Sea-Ice Bacteria Halomonas sp. Strain 363 and Paracoccus sp. Strain 392 Produce Multiple Types of Poly-3-Hydroxyalkaonoic Acid (PHA) Storage Polymers at Low Temperature.

Poly-3-hydroxyalkanoic acids (PHAs) are bacterial storage polymers commonly used in bioplastic production. Halophilic bacteria are industrially interesting organisms, as their salinity tolerance and psychrophilic nature lowers sterility requirements and subsequent production costs. We investigated PHA synthesis in two bacterial strains, Halomonas sp. 363 and Paracoccus sp. 392, isolated from Southern Ocean sea ice and elucidated the related PHA biopolymer accumulation and composition with various approaches, such as transcriptomics, microscopy, and chromatography. We show that both bacterial strains produce PHAs at 4°C when the availability of nitrogen and/or oxygen limited growth. The genome of Halomonas sp. 363 carries three phaC synthase genes and transcribes genes along three PHA pathways (I to III), whereas Paracoccus sp. 392 carries only one phaC gene and transcribes genes along one pathway (I). Thus, Halomonas sp. 363 has a versatile repertoire of phaC genes and pathways enabling production of both short- and medium-chain-length PHA products. IMPORTANCE Plastic pollution is one of the most topical threats to the health of the oceans and seas. One recognized way to alleviate the problem is to use degradable bioplastic materials in high-risk applications. PHA is a promising bioplastic material as it is nontoxic and fully produced and degraded by bacteria. Sea ice is an interesting environment for prospecting novel PHA-producing organisms, since traits advantageous to lower production costs, such as tolerance for high salinities and low temperatures, are common. We show that two sea-ice bacteria, Halomonas sp. 363 and Paracoccus sp. 392, are able to produce various types of PHA from inexpensive carbon sources. Halomonas sp. 363 is an especially interesting PHA-producing organism, since it has three different synthesis pathways to produce both short- and medium-chain-length PHAs.

Clonal Analysis of Regulatory T Cell Defect in Patients with Autoimmune Polyendocrine Syndrome Type 1 Suggests Intrathymic Impairment.

Mutations in the autoimmune regulator gene disrupt thymic T cell development and negative selection, leading to the recessively inherited polyendocrine autoimmune disease autoimmune polyendocrine syndrome type 1 (APS-1). The patients also have a functional defect in the FOXP3+ regulatory T cell population, but its origin is unclear. Here, we have used T cell receptor sequencing to analyse the clonal relationship of major CD4+ T cell subsets in three patients and three healthy controls. The naive regulatory T cells showed little overlap with helper T cell subsets, supporting divergence in the thymus. The activated/memory regulatory T cell subset displayed more sharing with helper T cells, but was mainly recruited from the naive regulatory T cell population. These clonal patterns were very similar in both patients and controls. However, naive regulatory T cells isolated from the patients had a significantly longer T cell receptor complementarity-determining region 3 than any other population, suggesting failure of thymic selection. These data indicate that the peripheral differentiation of regulatory T cells in APS-1 patients is not different from that in healthy controls. Rather, the patients' naive regulatory T cells may have an intrinsic defect imprinted already in the thymus.

An experimental and theoretical study of the gas phase kinetics of atomic chlorine reactions with CH3NH2, (CH3)2NH, and (CH3)3N.

The rate coefficients for the reactions of Cl((2)PJ) with methylamine (R1), dimethylamine (R2) and trimethylamine (R3) have been measured using the laser flash photolysis - resonance fluorescence technique as a function of temperature (274-435 K) and pressure (25-400 Torr N2). The experimental data are well-represented by the following temperature- and pressure-independent rate coefficients (10(10) × k/cm(3) molecule(-1) s(-1)): kR1 = 2.90 ± 0.44, kR2 = 3.89 ± 0.58, kR3 = 3.68 ± 0.55; the uncertainties are estimates of accuracy at the 95% confidence level. Potential energy surfaces (PES) for the reactions have been characterized at the MP2/cc-pVTZ level and improved single point energies of stationary points obtained in CCSD(T)-F12a calculations. The PES for all reactions are characterized by the formation of pre and post reaction complexes and submerged barriers. Rate coefficients for the reactions were calculated as a function of temperature and pressure using a master equation model based on the coupled cluster theory results. The calculated rate coefficients are in good agreement with experiment; the overall rate coefficients are relatively insensitive to variations of the barrier heights within typical chemical accuracy, but the predicted branching ratios vary significantly. The inclusion of tunnelling has no effect.

