Dynamic layer rearrangement during growth of layered oxide films by molecular beam epitaxy

The A(n+1)B(n)O(3n+1) Ruddlesden-Popper homologous series offers a wide variety of functionalities including dielectric, ferroelectric, magnetic and catalytic properties. Unfortunately, the synthesis of such layered oxides has been a major challenge owing to the occurrence of growth defects that result in poor materials behaviour in the higher-order members. To understand the fundamental physics of layered oxide growth, we have developed an oxide molecular beam epitaxy system with in situ synchrotron X-ray scattering capability. We present results demonstrating that layered oxide films can dynamically rearrange during growth, leading to structures that are highly unexpected on the basis of the intended layer sequencing. Theoretical calculations indicate that rearrangement can occur in many layered oxide systems and suggest a general approach that may be essential for the construction of metastable Ruddlesden-Popper phases. We demonstrate the utility of the new-found growth strategy by performing the first atomically controlled synthesis of single-crystalline La3Ni2O7.

Measurement of a drowning incidence rate combining direct observation of an exposed population with mortality statistics

Drowning risk factors may be identified by comparing drowning incidence rates for comparable at-risk populations but precise methods are lacking. To address this knowledge gap, an ecological study extrapolated crude time-duration exposure to water for a specified at-risk sample of surf bathers to estimate the bather population for all wave-dominated beaches in Victoria, Australia, over a four-year summer season period. An incidence rate was calculated using surf bather drowning deaths frequencies matched for time and location. For the sample, 47,341 hours of surf bathing were estimated from 177,528 bathing episodes. Generalising these results to Victoria, the crude drowning deaths incidence rate in the summer season was 0.41 per 1,000,000 person-hours of surf bathing (95% CI 0.37-0.45). Further application of the method, particularly in open water settings, may be used to identify candidate drowning risk factors to advance drowning prevention strategies.

Outbreak of Shiga toxin-producing E. coli O157 associated with consumption of watercress, United Kingdom, August to September 2013

An increase in the number of cases of Shiga toxin-producing Escherichia coli O157 PT 2 stx2 infection was reported in the United Kingdom on 9 September 2013. Of the 19 cases, 13 were interviewed, of which 10 reported consuming watercress purchased from one retailer. The retailer recalled pre-packed bagged salads containing watercress on 12 September. The descriptive epidemiology was supported by a case–case study performed after control measures were implemented.

First Report of Lasiodiplodia theobromae Associated with Stem Canker of Almond in California

California is a major almond (Prunus dulcis) producer in the world. In September 2012, 2-year-old almond trees from an orchard in Fresno Co. with stem cankers were submitted for disease diagnosis. In a survey of the orchard, 12 ha (1,500 Nonpareil and 1,800 Monterey almond trees) of 48 ha trees had been killed apparently due to a stem canker. The cankers developed above the graft union, were covered with amber sap, and often girdled the trunk. Isolations made from tissues at the canker margins onto acidified potato dextrose agar (PDA) yielded two fungi, Macrophomina phaseolina (Tassi) Goid and Lasiodiplodia theobromae (Pat.) Griffon & Maubl (1). M. phaseolina and L. theobromae were isolated from eight and two of 10 cankered trees, respectively. No mixed infections were found. M. phaseolina isolates were characterized by gray hyphae that turned black with developing microsclerotia. L. theobromae isolates were characterized by white, aerial mycelium that turned mouse gray after 5 days. Young conidia were ellipsoidal, thick walled, initially hyaline, granular, and nonseptate; aged conidia were brown, 1-septate with longitudinal striations in the wall. Identity was confirmed by analyses of the internal transcribed spacer (ITS), β-tubulin 2 (BT2), and the translation elongation factor 1-alpha (TEF-1α) gene regions. BLAST searches at GenBank showed a high identity with reference sequences of type specimens both for M. phaseolina (isolates 7E64 to 7E69: ITS, 100%; BT2, 99%; TEF-1α, 99%) and L. theobromae (isolates 7E86 to 7E88: ITS, 99%; BT2, 99%; TEF-1α, 100%). Sequences of three gene regions were deposited as GenBank accessions KC357271 to KC357279 (ITS); KC357280 to KC357288 (BT2); and KC357289 to KC357297 (TEF-1α). The pathogenicity of M. phaseolina and L. theobromae to P. dulcis cultivars Butte, Carmel, Nonpareil, and Padre was investigated in an orchard at KARE using four isolates of M. phaseolina (7E64, 7E65, 7E66, and 7E69) and two isolates of L. theobromae (7E86 and 7E88). Ten 2-year-old branches per isolate from 7-year-old trees were inoculated with each isolate in late September 2012, after removing the bark with a 7-mm cork borer and placing a 7-day-old 7-mm-diameter agar plug bearing mycelium of each isolate directly into the fresh wound, mycelium side down. Ten additional branches of each of the four cultivars were inoculated with sterile PDA plugs and served as negative controls. Three weeks after inoculation, the average lesion produced by M. phaseolina on Butte, Carmel, Nonpareil, and Padre was 53, 52, 41, and 37 mm in length, respectively. Lesions produced by L. theobromae were 191, 206, 194, and 103 mm in length on the four cultivars, respectively. No disease lesion, only wounds, were produced on negative controls. Lesions produced by both pathogens were longer (P < 0.05) than wounds on the controls (average length 10 mm on all cultivars). Both L. theobromae isolates killed branches of cultivars Butte, Carmel, and Nonpareil in 2 weeks. M. phaseolina and L. theobromae were reisolated from the inoculated branches, and no fungus was reisolated from controls. Based on pathogenicity results, L. theobromae is more virulent to almond branches than M. phaseolina. To our knowledge, this is the second report of M. phaseolina (2) and the first report of L. theobromae as pathogens of P. dulcis trees in California. References: (1) A. Alves et al. Fungal Diversity 28:1, 2008. (2) P. Inderbitzin et al. Mycologia 102:1350, 2010.

