bluuebunny/crossref_metadata_2025 huggingface dataset:
Hammett-Streitwieser Reaction Constants for the Electroreduction of Diaryl Ketones in Aprotic Media
Authors: Wagnerczauderna E , Kalinowski MK
Published: November 2018

Cyclic voltammetry has been used to measure formal potentials of seven aromatic ketone/ketyl radical anion systems in benzonitrile, acetonitrile , propylene carbonate, acetone, N,N- dimethylformamide, N-methylpyrrolidin-2-one, dimethyl sulfoxide and hexamethylphosphoric triamide. The values measured in each solvent obey the Hammett- Streitwieser equation; the reaction constants were found to depend on the solvent acidity and basicity expressed by acceptor and donor numbers, respectively. The results are discussed in terms of the solvation of the products and reactants of the electrode reaction.
Synthesis of Some Hydrazone Derivatives Structurally Related to the Insecticide Pymetrozine
Authors: Ali AS , Wilkie JS , Winzenberg KN
Published: November 2018

Reaction of pyridine-3-carbaldehyde methylhydrazone with 1,1'-carbonylbis-1H-imidazole afforded (E)-1'-methyl-2'-(3"-pyridyl) methylidene ]-1H-imidazole-1-carbohydrazide (2). Reaction of (2) with ethylamine, ethanol, ethanethiol, hydrazine monohydrate and methoxyamine afforded the corresponding semicarbazide, carbazate, thiocarbazate, carbonohydrazide and 4-methoxysemicarbazide derivatives (3a-d,g). Reaction of (2) with methylhydrazine gave the carbonohydrazide derivative (3f) together with 2,4-dimethyl-6-(3'-pyridyl)-1,4,5,6-tetrahydro-1,2,4,5-tetrazin-3(2H)-one (4a). The preparation of (E)-3-[(3'-pyridyl) methylideneamino ]oxazolidin-2-one (5a) and (E)-3-[(3'-pyridyl) methylideneamino ]tetrahydro-2H-1,3-oxazin-2-one (5b) is described.
The Chemistry of Biology: Molecular Evolution, the Total Synthesis of Proteins, and DNA Restriction and Modification
Authors: Lambert JN
Published: November 2018

Three topics of current interest in modern biological organic chemistry are presented: molecular evolution, the total synthesis of proteins, and the study of DNA restriction and modification systems. These topics are used to illustrate the application of chemical understanding to the study of chemistry in a biological context.
Experiments Directed Towards the Synthesis of Anthracyclinones. XXX. Formation and Use of an Anthraquinone Formyl Ester
Authors: Cambie RC , Milbank JBJ , Rutledge PS
Published: November 2018

Methods for the preparation of methyl 3-formyl-1,4-dimethoxy-9,10-dioxo-9,10-dihydroanthracene-2-acetate (1) from quinizarin (8) have been investigated. Reaction of the ester (1) with either a titanium enolate of acetone or with acetone trimethylsilyl enol ether and titanium tetrachloride gave the aldol (29) which was then converted into the pentacyclic lactone mixture (41) and (42). While hydrolysis of (41) and (42) with base for long periods (>30 min) gave α,β -unsaturated ketones , brief (2 min) treatment gave the dimethyl ether (5) of the 4-deoxyanthracyclinone (6) corresponding to the antitumour anthracycline 14A10.
New Chromenols From a Southern Australian Tunicate, Aplidium solidum
Authors: Rochfort SJ , Metzger R , Hobbs L , Capon RJ
Published: November 2018

Two new chromenols, namely (R)-2-methyl-2-(4-methylpenta-1,3-dienyl)-2H-chromen-6-ol (7) and 1-[(R)-6-hydroxy-2-methyl-2H-chromen-2-yl]-4-methylpentan-2-one (8), have been isolated from a southern Australian tunicate, Aplidium solidum. The structures of (7) and (8) were assigned by spectroscopic analysis, and the absolute stereochemistry of (7) by chemical degradation.
The Synthesis of a Fluorescent Cholesteryl Oleate Analogue
Authors: Best WM , Mortimer BC , Redgrave TG , Stick RV
Published: November 2018

A fluorescent analogue of cholesteryl oleate , namely 22-[ethyl(2'-naphthyl)amino]-23,24-dinorchol-5-en-3β-yl oleate, has been prepared from a steroidal carboxylic acid, 2-naphthylamine and oleic acid.
Corrigendum to: Soil phosphorus–crop response calibration relationships and criteria for winter cereal crops grown in Australia
Authors: Bell Richard , Reuter Douglas , Scott Brendan , Sparrow Leigh , Strong Wayne , Chen the late Wen
Published: November 2018