Female Baltic herring Clupea harengus allocate resources from growth to reproduction in poor feeding conditions.

The trade-off between somatic growth and reproduction in the female Baltic herring Clupea harengus was investigated from 1984 to 2002. During the study period, growth decreased, as a consequence of decreasing salinity and weakening of feeding conditions. Production of muscle and ovarian tissue decreased in repeat spawners, but investment in reproduction took an increasing amount of the total production of new tissues. This suggested that a shift in allocation to reproduction takes precedence over body growth in the reproductive strategy of C. harengus. The process also indicated one possible mechanism leading to dwarf forms in fish populations.

G.3.2 is a novel allele of the gene connector enhancer of ksr ( cnk ) in Drosophila melanogaster.

Genetic screens in Drosophila melanogaster have long been used to identify genes found in a variety of developmental, cellular, and behavioral processes. Here we describe the characterization and mapping of a mutation identified in a conditional screen for genetic regulators of cell growth and cell division. Within a Flp/FRT system, mutant G.3.2 results in a reduction of mutant tissue and a rough eye phenotype. We find that G.3.2 maps to the gene cnk , providing further support that cnk is a critical gene in Drosophila eye development. This mutant was characterized, mapped and sequenced by undergraduate students within the Fly-CURE consortium.

Temperament, character and serotonin activity in the human brain: a positron emission tomography study based on a general population cohort.

BACKGROUND: The psychobiological model of personality by Cloninger and colleagues originally hypothesized that interindividual variability in the temperament dimension 'harm avoidance' (HA) is explained by differences in the activity of the brain serotonin system. We assessed brain serotonin transporter (5-HTT) density in vivo with positron emission tomography (PET) in healthy individuals with high or low HA scores using an 'oversampling' study design. Method Subjects consistently in either upper or lower quartiles for the HA trait were selected from a population-based cohort in Finland (n = 2075) with pre-existing Temperament and Character Inventory (TCI) scores. A total of 22 subjects free of psychiatric and somatic disorders were included in the matched high- and low-HA groups. The main outcome measure was regional 5-HTT binding potential (BPND) in high- and low-HA groups estimated with PET and [11C]N,N-dimethyl-2-(2-amino-4-methylphenylthio)benzylamine ([11C]MADAM). In secondary analyses, 5-HTT BPND was correlated with other TCI dimensions. RESULTS: 5-HTT BPND did not differ between high- and low-HA groups in the midbrain or any other brain region. This result remained the same even after adjusting for other relevant TCI dimensions. Higher 5-HTT BPND in the raphe nucleus predicted higher scores in 'self-directedness'. CONCLUSIONS: This study does not support an association between the temperament dimension HA and serotonin transporter density in healthy subjects. However, we found a link between high serotonin transporter density and high 'self-directedness' (ability to adapt and control one's behaviour to fit situations in accord with chosen goals and values). We suggest that biological factors are more important in explaining variability in character than previously thought.

In vivo trans-specific gene silencing in fungal cells by in planta expression of a double-stranded RNA.

BACKGROUND: Self-complementary RNA transcripts form a double-stranded RNA (dsRNA) that triggers a sequence-specific mRNA degradation, in a process known as RNA interference (RNAi), leading to gene silencing. In vascular plants, RNAi molecules trafficking occur between cells and systemically throughout the plant. RNAi signals can spread systemically throughout a plant, even across graft junctions from transgenic to non-transgenic stocks. There is also a great interest in applying RNAi to pathogenic fungi. Specific inhibition of gene expression by RNAi has been shown to be suitable for a multitude of phytopathogenic filamentous fungi. However, double-stranded (ds)RNA/small interfering (si)RNA silencing effect has not been observed in vivo. RESULTS: This study demonstrates for the first time the in vivo interference phenomenon in the pathogenic fungus Fusarium verticillioides, in which expression of an individual fungal transgene was specifically abolished by inoculating mycelial cells in transgenic tobacco plants engineered to express siRNAs from a dsRNA corresponding to the particular transgene. CONCLUSION: The results provide a powerful tool for further studies on molecular plant-microbe and symbiotic interactions. From a biotechnological perspective, silencing of fungal genes by generating siRNAs in the host provides a novel strategy for the development of broad fungi-resistance strategies in plants and other organisms.

A Semi-supervised Learning-Based Diagnostic Classification Method Using Artificial Neural Networks.

