Temperature-dependent development and oviposition models of Ramulus irregulariterdentatus (Phasmida: Phasmatidae)

Public interest in Ramulus irregulariterdentatus as a pet insect in Korea is increasing, although it is also considered as a potential forest insect pest. The objective of this study was to construct development and oviposition models of R. irregulariterdentatus. Development rates were fitted with a nonlinear Briére model which estimated optimal temperatures to be 24.5 and 26.2?°C with upper development thresholds of 29.3 and 31.4?°C for egg and nymph, respectively. In a linear model, lower development thresholds were 7.6 and 5.2?°C for egg and nymph, respectively. Survivorship was the highest at 21.0 and 22.2?°C for egg and nymph, respectively. Mean fecundity ranged from 14.4 eggs at 17.5?°C to 32.0 eggs at 23.5?°C. It was fitted to an extreme value function. Adult survival and cumulative oviposition rate of R. irregulariterdentatus were fitted to a sigmoid function and a two-parameter Weibull function, respectively. These models can be used to forecast phenology and population dynamics of R. irregulariterdentatus in the fields and optimize environmental conditions for rearing R. irregulariterdentatus.     

Carbon Stocks in an African Woodland Landscape: Spatial Distributions and Scales of Variation

Current knowledge of Africa’s carbon (C) pools is limited despite its importance in the global C budget. To increase the understanding of C stocks in African woodlands, we asked how C stocks in soil and vegetation vary across a miombo woodland landscape and to what degree and at what scales are these stocks linked? We sampled along a 5-km transect using a cyclic sampling scheme to allow geostatistical analyses. Soil C stocks in the top 5?cm (12.1?±?0.6?Mg?C?ha^?1 (±?SE)) and 30?cm depths (40.1?±?2.5?Mg?C?ha^?1) varied significantly at scales of a few meters (autocorrelation distance 14?m in 0–5-cm and 26?m in 0–30-cm interval), and aboveground (AG) woody C stocks (20.7?±?1.8?Mg?C?ha^?1) varied significantly at kilometer scales (1,426?m). Soil textural distributions were linked to topography (r ²?=?0.54) as were large-tree AG C stocks (r ²?=?0.70). AG C stocks were constrained to an upper boundary by soil texture with greater AG C being associated with coarser textured soils. Vegetation and soil C stocks were coupled in the landscape in the top 5?cm of soil (r ²?=?0.24) but not with deeper soil C stocks, which were coupled to soil clay content (r ²?=?0.38). This study is one of the most complete transect studies in an African miombo woodland, and suggests that C stock distributions are strongly linked to topography and soil texture. To optimize sampling strategies for C stock assessments in miombo, soil C should be sampled at more than 26?m apart, and AG C should be sampled at more than 1,426?m apart in plots larger than 0.5?ha.     

Molecular identification and characterization of leucine aminopeptidase 2, an excretory-secretory product of Clonorchis sinensis

Aminopeptidases serve vital roles in metabolism of hormones, neurotransmission, turnover of proteins and immunological regulations. Leucine aminopeptidases catalyze the hydrolysis of amino-acid residues from the N-terminus of proteins and peptides. In the present study, leucine aminopeptidase 2 (LAP2) gene of Clonorchis sinensis (C. sinensis) was isolated and identified from an adult cDNA library of C. sinensis. Recombinant CsLAP2 was expressed and purified in Escherichia coli BL21. The open reading frame of LAP2 contains 1,560?bp equivalent to 519 amino acids, a similarity analysis showed a relatively low homology with Homo sapiens (19.0?%), Trypanosoma cruzi (18.0?%), Mus musculus (19.3?%), and relatively high homology with Schistosoma mansoni (65.6?%). The optimum condition of rCsLAP2 enzyme activity was investigated using a fluorescent substrate of Leu-MCA at 37?°C and pH 7.5. The K (m) and V (max) values of rCsLAP2 were 18.2?μM and 10.7?μM/min, respectively. CsLAP2 gene expression can be detected at the stages of the adult worm, metacercaria, excysted metacercaria and egg of C. sinensis using real-time PCR, no difference was observed at the stages of the adult worm, metacercaria and egg. However, CsLAP2 showed a higher expression level at the stage of excysted metacercaria than the adult worm (3.90-fold), metacercaria (4.60-fold) and egg (4.59-fold). Histochemistry analysis showed that CsLAP2 was located at the tegument and excretory vesicle of metacercaria, and the tegument and intestine of adult worm. The immune response specific to rCsLAP2 was characterized by a mixed response patterns of Th1 and Th2, indicating a compounded humoral and cellular immune response. The combined results from the present study indicate that CsLAP2 was an important antigen exposed to host immune system, and probably implicated as potential role in interaction with host cells in clonorchiasis.     