Soil testing is the most widely used tool to predict the need for fertiliser phosphorus (P) application to crops. This study examined factors affecting critical soil P concentrations and confidence intervals for wheat and barley grown in Australian soils by interrogating validated data from 1777 wheat and 150 barley field treatment series now held in the BFDC National Database. To narrow confidence intervals associated with estimated critical P concentrations, filters for yield, crop stress, or low pH were applied. Once treatment series with low yield (CaCl2 1 t/ha). There was a clear increase in critical P concentration from early trials when full tillage was common compared with those conducted in 1995–2011, which corresponds to a period of rapid shift towards adoption of minimum tillage. For wheat, critical Colwell-P concentrations associated with 90 or 95% of maximum yield varied among Australian Soil Classification (ASC) Orders and Sub-orders: Calcarosol, Chromosol, Kandosol, Sodosol, Tenosol and Vertosol. Soil type, based on ASC Orders and Sub-orders, produced critical Colwell-P concentrations at 90% of maximum relative yield from 15 mg/kg (Grey Vertosol) to 47 mg/kg (Supracalcic Calcarosols), with other soils having values in the range 19–27 mg/kg. Distinctive differences in critical P concentrations were evident among Sub-orders of Calcarosols, Chromosols, Sodosols, Tenosols, and Vertosols, possibly due to differences in soil properties related to P sorption. However, insufficient data were available to develop a relationship between P buffering index (PBI) and critical P concentration. In general, there was no evidence that critical concentrations for barley would be different from those for wheat on the same soils. Significant knowledge gaps to fill to improve the relevance and reliability of soil P testing for winter cereals were: lack of data for oats; the paucity of treatment series reflecting current cropping practices, especially minimum tillage; and inadequate metadata on soil texture, pH, growing season rainfall, gravel content, and PBI. The critical concentrations determined illustrate the importance of recent experimental data and of soil type, but also provide examples of interrogation pathways into the BFDC National Database to extract locally relevant critical P concentrations for guiding P fertiliser decision-making in wheat and barley.
Impact of waterlogging on the nutrition of cotton (Gossypium hirsutum L.) produced in sodic soils
Authors: Dodd K. , Guppy C. N. , Lockwood P. V. , Rochester I. J.
Published: November 2018

Sodicity in Vertosols used for agricultural production can adversely affect the growth and nutrition of cotton (Gossypium hirsutum L.) plants. Cotton produced in sodic soils has reduced dry matter and lint yield and can develop toxic plant tissue concentrations of sodium (Na) but limited tissue concentrations of phosphorus (P,) potassium (K), and micronutrients. Crops produced on sodic soils frequently suffer from aeration stress after an irrigation or rainfall event, and it was hypothesised that the adverse physical and/or chemical conditions of sodic soils may exacerbate the effects of waterlogging. We measured the impacts of sodicity on the growth, nutrition, and root recovery time of cotton during and after waterlogging in two experiments. In the first, cotton plants were subjected to a 7-day period of inundation in Grey Vertosols with a range of exchangeable sodium percentage (ESP) values from 2 to 25%; 32P was placed in the pots and its accumulation in the plant was used to indicate root activity and recovery after the waterlogging event. In a second experiment, agar was dissolved in nutrient solutions with a range of Na concentrations (9, 30, and 52 mm) matching soil solution Na concentrations in sodic soils, in order to simulate a waterlogging event. Following the waterlogging event, the solutions were labelled with 32P, in order to determine the effect of sodic soil solution chemistry on the rate of recovery of cotton root function after the event. Plant nutrient analysis was used to determine the effects of sodicity and waterlogging on cotton nutrition. In both experiments, waterlogging reduced root activity and reduced the uptake and transport of labelled P by the cotton plants, decreased plant P and K concentrations, and increased the plant Na concentrations. Sodicity exacerbated the effects of waterlogging on root function and cotton nutrition in the soil experiment but not in the nutrient solution experiment, suggesting that any contribution of waterlogging to the patterns of nutrient accumulation in cotton crops produced in sodic fields occurs due to soil physical factors rather than soil solution chemistry.
Maximum ambient temperature can influence carbon storage in Vertosols sown with cotton-based farming systems
Authors: Hulugalle N. R.
Published: November 2018