Surf lifeguard rescues

OBJECTIVE

This study assessed the utility of lifeguard rescue data for providing information on person and situation factors to inform surf bather drowning prevention research.

METHODS

The dataset comprised 872 beach-days (daily lifeguard reports) obtained from 26 beaches over a 95-day period in Victoria, Australia.

RESULTS

The rescue rate was 128 per 100,000 in-water bathers. One or more rescues were required on 125 beach-days (14%). Rescue on a beach-day was more likely for offshore wind conditions, relatively high daily air temperatures, and high bather numbers (P < .05). Compared to female bathers, males were more frequently rescued (65%) and more likely (P < .05) to be from a younger age group (30 years or less), although being older was associated with a relatively poorer condition on rescue.

CONCLUSIONS

Although rescues are proportional to water exposure, frequencies are also influenced by situation and person factors. Bathers at relatively high risk of rescue are hypothesized to be overrepresented in amenable sea and weather conditions, and poor patient condition on rescue may be associated with exposure to a preexisting health condition.

Dielectric and thermophysical properties of meat batters over a temperature range of 5-85 °C

Dielectric (dielectric constant (ε(')) and loss factor (ε″)) and thermal (heat capacity (c), thermal conductivity (k) and thermal diffusivity (α))) properties of two meat batters (pork luncheon roll (PLR) and white pudding (WP)) were measured between 5 and 85 °C. Radio frequency (RF) and microwave (MW) ε″ values varied across 5-85 °C (P<0.05). MW ε(') and ε″ values for WP tended to peak at 45 °C and decrease thereafter, whereas for PLR, ε(') and ε″ peaked at 65 °C which appeared to match potato starch gelatinisation within this product. WP and PLR had significantly higher c values at 25 °C, which corresponded to the MP of pork fat. For PLR, an additional c peak was noted at 65 °C, which appeared to correspond to potato starch gelatinisation. At 85 °C, k values were higher (P<0.05) than at 5, 25 and 45 °C but were not higher than values at 65 °C. α values increased with temperature (P<0.05).

Angiotensin II-induced JNK activation is mediated by NAD(P)H oxidase in isolated rat pancreatic islets

Angiotensin II (AII), the active component of the renin angiotensin system (RAS), plays a vital role in the regulation of physiological processes of the cardiovascular system, but also has autocrine and paracrine actions in various tissues and organs. Many studies have shown the existence of RAS in the pancreas of humans and rodents. The aim of this study was to evaluate potential signaling pathways mediated by AII in isolated pancreatic islets of rats. Phosphorylation of MAPKs (ERK1/2, JNK and p38MAPK), and the interaction between proteins JAK/STAT were evaluated. AII increased JAK2/STAT1 (42%) and JAK2/STAT3 (100%) interaction without altering the total content of JAK2. Analyzing the activation of MAPKs (ERK1/2, JNK and p38MAPK) in isolated pancreatic islets from rats we observed that AII rapidly (3 min) promoted a significant increase in the phosphorylation degree of these proteins after incubation with the hormone. Curiously JNK protein phosphorylation was inhibited by DPI, suggesting the involvement of NAD(P)H oxidase in the activation of protein.