Production by freshwater vascular plant (Macrophyte) communities of lakes and reservoirs in the European part of the U.S.S.R.

Data on the annual net primary production by macrophyte vegetation are given for 5 lakes in northern Russia and for altogether 8 river reservoirs, 5 on the Volga and 3 on the Dnieper rivers. The monozonal (littoral) lakes La?a, Vo?e and Kubenskoje are by one to two orders of magnitude more productive in macrophytes (per unit lake area) than the polyzonal large lakes Ladoga and Onega. In the 5 Volga river reservoirs, the annual macrophyte production decreases downstream, from some 92 to 3.5 g C per 1 m². In the Dnieper river reservoirs, the macrophyte production varies from 19.3 to 7.9 g C per 1 m² per year.     

Catalytic efficiency and some structural properties of cold-active protein-tyrosine-phosphatase

A procedure was established for expression and purification of abundant recombinant cold-active protein-tyrosine-phosphatase (RCPTPase), which showed identical enzymatic characteristics to the native enzyme (NCPTPase). The purified RCPTPase showed high catalytic activity at low temperature and maximal activity at 30 degrees C. RCPTPase has a thermodynamic characteristic in that its activation enthalpy was determined to be low, 4.3 kcal/mol, at temperatures below 19.3 degrees C, where the Arrhenius relationship exhibited an inflection point, in comparison with 20.3 kcal/mol above 19.3 degrees C. Also, the thermostability, DeltaG(water), of the catalytic site in the RCPTPase molecule was increased with a decrease in temperature. It was considered that cold-active protein-tyrosine-phosphatase could maintain its catalytic site in a stable conformation for eliciting high catalytic activity with low activation enthalpy at low temperature.     

Effects of drying conditions on moisture distribution in rehydrated spaghetti

Moisture distributions in spaghettis prepared at a maximum temperature of 50, 70, or 85?°C, designated as LT-, HT-, or VHT-spaghetti, respectively, and cooked to the average moisture content of 1.71?±?0.01?kg-H₂O/kg-d.m., were measured. The moisture contents near the surface and at the center of the LT-spaghetti were lower and higher, respectively, than those of HT- and VHT-spaghetti.     

Windstorm damage and forest recovery: accelerated succession, stand structure, and spatial pattern over 25?years in two Minnesota forests

We evaluated 25?years of change in wind-impacted oak and pine-dominated sites in the Cedar Creek Ecosystem Science Reserve, Minnesota, USA. We address the question: how did the storm alter stand architecture and spatial pattern and how did this affect recovery and recruitment? We mapped and marked all stems greater than 1?cm in diameter in a 0.25?ha oak-dominated plot and a 0.30?ha pine-dominated plot. After the initial sampling in 1983, plots were resurveyed four times in the 25?years following the windstorm. We used ordination and diameter distributions to describe compositional and structural characteristics of the sites. The stands are compositionally converging after the windstorm with both moving towards a late-successional forest type dominated by shade-tolerant tree species. The architecture in both sites is similar through time; sites have transitioned from bimodal diameter distributions to reverse-J distributions. We used Ripley??s K point pattern analysis to assess spatial patterns of tree mortality and recruitment within each site. In the pine site, surviving trees were significantly clumped, but mortality and recruitment patterns did not significantly differ from random. In the oak site, the storm did not substantially alter the spatial pattern of surviving trees, but subsequent recruitment was significantly associated with trees killed by the storm at scales within 6?C8?m and significantly dissociated with surviving trees at scales greater than 1?m. The dynamics of accelerated succession observed here are mediated by the damage and mortality initially sustained and its corresponding effects on spatial patterns of surviving and recruiting trees.     