Partial mitigation of global warming caused by accelerated emissions of greenhouse gases such as carbon dioxide may be possible by storing atmospheric carbon in soils. Carbon storage is influenced by processes and properties that affect soil aggregation, such as clay and silt concentrations and mineralogy, intensity and frequency of wet/dry cycles, and microbial activity. Microbial activity, in turn, is influenced by factors such as temperature, nutrient and water availability, and residue quality. The objective of this study was to assess the influence of average annual maximum temperature on soil carbon storage in Vertosols under cotton-based farming systems. This paper reports a re-evaluation of results obtained from a series of experiments on cotton-farming systems conducted in eastern Australia between 1993 and 2010. The experimental sites were in the Macquarie and Namoi Valleys of New South Wales, and the Darling Downs and Central Highlands of Queensland.
Average soil organic carbon storage in the 0–0.6 m depth was highest in a Black Vertosol in Central Queensland and lowest in a Grey Vertosol that was irrigated with treated sewage effluent at Narrabri. At other sites, average values were generally comparable and ranged from 65 to 85 t C/ha. Climatic parameters such as ambient maximum temperature, Tmax, and rainfall at rainfed sites (but not irrigated sites) were also related to soil organic carbon storage. At most sites, variations in carbon storage with average ambient maximum temperature were described by Gaussian models or bell-shaped curves, which are characteristic of microbial decomposition. Carbon storage occurred at peak rates only for a very limited temperature range at any one site, with these temperatures increasing with decreasing distance from the equator. The exception was a site near Narrabri that was irrigated with treated sewage effluent, where the relationship between soil organic carbon and Tmax was linear. The decrease or absence of change in soil carbon storage with time reported in many Australian studies of annual cropping systems may be due to carbon storage occurring within a limited temperature range, whereas intra-seasonal average maximum temperatures can range widely. Further research needs to be conducted under field conditions to confirm these observations.
Use of plant water relations to assess forage quality and growth for two cultivars of Napier grass (Pennisetum purpureum) subjected to different levels of soil water supply and temperature regimes
Authors: Mwendia S. W. , Yunusa I. A. M. , Whalley R. D. B. , Sindel B. M. , Kenney D. , Kariuki I. W.
Published: November 2018

Napier grass (Pennisetum purpureum Schumach.) is an important fodder and relatively drought-tolerant crop in tropical and subtropical regions, especially in developing countries. For this and other species, tools are needed for identifying drought-tolerant cultivars to aid selection for semi-arid environments. We determined tissue water status, carbon assimilation, biomass yield and forage quality for Napier grass cvv. Bana and Atherton grown in bins and subjected to three soil-water supply levels (100, 50 or 25% of field capacity) in glasshouses set at either low (15−25°C) or high (25−35°C) temperature regimes, over three growing cycles. Our aim was to explore whether differences in leaf water potential (LWP) and carbon assimilation rates could be reliable indicators of the relative yield potential and forage quality of the two cultivars in environments prone to water and heat stresses.
At the low soil-water supply of 25% and low temperature, Bana had lower (more negative) LWP and relative water content (RWC) than Atherton, while at 50% and 100% soil-water supply, Bana had a higher tissue water status. Under the high temperature regime, Bana had consistently more positive LWP and RWC than Atherton, but the differences were not significant. The two cultivars had a similar CO2 assimilation rate (A) and there were no significant differences in the total dry matter yields over the three growing cycles. Water-use efficiency for above-ground biomass (kg ha–1 mm–1) was similar for both cultivars and was 28.5–35.1 under the low temperature regime and 16.9–22.9 under the high temperature regime. Neutral detergent fibre (NDF) was often higher for Bana at low water supply and low temperature than for Atherton, but the trend was reversed under the high temperature regime. Digestibility was generally improved under water-stressed conditions, and there was a positive correlation between NDF and both LWP and RWC measured at midday, but only under the low temperature regime. We conclude that LWP, RWC and A, alone or together, are inadequate for selecting cultivars for dry and hot environments, because cultivars may differ in other mechanistic responses to water stress and high temperatures.
Effect of competition from a C4 grass on the phosphorus response of a subtropical legume
Authors: Haling Rebecca E. , Campbell Chris D. , Tighe Matthew K. , Guppy Chris N.
Published: November 2018

Tropical pasture systems are typically dominated by C4 grasses growing on nitrogen (N) deficient soils. Under these conditions, N2-fixing legumes should have a competitive advantage, yet low legume contents are often reported in these systems. This work investigates whether below-ground competition for phosphorus (P) is limiting the ability of legumes to compete in swards of C4 grasses when grown in a sand matrix. The external P requirement of a subtropical legume (butterfly pea, Clitoria ternatea L.) and a C4 grass (buffel grass, Cenchrus ciliaris L.) were initially determined in a P-response experiment. Four rates of P (4.6–78.2 mg P kg–1 of Colwell P) were subsequently selected to investigate the growth response of the butterfly pea when grown with and without competition from a sward of N-deficient buffel grass. Shoot dry matter was determined over successive cuts and P uptake determined at the final harvest at 72 days. Buffel grass dominated the mixed swards and reduced the shoot dry matter production of the butterfly pea by >50% relative to the pure swards. A significant difference in the soil P response curve and shoot P uptake of butterfly pea was not detected between pure swards and those with competition from buffel grass. The ability of C4 grasses to acquire and convert resources (i.e. light, water and nutrients) more efficiently into shoot dry matter is likely to be a major factor resulting in grass-dominated pastures in tropical systems.
Targeted exploitation of gene pools of alien Triticeae species for sustainable and multi-faceted improvement of the durum wheat crop
Authors: Ceoloni Carla , Kuzmanović Ljiljana , Forte Paola , Gennaro Andrea , Bitti Alessandra
Published: November 2018

