in ‘Tsukushiroman’ and greatly decreased under high temperature. From 14 to 21 days after heading, the expression of the sucrose transporter gene, OsSUT1, was higher in the stem of ‘Genkitsukushi’ grown under high temperature than in ‘Tsukushiroman’. In addition, the expression of OsSUT1 in the grains of ‘Genkitsukushi’ was significantly higher than in ‘Tsukushiroman’ during the ripening period. These results indicate that sugar transport functions more effectively in ‘Genkitsukushi’ than in ‘Tsukushiroman’, and that the effectiveness of sugar transport contributes to maintaining high grain quality in ‘Genkitsukushi’ under high-temperature conditions.     

Molecular characterization and expression analysis of ubiquitin-activating enzyme E1 gene in Citrus reticulata

Ubiquitin-activating enzyme E1 (UBE1) catalyzes the first step in the ubiquitination reaction, which targets a protein for degradation via a proteasome pathway. UBE1 plays an important role in metabolic processes. In this study, full-length cDNA and DNA sequences of UBE1 gene, designated CrUBE1, were obtained from ‘Wuzishatangju’ (self-incompatible, SI) and ‘Shatangju’ (self-compatible, SC) mandarins. 5 amino acids and 8 bases were different in cDNA and DNA sequences of CrUBE1 between ‘Wuzishatangju’ and ‘Shatangju’, respectively. Southern blot analysis showed that there existed only one copy of the CrUBE1 gene in genome of ‘Wuzishatangju’ and ‘Shatangju’. The temporal and spatial expression characteristics of the CrUBE1 gene were investigated using semi-quantitative RT-PCR (SqPCR) and quantitative real-time PCR (qPCR). The expression level of the CrUBE1 gene in anthers of ‘Shatangju’ was approximately 10-fold higher than in anthers of ‘Wuzishatangju’. The highest expression level of CrUBE1 was detected in pistils at 7 days after self-pollination of ‘Wuzishatangju’, which was approximately 5-fold higher than at 0 h. To obtain CrUBE1 protein, the full-length cDNA of CrUBE1 genes from ‘Wuzishatangju’ and ‘Shatangju’ were successfully expressed in Pichia pastoris. Pollen germination frequency of ‘Wuzishatangju’ was significantly inhibited with increasing of CrUBE1 protein concentrations from ‘Wuzishatangju’.     

铝盐-淀粉复合絮凝剂污水处理效果研究

以模拟废水、生活污水、市政污水和制浆造纸废水为实验对象,检验了一种新合成铝盐一淀粉复合絮凝剂中试产品(CAS)的污水处理效果．结果表明,与聚合氯化铝(PAC)相比较,CAS处理不同浓度(100、400和2000mg·L^-1)高岭土模拟废水时最佳投加量分别为3．0、2．0和2．0mg·L^-1,为PAC最佳投加量的60％、50％和50％;同时CAS对该废水、生活污水、市政污水的浊度去除效果略优于PAC,但COD去除率明显高于相同剂量的PAC;处理高浓度制浆造纸污水时,CAS投加量相当于PAC用量的70％。COD处理率提高10％,污泥量减少40％.     

Patterns in rotifer diapausing egg banks: Density and viability

Here we present a quantitative study on the density, age and viability of the diapausing egg banks of the rotifer species complex Brachionus plicatilis in the sediments of 15 water bodies from Eastern Spain. Sampled ponds, located in coastal and inland areas, varied in salinity and ranged in size, depth and permanence. By identifying ‘hatched’, ‘deteriorated’ and ‘viable’ diapausing eggs in the sediment samples, we estimated production, hatching and deterioration in relation to the habitat properties of each pond. Our results indicate the presence of large numbers of diapausing eggs in the sediments of almost all of the ponds studied (2-115 eggs cm^− 2). Inland ponds tended to have higher densities than coastal lagoons. The vertical distribution of eggs in the sediments frequently showed a non-decreasing pattern, which suggested a high among-year variation in egg production. Despite maximum age of eggs of 60-80 years, the median age (3-30 years) suggests that rotifer egg banks are young in the studied ponds. Egg senescence is suggested by the declining abundance of ‘healthy-looking’ eggs with depth. The proportion of ‘deteriorated’ eggs ranged 75-99% suggesting that deterioration rates in the sediments are high and vary among habitats. Hatching and deterioration rates, as estimated from the counts of ‘hatched’, ‘deteriorated’ and ‘healthy-looking’ eggs in the sediments, largely varied among ponds. An association between hatching and deterioration rates is suggested by our data. This is in agreement with the hypothesis that hatching rates of diapausing eggs depended not only on the risks associated with the water column, as initially expected by the general theory on diapause, but they are also related to the incidence of deterioration processes in the sediment.     

