Phosphorus deprivation effects on water relations of <Emphasis Type="Italic">Nicotiana tabacum</Emphasis> plant via reducing plasma membrane permeability

Plants grown in phosphorus-deprived solutions often exhibit disruption of water transport due to reduction in root hydraulic conductivity (Lp_r). To uncover the relationship between root Lp_r and water permeability coefficient (P_f) of plasma membrane and the role of aquaporins, we evaluated P_f of plasma membrane and also PIP-type aquaporin gene expression in tobacco (Nicotiana tabacum L.) plant roots after seven days P-deprivation. The results showed significant reduction in sap flow rate (J_v) and osmotic root hydraulic conductivity (L_pr-o) in P-deprived roots. These effects were reversed 24 h after P-resupplying. Interestingly, the P_f of root protoplasts was 57% lower in P-deprived plants compared with P-sufficient ones. The expression of NtPIP1;1 and NtPIP2;1 aquaporins did not change significantly in P-deprived plants compared with P-sufficient ones, but the copy number of NtAQP1 increased significantly in P-deprived plants. P-deprivation did not change Lpr-o significantly in antisense NtAQP1 plants. Taken together, these findings suggest that P-deprivation may play an important role in modulation of root hydraulic conductivity by affecting P_f in transcellular pathway of water flow across roots and aquaporins. Finally, we concluded that dominant water transport pathway under P-deprivation was transcellular one.     

Filamentous Aggregation of Sequestosome-1/p62 in Brain Neurons and Neuroepithelial Cells upon <Emphasis Type="Italic">Tyr-Cre</Emphasis>-Mediated Deletion of the Autophagy Gene <Emphasis Type="Italic">Atg7</Emphasis>

Defects in autophagy and the resulting deposition of protein aggregates have been implicated in aging and neurodegenerative diseases. While gene targeting in the mouse has facilitated the characterization of these processes in different types of neurons, potential roles of autophagy and accumulation of protein substrates in neuroepithelial cells have remained elusive. Here we report that Atg7^f/f Tyr-Cre mice, in which autophagy-related 7 (Atg7) is conditionally deleted under the control of the tyrosinase promoter, are a model for accumulations of the autophagy adapter and substrate sequestosome-1/p62 in both neuronal and neuroepithelial cells. In the brain of Atg7^f/f Tyr-Cre but not of fully autophagy competent control mice, p62 aggregates were present in sporadic neurons in the cortex and other brain regions as well in epithelial cells of the choroid plexus and the ependyma. Western blot analysis confirmed a dramatic increase of p62 abundance and formation of high-molecular weight species of p62 in the brain of Atg7^f/f Tyr-Cre mice relative to Atg7^f/f controls. Immuno-electron microscopy showed that p62 formed filamentous aggregates in neurons and ependymal cells. p62 aggregates were also highly abundant in the ciliary body in the eye. Atg7^f/f Tyr-Cre mice reached an age of more than 2 years although neurological defects manifesting in abnormal hindlimb clasping reflexes were evident in old mice. These results show that p62 filaments form in response to impaired autophagy in vivo and suggest that Atg7^f/f Tyr-Cre mice are a model useful to study the long-term effects of autophagy deficiency on the homeostasis of different neuroectoderm-derived cells.     

Exocyst Complex Member EXOC5 Is Required for Survival of Hair Cells and Spiral Ganglion Neurons and Maintenance of Hearing