Enlarging the genetic basis of essential crop species such as the polyploid wheats is a priority in breeding outlooks for the new millennium. To this end, one feasible approach to exploit the wide and largely untapped variation present in the gene pools of alien Triticeae species is chromosome engineering, which enables the transfer of alien chromosomal segments carrying targeted genes to wheat chromosomes. Recent progress in molecular marker technology, molecular cytogenetic techniques, and in genome knowledge has greatly enhanced the ability of chromosome engineering to contribute breeder-friendly germplasm, even in the case of durum wheat, considered more sensitive to genome manipulations than bread wheat. Using finely tuned chromosome engineering, stable incorporation into durum has been achieved for various alien segments containing genes for disease resistance, quality attributes, and even yield-related traits, both separately and in combination. The state of the art and the breeding potential of such transfers are reviewed and updated.
Crop design for specific adaptation in variable dryland production environments
Authors: Hammer Graeme L. , McLean Greg , Chapman Scott , Zheng Bangyou , Doherty Al , Harrison Matthew T. , van Oosterom Erik , Jordan David
Published: November 2018

Climatic variability in dryland production environments (E) generates variable yield and crop production risks. Optimal combinations of genotype (G) and management (M) depend strongly on E and thus vary among sites and seasons. Traditional crop improvement seeks broadly adapted genotypes to give best average performance under a standard management regime across the entire production region, with some subsequent manipulation of management regionally in response to average local environmental conditions. This process does not search the full spectrum of potential G × M × E combinations forming the adaptation landscape. Here we examine the potential value (relative to the conventional, broad adaptation approach) of exploiting specific adaptation arising from G × M × E. We present an in-silico analysis for sorghum production in Australia using the APSIM sorghum model. Crop design (G × M) is optimised for subsets of locations within the production region (specific adaptation) and is compared with the optimum G across all environments with locally modified M (broad adaptation). We find that geographic subregions that have frequencies of major environment types substantially different from that for the entire production region show greatest advantage for specific adaptation. Although the specific adaptation approach confers yield and production risk advantages at industry scale, even greater benefits should be achievable with better predictors of environment-type likelihood than that conferred by location alone.
Cell membrane stability and chlorophyll content variation in wheat (Triticum aestivum) genotypes under conditions of heat and drought
Authors: Rehman Shoaib Ur , Bilal Muhammad , Rana Rashid Mehmood , Tahir Muhammad Naveed , Shah Muhammad Kausar Nawaz , Ayalew Habtamu , Yan Guijun
Published: November 2018

Heat and drought are among the major obstacles confronting crop production under climate change. The present study was conducted to evaluate 50 diverse wheat genotypes for cell membrane stability (CMS) and chlorophyll content at seedling and anthesis stages under heat and drought stress conditions, to understand the effect of the two abiotic factors and to find promising genotypes for future breeding. Experiments were conducted in the glasshouse (seedling stage) and the field (anthesis stage). Analysis of variance showed significant variation (P ≤ 0.05) for all of the traits at seedling and anthesis stages. High levels of broad-sense heritability and genetic advance at 5% selection intensity indicated the presence of a high genetic component of variation and potential for genetic improvement through selection among the existing genetic variation. CMS showed a significant positive correlation with 1000-grain weight (TGW) under heat and drought conditions at both seedling and anthesis stages. Chlorophyll a/b ratio at seedling stage exhibited a significant negative correlation (r = –0.39, P < 0.05) with TGW under heat stress. Total chlorophyll content was significantly (r = 0.42, P < 0.05) correlated with TGW under heat stress at anthesis. Genotypes ETAD248 and ETAD7 showed the highest CMS and TGW values, whereas their chlorophyll a/b values were lowest, at both seedling and anthesis stages under heat and drought stress conditions. Higher CMS and total chlorophyll content, and lower chlorophyll a/b, were found to be useful indicators to identify genotypes with high TGW under heat and drought stress conditions. This study indicated the possibility of using seedling resistance as an indicator for later stage response in breeding for heat and drought resistance. The resistant genotypes identified can be used as potential germplasm in breeding programs.
Waterlogging at tillering affects spike and spikelet formation in wheat
Authors: Arduini I. , Orlandi C. , Pampana S. , Masoni A.
Published: November 2018

Waterlogging stress is one of the limiting factors influencing wheat (Triticum aestivum L.) production. Wheat tolerance to waterlogging is related to the duration of the waterlogging event, the crop development stage in which waterlogging occurs, and the sensitivity of genotype. In this paper we investigated the impact of eight waterlogging durations (from 0 to 60 days) imposed at 3-leaf and 4-leaf growth stages (~30 and 40 days after sowing) on grain yield, grain yield components, straw and root dry weight and nitrogen concentration of grain, straw, and roots of two cultivars of wheat. The results showed that of the two cultivars, one (cv. Blasco) was tolerant to waterlogging and the other (cv. Aquilante) was sensitive, thus confirming that there are high genotypic differences in terms of tolerance to waterlogging in wheat. The sensitive cultivar showed a significant reduction in grain yield and straw and root dry weight only when waterlogging was prolonged for more than 20 days. Waterlogging depressed the grain yield of the sensitive cultivar, slowing tiller formation and consequently preventing many culms from producing spikes. It slowed down spikelet formation, consequently reducing the number of spikelets per spike, and reduced floret formation per spikelet, thus reducing the number of kernels per spike.
Human papillomavirus and papillomavirus vaccines: knowledge, attitudes and intentions of general practitioners and practice nurses in Christchurch
Authors: Henninger Judith
Published: November 2018