Quantum biology at the cellular level—Elements of the research program

Quantum biology is emerging as a new field at the intersection between fundamental physics and biology, promising novel insights into the nature and origin of biological order. We discuss several elements of QBCL (quantum biology at cellular level) – a research program designed to extend the reach of quantum concepts to higher than molecular levels of biological organization. We propose a new general way to address the issue of environmentally induced decoherence and macroscopic superpositions in biological systems, emphasizing the ‘basis-dependent’ nature of these concepts. We introduce the notion of ‘formal superposition’ and distinguish it from that of Schroedinger's cat (i.e., a superposition of macroscopically distinct states). Whereas the latter notion presents a genuine foundational problem, the former one contradicts neither common sense nor observation, and may be used to describe cellular ‘decision-making’ and adaptation. We stress that the interpretation of the notion of ‘formal superposition’ should involve non-classical correlations between molecular events in a cell. Further, we describe how better understanding of the physics of Life can shed new light on the mechanism driving evolutionary adaptation (viz., ‘Basis-Dependent Selection’, BDS). Experimental tests of BDS and the potential role of synthetic biology in closing the ‘evolvability mechanism’ loophole are also discussed.     

The Humanness of Macaque Antibody Sequences

Chimeric, humanized and human antibodies have successively been exploited as therapeutics because their increasing human (‘self’) character is expected to correspond with decreased immunogenicity, which is critical for their clinical development. Thus, humanness has been inferred to predict antibody immunogenicity. Humanness of antibody variable regions (V-regions) has recently been studied using a parameter (here referred to as the H-score) that evaluates similarity to expressed human sequences. Macaque (Macaca fascicularis) antibody sequences are of particular interest because they have been suggested to have extremely human-like character and, recently, macaque single-chain variable fragments with very high affinity for various antigens have been isolated. In this study, the H-scores of all macaque antibody V-regions available in sequence data banks were compared with those of their human counterparts using statistical tests. The results were found to be influenced by the relative size of the human families to which the macaque V-regions are related. As the relevance of families to immunogenicity is suspected but unproven, a new parameter (the ‘G-score’) was derived from the H-score to avoid this influence, and macaque V-region sequences were reanalyzed using the G-score. Both parameters show that these regions cannot be regarded as human when they derive from heavy chains, but the humanness of light chains is variable. It was shown that ‘germline humanization’ of a macaque V-region favourably influenced its humanness, as evaluated by both H-score and G-score. In addition, the humanness of macaque sequences presented in patents has been analyzed. The H-score and G-score define objectively the humanness of antibody V-regions, and their use is exemplified here.     

Distribution of beta-globin haplotypes among the tribes of southern Gujarat,India

The present study was carried out in Indo-European speaking tribal population groups of southern Gujarat (India) to elucidate the allelic and haplotypic content of β-globin system in individuals with HbAA genotypes. 6 neutral restriction sites of the β-globin system were analysed and various statistical parameters were estimated to draw meaningful interpretations. All the 6 sites were found to be polymorphic and most were in Hardy–Weinberg Equilibrium in the studied group. Haplotypes were constructed using two different combinations of the 6 restriction sites analysed. Analysis of the 5 sites revealed a set of three predominant haplotypes, ‘+−−−−’, ‘−++−+’ and ‘−+−++’; and haplotypes ‘+−−’, ‘++−’ and ‘+++’ were found to be the most frequent when the 3 sites were used to construct the haplotypes. Haplotypic heterozygosity levels (> 83%) observed in the present study group were comparable to those observed in African and Afro-American populations and greater than other world populations. All the ancestral haplotypes, +−−−−−, −++−+, −+−++ and −−−−+ were found in the study group. The distribution pattern of various haplotypes was consistent with the global pattern. The paucity of comparable data from other Indian populations restricted one from making interpretations about the study group's relationships with other Indian populations but the results were indicative of older population histories or experience of gene flow by the study group and their affinities with populations of southern India.     