The exocyst, an octameric protein complex consisting of Exoc1 through Exoc8, was first determined to regulate exocytosis by targeting vesicles to the plasma membrane in yeast to mice. In addition to this fundamental role, the exocyst complex has been implicated in other cellular processes. In this study, we investigated the role of the exocyst in cochlear development and hearing by targeting EXOC5, a central exocyst component. Deleting Exoc5 in the otic epithelium with widely used Cre lines resulted in early lethality. Thus, we generated two different inner ear-specific Exoc5 knockout models by crossing Gfi1^Cre mice with Exoc5^f/f mice for hair cell-specific deletion (Gfi1^Cre/+;Exoc5^f/f) and by in utero delivery of rAAV-iCre into the otocyst of embryonic day 12.5 for deletion throughout the otic epithelium (rAAV2/1-iCre;Exoc5^f/f). Gfi1^Cre/+;Exoc5^f/f mice showed relatively normal hair cell morphology until postnatal day 20, after which hair cells underwent apoptosis accompanied by disorganization of stereociliary bundles, resulting in progressive hearing loss. rAAV2/1-iCre;Exoc5^f/f mice exhibited abnormal neurite morphology, followed by apoptotic degeneration of spiral ganglion neurons (SGNs) and hair cells, which led to profound and early-onset hearing loss. These results demonstrate that Exoc5 is essential for the normal development and survival of cochlear hair cells and SGNs, as well as the functional maintenance of hearing.     

Gene <Emphasis Type="Italic">angora</Emphasis> as a modifier of the <Emphasis Type="Italic">hairless</Emphasis> gene in mouse

The interaction between mouse angora-Y (Fgf5 ^go-Y) and hairless (hr) genes have been studied. Homozygous mutant gene Fgf5 ^go-Y increases length of all hair types, while homozygotes for the h gene lose hair completely starting on day 14 after birth. We obtained mice with genotypes +/+ hr/hr F₂, +/Fgf5 ^go-Y hr/hr and Fgf5 ^go-Y/Fgf5 ^go-Y hr/hr. Both +/Fgf5 ^go-Y hr/hr and +/+ hr/hr mice began to loose hair from their heads on day 14. This further extended on the whole body. On day 21 the mice were completely deprived of hair. Therefore a single dose of gene Fgf5 ^go-Y does not modify alopecia in mice homozygous for hr. However in double homozygotes Fgf5 ^go-Y/Fgf5 ^go-Y hr/hr alopecia started 4 days later, namely on day 18. It usually finished 10–12 days after detection of first bald patches. On days 28–30 double homozygotes lose coat completely. Hair loss in double homozygous mice was 1.5-fold slower than in +/+ hr/hr mice. This resulted from a significant extension of anagen phase induced by a mutant homozygous gene Fgf5 ^go-Y in morphogenesis of the hair follicle. The hr gene was expressed at the transmission phase from anagen to catagen. Our data shows that the angora gene is a modifier of the hairless gene and this results in a strong repression of alopecia progression in double homozygous mice compared to +/+ hr/hr animals.     

Effect of cold adaptation of α-and β-adrenergic responses of blood pressure in hindlimb and small intestine in situ and systemic blood pressure in rabbits

Changes in the main parameters of α-and β-adrenergic responses, sensitivity to agonists (EC ₅₀) and maximum response (P _m) of hindlimb and small intestinal blood pressure in situ and systemic blood pressure were studied in rabbits adapted to cold for 1–30 days (daily exposures to ?10°C for 6 h). The responses to phenylephrine, noradrenaline, adrenaline, clonidine (α-agonists), and isopropylnoradrenaline (β-agonist) corresponded to the equation p = (P _m A ⁿ )/(EC ₅₀ ⁿ + A ⁿ ) (1) with n = 1 and n = 2, respectively. Cold adaptation induced reciprocal changes in the response of both EC ₅₀ and P _m to α-agonists and in the response of P _m alone to isopropylnoradrenaline. The significant differences of the parameters from control observed during the first 5 days of adaptation gradually decreased by day 30. After 10 days of adaptation, the efficiency (E = P _m/2EC ₅₀) of response to α-and β-agonists of adrenoceptors significantly increased.     