INTRODUCTION: General practitioners (GP) and practice nurses (PN) perform the majority of cervical screening in Christchurch and will have a key role in influencing uptake of human papillomavirus (HPV) immunisation. AIM: To assess and compare GP and PN knowledge about HPV disease, attitudes concerning adolescent sexual behaviour and intentions to recommend HPV immunisation. METHODS: A self-administered, anonymous questionnaire was distributed to GPs and PNs in Christchurch, New Zealand who attended peer-led small group meetings hosted by Pegasus Health Independent Provider Association in May 2008. RESULTS: Participation rate was 39%. Overall, 94% of respondents knew that HPV immunisation will not replace cervical cancer screening; 73% knew that HPV is the cause of cervical cancer; 48% knew that most HPV infections will clear without medical treatment; 20% correctly reported that anogenital warts are not cervical cancer precursors. More GPs reported comfort discussing sexual behaviour with adolescents than PNs (p < .008). While 95% of participants intend to recommend immunisation for 13–15-yearold girls, PNs were more likely than GPs to recommend HPV immunisation to older female adolescents and more often indicated that HPV vaccination may lead to risky sexual behaviour (p < .0001). DISCUSSION: This is the first New Zealand study to assess primary care knowledge and attitudes about HPV and HPV immunisations. The results are encouraging, provide a baseline for future research and may guide the development of training materials for GPs and PNs. KEYWORDS: Papillomavirus, human; papillomavirus vaccines; family physician; primary health care
New Zealand men’s health care: are we meeting the needs of men in general practice?
Authors: McKinlay Eileen , Kljakovic Marjan , McBain Lynn
Published: November 2018

AIM: To describe and compare how men and health professionals perceive men’s health and health care. METHOD: A qualitative study with an inductive thematic analysis of transcripts from three sequential sets of focus groups. The first set included groups totalling 21 general practitioners and 10 practice nurses; the second set with a group of 12 men under 25 years and a group of 10 older men over 35 years; and the third set with the original groups of health professionals. Datasets were analysed individually, sequentially and comparatively for men’s and health professionals’ beliefs about health and health care. RESULTS: In the initial focus groups, health professionals reported system, structural, and attitudinal barriers inhibiting men attending general practice. Men reported broad-based health beliefs and, despite reluctance to seek formal health care, men value general practice care and want recognition of their preferred consulting styles. In the final focus groups, researchers fed-back analysis of the health professionals’ and men’s focus group data with the aim of encouraging further focussed men’s health initiatives. However, there was a general lack of enthusiasm from health professionals to do more than what was being done already. CONCLUSIONS: Despite men and health professionals recognising the importance of men’s health, there is general unwillingness on the part of both men and health professionals, for different reasons, to engage with men’s health care in general practice. Understanding how men view health and health care delivery has the potential to inform alternative approaches in general practice care. KEYWORDS: New Zealand; men’s health; general practice; general practitioner; practice nurse
Intracellular localisation of platelet-activating factor during mammalian embryo development in vitro: a comparison of cattle, mouse and human
Authors: Vandenberghe L. T. M. , Heindryckx B. , Smits K. , Popovic M. , Szymanska K. , Bonte D. , Peelman L. , Deforce D. , De Sutter P. , Van Soom A. , De Schauwer C.
Published: November 2018

Platelet-activating factor (PAF) is a well-known marker for embryo quality and viability. For the first time, we describe an intracellular localisation of PAF in oocytes and embryos of cattle, mice and humans. We showed that PAF is represented in the nucleus, a signal that was lost upon nuclear envelope breakdown. This process was confirmed by treating the embryos with nocodazole, a spindle-disrupting agent that, as such, arrests the embryo in mitosis, and by microinjecting a PAF-specific antibody in bovine MII oocytes. The latter resulted in the absence of nuclear PAF in the pronuclei of the zygote and reduced further developmental potential. Previous research indicates that PAF is released and taken up from the culture medium by preimplantation embryos invitro, in which bovine serum albumin (BSA) serves as a crucial carrier molecule. In the present study we demonstrated that nuclear PAF does not originate from an extracellular source because embryos cultured in polyvinylpyrrolidone or BSA showed similar levels of PAF in their nuclei. Instead, our experiments indicate that cytosolic phospholipase A2 (cPLA2) is likely to be involved in the intracellular production of PAF, because treatment with arachidonyl trifluoromethyl ketone (AACOCF3), a specific cPLA2 inhibitor, clearly lowered PAF levels in the nuclei of bovine embryos.
The E3 ligase VHL controls alveolar macrophage function via metabolic–epigenetic regulation
Authors: Zhang Wen , Li Qian , Li Dulei , Li Jia , Aki Daisuke , Liu Yun-Cai
Published: November 2018