The purpose of cognitive diagnostic modeling (CDM) is to classify students' latent attribute profiles using their responses to the diagnostic assessment. In recent years, each diagnostic classification model (DCM) makes different assumptions about the relationship between a student's response pattern and attribute profile. The previous research studies showed that the inappropriate DCMs and inaccurate Q-matrix impact diagnostic classification accuracy. Artificial Neural Networks (ANNs) have been proposed as a promising approach to convert a pattern of item responses into a diagnostic classification in some research studies. However, the ANNs methods produced very unstable and unappreciated estimation unless a great deal of care was taken. In this research, we combined ANNs with two typical DCMs, the deterministic-input, noisy, "and" gate (DINA) model and the deterministic-inputs, noisy, "or" gate (DINO) model, within a semi-supervised learning framework to achieve a robust and accurate classification. In both simulated study and real data study, the experimental results showed that the proposed method could achieve appreciated performance across different test conditions, especially when the diagnostic quality of assessment was not high and the Q-matrix contained misspecified elements. This research study is the first time of applying the thinking of semi-supervised learning into CDM. Also, we used the validating test to choose the appropriate parameters for the ANNs instead of using typical statistical criteria.

Mucosal impact of alcoholic povidone-iodine indicated in preoperative disinfection.

BACKGROUND: Alcoholic povidone-iodine (API) used as skin disinfection reduces the risk of postoperative infection but there is no evidence for its use on mucous membranes. We therefore conducted a tolerance study on the glans of men operated in urology. AIM: To confirm the safety of using API on mucous membranes. METHODS: The impact of applying API on the glans mucosa was measured using a chromameter. Caucasian men, without any dermatological lesion of the glans, operated by endoscopic transurethral route, were included. Measurements (L*a*b*) were made preoperatively and postoperatively by an independent person. Parameters were compared using the recognized formula ΔE = √(ΔL2 + Δa2 + Δb2). FINDINGS: Ninety-six patients, average age 68.9 ± 10.4 years, were included. For L*, the mean pre- and postoperative difference was +2.36 (P = 0.168). For a* and b*, the mean pre- and postoperative differences were +0.13 (P = 0.9085) and -0.12 (P = 0.17089), respectively. ΔE was equal to 13.92 ± 17.49 (non-significant difference). CONCLUSION: Our study is the first to analyse the impact of API on genital mucous membranes. In our study conditions, API had no impact on the mucous membranes, suggesting that it can be used safely.

Assessing Growth in a Diagnostic Classification Model Framework.

A common assessment research design is the single-group pre-test/post-test design in which examinees are administered an assessment before instruction and then another assessment after instruction. In this type of study, the primary objective is to measure growth in examinees, individually and collectively. In an item response theory (IRT) framework, longitudinal IRT models can be used to assess growth in examinee ability over time. In a diagnostic classification model (DCM) framework, assessing growth translates to measuring changes in attribute mastery status over time, thereby providing a categorical, criterion-referenced interpretation of growth. This study introduces the Transition Diagnostic Classification Model (TDCM), which combines latent transition analysis with the log-linear cognitive diagnosis model to provide methodology for analyzing growth in a general DCM framework. Simulation study results indicate that the proposed model is flexible, provides accurate and reliable classifications, and is quite robust to violations to measurement invariance over time. The TDCM is used to analyze pre-test/post-test data from a diagnostic mathematics assessment.

Development and Psychometric Evaluation of the Autism Stigma and Knowledge Questionnaire (ASK-Q).

ASD knowledge deficits contribute to disparities in the timing and quality of ASD services. To address the limitations with existing measures of ASD knowledge, we developed and examined the Autism Stigma and Knowledge Questionnaire (ASK-Q), which comprehensively assesses multiple subdomains of ASD knowledge while maintaining strong psychometric support and cross-cultural utility. ASK-Q items derived from the published research are organized into four subscales: (i) diagnosis, (ii) etiology, (iii) treatment, and (iv) stigma. ASK-Q items were selected based on ratings of face, construct, and cross-cultural validity by a group of 16 international researchers. Using Diagnostic Classification Modeling we confirmed the proposed factor structure and evaluated the statistical validity of each item among a lay sample of 617 participants.

Adventitial mast cells connect with sensory nerve fibers in atherosclerotic coronary arteries.