The complete mitochondrial genome of the leafminer Liriomyza sativae (Diptera: Agromyzidae): great difference in the A+T-rich region compared to Liriomyza trifolii

The complete mitochondrial genome sequence of Liriomyza sativae Blanchard (15,551 bp) was determined and analyzed in this study. The circular genome contained 37 genes including 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and an A + T-rich region. The initiation codons of COI and ND1 were ‘ATCA’ and ‘GTG’, respectively. ND2 gene used the truncated termination codon ‘T’. All the tRNA genes had the typical cloverleaf secondary structures except for tRNA^Ser(AGN) gene, which was found with the absence of a DHU arm. In addition, a tRNA-like secondary structure (tRNA^Met) was found in the A + T-rich region. The great difference was that the length of L. sativae A + T-rich region was 597 bp shorter than that of Liriomyza trifolii (Burgess). Meanwhile, some minor differences such as ‘TATA’ block were also observed in L. sativae in contrast to ‘TACA’ block in L. trifolii. There were also some essential structure elements such as ‘TATA’ block, ‘G(A)_nT’ block, poly-T stretch and stem-and-loop structure in the A + T-rich region of L. sativae mitochondrial genome.     

Impact of Phyllostachys heterocycla ‘Pubescens’ expansion on mycorrhizal associations of the adjacent forests

 毛竹(Phyllostachys heterocycla ‘Pubescens’)凭借其独特的生长特性极易扩张进入周边的常绿或针阔混交森林群落并取而代之。菌根减弱假说对毛竹林扩张导致周边林分枯亡并抑制林下幼苗更新的机制进行了解释, 即毛竹林的成功扩张是由于毛竹蔓延引起森林群落的菌根系统紊乱, 使宿主植物与菌根真菌的共生关系受到干扰, 进而影响了宿主植物的分布与更新。该研究以浙江省西天目山国家自然保护区为研究区域, 对菌根减弱假说进行了检验。通过在毛竹-针阔混交林交接区沿毛竹扩张方向设置毛竹纯林、竹-林过渡带、针阔混交林3种类型的样带, 选取在针阔混交林、竹-林过渡带同时存在的6种优势乔灌树种——杉木(Cunninghamia lanceolata)、枫香树(Liquidambar formosana)、青冈(Cyclobalanopsis glauca)、柳杉(Cryptomeria fortunei)、江浙山胡椒(Lindera chienii)、毛柄连蕊茶(Camellia fraterna), 测定这6个树种在两样带中的菌根侵染频率和强度, 检测在毛竹林扩张中周边森林群落菌根的响应, 同时对比了毛竹在毛竹纯林和竹-林过渡带菌根感染率和强度的变化, 检验该假设。实验结果表明: 1)针阔混交林和竹-林过渡带的主要树种菌根都具有较高的菌根侵染频率(> 95%), 且不同林分间林木的侵染频率无显著差异(p > 0.1); 2)在竹-林过渡带杉木和江浙山胡椒的丛枝菌根侵染强度较针阔混交林明显增加(p < 0.1); 3)毛竹的丛枝菌根侵染频率和强度远低于其他针阔树种, 且在扩张前后没有显著变化(p > 0.1)。实验结果否定菌根减弱假说。     

Adult hippocampal cell proliferation is suppressed with estrogen withdrawal after a hormone-simulated pregnancy