Metabolic pathways such as glycolysis or oxidative phosphorylation play a key role in regulating macrophage function during inflammation and tissue repair. However, how exactly the VHL–HIF–glycolysis axis is involved in the function of tissue-resident macrophages remains unclear. Here we demonstrate that loss of VHL in myeloid cells resulted in attenuated pulmonary type 2 and fibrotic responses, accompanied by reduced eosinophil infiltration, decreased IL-5 and IL-13 concentrations, and ameliorated fiber deposition upon challenge. VHL deficiency uplifted glycolytic metabolism, decreased respiratory capacity, and reduced osteopontin expression in alveolar macrophages, which impaired the function of type 2 innate lymphoid cells but was significantly reversed by HIF1α inhibition or ablation. The up-regulated glycolysis altered the epigenetic modification of osteopontin gene, with the metabolic intermediate 3-phosphoglyceric acid as a key checkpoint controller. Thus, our results indicate that VHL acts as a crucial regulatory factor in lung inflammation and fibrosis by regulating alveolar macrophages.
Geometric criteria for overtwistedness
Authors: Casals Roger , Murphy Emmy , Presas Francisco
Published: November 2018

In this article we establish efficient geometric criteria to decide whether a contact manifold is overtwisted. Starting with the original definition, we first relate overtwisted disks in different dimensions and show that a manifold is overtwisted if and only if the Legendrian unknot admits a loose chart. Then we characterize overtwistedness in terms of the monodromy of open book decompositions and contact surgeries. Finally, we provide several applications of these geometric criteria.
Interphase cohesin regulation ensures mitotic fidelity after genome reduplication
Authors: Stormo Benjamin M. , Fox Donald T.
Published: November 2018

To ensure faithful genome propagation, mitotic cells alternate one round of chromosome duplication with one round of chromosome separation. Chromosome separation failure thus causes genome reduplication, which alters mitotic chromosome structure. Such structural alterations are well documented to impair mitotic fidelity following aberrant genome reduplication, including in diseased states. In contrast, we recently showed that naturally occurring genome reduplication does not alter mitotic chromosome structure in Drosophila papillar cells. Our discovery raised the question of how a cell undergoing genome reduplication might regulate chromosome structure to prevent mitotic errors. Here, we show that papillar cells ensure mitotic fidelity through interphase cohesin regulation. We demonstrate a requirement for cohesins during programmed rounds of papillar genome reduplication known as endocycles. This interphase cohesin regulation relies on cohesin release but not cohesin cleavage and depends on the conserved cohesin regulator Pds5 . Our data suggest that a distinct form of interphase cohesin regulation ensures mitotic fidelity after genome reduplication.
Chest ultrasound for the diagnosis of paediatric pulmonary diseases: a systematic review and meta-analysis of diagnostic test accuracy
Authors: Heuvelings Charlotte C , Bélard Sabine , Familusi Mary A , Spijker Rene , Grobusch Martin P , Zar Heather J
Published: November 2018

Background

Chest ultrasound is an emerging imaging modality, for several paediatric pulmonary diseases.

Sources of data

MEDLINE and EMBASE (1946–47 to 10 March 2017) were searched to collect evidence on the diagnostic accuracy of chest ultrasound, compared to other imaging modalities, for the diagnosis of paediatric pulmonary diseases.

Areas of agreement

Eighteen pneumonia studies, comprising 2031 children, were included for meta-analysis; the summary estimate sensitivity was 95.0% (95%CI: 90.7–97.3%) and specificity was 96.1% (95%CI: 89.1–98.7%).

Areas of controversy

Other pulmonary diseases also yielded high sensitivity and specificity, but a meta-analysis could not be conducted due to a limited number of studies includable, and their heterogeneity.

Growing points

Chest ultrasound should be considered as a first-line imaging modality for children with suspected pneumonia.

Areas timely for developing research

Further research should focus on the diagnostic accuracy of chest ultrasound for the diagnosis of paediatric pulmonary diseases, other than pneumonia, comparing against a valid gold standard.
In the Eyes of Those Who Were Randomized: Perceptions of Disadvantaged Older Adults in a Tai Chi Trial
Authors: Lo On-Yee , Conboy Lisa A , Rukhadze Alexandra , Georgetti Caroline , Gagnon Margaret M , Manor Brad , Lachman Margie E , Lipsitz Lewis A , Wayne Peter M
Published: November 2018

Background and Objectives

Older adults living in subsidized housing have typically been excluded from exercise intervention studies. We conducted a qualitative study to explore the perceived physical, psychological, social, and economic factors that influenced participation in and adherence to a year-long Tai Chi intervention within an ongoing cluster-randomized controlled trial (RCT) for older adults living within subsidized housing facilities.