Calorimetric studies of flavin-binding proteins: FMN and FAD binding to hen egg riboflavin-binding proteins

Systematic thermodynamic studies have been conducted for flavin (FMN, FAD) binding to purified riboflavin-binding proteins from hen egg white and egg yolk. These studies were conducted under a variety of temperature (14, 26, and 38 °C), pH (4.5, 5.5, 6.5, 7.4, and 9.0), and buffer conditions, and an extensive thermodynamic profile was constructed. Enthalpies of binding FMN to white riboflavin-binding protein and yolk riboflavin-binding protein were ?19.3 and ?14.4 kcal/mol, respectively, at pH 7.4 and 38 °C. FAD bound to white and yolk riboflavin-binding proteins under the same conditions with ΔH values of ?11.7 and ?6.0, respectively. Binding constants of about 10⁵ and 10⁴ were obtained for FMN and FAD, respectively, and were the same for both proteins under all conditions studied. Using established thermodynamic relationships, we were able to calculate entropy and free energy changes. Entropies indicated a large degree of ordering in the system upon flavin binding with FMN (about ?40 cal/mol/ °C) twice as large as FAD (about ?15 to ?25 cal/mol/ °C), which may indicate a structured solvent interaction with the charged phosphate group, or steric limitations placed on the ribityl side chain in the bound state. Our thermodynamic data support the idea that flavin binding is a mixture of forces, with no one predominant. Analysis of the data suggests that the nucleotide may bind both as the mono- or dianion, that flavin binding occurs with no significant change in the pK of any functional group in the system, except at low pH for FAD binding, and that the temperature variation of the enthalpy change is quite small. These findings are combined with other published data to outline a general scheme of flavin binding with a histidine residue implicated in hydrogen bonding to the adenine portion of FAD, which may be in the unstacked form.     

Effect of Temperature on the Embryogenesis of Geographic Populations of Rotylenchulus reniformis

The effect of temperature on the embryonic development of three populations of reniform nematode (Rotylenchulus reniformis) from the southeastern United States was studied. The development of eggs from single-cell stage to eclosion of second-stage juvenile was monitored at 20, 25, 30, and 35°C. All populations completed embryogenesis in 7 days at 25°C. The greatest differences among populations in time to completion of embryogenesis were observed at 20 and 35°C. Results at the intermediate temperatures (25 and 30°C) were similar for the three populations. The optimal temperature for embryogenesis was calculated to be 31.4°C for the population from Alabama, 28.4°C for the one from Mississippi, and 37.5°C for the one from South Carolina.     

Cold hardiness of Helicoverpa zea (Lepidoptera: Noctuidae) pupae

An insect's cold hardiness affects its potential to overwinter and outbreak in different geographic regions. In this study, we characterized the response of Helicoverpa zea (Boddie) pupae to low temperatures by using controlled laboratory measurements of supercooling point (SCP), lower lethal temperature (LT(50)), and lower lethal time (LLTime). The impact of diapause, acclimation, and sex on the cold hardiness of the pupae also were evaluated. Sex did not significantly affect the SCP, LT(50), or LLTime. However, the mean SCP of diapausing pupae (-19.3°C) was significantly lower than nondiapausing pupae (-16.4°C). Acclimation of nondiapausing pupae to constant temperatures from 10 to 20°C before supercooling also produced a significantly lower SCP than nondiapausing pupae held at 25°C. The LT(50)s of nondiapausing and diapausing were not significantly different, but confirmed that H. zea pupae are chill-intolerant because these lethal temperatures are warmer than the corresponding mean SCPs. Diapausing pupae survived longer than nondiapausing pupae at the same, constant, cold temperatures, a finding consistent with the SCP results. Both of these results suggest enhanced cold hardiness in diapausing pupae. When laboratory results were compared with field temperatures and observed distributions of H. zea in the contiguous United States, the laboratory results corroborated what is currently perceived to be the northern overwintering limit of H. zea; approximately the 40(th) parallel. Moreover, our research showed that areas north of this limit are lethal to overwintering pupae not because of low temperature extremes, but rather the length of time spent at near-zero temperatures.     