BACKGROUND: The number of activated mast cells is increased in the adventitia of coronary segments with plaque rupture and in spastic atherosclerotic coronary segments. Neurogenic activation of mast cells has been demonstrated previously in other tissues. Here we identified and quantified contacts between mast cells and nerves in the adventitia of normal and atherosclerotic coronary segments. METHODS AND RESULTS: Normal (types 0 or I) and atherosclerotic (lesion types II, III, and IV) coronary segments from 22 unselected autopsy cases were stained for mast cells and sensory nerves by a histochemical double-labeling method. Contacts between mast cells and sensory nerves were quantified morphometrically and also identified by confocal microscopy. Coronary arteries obtained during heart transplantation were stained for the neuropeptides capable of stimulating mast cells, ie, substance P and calcitonin gene-related peptide. In the adventitia of atherosclerotic coronary segments with type IV lesions, the numbers of mast cells and mast cell-nerve contacts (104+/-15 mast cells/mm(2) and 30+/-5 nerve contacts/mm(2); mean+/-SEM) were significantly greater than in segments with type III lesions (79+/-12 [P<0.001] and 24+/-6 [P<0.001]), those with type II lesions (54+/-4 [P<0.001] and 12+/-2 [P<0.001]), or those with normal intima (31+/-3 [P<0.001] and 4+/-1 [P<0.001]). The nerve fibers connected with mast cells contained both substance P and calcitonin gene-related peptide, which identified them as sensory nerves. CONCLUSIONS: Neurogenic stimulation of mast cells in the adventitia of coronary arteries may release vasoactive compounds, such as histamine and leukotrienes, which can contribute to the complex neurohormonal response that leads to abnormal coronary vasoconstriction.

The Effects of Q-Matrix Design on Classification Accuracy in the Log-Linear Cognitive Diagnosis Model.

Diagnostic classification models are psychometric models that aim to classify examinees according to their mastery or non-mastery of specified latent characteristics. These models are well-suited for providing diagnostic feedback on educational assessments because of their practical efficiency and increased reliability when compared with other multidimensional measurement models. A priori specifications of which latent characteristics or attributes are measured by each item are a core element of the diagnostic assessment design. This item-attribute alignment, expressed in a Q-matrix, precedes and supports any inference resulting from the application of the diagnostic classification model. This study investigates the effects of Q-matrix design on classification accuracy for the log-linear cognitive diagnosis model. Results indicate that classification accuracy, reliability, and convergence rates improve when the Q-matrix contains isolated information from each measured attribute.

Effects of low temperature on nitrate uptake, and xylem and phloem flows of nitrogen, in Secale cereale L. and Brassica napus L.

The effect of low temperature on nitrate uptake and subsequent N translocation and cycling was investigated in Secale cereale L. and Brassica napus L. transferred to 7 °C for 9 d or kept at a warm temperature (20 °C). Some plants were grown with a split root system and 15 NO3 - , labelled to measure NO3 - uptake, root-to-shoot and shoot-to-root translocation of N from NO3 - , taken up. Other plants with single-root system were subjected to 15 N pulse-chase labelling to quantify endogenous N remobilization. Lowering growth temperature from 20 to 7 °C reduced nitrate uptake more strongly in rye (-59%) than in winter rape (-28%). A very large proportion of the nitrate taken up was further translocated to shoots in both species. However, lowering the temperature decreased, xylem N translocation by about 60 and 30% in S. cereale and B. napus, respectively. Most root N in the latter species came directly from root absorption, while in rye roots the proportions ascribe able to direct root allocation and phloem flow were well balanced. Cold treatment did not significantly modify the imbalance between the two origins. Mobilization of endogenous N from roots to shoot, estimated by pulse-chase labelling, was limited in B. napus and significant in S. cereale despite a depressive effect of low temperature. In general, low temperature led to an increase in root N concentration in both species. It is Suggested that low temperature may directly affect the nitrate uptake system, and also that N accumulation in the roots (resulting from greater inhibition of N xylem flow than of NO3 - uptake) might increase the inhibition of uptake by higher cellular NO3 , and/or amino acid content. The usefulness (for spring growth) of root N accumulation triggered by low temperature is discussed.

Bromine and thyroid hormone activity.