Research Design and Methods

Focus groups were held with participants of the RCT who were allocated to the trial’s Tai Chi intervention. Individual phone interviews were conducted with those allocated to Tai Chi who had low adherence or who had withdrawn their participation from the study. Emergent themes were extracted using grounded-theory methods.

Results

In this qualitative study, we enrolled 41 participants who were allocated to the RCT’s Tai Chi intervention: 38 completed and 3 withdrew from the study. Average Tai Chi class attendance was 64.3%. Pragmatic factors that led to higher adherence and retention included: locating classes within each facility; providing programs at no cost; and deployment of a skilled research support team. In addition, the use of an accessible, simplified Tai Chi program improved confidence, social support, self-efficacy, and self-reported improvements in physical and psychological well-being.

Discussion and Implications

Perceived physical, psychological, social benefits, and self-efficacy likely enhance adherence and retention to research-based Tai Chi interventions for older adults. Delivering an on-site, no cost, and supportive program appears critical to overcoming financial and environmental barriers to participation for those living within subsidized housing.
Hamiltonian Monte Carlo solution of tomographic inverse
problems
Authors: Fichtner Andreas , Zunino Andrea , Gebraad Lars
Published: November 2018

We present the theory for and applications of Hamiltonian Monte Carlo (HMC) solutions of linear and nonlinear tomographic problems. HMC rests on the construction of an artificial Hamiltonian system where a model is treated as a high-dimensional particle moving along a trajectory in an extended model space. Using derivatives of the forward equations, HMC is able to make long-distance moves from the current towards a new independent model, thereby promoting model independence, while maintaining high acceptance rates. Following a brief introduction to HMC using common geophysical terminology, we study linear (tomographic) problems. Though these may not be the main target of Monte Carlo methods, they provide valuable insight into the geometry and the tuning of HMC, including the design of suitable mass matrices and the length of Hamiltonian trajectories. This is complemented by a self-contained proof of the HMC algorithm in Appendix A. A series of tomographic/imaging examples is intended to illustrate (i) different variants of HMC, such as constrained and tempered sampling, (ii) the independence of samples produced by the HMC algorithm and (iii) the effects of tuning on the number of samples required to achieve practically useful convergence. Most importantly, we demonstrate the combination of HMC with adjoint techniques. This allows us to solve a fully nonlinear, probabilistic traveltime tomography with several thousand unknowns on a standard laptop computer, without any need for supercomputing resources.
Reporting Quality of Systematic Review Abstracts Published in Leading Neurosurgical Journals: A Research on Research Study
Authors: O’Donohoe Tom J , Dhillon Rana , Bridson Tahnee L , Tee Jin
Published: November 2018

BACKGROUND

Systematic review (SR) abstracts are frequently relied upon to guide clinical decision-making. However, there is mounting evidence that the quality of abstract reporting in the medical literature is suboptimal.

OBJECTIVE

To appraise SR abstract reporting quality in neurosurgical journals and identify factors associated with improved reporting.

METHODS

This study systematically surveyed SR abstracts published in 8 leading neurosurgical journals between 8 April 2007 and 21 August 2017. Abstracts were identified through a search of the MEDLINE database and their reporting quality was determined in duplicate using a tool derived from the Preferred Reporting Items for Systematic Reviews and Meta-analyses for Abstracts (PRISMA-A) statement. All SR abstracts that provided comparison between treatment strategies were eligible for inclusion. Descriptive statistics were utilized to identify factors associated with improved reporting.

RESULTS

A total of 257 abstracts were included in the analysis, with a mean of 22.8 (±25.3) included studies. The overall quality of reporting in included abstracts was suboptimal, with a mean score of 53.05% (±11.18). Reporting scores were higher among abstracts published after the release of the PRISMA-A guidelines (M = 56.52; 21.74-73.91) compared with those published beforehand (M = 47.83; 8.70-69.57; U = 4346.00, z = –4.61, P < .001). Similarly, both word count (r = 0.338, P < .001) and journal impact factor (r = 0.199, P = .001) were associated with an improved reporting score.

CONCLUSION

This study demonstrates that the overall reporting quality of abstracts in leading neurosurgical journals requires improvement. Strengths include the large number abstracts assessed, and its weaknesses include the fact that only neurosurgery-specific journals were surveyed. We recommend that attention be turned toward strengthening abstract submission and peer-review processes.
Current Status ofFusarium oxysporum FormaeSpecialesand Races
Authors: Edel-Hermann V. , Lecomte C.
Published: November 2018

