Seaweed Allelopathy Against Coral: Surface Distribution of a Seaweed Secondary Metabolite by Imaging Mass Spectrometry

Coral reefs are in global decline, with seaweeds increasing as corals decrease. Although seaweeds inhibit coral growth, recruitment, and survivorship, the mechanism of these interactions is poorly understood. Here, we used field experiments to show that contact with four common seaweeds induces bleaching on natural colonies of Porites rus. Controls in contact with inert, plastic mimics of seaweeds did not bleach, suggesting seaweed effects resulted from allelopathy rather than shading, abrasion, or physical contact. Bioassay-guided fractionation of the hydrophobic extract from the red alga Phacelocarpus neurymenioides revealed a previously characterized antibacterial metabolite, neurymenolide A, as the main allelopathic agent. For allelopathy of lipid-soluble metabolites to be effective, the compounds would need to be deployed on algal surfaces where they could transfer to corals on contact. We used desorption electrospray ionization mass spectrometry (DESI-MS) to visualize and quantify neurymenolide A on the surface of P. neurymenioides, and we found the molecule on all surfaces analyzed, with highest concentrations on basal portions of blades.     

Discovery of Ubonodin,an Antimicrobial Lasso Peptide Active against Members of the Burkholderia cepacia Complex

We report the heterologous expression, structure, and antimicrobial activity of a lasso peptide, ubonodin, encoded in the genome of Burkholderia ubonensis. The topology of ubonodin is unprecedented amongst lasso peptides, with 18 of its 28 amino acids found in the mechanically bonded loop segment. Ubonodin inhibits RNA polymerase in vitro and has potent antimicrobial activity against several pathogenic members of the Burkholderia genus, most notably B. cepacia and B. multivorans, causative agents of lung infections in cystic fibrosis patients.     

Fatty Acid Composition, Antioxidant Properties, and Antiproliferative Capacity of Selected Cold-Pressed Seed Flours

Cold-pressed seed flours from pumpkin, parsley, mullein, cardamom, and milk thistle were examined for total oil, fatty acid profile of the oil, total phenolic content (TPC), scavenging activities against peroxyl (ORAC), hydroxyl (HOSC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) (RDSC) radicals, and antiproliferative capacity against HT-29 human colon cancer cells. The cold-pressed parsley seed flour contained a very high concentration of total oil—17.6 g/100 g flour—with primarily C18:1 fatty acid at 86.2 g/100 g fatty acids. All other flour oils had relatively high levels of saturated fats, ranging from 39.0 to 62.9 g/100 g fatty acids. The tested seed flours demonstrated significant TPC and free radical scavenging activities. Milk thistle seed flour had the highest TPC value of 25.2 mg gallic acid equivalent per g flour (GAE mg/g) followed by that of parsley seed flour at 8.1 GAE mg/g. Milk thistle seed-flour extract also had significantly higher antioxidant activities than all other extracts against all tested radicals. The milk thistle seed-flour extract had an ORAC value of 1131 μmol trolox equivalents (TE) per g flour (TE μmol/g), a HOSC value of 893 TE μmol/g, and an RDSC value of 61 TE μmol/g. Also, ORAC, HOSC, and TPC values were significantly correlated (P < 0.01) under the experimental conditions. The cold-pressed milk thistle seed flour inhibited the proliferation of HT-29 cancer cells in a dose-dependent manner. Results from this study suggest that these cold-pressed seed flours may serve as natural sources of antioxidants and may be used to improve human health.     

Enhanced photocatalytic properties of N–P co-doped TiO<Subscript>2</Subscript> nanosheets with {001} facets

Nitrogen (N) and phosphorus (P) co-doped anatase TiO₂ nanosheets were realized by low-temperature self-doping N–TiO₂ followed by high-temperature P doping with foreign precursor. It is found that P doping process can maintain good TiO₂ nanosheets morphology with exposed {001} facets. Chemical state of dopants indicates that N and P atoms replace O on O sites in TiO₂ lattice. Compared with pure TiO₂ and N-doped TiO₂, N–P co-doped TiO₂ nanosheets exhibits stronger optical absorption and higher degradation rate of dye molecules in visible light regime. The enhanced photocatalytic properties are attributed to two factors. On one hand, N–P co-doping can effectively reduce band gap of TiO₂ from 3.20 to 2.48 eV, leading to an enhancement of the absorption in visible light regime. On the other hand, the presence of exposed {001} facets of TiO₂ nanosheets can induce the effective separation of photogenerated electrons and holes in reaction.     

Are staff management practices and inspection risk ratings associated with foodborne disease outbreaks in the catering industry in England and Wales?

Despite structured enforcement of food hygiene requirements known to prevent foodborne disease outbreaks, catering businesses continue to be the most common setting for outbreaks in the United Kingdom. In a matched case control study of catering businesses, 148 businesses associated with outbreaks were compared with 148 control businesses. Hazard analysis critical control point systems and/or formal food hygiene training qualifications were not protective. Food hygiene inspection scores were not useful in predicting which catering businesses were associated with outbreaks. Businesses associated with outbreaks were more likely to be larger small and medium-sized enterprises (SMEs) or to serve Chinese cuisine and less likely to have the owner or manager working in the kitchen, but when size of the SME was taken into account these two differences were no longer significant. In larger businesses, case businesses were more likely to be hotels and were more commonly associated with viral foodborne outbreaks, but there was no explanation within the data for this association.     