Inheritance of Traits Controlled by Odd Chromosomes Using Data on Transmission of Monosomic Addition S<Superscript>t</Superscript> Chromosome of the <Emphasis Type="Italic">Elymus Sibiricus</Emphasis> Genome

On the basis of the winter bread wheat cultivar Obryi, two independent disomic addition lines BC₁₂F_∞ with the chromosome of the E. sibiricus S^t genome are created. A practical algorithm for determining the probabilities of transmission of the odd chromosome separately through male and female gametes in selfpollination of hemizygous hybrids from the equation p²–(1 + f₁–f₄) × p + f₁ = 0 is proposed, where p is the probability of the formation of viable gametes with the considered chromosome and f₁ and f₄ are the empirical frequencies of the corresponding homozygotes with and without the trait. The probability of transmission of an alien univalent chromosome through pollen (p_♂) is associated with the frequency of its transmission through the egg cell (p_♀) in backcrosses and in self-pollination (1–f₄) by the equation p_♂ = 1–f₄/(1–p_♀). The calculated empirically dependent estimates of the probabilities of transmission of the added chromosome through the egg cell p_♀ = 18.7% and through pollen p_♂ = 4.3% correspond to the empirical frequencies obtained for backcrosses. The coefficients of the gamete selection V_♀ = 0.748 and V_♂ = 0.172 are calculated, and the expected segregation for the alien trait controlled by a dominant gene located in the added chromosome is determined—with the trait: without the trait is 0.222: 0.778 in F₂; 0.187: 0.813 in equational and 0.043: 0.957 in certational backcrosses.     

Natively oxidized amino acid residues in the spinach cytochrome <Emphasis Type="Italic">b</Emphasis><Subscript><Emphasis Type="Italic">6</Emphasis></Subscript><Emphasis Type="Italic">f</Emphasis> complex

The cytochrome b ₆ f complex of oxygenic photosynthesis produces substantial levels of reactive oxygen species (ROS). It has been observed that the ROS production rate by b ₆ f is 10–20 fold higher than that observed for the analogous respiratory cytochrome bc₁ complex. The types of ROS produced (O₂^{??, 1}O₂, and, possibly, H₂O₂) and the site(s) of ROS production within the b ₆ f complex have been the subject of some debate. Proposed sources of ROS have included the heme b _p , PQ _p ^?? (possible sources for O₂^??), the Rieske iron–sulfur cluster (possible source of O₂^?? and/or ¹O₂), Chl a (possible source of ¹O₂), and heme c _n (possible source of O₂^?? and/or H₂O₂). Our working hypothesis is that amino acid residues proximal to the ROS production sites will be more susceptible to oxidative modification than distant residues. In the current study, we have identified natively oxidized amino acid residues in the subunits of the spinach cytochrome b ₆ f complex. The oxidized residues were identified by tandem mass spectrometry using the MassMatrix Program. Our results indicate that numerous residues, principally localized near p-side cofactors and Chl a, were oxidatively modified. We hypothesize that these sites are sources for ROS generation in the spinach cytochrome b ₆ f complex.     

Longitudinal assessment of the effect of concentration on stream N uptake rates in an urbanizing watershed

We examined the effect of concentration on nitrogen uptake patterns for a suburban stream in Maryland and addressed the question: How does NO₃ ^? uptake change as a function of concentration and how do uptake patterns compare with those found for NH₄ ⁺? We applied a longitudinal (stream channel corridor) approach in a forested stream section and conducted short-term nutrient addition experiments in late summer 2004. In the downstream direction, NO₃ ^? concentrations decreased because of residential development in headwaters and downstream dilution; NH₄ ⁺ concentrations slightly increased. The uptake patterns for NO₃ ^? were very different from NH₄ ⁺. While NH₄ ⁺ had a typical negative relationship between first-order uptake rate constant (K _c ) and stream size, NO₃ ^? had a reverse pattern. We found differences for other metrics, including uptake velocity (V _f ) and areal uptake rate (U). We attributed these differences to a stream size effect, a concentration effect and a biological uptake capacity effect. For NO₃ ^? these combined effects produced a downstream increase in K _c , V _f and U; for NH₄ ⁺ they produced a downstream decrease in K _c and V _f , and a not well defined pattern for U. We attributed a downstream increase in NO₃ ^? uptake capacity to an increase in hyporheic exchange and a likely increase in carbon availability. We also found that K _c and V _f were indirectly related with concentration. Similar evidence of ‘nutrient saturation’ has been reported in other recent studies. Our results suggest that higher-order uptake models might be warranted when scaling NO₃ ^? uptake across watersheds that are subject to increased nitrogen loading.     

