Nitrous oxide emissions from fertilized, irrigated cotton (Gossypium hirsutum L.) in the Aral Sea Basin, Uzbekistan : influence of nitrogen applications and irrigation practices

Nitrous oxide emissions were monitored at three sites over a 2-year period in irrigated cotton fields in Khorezm, Uzbekistan, a region located in the arid deserts of the Aral Sea Basin. The fields were managed using different fertilizer management strategies and irrigation water regimes. N2O emissions varied widely between years, within 1 year throughout the vegetation season, and between the sites. The amount of irrigation water applied, the amount and type of N fertilizer used, and topsoil temperature had the greatest effect on these emissions. Very high N2O emissions of up to 3000 μg N2O-N m−2 h−1 were measured in periods following N-fertilizer application in combination with irrigation events. These “emission pulses” accounted for 80–95% of the total N2O emissions between April and September and varied from 0.9 to 6.5 kg N2O-N ha−1.. Emission factors (EF), uncorrected for background emission, ranged from 0.4% to 2.6% of total N applied, corresponding to an average EF of 1.48% of applied N fertilizer lost as N2O-N. This is in line with the default global average value of 1.25% of applied N used in calculations of N2O emissions by the Intergovernmental Panel on Climate Change. During the emission pulses, which were triggered by high soil moisture and high availability of mineral N, a clear diurnal pattern of N2O emissions was observed, driven by daily changes in topsoil temperature. For these periods, air sampling from 8:00 to 10:00 and from 18:00 to 20:00 was found to best represent the mean daily N2O flux rates. The wet topsoil conditions caused by irrigation favored the production of N2O from NO3− fertilizers, but not from NH4+ fertilizers, thus indicating that denitrification was the main process causing N2O emissions. It is therefore argued that there is scope for reducing N2O emission from irrigated cotton production; i.e. through the exclusive use of NH4+ fertilizers. Advanced application and irrigation techniques such as subsurface fertilizer application, drip irrigation and fertigation may also minimize N2O emission from this regionally dominant agro-ecosystem.

Ectopic overexpression of a mungbean vacuolar Na+/H+ antiporter gene (VrNHX1) leads to increased salinity stress tolerance in transgenic Vigna unguiculata L. Walp

Salinity is a major threat to sustainable agriculture worldwide. Plant NHX exchangers play an important role in conferring salt tolerance under salinity stress. In this study, a vacuolar Na+/H+ antiporter gene VrNHX1 (Genbank Accession No. JN656211.1) from mungbean (Vigna radiata) was introduced into cowpea (Vigna unguiculata) by the Agrobacterium tumefaciens-mediated transformation method. Polymerase chain reaction and Southern blot hybridization confirmed the stable integration of VrNHX1 into the cowpea genome. Comparative expression analysis by semi-quantitative RT-PCR revealed higher expression of VrNHX1 in transgenic cowpea plants than wild-type. Under salt stress conditions, T2 transgenic 35S:VrNHX1 cowpea lines exhibited higher tolerance to 200 mM NaCl treatment than wild-type. Furthermore, T2 transgenic 35S:VrNHX1 lines maintained a higher K+/Na+ ratio in the aerial parts under salt stress and accumulated higher [Na+] in roots than wild-type. Physiological analysis revealed lower levels of lipid peroxidation, hydrogen peroxide and oxygen radical production but higher levels of relative water content and proline, ascorbate and chlorophyll contents in T2 transgenic 35S:VrNHX1 lines.

Biolistic transformation of elite indica rice (Oryza sativa L.) cultivars through semi-solid and liquid medium selection systems

Following microprojectile mediated delivery of a plasmid construct (pAHC-25) encoding bar (bialophos resistance) gene into five-day-old scutellar calli derived from mature embryos, the effectiveness of selection procedure for bar-gene expressing tissue was compared for two indica rice cultivars (IR-64 and Karnal Local). While IR-64 transformants could be selected through the generally used semi-solid selection medium, the same procedure was not effective in the basmati cultivar Karnal Local. In the latter case, while lower concentrations (2–4 mg 1−1) of the selective agent phosphinothricin (PPT) yielded only escapes, higher concentrations (6–8 mg l−1) inhibited proliferation of transformed as well as untransformed sectors. For Karnal Local, a liquid medium based selection system was successfully utilized for recovering transformed sectors and, eventually, regenerants. The study demonstrates the generation of transformants of two elite indica cultivars using the environment-independent system of mature embryos from seeds.