AIMS: To examine the possible consequences of high plasma concentrations of bromine on thyroid hormone. METHODS: Bromine was measured by inductively coupled plasma mass spectrometry in the plasma of 799 patients consulting for thyroid disorders. Because the mean (SD) bromine concentration in the plasma of healthy subjects is 4 (1) mg/l, concentrations above 6 mg/l were regarded as outside the normal range. Bromine, free thyroxine (FT4), and thyroid stimulating hormone (TSH) values were compared. RESULTS: The percentage of patients with normal, low, and high FT4 and TSH plasma activities, measured separately, did not differ between patients with low and high bromine concentrations. The percentage of patients with high TSH but normal FT4 values was significantly higher in the group with bromine values of more than 6 mg/l than in the group with bromine concentrations below this (p < 0.02). CONCLUSION: An increase in plasma bromine could potentiate an increase in plasma TSH concentration, probably as a consequence of a minor inhibitory effect on thyroid activity.

Sustained fields of tones and glides reflect tonotopy of the auditory cortex.

Cortical activation in response to two types of auditory stimuli, constant-frequency tones and frequency glides, was studied by measuring the magnetic field outside the head using a whole-head 122-channel magnetometer. Both the magnetic N1m and sustained responses were located in the supratemporal plane of the primary auditory cortex. The sustained responses both to constant-frequency tones and frequency glides reflect tonotopic organization of the auditory cortex both in depth and direction, thus revealing the underlying neuroanatomical structure of the auditory cortex.

Activation of ipsilateral primary sensorimotor cortex by median nerve stimulation.

We report evidence for activation of ipsilateral primary sensorimotor cortex (SMI) after median nerve stimulation recorded with magnetoencephalography (MEG). We measured somatosensory evoked magnetic fields (SEFs) to median nerve stimulation with a 122-channel helmet-shaped magnetometer in 10 healthy subjects. In five, the magnetic field patterns suggested long-latency activation of the ipsilateral SMI. Source locations found by current dipole fitting corresponded to the SMI hand area, as determined by contralateral stimulation. Further evidence for the origin of the ipsilateral responses in SMI was provided by the suppression of these responses during movement of the contralateral fingers. Sensory input to ipsilateral SMI could play a role in sensorimotor integration of bilateral movements.

Collagenases in different categories of peri-implant vertical bone loss.

The loosening of dental implants is associated with peri-implant vertical bone loss. The mechanisms and mediators of this bone destruction are not known. To test the hypothesis that collagenase-2 and collagenase-3 might be markers or maybe even mediators in this process, we measured collagenase-2 (time-resolved immunofluorometric assay) and collagenase-3 (quantitative immunoblot) in peri-implant sulcus fluid in 49 implant sites in 13 patients. Vertical bone loss was graded as being < 1 mm, from 1 to 3 mm, or > 3 mm. The severity of inflammation, as rated according to Gingival Index, did not correlate with the category of bone loss (p > 0.05). Collagenase-2 and collagenase-3 were higher (p < 0.05) in the group which had lost > 3 mm of bone than in the two other groups. Gingival Index is not a clinically important marker for bone loss, but collagenase-2 and collagenase-3 in peri-implant sulcus fluid are. They might participate in peri-implant osteolysis.

Brain imaging in alcoholism.

Copyright Rapid Science Ltd

Five-year follow-up study of saliva, mutans streptococci, lactobacilli and yeast counts in lymphoma patients.

Twenty-two patients out of the 79 that were originally included were examined 5 years after beginning anticancer therapy for lymphomas. The patients' cumulative data on salivary flow rate, buffering capacity and acidogenic microbial counts were compared with respective data of 17 patients who died during the follow-up. Stimulated saliva samples had been taken at baseline and during the cytostatic treatment with combination chemotherapy, and 1 year and 5 years later. Chair-side kits were used at the hospital ward for the assessment of the study parameters. Mean saliva flow at baseline was 1.5 +/- 0.7 ml/min in the surviving group and 1.5 +/- 0.8 ml/min in the deceased. Salivary flow rates were not affected by the anticancer treatment and there was no statistically significant difference between the groups in this respect. A significant difference was observed between the groups in salivary buffering capacity values at baseline: only 32% of the survived had low buffering capacity in comparison to 69% of those who later died (P < 0.02). Buffering capacity values remained low in 50% of the surviving patients 5 years later. Higher mutans streptococci and lactobacilli counts were seen among the deceased than in the survived patients but mutans streptococci decreased significantly in both groups after the start of the anticancer therapy (P < 0.05). The number of positive yeast counts increased consistently during the chemotherapy in both groups, being higher in the survived when compared with the deceased patients. Yeast counts remained positive 5 years later in 73% of the survived patients, while the mean mutans streptococci and lactobacilli counts decreased below baseline values. The results showed that persistently high salivary microbial counts and low buffering capacity may be linked with poor prognosis.