<Emphasis Type="Italic">Phenylobacterium terrae</Emphasis> sp. nov., isolated from a soil sample of Khyber-Pakhtun-Khwa,Pakistan

A Gram-stain negative, aerobic, motile, non-spore-forming and rod-shaped bacterial strain, designated YIM 730227^T, was isolated from a soil sample, collected from Karak district, Khyber-Pakhtun-Khwa, Pakistan. The bacterium was characterized using a polyphasic taxonomic approach. Pairwise comparison of the 16S rRNA gene sequences showed that strain YIM 730227^T is closely related to Phenylobacterium lituiforme FaiI3^T (97.5% sequence similarity), Phenylobacterium muchangponense A8^T (97.4%), Phenylobacterium panacis DCY109^T (97.1%), Phenylobacterium immobile E^T (97.1%) and Phenylobacterium composti 4T-6^T (97.0%), while also sharing 98.0% sequence similarity with Phenylobacterium hankyongense HKS-05^T after NCBI blast, showing it represents a member of the family Caulobacteraceae. The major respiratory quinone was Q-10 and the major fatty acids were C_16:0, summed feature 8 (comprising C_18:1ω7c and/or C_18:1ω6c), C_18:1ω7c 11-methyl and C_17:0. The polar lipids were phosphatidylglycerol, unidentified glycolipids, phospholipid and unidentified lipid. The G?+?C content of the genomic DNA was 68.2 mol%. The DNA–DNA relatedness values of strain YIM 730227^T with P. hankyongense HKS-05^T, P. lituiforme FaiI3^T, P. muchangponense A8^T, P. panacis DCY109^T, P. immobile E^T and P. composti 4T-6^T were 31.3?±?0.6, 26.1?±?0.2, 24.3?±?0.1, 21.8?±?0.9, 19.8?±?0.6 and 18.2?±?1.1%, respectively, values lower than 70%. Besides the morphological and chemotaxonomic characteristics, phylogenetic analyses of 16S rRNA gene sequences and the biochemical characteristics indicated that the strain YIM 730227^T represents a novel member of the genus Phenylobacterium, for which the name Phenylobacterium terrae sp. nov. (type strain YIM 730227^T =?KCTC62324^T?=?CGMCC 1.16326^T) is proposed.     

The <Emphasis Type="Italic">angora</Emphasis> gene weakens the effect of interaction of the mutant genes <Emphasis Type="Italic">wellhaarig</Emphasis> and <Emphasis Type="Italic">waved alopecia</Emphasis> in mice

The interaction of the mutant genes wellhaarig (we) and waved alopecia (wal) in mice was earlier demonstrated in our laboratory. The we gene significantly accelerates the appearance of alopecia in double we/wewal/wal homozygotes as compared to that in single +/+wal/wal homozygotes. It has been found in this work that the mutant gene angora-Y (Fgf5 ^go-Y ) weakens the effect of interaction of the we and wal genes. The first signs of alopecia appear in mice of the we/wewal/wal genotype at the age of 14 days, in triple Fgf5 ^go-Y /Fgf5 ^go-Y we/wewal/wal homozygotes alopecia is observed seven days later, i. e., in 21-day-old animals. The progression of alopecia in triple homozygotes is expressed to a lesser degree than in double +/+we/wewal/wal homozygotes. A single dose of the Fgf5 ^go-Y gene also decreases the effect of interaction of the we and wal genes, but less than a double dose of this gene. The first signs of alopecia in mice of the +/Fgf5 ^go-Y we/wewal/wal genotype appear only three days later than in double +/+we/wewal/wal homozygotes. The data obtained demonstrate that the Fgf5 ^go-Y gene is a powerful modifier of mutant genes determining the process of alopecia.     