Novel method of niosome generation using supercritical carbon dioxide part I: process mechanics

Abstract

A novel method for the production of non-ionic surfactant vesicles (niosomes) using an rapid expansion of supercritical solution (RESS)-based process coupled with a gas ejector is presented along with an investigation of parameters affecting niosome morphology, size and encapsulation efficiency of a 0.2?M d-glucose solution in Tris buffer at physiological pH. The solubility of the non-ionic surfactant polyoxyethylene(4) sorbitan monostearate in SC-CO₂ was determined at three pressures (10, 15 and 20?MPa) and three temperatures (40, 50 and 60?°C). Mole fraction of Tween61 in the vapor phase increased with pressure at 40?°C, but did not change with pressure at 50 or 60?°C. Solubility data were correlated using the Peng–Robinson equation of state (PREOS) with the Panagiotopoulos and Reid mixing rule. Vesicles were either multilamellar or unilamellar, depending on the degree of precipitation of the lipid formulation at the point of aqueous cargo introduction. Vesicle particle size distributions were bimodal, with the 80–99% of the liposomal volume contributed niosomes ranging in size from 3 to 7?μm and the remaining niosomes ranging from 239 to 969?nm, depending on the system configuration. Encapsulation efficiency as high as 28% using the gas ejector to introduce the glucose cargo solution was achieved. Vesicle particle size and encapsulation efficiency were shown to be dependent on cargo droplet formation.     

Prevalence and intensity of Haemoproteus columbae in three species of wild doves from Brazil

The prevalence and intensity of blood parasites in three species of wild doves were studied in the municipality of Junqueirópolis, in the western region of the State of S?o Paulo, Brazil. Three species of doves were surveyed: 331 specimens of Zenaida auriculata Des Murs, 1847, 62 specimens of Columbina talpacoti Temminck, 1811 and 57 specimens of Scardafella squammata Lesson, 1831. Haemoproteus columbae Kruse, 1890 was found in blood from all the doves species. The prevalence of this parasite was 100% in Z. auriculata, 51.6% in C. talpacoti and 19.3% in S. squammata. Specimens of Z. auriculata had a higher intensity of infection than the other doves species.     

Cold hardiness in various organs and tissues of Rhododendron species and the supercooling ability of flower buds as the most susceptible organ

The freezing resistance of various organs and tissues was determined in 24 Rhododendron species (mainly Subgenus Tsutsutsi) having different ecological distributions. The order of hardiness for organ or tissue is as follows: leaf bud > wood ≧ bark > flower bud, and the flower bud is characterized as the most cold-susceptible organ. The relationship of killing temperature (KT) to northern distribution was the most significant in leaf buds compared to other organs and tissues. KTs of leaf buds for the most hardy species were ?45 °C (or below) and those for the most tender species were about ?23 °C, while KTs of flower buds were about ?28 °C for the former and ?16 °C for the latter. Although KTs of flower buds native to southwestern Japan were well correlated with the exothermic temperature distribution (ETD) of florets, those in the more northern species were generally lower than ETDs. The supercooling ability of flower buds appears to be sufficient to avoid the freezing stress since the extreme minimum temperature (EMT) at the northern limit of natural distribution for each tree species examined was not lower than the KT and ETD of the flower buds.     