Breathe easier online : evaluation of a randomized controlled pilot trial of an internet-based intervention to improve well-being in children and adolescents with a chronic respiratory condition

Background Chronic respiratory illnesses are the most common group of childhood chronic health conditions and are overrepresented in socially isolated groups. Objective To conduct a randomized controlled pilot trial to evaluate the efficacy of Breathe Easier Online (BEO), an Internet-based problem-solving program with minimal facilitator involvement to improve psychosocial well-being in children and adolescents with a chronic respiratory condition. Methods We randomly assigned 42 socially isolated children and adolescents (18 males), aged between 10 and 17 years to either a BEO (final n = 19) or a wait-list control (final n = 20) condition. In total, 3 participants (2 from BEO and 1 from control) did not complete the intervention. Psychosocial well-being was operationalized through self-reported scores on depression symptoms and social problem solving. Secondary outcome measures included self-reported attitudes toward their illness and spirometry results. Paper-and-pencil questionnaires were completed at the hospital when participants attended a briefing session at baseline (time 1) and in their homes after the intervention for the BEO group or a matched 9-week time period for the wait-list group (time 2). Results The two groups were comparable at baseline across all demographic measures (all F < 1). For the primary outcome measures, there were no significant group differences on depression (P = .17) or social problem solving (P = .61). However, following the online intervention, those in the BEO group reported significantly lower depression (P = .04), less impulsive/careless problem solving (P = .01), and an improvement in positive attitude toward their illness (P = .04) compared with baseline. The wait-list group did not show these differences. Children in the BEO group and their parents rated the online modules very favorably. Conclusions Although there were no significant group differences on primary outcome measures, our pilot data provide tentative support for the feasibility (acceptability and user satisfaction) and initial efficacy of an Internet-based intervention for improving well-being in children and adolescents with a chronic respiratory condition. Trial registration Australian New Zealand Clinical Trials Registry number: ACTRN12610000214033;

Author response to : Brough et al. in response to the recently published article : Lottering,N., MacGregor,D.M.,Barry,M.D.,Reynolds,M.S., Gregory,L.S., 2014. Introducing standardized protocols for anthropological measurement of virtual sub-adult crania using computed tomography 2(1),34–38

Firstly, we would like to thank Ms. Alison Brough and her colleagues for their positive commentary on our published work [1] and their appraisal of our utility of the “off-set plane” protocol for anthropometric analysis. The standardized protocols described in our manuscript have wide applications, ranging from forensic anthropology and paleodemographic research to clinical settings such as paediatric practice and orthopaedic surgical design. We affirm that the use of geometrically based reference tools commonly found in computer aided design (CAD) programs such as Geomagic Design X® are imperative for more automated and precise measurement protocols for quantitative skeletal analysis. Therefore we stand by our recommendation of the use of software such as Amira and Geomagic Design X® in the contexts described in our manuscript...

Synthesis and toxicological evaluation of a chitosan‑L‑leucine conjugate for pulmonary drug delivery applications

Herein are reported the synthesis of a conjugate of chitosan with L-leucine, the preparation of nanoparticles from both chitosan and the conjugate for use in pulmonary drug delivery, and the in vitro evaluation of toxicity and inflammatory effects of both the polymers and their nanoparticles on the bronchial epithelial cell line, BEAS-2B. The nanoparticles, successfully prepared both from chitosan and the conjugate, had a diameter in the range of 10−30 nm. The polymers and their nanoparticles were tested for their effects on cell viability by MTT assay, on trans-epithelial permeability by using sodium fluorescein as a fluid phase marker, and on IL-8 secretion by ELISA. The conjugate nanoparticles had a low overall toxicity (IC50 = 2 mg/mL following 48 h exposure; no induction of IL-8 release at 0.5 mg/mL concentration), suggesting that they may be safe for pulmonary drug delivery applications.

Pharmacokinetics and tumor disposition of PEGylated, methotrexate conjugated poly-l-lysine dendrimers

Dendrimers have potential for delivering chemotherapeutic drugs to solid tumours via the enhanced permeation and retention (EPR) effect. The impact of conjugation of hydrophobic anticancer drugs to hydrophilic PEGylated dendrimer surfaces, however, has not been fully investigated. The current study has therefore characterised the effect on dendrimer disposition of conjugating α-carboxyl protected methotrexate (MTX) to a series of PEGylated 3H-labelled poly-L-lysine dendrimers ranging in size from generation 3 (G3) to 5 (G5) in rats. Dendrimers contained 50% surface PEG and 50% surface MTX. Conjugation of MTX generally increased plasma clearance when compared to conjugation with PEG alone. Conversely, increasing generation reduced clearance, increased metabolic stability and reduced renal elimination of the administered radiolabel. For constructs with molecular weights >20 kDa increasing the molecular weight of conjugated PEG also reduced clearance and enhanced metabolic stability but had only a minimal effect on renal elimination. Tissue distribution studies revealed retention of MTX conjugated smaller (G3-G4) PEG570 dendrimers (or their metabolic products) in the kidneys. In contrast, the larger G5 dendrimer was concentrated more in the liver and spleen. The G5 PEG1100 dendrimer was also shown to accumulate in solid Walker 256 and HT1080 tumours and comparative disposition data in both rats (1 to 2% dose/g in tumour) and mice (11% dose/g in tumour) are presented. The results of this study further illustrate the potential utility of biodegradable PEGylated poly-L-lysine dendrimers as long circulating vectors for the delivery and tumour-targeting of hydrophobic drugs.