Estradiol withdrawal after pregnancy is hypothesized to precipitate depressive symptoms in vulnerable women. A hormone-simulated pregnancy was induced in female rats and the effects of a ‘postpartum’ drop in estradiol on hippocampal cell proliferation were examined. All groups were ovariectomized or given sham surgery prior to treatment. Rats were randomly assigned to ‘postpartum’, ‘postpartum’ + EB (estradiol benzoate), ‘postpartum’ + DPN (diarylpropionitrile; an ERβ agonist), ‘postpartum’ + IMI (imipramine; a tricyclic antidepressant), sham, ovariectomized (OVX), sham + IMI or OVX + IMI groups. All ‘postpartum’ groups received hormone injections (estradiol and progesterone) over 23 days to simulate pregnancy, while IMI groups also received daily imipramine injections. After day 23, ‘postpartum’ rats were withdrawn from the hormone-simulated pregnancy (mimicking the postpartum drop in gonadal hormones), while other ‘postpartum’ treatment groups received daily injections of DPN, EB or IMI. On day 3 ‘postpartum’ all rats were injected with bromodeoxyuridine (BrdU; a DNA synthesis marker) and perfused 24 h later to assess cell proliferation and cell death in the dentate gyrus. ‘Postpartum’ hormone withdrawal decreased hippocampal cell proliferation in the ‘postpartum’ and ‘postpartum’ + EB groups only. Chronic imipramine significantly increased hippocampal cell proliferation in sham + IMI, but not OVX + IMI rats suggesting that imipramine's effects to increase hippocampal cell proliferation in female rats is related to reproductive status. Cell death (pyknotic cells) was decreased only in the ‘postpartum’ group. Together, these results suggest an important, though complex, role for gonadal hormones in the cellular changes accompanying this model of postpartum depression.     

Is 'hand preference' coded in the hominin skeleton? An in-vivo study of bilateral morphological variation

The presumed link between bilateral asymmetry and lateralized habitual activity in extinct hominins is the basis upon which inferences of ‘hand preference’ often derive. While this presumption is reasonable, in-vivo comparisons of skeletal asymmetries and self-reported handedness are rare, and as a result the accuracy of these inferences is questionable. To assess this relationship in living humans, reported ‘handedness’ was compared against peripheral quantitative computed tomography (pQCT) derived bilateral measurements of humeral, ulnar, and tibial midshaft cortical area (CA) and torsional rigidity (J). Significant bilateral differences were found in the humerus for all groups, and in the ulna for the cricketer and field hockey sub-samples. Additionally, cricketers’ non-dominant tibiae were more robust than their dominant tibiae. An assessment of ‘Dominance Asymmetry’ revealed that measures of CA and J were higher in the dominant humeri in ∼90% of participants; in the ulna this was true in ∼75% of cases, and in the tibia CA and J were higher in the dominant limb less than 50% of the time. Comparisons of (self)‘Reported’ hand preference against ‘Predicted’ hand preference (based on the calculation of % Directional Asymmetry) revealed a low level of error for predictions based on both humeral (∼4-5% error) and ulnar (6-11% error) asymmetry. Error was decreased with the exclusion of individuals displaying less than 2.5-5% asymmetry. Contrarily, predictions based on tibial analyses had a much higher level of ‘error’ (∼45%). Overall, the results support currently accepted approaches for inferring ‘hand preference’ from measures of upper limb geometric asymmetry in the hominin skeleton.     

Discovery of new photoactivatable diaryltetrazoles for photoclick chemistry via 'scaffold hopping'

We report the discovery of two long-wavelength (365 nm) photoactivatable diaryltetrazoles through screening a small library of diaryltetrazoles that were designed using a ‘scaffold hopping’ strategy. A naphthalene-derived tetrazole showed excellent reactivity in the photoinduced cycloaddition reaction with methyl methacrylate under 365 nm photoirradiation in acetonitrile PBS buffer mixture. Besides, the brightly fluorescent pyrazoline cycloadducts that were formed further increase the potential utility of these new diaryltetrazoles as ‘photoclick’ reagents and as reporters in biological studies.     

Application of Lake-model based indices from chlorophyll fluorescence on sugarcane seedling Application of Lake-model based indices from chlorophyll fluorescence on sugarcane seedling