Impact of Sur1 gene inactivation on the morphology of mouse pancreatic endocrine tissue

In congenital hyperinsulinism of infancy (CHI), the loss of K-ATP channels (composed of Kir6.2 and SUR1 subunits) in β cells induces permanent insulin secretion and severe hypoglycaemia. By contrast, Sur1 ^?/? mice do not present such defects. We have investigated the impact of Sur1 gene inactivation on mouse islet cell morphology, structure and basic physiology. Pancreata were collected from young, adult and old wild-type (WT) and Sur1 ^?/? mice. After immunostaining for hormone, the total endocrine tissue, cell proportion, cell size and intra-insular distribution, hormone content and Glut-2 expression were quantified by morphometry. Basic physiological parameters were also measured. In young Sur1 ^?/? mice, the total endocrine tissue and proportion of β cells were higher (P<0.05) than in WT mice, whereas the proportion of δ cells was lower (P<0.01). In old Sur1 ^?/? mice, α cells were frequently located in the central regions of islets (unlike WT islets) and their proportion was increased (P<0.05). Glut-2 protein and mRNA levels were lower in old Sur1 ^?/? islets (P<0.02). Insulinaemia, fasting insulin and glucagon contents were equivalent in both groups of pancreata. Thus, the islets of Sur1 ^?/? mice present morphological modifications that have not been described in CHI and that might reflect an adaptive mechanism controlling insulin secretion in these mice.     

Short-term effects of crop rotation,residue management,and soil water on carbon mineralization in a tropical cropping system

The purpose of this study was to investigate the short-term effects of maize (Zea mays)-fallow rotation, residue management, and soil water on carbon mineralization in a tropical cropping system in Ghana. After 15 months of the trial, maize–legume rotation treatments had significantly (P?C ₀ (μg CO₂–C g^?1) than maize–elephant grass (Pennisetum purpureum) rotations. The C ₀ for maize–grass rotation treatments was significantly related to the biomass input (r?=?0.95; P?=?0.05), but that for the maize–legume rotation was not. The soil carbon mineralization rate constant, k (per day), was also significantly related to the rotation treatments (P?k values for maize–grass and maize–legume rotation treatments were 0.025 and 0.036 day^?1 respectively. The initial carbon mineralization rate, m ₀ (μg CO₂–C g^?1 day ^?1), was significantly (P?θ. The m ₀ ranged from 3.88 to 18.67 and from 2.30 to 15.35 μg CO₂–C g^?1 day^?1 for maize–legume and maize–grass rotation treatments, respectively, when the soil water varied from 28% to 95% field capacity (FC). A simple soil water content (θ)-based factor, f _w, formulated as: \(f_{\text{w}} = \left[ {\frac{{\theta - \theta _{\text{d}} }}{{\theta _{{\text{FC}}} - \theta _{\text{d}} }}} \right]\), where θ _d and θ _FC were the air-dry and field capacity soil water content, respectively, adequately described the variation of the m ₀ with respect to soil water (R ²?=?0.91; RMSE?=?1.6). Such a simple relationship could be useful for SOC modeling under variable soil water conditions.     

A note on imitative behavior

In a preceding paper (Bull. Math. Biophysics,27, 175–185) the distribution function ofφ=? ₁-? ₂,—the difference of excitations in the two mutually inhibiting centers, has been derived in terms of the distribution functionsf ₁(? ₁) andf ₂(? ₂) of the two excitations. In the present note some properties of the distribution functionf(?) in terms of the propertiesf ₁(? ₁) andf ₂(? ₂) are derived.     