Polymorphic markers of endothelial NO-synthase and angiotensin II vascular receptor genes and predisposition to ischemic heart disease

Allele and genotype frequency distribution patterns of the polymorphic regions at the genes for human endothelial NO-synthase (NOS3) (the ecNOS4a/4b VNTR and the Glu298Asp substitution) and the angiotensin II type 1 receptor (AT1)(the A1166C substitution) were compared in 83 unrelated healthy individuals and 88 patients with ischemic heart disease (IHD). In the group of patients statistically significantly higher frequencies of the NOS3 allele 4a (45.5 versus 19.3%), as well as the 4a/4a (15.9 versus 2.4%) and 4a/4b (59.1 versus 33.7%) genotypes were observed. Frequencies of the allele 4b (54.5% versus 80.7%) and the 4b/4b homozygotes (25.0 versus 63.9%) were statistically significantly lower in the group of IHD patients than in healthy individuals. The IHD patients were statistically significantly different from the healthy subjects also in the distributions of the AT1 genotypes. In the former group, a significantly decreased frequency of the AA homozygotes (51.1 versus 65.1%) and an increased frequency of AC heterozygotes (40.9 versus 27.7%) were observed. Thus, in the Moscow population the ecNOS4a/4b VNTR of the NOS3 gene and the A1166C polymorphism of the AT1 gene are associated with the IHD development. Furthermore, the correlation with the IHD revealed was much stronger for the NOS3 VNTR locus.     

Population genetics of four PKLR intragenic polymorphisms in Portugal and S?o Tomé e Príncipe (Gulf of Guinea).

Four intragenic PKLR polymorphisms [1705A/C, 1738C/T. T10/19, and (ATT)n microsatellite] were studied in normal population samples of Central Portugal and S?o Tomé e Príncipe, a small archipelago located in the Gulf of Guinea, West Africa. For all loci, the observed genotype distributions do not deviate from Hardy-Weinberg equilibrium. The allele frequencies found in the Portuguese population are similar to those previously described in Caucasian populations. Mother-child pair analysis for the (ATT)n microsatellite does not show deviations to the Mendelian rules. In S?o Tomé e Príncipe the biallelic polymorphisms 1705A/C, 1738C/T, and T10/19 presented inverse allelic frequencies when compared with the Portuguese population. Two new alleles were found at the (ATT)n microsatellite. Significant statistical differences were found between both populations. The results showed that S?o Tomeans had higher haplotype diversity and lower linkage disequilibrium among the polymorphic sites. The PKLR intragenic polymorphisms, commonly used in haplotype analysis with the gene mutations in PK-deficient patients, can thus be successfully employed in anthropological genetics.     

南京市正常人群NQO1、CYP1A1、mEH基因的多态性研究

应用PCR技术,对南京市正常人群中NQO1、CYP1A1、mEH-外显子3、mEH－外显子4基因型多态性进行了研究。88例样本中,相关基因野生型纯合子（wt/wt）、杂合子（wt/vt）、突变型纯合子（vt/vt）三种基因型的频率分布及基因频率分别是：NQO1 29.5%（0.304）,51.1%(0.495)和19.3%(0.202);CYP1A?135.2%(0.329)、44.3%(0.489)和20.5%(0.181);mEH－外显子3为26.1%(0.297),56.8%(0.496),17.0%(0.207);mEH－外显子4为83.0%(0.826),15.9%(0.165),1.1%(0.008)。以上结果与国外的有关报道存在一定差异,在不同地区中国人群的频率分布特征基本一致,种族差异可能是造成有关基因型分布差异的重要原因。 Abstract：The polymorphisms of NQO1, CYP1A1, mEH-Exon3 ,and mEH-Exon4 genes in normal Nanjing population (88 cases) were investigat ed by PCR approach. The results showed that the population frequency distributio ns of genotypes of wild-type,heterozygote, homozygous variant were respectively: NQO1? 29.5%,51.1%,19.3%;CYP 1A1 35.2%,44.3%,20.5%;mEH-exon3 26.1 %,56.8%,17.0%;mEH-exon4 83.0%,15.9%,1.1%. The frequency distributions o f genotypes in Nanjing population differ from those of other countries and do no t show marked differences compared with other different area in Chinese populati on. The ethnic difference might be an important reason which results in the diff erences of related genotypes.     