 为从能量平衡及分配的角度研究干旱胁迫下甘蔗(Saccharum officinarum)苗期光系统的运转状况, 进而为丰富不同甘蔗品种的抗旱性评价指标及实现对季节性干旱胁迫的快速诊断提供理论依据, 该研究通过对基于Lake模型的叶绿素荧光参数在不同入射光强下变化的动态分析, 研究光合电子传递链中能量平衡状态对不同水分梯度(40%、25%、10%、8%)的响应。结果表明: 两个供试品种(耐旱品种‘ROC22’和非耐旱品种‘ROC16’)的最大光能利用效率(F_v/F_m)、相对电子传递速率(rETR)、光系统II(PSII)量子效率(Φ_II)和光化学猝灭(q_L)均随着干旱胁迫程度的增加而下降, 可调节性能量耗散(Φ_NPQ)和非调节性能量耗散(Φ_NO)则随着干旱胁迫程度的增加而上升。除Φ_NO之外的叶绿素荧光参数的变化幅度均随着光合有效辐射(PAR)的增加而增大。在干旱胁迫的前中期, 相对于‘ROC22’, ‘ROC16’的PSII反应中心能够维持较高的开放程度; 但‘ROC22’调节能量耗散的能力和对干旱胁迫的敏感程度均高于‘ROC16’, 说明较强的光保护能力是‘ROC22’的抗旱性高于‘ROC16’的主要原因之一。对干旱胁迫敏感且在不同PAR下较为稳定的Φ_NO可作为甘蔗苗期抗旱性的快速诊断和评价指标。rETR对递增的PAR的响应表现为随着干旱胁迫程度的增加而提前出现峰值或下降趋势, 但是不同水分梯度下的rETR在PAR较低时并无显著差异, 表明干旱胁迫下光抑制现象的提早出现是造成光系统损伤的首要因素, 高光强对干旱胁迫信号起放大作用。     

Assessment of agroeconomic indices in polycultures of lettuce, rocket and carrot through uni- and multivariate approaches in semi-arid Brazil

The polyculture among vegetables is an activity that to have good results, needs a proper planning. Although it often requires more labor, has several advantages over monoculture, among them is that polycultures are generally are more productive, provide with productivity of various plant constituents and a more balanced human diet, contribute to economic return, economic and yield stability, social benefits and farmer's direct participation in decision-making. The objective of this study was to evaluate agroeconomic indices of polycultures derived from the combination of two cultivars of lettuce with two cultivars of rocket in two cultures strip-intercropped with carrot cultivar ‘Brasilia’ through uni-multivariate approaches in semi-arid Brazil. The experimental design used was of randomized complete blocks with five replications and the treatments arranged in a factorial scheme of 2 × 2. The treatments consisted of the combination of two lettuce cultivars (Babá de Verão and Tainá) with two rocket cultivars (Cultivada and Folha Larga) in two cultures associated with carrot cv. Brasília. In each block were grown plots with two lettuce cultivars and two rocket cultivars, and carrot in sole crop. In each system was determined the lettuce leaf yield, rocket green mass yield and carrot commercial yield. Agrieconomic indices such as operational cost, gross and net income, monetary advantage, rate of return, profit margin, land equivalent ratio and yield efficiency for DEA were used to measure the efficiency of intercropping systems. In the bicropping of lettuce and rocket associated with carrot cv. ‘Brasilia’, suggests the use of lettuce cultivar ‘Tainá’ combined with rocket cultivars ‘Cultivada’ or ‘Folha Larga’. It was observed significant effect of lettuce cultivars in the evaluation of polycultures of lettuce, carrot and rocket, with strong expression for the lettuce cultivar ‘Tainá’. Both uni- and multivariate approaches were effective in the discrimination of the best polycultures.     

The neural basis of colour vision in the butterfly, Heliconius erato

Single unit recordings from visual interneurons in the protocerbrum of the neotropical butterfly Heliconius erato, revealed a variety of fibre types with wavelength specific patterns of activity. These ‘colour fibres’ were divided into four broad categories based upon the nature of their response to a flash of monochromatic light: (1) ‘simple’ colour fibres, which respond with excitation, when the eye is stimulated with some specific, narrow portion of the visible spectrum; (2) ‘on-off’ fibres, which produce ‘on’ bursts in response to certain portions of the spectrum, and ‘off’ effects when stimulated with other wavelengths; (3) ‘variable latency’ units which demonstrate dramatic shifts in latency, with comparatively small changes in the stimulating wavelength; and (4) ‘red-blue movement’ units which demonstrate bursts of activity when stimulated with flashes of red or blue light, and also serve as a non-directional movement detector. The wide variety of colour fibres appears to be correlated with the great behavioural significance of colour to this species.