Assessment of photosynthetic potential of indoor plants under cold stress

Photosynthetic parameters including net photosynthetic rate (P_N), transpiration rate (E), water-use efficiency (WUE), and stomatal conductance (g_s) were studied in indoor C₃ plants Philodendron domesticum (Pd), Dracaena fragans (Df), Peperomia obtussifolia (Po), Chlorophytum comosum (Cc), and in a CAM plant, Sansevieria trifasciata (St), exposed to various low temperatures (0, 5, 10, 15, 20, and 25°C). All studied plants survived up to 0°C, but only St and Cc endured, while other plants wilted, when the temperature increased back to room temperature (25°C). The P_N declined rapidly with the decrease of temperature in all studied plants. St showed the maximum P_N of 11.9 μmol m^?2 s^?1 at 25°C followed by Cc, Po, Pd, and Df. E also followed a trend almost similar to that of P_N. St showed minimum E (0.1 mmol m^?2 s^?1) as compared to other studied C₃ plants at 25°C. The E decreased up to ≈4-fold at 5 and 0°C. Furthermore, a considerable decline in WUE was observed under cold stress in all C₃ plants, while St showed maximum WUE. Similarly, the g_s also declined gradually with the decrease in the temperature in all plants. Among C₃ plants, Pd and Po showed the maximum g_s of 0.07 mol m^?2 s^?1 at 25°C followed by Df and Cc. However, St showed the minimum g_s that further decreased up to ～4-fold at 0°C. In addition, the content of photosynthetic pigments [chlorophyll a, b, (a+b), and carotenoids] was varying in all studied plants at 0°C. Our findings clearly indicated the best photosynthetic potential of St compared to other studied plants. This species might be recommended for improving air quality in high-altitude closed environments.     

The mathematical model of concentration polarization coefficient in membrane transport and volume flows

In this paper, the authors investigate the membrane transport of aqueous non-electrolyte solutions in a single-membrane system with the membrane mounted horizontally. The purpose of the research is to analyze the influence of volume flows on the process of forming concentration boundary layers (CBLs). A mathematical model is provided to calculate dependences of a concentration polarization coefficient (ζ _s ) on a volume flux (J _vm ), an osmotic force (Δπ) and a hydrostatic force (ΔP) of different values. Property ζ _s ?=?f(J _vm ) for J _vm ?>?0 and for J _vm ?≈?0 and property ζ _s ?=?f(ΔC ₁) are calculated. Moreover, results of a simultaneous influence of ΔP and Δπ on a value of coefficient ζ _s when J _vm ?=?0 and J _vm ?≠?0 are investigated and a graphical representation of the dependences obtained in the research is provided. Also, mathematical relationships between the coefficient ζ _s and a concentration Rayleigh number (R _C ) were studied providing a relevant graphical representation. In an experimental test, aqueous solutions of glucose and ethanol were used.     

Polymorphism of the genes for antioxidant defense enzymes and their association with the development of chronic obstructive pulmonary disease in the population of Bashkortostan