Population genetic structure and historical demography of Oratosquilla oratoria revealed by mitochondrial DNA sequences

Genetic diversity, population genetic structure and molecular phylogeographic pattern of mantis shrimp Oratosquilla oratoria in Bohai Sea and South China Sea were analyzed by mitochondrial DNA sequences. Nucleotide and haplotype diversities were 0.00409?C0.00669 and 0.894?C0.953 respectively. Neighbor-Joining phylogenetic tree clustered two distinct lineages. Both phylogenetic tree and median-joining network showed the consistent genetic structure corresponding to geographical distribution. Mismatch distributions, negative neutral test and ??star-like?? network supported a sudden population expansion event. And the time was estimated about 44000 and 50000 years ago.     

Comparative studies on populations of Pauesia juniperorum (Hymenoptera: Braconidae), a biological control agent for Cinara cupressivora (Hemiptera: Aphididae)

Pauesia juniperorum (Stary), a solitary endoparasitoid which attacks several Cinara spp. in the subgenus Cupressobium, was introduced into Africa for the control of the cypress aphid Cinara cupressivora Watson & Voegtlin (previously identified as Cinara cupressi (Buckton)) and is now established. Data on its biology including a comparison of populations from different hosts and geographical locations are presented. From the UK this consisted of populations reared from Cinara cupressivora, Cinara fresai Blanchard and Cinara juniperi De Geer, and from France, Cinara ?fresai. Between different populations, the duration of development varied within a narrow range (15.5-18.1 days) at 22 degrees C. Data on duration of development over a range of temperatures (15-26 degrees C) for two populations, from the UK and France ranged between 14.0-31.4 days for males and 14.7-32.8 days for females. The threshold temperature for development was 6.2 degrees C and 4.1 degrees C for the populations from the UK and France, respectively. The mean egg load for different populations ranged between 46.4 and 78.5 eggs. The host species had a significant effect on egg load which was directly related to size of the respective host aphids. The lowest egg load was recorded on specimens reared from C. cupressivora which was the smallest aphid. The population from the UK had a higher intrinsic rate of increase (0.232) than the one from France (0.207).     

Microbial degradation of disodium terephthalate by alkaliphilic Dietzia sp. strain GS-1

An alkaliphilic Dietzia sp., strain GS-1, which degraded disodium terephthalate (DT), was isolated from soil. Strain GS-1 degraded 19.3 mM of DT in 168 h at pH 10. The maximum degradation velocity was 0.46 mM/h. The resting cells efficiently degraded 28.7 mM of DT in 51 h at 28 degrees C and pH 10. The degradation velocity was 0.41 mM/(h g-wet cell).     

内蒙古温带草原土壤微生物生物量碳的空间分布及驱动因素

【目的】探索内蒙古温带草原土壤微生物生物量碳的空间分布特征以及驱动因素。【方法】在内蒙古自治区境内沿着年均温、年降水梯度选择17个草原样点,在土壤剖面上分0-10 cm、10-20 cm、20-40 cm、40-60 cm、60-100 cm五层,分别采集土壤样品,测定土壤微生物生物量碳以及主要的环境和生物影响因子,分析不同草地类型以及不同土壤深度土壤微生物生物量碳的差异,探索非生物因子和生物因子对土壤微生物量碳的影响。【结果】草甸草原土壤微生物量碳最高,典型草原次之,荒漠草原最低。在0-10 cm土壤中,草地类型间的微生物量碳变异系数高于草甸草原和典型草原,低于荒漠草原;在0-100 cm土壤中,草甸草原样点间的微生物量碳的变异系数低于典型草原和荒漠草原。土壤微生物量碳与年降水、土壤含水量、粘粒含量、土壤养分元素、地上生物量、地下生物量呈显著正相关,与年均温和土壤p H值呈显著负相关关系。随着土壤深度的增加,土壤微生物量碳显著减少,非生物因子与微生物量碳的相关性减弱,草地类型间以及同一草地类型不同样点间的变异系数增加。0-10 cm土壤微生物量碳与10-40 cm土壤微生物量碳的相关指数高于0.5,与40-100 cm的土壤微生物量碳的相关指数小于0.3。【结论】内蒙古温带草原土壤微生物量碳的垂直分布呈现一定的规律性,且非生物因子对微生物量碳的影响也呈现垂直减弱的规律。