National outbreak of Salmonella Enteritidis phage type 14b in England, September to December 2009: case-control study

We conducted an unmatched retrospective case–control study to investigate an upsurge of non-travel-related sporadic cases of infection with Salmonella enterica subsp. enterica serotype Enteritidis phage type 14b with antimicrobial resistance to nalidixic acid and partial resistance to ciprofloxacin (S. Enteritidis PT 14b NxCp(L)) that was reported in England from 1 September to 31 December 2009. We analysed data from 63 cases and 108 controls to determine whether cases had the same sources of infection as those found through investigation of 16 concurrent local foodborne outbreaks in England and Wales. Multivariable logistic regression analysis adjusting for age and sex identified food consumption at restaurants serving Chinese or Thai cuisine (odds ratio (OR): 4.4; 95% CI: 1.3–14.8; p=0.02), egg consumed away from home (OR: 5.1; 95% CI: 1.3–21.2; p=0.02) and eating vegetarian foods away from home (OR: 14.6; 95% CI: 2.1–99; p=0.006) as significant risk factors for infection with S. Enteritidis PT 14b NxCp(L). These findings concurred with those from the investigation of the16 outbreaks, which identified the same Salmonella strain in eggs from a specified source outside the United Kingdom. The findings led to a prohibition of imports from this source, in order to control the outbreak.

National outbreak of Salmonella Enteritidis phage type 14b in England, September to December 2009: case–control study

Binary file ES_Abstracts_Final_ECDC.txt matches

Public health argument to retain current UK national controls for tick and tapeworms under the Pet Travel Scheme

At present, the European Council is debating whether the current national controls under the Pet Travel Scheme (PETS), which aims to prevent the introduction of rabies and tapeworms or live ticks and their associated diseases into the United Kingdom (UK), should be harmonized amongst European Union (EU) Member States. There is a strong case to support the retention of control measures on human health grounds. Although many are aware of the implications of rabies infection, few realize the risk to the UK population if current tick and tapeworm controls under PETS were to be removed. If this were to occur, there is a risk that a number of diseases of human health importance may be introduced and become established in the UK. Such diseases include alveolar echinococcosis, tick borne encephalitis, tularaemia and Mediterranean spotted fever; all of which are found in other EU Member States but do not occur in the UK. These four diseases are responsible for a significant burden of disease in Europe, and current national controls under PETS have been highly effective in so far preventing their introduction into the UK.

Immunotherapy for Alzheimer's disease

In the year 1999, a vaccine approach was found to reduce amyloid deposits in transgenic mice overproducing the amyloid precursor protein. This was followed closely by demonstrations that vaccines or passive immunotherapy could rescue memory deficits in these mice. Initial human clinical trials revealed apparent autoimmune reactions in a subset of patients, but also some cases of cognitive benefit and amyloid clearance. Further work with passive immunotherapy in mouse models confirmed exceptional clearing abilities of anti-amyloid antibodies even in older mice. However, in parallel with parenchymal amyloid clearance was the appearance of microhaemorrhages and increased vascular amyloid deposition. Additional clinical trials with passive immunotherapy confirmed occasional appearance of microhaemorrhage and occurrence of vasogenic oedema in some patients, particularly those with the apolipoprotein E4 genotype. Recent data with positron emission tomography demonstrates trial participants passively immunized with anti-Aß antibodies have reduced signals with amyloid binding ligands after 18 months of therapy. Several anti-Aß immunotherapies have reached phase 3 testing, and immunotherapy is likely to be the first test of the amyloid hypothesis of Alzheimer's disease. Identifying antibody variants that retain amyloid clearance with fewer adverse reactions remains a major focus of translational research in this area.

New evidence for the inverse dependence of mechanical and chemical effects on the frequency of ultrasound

Acoustic cavitation has been the subject of research and discussion for many years and it is the underlying driving force for sonochemistry. The collapse of acoustic cavitation bubbles in water near to a surface can bring about significant surface modification in terms of the mechanical damage caused by the asymmetric collapse of the bubbles which cause erosion and abrasion. A second effect of acoustic cavitation is the formation of short lived radicals caused by the breakdown of water inside the bubble. For the first time the dependence of these effects has been observed on the surface of a plastic material as a function of ultrasonic frequency.