In this study, frequencies of the polymorphic variants of the genes encoding antioxidant enzymes, GSTM1, GSTT1, GSTP1, CAT, GPX1, NQO1, SOD1, and SOD3 were examined in three ethnic groups of healthy subjects from the Republic of Bashkortostan (Russians, Tatars, and Bashkirs). An association of these markers with the development of chronic obstructive pulmonary disease (COPD) was tested. Interethnic differences relative to the distribution of the polymorphic variants of the GSTP1 locus Ile105Val and the NQO1 locus 609C/T were revealed. Relative to the genotype distribution at the Ile105Val locus of the GSTP1 gene, ethnic group of Bashkirs was found to be statistically significantly different from Tatars (χ² = 8.819; d.f. = 2; P = 0.012). Relative to the genotype frequency distribution pattern at the NQO1 locus 609C/T, the group of Bashkirs differed from Russians (χ² = 8.913; d.f. = 2; P = 0.012). An association of genotype Val/Val of the GSTP1 Ile105Val locus with the risk of COPD in Russians (χ² = 5.25; P = 0.022; P _cor = 0.044; OR = 4.09), and of the GSTP1 haplotype *D in Tatars, was demonstrated (χ² = 11.575; P = 0.0014; P _cor = 0.0042; OR = 3.178). Genotype TT of the CAT ?262C/T locus marked resistance to the COPD development in Russians (χ² = 6.82; P = 0.0098; P _cor = 0.0196; OR = 0.31; 95%CI, 0.119 to 0.77). The risk for COPD in the ethnic group of Tatars was associated with the CAT haplotype (?262)C/(1167)T (χ² = 6.038; P = 0.0147; P _cor = 0.044; OR = 1.71). Analysis of the NQO1 haplotypes at the 465C/T and 609C/T loci showed that haplotype 465C/609T was associated with COPD in Russians (χ² = 4.571; P = 0.0328; P _cor = 0.01; OR = 1.799). It was demonstrated that Gly allele of the Arg213Gly polymorphic locus of the SOD3 gene marked the risk for COPD in the ethnic group of Tatars (OR = 2.23; 95%CI, 1.22 to 4.1). Thus, GSTP1, CAT, NQO1, and SOD3 polymorphisms play an important role in the development of COPD among the population of Bashkortostan.     

Modelling photosynthesis in shallow algal production ponds

Shallow ponds with rapidly photosynthesising cyanobacteria or eukaryotic algae are used for growing biotechnology feedstock and have been proposed for biofuel production but a credible model to predict the productivity of a column of phytoplankton in such ponds is lacking. Oxygen electrodes and Pulse Amplitude Modulation (PAM) fluorometer technology were used to measure gross photosynthesis (P _G) vs. irradiance (E) curves (P _G vs. E curves) in Chlorella (chlorophyta), Dunaliella salina (chlorophyta) and Phaeodactylum (bacillariophyta). P _G vs. E curves were fitted to the waiting-in-line function [P _G = (P _Gmax × E/E_opt) × exp(1 — E/E_opt)]. Attenuation of incident light with depth could then be used to model P _G vs. E curves to describe P _G vs. depth in pond cultures of uniformly distributed planktonic algae. Respiratory data (by O2-electrode) allowed net photosynthesis (P _N) of algal ponds to be modelled with depth. Photoinhibition of photosynthesis at the pond surface reduced P _N of the water column. Calculated optimum depths for the algal ponds were: Phaeodactylum, 63 mm; Dunaliella, 71 mm and Chlorella, 87 mm. Irradiance at this depth is ≈ 5 to 10 μmol m^?2 s^?1 photosynthetic photon flux density (PPFD). This knowledge can then be used to optimise the pond depth. The total net P _N [μmol(O2) m^?2 s^?1] were: Chlorella, ≈ 12.6 ± 0.76; Dunaliella, ≈ 6.5 ± 0.41; Phaeodactylum ≈ 6.1 ± 0.35. Snell’s and Fresnel’s laws were used to correct irradiance for reflection and refraction and thus estimate the time course of P _N over the course of a day taking into account respiration during the day and at night. The optimum P _N of a pond adjusted to be of optimal depth (0.1–0.5 m) should be approximately constant because increasing the cell density will proportionally reduce the optimum depth of the pond and vice versa. Net photosynthesis for an optimised pond located at the tropic of Cancer would be [in t(C) ha^?1 y^?1]: Chlorella, ≈ 14.1 ± 0.66; Dunaliella, ≈ 5.48 ± 0.39; Phaeodactylum, ≈ 6.58 ± 0.42 but such calculations do not take weather, such as cloud cover, and temperature, into account.     