Determination of l-dopa using electropolymerized 3,3′,3″,3‴-tetraaminophthalocyanatonickel(II) film on glassy carbon electrode

Electropolymerized film of 3,3′,3″,3‴-tetraaminophthalocyanatonickel(II) (p-NiIITAPc) on glassy carbon (GC) electrode was used for the selective and stable determination of 3,4-dihydroxy-l-phenylalanine (l-dopa) in acetate buffer (pH 4.0) solution. Bare GC electrode fails to determine the concentration of l-dopa accurately in acetate buffer solution due to the cyclization reaction of dopaquinone to cyclodopa in solution. On the other hand, p-NiIITAPc electrode successfully determines the concentration of l-dopa accurately because the cyclization reaction was prevented at this electrode. It was found that the electrochemical reaction of l-dopa at the modified electrode is faster than that at the bare GC electrode. This was confirmed from the higher heterogeneous electron transfer rate constant (k0) of l-dopa at p-NiIITAPc electrode (3.35 × 10−2 cm s−1) when compared to that at the bare GC electrode (5.18 × 10−3 cm s−1). Further, it was found that p-NiIITAPc electrode separates the signals of ascorbic acid (AA) and l-dopa in a mixture with a peak separation of 220 mV. Lowest detection limit of 100 nM was achieved at the modified electrode using amperometric method. Common physiological interferents like uric acid, glucose and urea does not show any interference within the potential window of l-dopa oxidation. The present electrode system was also successfully applied to estimate the concentration of l-dopa in the commercially available tablets.

Genetic divergence and echolocation call frequency in cryptic species of Hipposideros larvatus s.l. (Chiroptera : Hipposideridae) from the Indo-Malayan region

The intermediate leaf-nosed bat (Hipposideros larvatus) is a medium-sized bat distributed throughout the Indo-Malay region. In north-east India, bats identified as H. larvatus captured at a single cave emitted echolocation calls with a bimodal distribution of peak frequencies, around either 85 kHz or 98 kHz. Individuals echolocating at 85 kHz had larger ears and longer forearms than those echolocating at 98 kHz, although no differences were detected in either wing morphology or diet, suggesting limited resource partitioning. A comparison of mitochondrial control region haplotypes of the two phonic types with individuals sampled from across the Indo-Malay range supports the hypothesis that, in India, two cryptic species are present. The Indian 98-kHz phonic bats formed a monophyletic clade with bats from all other regional populations sampled, to the exclusion of the Indian 85-kHz bats. In India, the two forms showed 12–13% sequence divergence and we propose that the name Hipposideros khasiana for bats of the 85-kHz phonic type. Bats of the 98-kHz phonic type formed a monophyletic group with bats from Myanmar, and corresponded to Hipposideros grandis, which is suggested to be a species distinct from Hipposideros larvatus. Differences in echolocation call frequency among populations did not reflect phylogenetic relationships, indicating that call frequency is a poor indicator of evolutionary history. Instead, divergence in call frequency probably occurs in allopatry, possibly augmented by character displacement on secondary contact to facilitate intraspecific communication.

The O-specific polysaccharide structure and gene cluster of serotype O:12 of the Yersinia pseudotuberculosis complex, and the identification of a novel L-quinovose biosynthesis gene

A major virulence factor for Yersinia pseudotuberculosis is lipopolysaccharide, including O-polysaccharide (OPS). Currently, the OPS based serotyping scheme for Y. pseudotuberculosis includes 21 known O-serotypes, with genetic and structural data available for 17 of them. The completion of the OPS structures and genetics of this species will enable the visualization of relationships between O-serotypes and allow for analysis of the evolutionary processes within the species that give rise to new serotypes. Here we present the OPS structure and gene cluster of serotype O:12, thus adding one more to the set of completed serotypes, and show that this serotype is present in both Y. pseudotuberculosis and the newly identified Y. similis species. The O:12 structure is shown to include two rare sugars: 4-C[(R)-1-hydroxyethyl]-3,6-dideoxy-d-xylo-hexose (d-yersiniose) and 6-deoxy-l-glucopyranose (l-quinovose). We have identified a novel putative guanine diphosphate (GDP)-l-fucose 4-epimerase gene and propose a pathway for the synthesis of GDP-l-quinovose, which extends the known GDP-l-fucose pathway.