Transition layer thickness in microlaminar deposits

A theoretical analysis was carried out on the change of composition of a deposit obtained by the dual pulse method of forming laminar metal foils, with transition from a low current to a high current pulse, both in the galvanostatic and the potentiostatic mode of deposition. It was shown that the existence of a transition layer of varying composition between a layer of pure metal 1 and a layer consisting predominantly of the metal 2 is an inherent consequence of the electrochemical process, primarily because of an induction period in the concentration polarization with respect to ions of metal 1. The importance of this transition layer increases as the thickness of the layers of the two metals decreases. Eventually this limits the possibility of obtaining a sharp boundary between the layers, when the nanometre region of layer thickness is reached. Equations are given for calculating the deposition current density and rate of stirring of the electrolyte which provide a deposit of a required level of metal 1 in the layer of metal 2, as well as a required sharpness of the boundary between two layers. Experimental proof of the correctness of the analysis was sought. It was found that significant changes in the properties of the deposit occur in the same range of layer thickness in which the transition of the composition takes places.Nomenclature _c,1, a_c,2 transfer coefficient of the cathodic processes - C interfacial capacitance - C₁, C₂ concentration of the ions of metals 1 and 2 at the interface r - C ₀ ¹ , C ₀ ² concentration of ions of the metals 1 and 2 in solution - D ₁ diffusion coefficient for the diffusion of ions of the metal 1 - E _r,1,E _r,2 reversible potentials of metals 1 and 2, respectively - F the Faraday constant - J ₀ ¹ ,J ₀ ² exchange current density of the metals 1 and 2, respectively - M ₁,M ₂ atomic weights of the metals 1 and 2, respectively - kinematic viscosity of solution - ₁, ₂ densities of the metals 1 and 2 respectively - rotation speed (r.p.s.) - z number of electrons exchanged in the deposition process This paper is dedicated to Professor Brian E. Conway on the occasion of his 65th birthday, and in recognition of his outstanding contribution to electrochemistry.     

Behavioral training for parents of retarded children: alternative formats based on instructional manuals

A series of instructional manuals in behavior modification with retarded children was tested as a self-contained resource and as part of three larger training programs involving different amounts of professional assistance to parents: telephone consultations, training groups, training groups plus home visits. One hundred and sixty families were randomly assigned to the four training conditions or to a delayed-treatment control group. The 20-week treatment period emphasized the programming of self-help skills, but also provided an introduction to programming language skills and managing behavior problems. The manuals-alone format was as effective as the more expensive training formats in producing gains in children's self-help skills and fostering knowledge of behavioral principles in mothers. The two group-training formats produced more efforts at behavior-problem management, greater gains in knowledge of principles by fathers, and higher self-confidence as teachers. Telephone consultation was generally the least effective training format; the manuals-alone condition was surprisingly effective. Some implications of the results for future strategies of family intervention were discussed.     

Role of estradiol-17 beta and progesterone in regulating constriction of ovine uterine arteries

Fistulas between the abdominal aorta and renal vein are exceedingly rare. Diagnostic delays are not unusual. Correction can be extremely difficult because of anatomical distortion and size of the arterialized veins. A young woman with such a fistula following a gunshot wound is presented. Four years following injury, the fistula was repaired successfully during intentional arrest of the circulation for 7 minutes. This was accomplished with deep hypothermia and cardiopulmonary bypass. No serious problems occurred during the operation. The patient tolerated the procedure well and has been relieved of her symptoms completely. Most patients with traumatic or spontaneous arteriovenous fistulas can be managed safely and effectively by conventional operative techniques. In selected situations, the risk of total circulatory arrest and deep hypothermia may be less than the risk of uncontrollable bleeding inherent in conventional techniques. Suggested indications for use of total circulatory arrest in vascular surgery are (1) inability to achieve vascular control by more conventional means, (2) massive distention of regional veins as occurrs in well established fistulas of the trunk, (3) one or more prior corrective attempts with use of conventional techniques, and (4) anticipated anatomical distortion and/or multiple abnormal vascular communications. This technique is a valuable approach to the correction of otherwise inoperable cardiovascular lesions.     

Germ-line mutations in the neurofibromatosis 2 gene: correlations with disease severity and retinal abnormalities

Neurofibromatosis 2 (NF2) features bilateral vestibular schwannomas, other benign neural tumors, and cataracts. Patients in some families develop many tumors at an early age and have rapid clinical progression, whereas in other families, patients may not have symptoms until much later and vestibular schwannomas may be the only tumors. The NF2 gene has been cloned from chromosome 22q; most identified germ-line mutations result in a truncated protein and severe NF2. To look for additional mutations and clinical correlations, we used SSCP analysis to screen DNA from 32 unrelated patients. We identified 20 different mutations in 21 patients (66%): 10 nonsense mutations, 2 frameshifts, 7 splice-site mutations, and 1 large in-frame deletion. Clinical information on 47 patients from the 21 families included ages at onset and at diagnosis, numbers of meningiomas, spinal and skin tumors, and presence of cataracts and retinal abnormalities. We compared clinical findings in patients with nonsense or frameshift mutations to those with splice-site mutations. When each patient was considered as an independent random event, the two groups differed (P < or = .05) for nearly every variable. Patients with nonsense or frameshift mutations were younger at onset and at diagnosis and had a higher frequency and mean number of tumors, supporting the correlation between nonsense and frameshift mutations and severe NF2. When each family was considered as an independent random event, statistically significant differences between the two groups were observed only for mean ages at onset and at diagnosis. A larger data set is needed to resolve these discrepancies. We observed retinal hamartomas and/or epiretinal membranes in nine patients from five families with four different nonsense mutations. This finding, which may represent a new genotype-phenotype correlation, merits further study.