Quantitative trait locus mapping of genes associated with vacuolation in the adrenal X-zone of the DDD/Sgn inbred mouse

Background

Adrenal gland of mice contains a transient zone between the adrenal cortex and the adrenal medulla: the X-zone. There are clear strain differences in terms of X-zone morphology. Nulliparous females of the inbred mouse DDD strain develop adrenal X-zones containing exclusively vacuolated cells, whereas females of the inbred mouse B6 strain develop X-zones containing only non-vacuolated cells. The X-zone vacuolation is a physiologic process associated with the X-zone degeneration and is tightly regulated by genetic factors. Identification of the genetic factors controlling such strain differences should help analyze the X-zone function. In this study, a quantitative trait locus (QTL) analysis for the extent of X-zone vacuolation was performed for two types of F₂ female mice: F₂A ^y mice (F₂ mice with the A ^y allele) and F₂ non-A ^y mice (F₂ mice without the A ^y allele). These were produced by crossing B6 females and DDD.Cg-A ^y males. DDD.Cg-A ^y is a congenic mouse strain for the A ^y allele at the agouti locus and is used for this study because a close association between the X-zone morphology and the agouti locus genotype has been suggested. The A ^y allele is dominant and homozygous lethal; therefore, living A ^y mice are invariably heterozygotes.

Results

Single QTL scans identified significant QTLs on chromosomes 1, 2, 6, and X for F₂ non-A ^y mice, and on chromosomes 2, 6, and 12 for F₂A ^y mice. The QTL on chromosome 2 was considered to be because of the agouti locus, which has been suggested to be associated with X-zone vacuolation. A significant QTL that interacted with the agouti locus was identified on chromosome 8.

Conclusions

The extent of X-zone vacuolation in DDD females was controlled by multiple genes with complex interactions. The murine X-zone is considered analogous structure to the human fetal zone. Therefore, the results of this study will aid in understanding function of not only of the X-zone but also of the human fetal zone. Identifying the genes responsible for the QTLs will be essential for understanding the molecular basis of X-zone function, which is currently unclear.

     

Chaotic Dynamics of Neuromuscular System Parameters and the Problems of the Evolution of Complexity

The evolution rate v(t) varies among diverse biosystems, but a general theory can be formulated when the dynamics of the biosystem stater x = x(t) = (x₁, x₂, x _m ) ^T is considered in the m-dimensional space of states. A mathematical approach is proposed for evaluating such processes and describes the processes in terms of particular chaos of the statistical distribution functions f(x). In the case of complex multicomponent systems with a high dimension number m (m ?1) of the phase space of states, we propose using pairwise comparison matrices of samples x(t) when homeostasis is constant and calculating the parameters of quasiattractors. The Glensdorff–Prigogine thermodynamic approach to estimating evolution is inefficient in assessing the third-type systems, while it is applicable and the Prigogine theorem works at the level of molecular systems. Alterations in the state of the human neuromuscular system were found to lead to chaotic changes in the statistical functions f(x) in tremor recording samples, while quasiattractor parameters demonstrate a certain regularity.     

Analysis of applicability of triplet-state emission of molecular hydrogen for spectral diagnostics of a DC discharge

The applicability of emission of the N ³Λ_σ triplet states of molecular hydrogen for spectral diagnostics of the positive column of a dc glow discharge in hydrogen at translational gas temperatures of 360–600 K, specific absorbed powers of 0.8–4.25 W/cm, gas pressures of p = 0.3–15.0 Torr, reduced fields of E/N = 30–130 Td, and electron densities of n _e = 4.0 × 10⁹–6.5 × 10¹⁰ cm^–3 is analyzed by using an advanced level-based semi-empirical collisional?radiative model. It is found that secondary processes make the main contribution to the population and decay of the N ³Λ_σ = a ³Σ⁺ _g , c ³Π _u , g ³Σ⁺ _g , h ³Σ⁺ _g , and i ³Π _g triplet states. The dipole-allowed transitions e ³Σ⁺ _g → a ³Σ⁺ _g , f ³Σ⁺ _g → a ³Σ⁺ _g , g ³Σ⁺ _g and k ³Π _u → a ³Σ⁺ _g can be used for spectral diagnostics of a dc discharge within a simplified coronal model.