Structure of the K2 capsule associated with the KL2 gene cluster of Acinetobacter baumannii

The repeat unit structure of the K2 capsule from an extensively antibiotic-resistant Acinetobacter baumannii global clone 2 (GC2) strain was determined. The oligosaccharide contains three simple sugars, d-glucopyranose, d-galatopyranose and N-acetyl-d-galactosamine, and the complex sugar, 5,7-diacetamido-3,5,7,9-tetradeoxy-l-glycero-l-manno-non-2-ulosonic acid (Pse5Ac7Ac or pseudaminic acid), which has not previously been reported in any A. baumannii capsule. The strain was found to carry all the genes required for the synthesis of the sugars and construction of the K2 structure. The linkages catalyzed by the initiating transferase, three glycosyltransferases and the Wzy polymerase were also predicted. Examination of publicly available A. baumannii genome sequences revealed that the same gene cluster, KL2, often occurs in extensively antibiotic-resistant GC2 isolates and in further strain types. The gene module responsible for the synthesis of pseudaminic acid was also detected in four other K loci. A related module including genes for an acylated relative of pseudaminic acid was also found in two new KL types. A polymerase chain reaction scheme was developed to detect all modules containing genes for sugars based on pseudaminic acid and to specifically detect KL2.

L-dopa modulates functional connectivity in striatal cognitive and motor networks: A double-blind placebo-controlled study

Functional connectivity (FC) analyses of resting-state fMRI data allow for the mapping of large-scale functional networks, and provide a novel means of examining the impact of dopaminergic challenge. Here, using a double-blind, placebo-controlled design, we examined the effect of L-dopa, a dopamine precursor, on striatal resting-state FC in 19 healthy young adults.Weexamined the FC of 6 striatal regions of interest (ROIs) previously shown to elicit networks known to be associated with motivational, cognitive and motor subdivisions of the caudate and putamen (Di Martino et al., 2008). In addition to replicating the previously demonstrated patterns of striatal FC, we observed robust effects of L-dopa. Specifically, L-dopa increased FC in motor pathways connecting the putamen ROIs with the cerebellum and brainstem. Although L-dopa also increased FC between the inferior ventral striatum and ventrolateral prefrontal cortex, it disrupted ventral striatal and dorsal caudate FC with the default mode network. These alterations in FC are consistent with studies that have demonstrated dopaminergic modulation of cognitive and motor striatal networks in healthy participants. Recent studies have demonstrated altered resting state FC in several conditions believed to be characterized by abnormal dopaminergic neurotransmission. Our findings suggest that the application of similar experimental pharmacological manipulations in such populations may further our understanding of the role of dopaminergic neurotransmission in those conditions.

Selectivity of human retinotopic visual cortex to S-cone-opponent, L/M-cone-opponent and achromatic stimulation

Our aim was to make a quantitative comparison of the response of the different visual cortical areas to selective stimulation of the two different cone-opponent pathways [long- and medium-wavelength (L/M)- and short-wavelength (S)-cone-opponent] and the achromatic pathway under equivalent conditions. The appropriate stimulus-contrast metric for the comparison of colour and achromatic sensitivity is unknown, however, and so a secondary aim was to investigate whether equivalent fMRI responses of each cortical area are predicted by stimulus contrast matched in multiples of detection threshold that approximately equates for visibility, or direct (cone) contrast matches in which psychophysical sensitivity is uncorrected. We found that the fMRI response across the two colour and achromatic pathways is not well predicted by threshold-scaled stimuli (perceptual visibility) but is better predicted by cone contrast, particularly for area V1. Our results show that the early visual areas (V1, V2, V3, VP and hV4) all have robust responses to colour. No area showed an overall colour preference, however, until anterior to V4 where we found a ventral occipital region that has a significant preference for chromatic stimuli, indicating a functional distinction from earlier areas. We found that all of these areas have a surprisingly strong response to S-cone stimuli, at least as great as the L/M response, suggesting a relative enhancement of the S-cone cortical signal. We also identified two areas (V3A and hMT+) with a significant preference for achromatic over chromatic stimuli, indicating a functional grouping into a dorsal pathway with a strong magnocellular input.

Design and fabrication of linear pixel arrays for organic photovoltaic modules to achieve scalable power output

We describe a design and fabrication method to enable simpler manufacturing of more efficient organic solar cell modules using a modified flat panel deposition technique. Many mini-cell pixels are individually connected to each other in parallel forming a macro-scale solar cell array. The pixel size of each array is optimized through experimentation to maximize the efficiency of the whole array. We demonstrate that integrated organic solar cell modules with a scalable current output can be fabricated in this fashion and can also be connected in series to generate a scalable voltage output.