The Fusarium oxysporum species complex includes both plant pathogenic and nonpathogenic strains, which are commonly found in soils. F. oxysporum has received considerable attention from plant pathologists for more than a century owing to its broad host range and the economic losses it causes. The narrow host specificity of pathogenic strains has led to the concept of formae speciales, each forma specialis grouping strains with the same host range. Initially restricted to one plant species, this host range was later found to be broader for many formae speciales. In addition, races were identified in some formae speciales, generally with cultivar-level specialization. In 1981, Armstrong and Armstrong listed 79 F. oxysporum formae speciales and mentioned races in 16 of them. Since then, the known host range of F. oxysporum has considerably increased, and many new formae speciales and races have been identified. We carried out a comprehensive search of the literature to propose this review of F. oxysporum formae speciales and races. We recorded 106 well-characterized formae speciales, together with 37 insufficiently documented ones, and updated knowledge on races and host ranges. We also recorded 58 plant species/genera susceptible to F. oxysporum but for which a forma specialis has not been characterized yet. This review raises issues regarding the nomenclature and the description of F. oxysporum formae speciales and races.
Silk-Based Biomaterials in Cutaneous Wound Healing: A Systematic Review
Authors: Kamalathevan Pragash , Ooi Peng S. , Loo Yew L.
Published: November 2018

OBJECTIVE:

Effective wound dressings should promote healing through cellular migration, neovascularization, and re-epithelialization. Silk fibroin (SF) and silk sericin (SS) are reported to have very good biocompatibility, excellent mechanical properties, and controlled biodegradability. This review investigates the use and performance of silk-based biomaterials in cutaneous wounds within in vitro, in vivo, and randomized controlled studies.

METHODS:

Study authors conducted a comprehensive literature search on the use of silk-based dressings in cutaneous wound healing and investigated reports of the advantages and disadvantages of SF and SS along with these materials’ methods of characterization, cell migration, neovascularization, wound closure, and cytotoxicity.

RESULTS:

In vitro and in vivo animal models have shown SF-based biomaterials promote good cellular adhesion and fibroblast proliferation in cutaneous wounds. The porosity and silk concentration of silk-based scaffolds are key determinants of biodegradation and plasmatic imbibition capabilities and can help promote wound healing. In reviewed studies, SF biomaterials promoted neovascularization as early as 7 days and better than common dressings, demonstrating low cytotoxicity and immunogenicity. That said, a concern with the use of SS is the tendency to cause a hypersensitivity reaction.

CONCLUSIONS:

The benefits of silk-based biomaterials seem evident based on promising preclinical studies. Both SF and SS have been shown to have excellent wound healing properties by promoting cell attachment, migration, and collagen deposition. The authors encourage the use of SF and SS in more trials for wound healing.
Turning Away From Industrial Health Care Toward Careful and Kind Care
Authors: Montori Victor M.
Published: November 2018

The health care industry is increasingly driven by the pursuit of value. The author of this Invited Commentary believes this value is nothing more than a business rebranding of efficiency with little connection to care. Overclocked clinicians, increasingly impaired by symptoms of burnout and too focused on documenting, cannot see patients in high definition. The author shows that treatment which is blind to patients’ contexts often overwhelms patients with medical errands, a topic absent from medical curricula. Care must not be the means by which health care satisfies its industrial mission but, rather, the end for which it mobilizes its means. In unhurried consultations, clinicians must appreciate and respond sensibly to patients’ problematic situation, and care for and about them. Medical training must cultivate future clinicians who value caring over caring for value. Medical educators and trainees at all levels must turn away from industrial health care, toward careful and kind care for all.
Crossing the Gap: Using Competency-Based Assessment to Determine Whether Learners Are Ready for the Undergraduate-to-Graduate Transition
Authors: Murray Katherine E. , Lane J. Lindsey , Carraccio Carol , Glasgow Tiffany , Long Michele , West Daniel C. , O’Connor Meghan , Hobday Patricia , Schwartz Alan , Englander Robert
Published: November 2018

In 2011, the Education in Pediatrics Across the Continuum (EPAC) Study Group recruited four medical schools (University of California, San Francisco; University of Colorado; University of Minnesota; and University of Utah) and their associated pediatrics clerkship and residency program directors to be part of a consortium to pilot a model designed to advance learners from undergraduate medical education (UME) to graduate medical education (GME) and then to fellowship or practice based on competence rather than time spent in training. The central design features of this pilot included predetermined expectations of performance and transition criteria to ensure readiness to progress from UME to GME, using the Core Entrustable Professional Activities for Entering Residency (Core EPAs) as a common assessment framework. Using this framework, each site team (which included, but was not limited to, the EPAC course, pediatric clerkship, and pediatric residency program directors) monitored learners’ progress, with the site’s clinical competency committee marking the point of readiness to transition from UME to GME (i.e., the attainment of supervision level 3a). Two of the sites implemented time-variable transition from UME to GME, based on when a learner met the performance expectations and transition criteria. In this Article, the authors describe each of the four sites’ implementation of Core EPA assessment and their approach to gathering the data necessary to determine readiness for transition. They conclude by offering recommendations and lessons learned from the pilot’s first seven years of development, adaptation, and implementation of assessment strategies across the sites, and discussing next steps.
Technologies of Exposure: Videoconferenced Distributed Medical Education as a Sociomaterial Practice
Authors: MacLeod Anna , Cameron Paula , Kits Olga , Tummons Jonathan
Published: November 2018

Purpose

Videoconferencing—a network of buttons, screens, microphones, cameras, and speakers—is one way to ensure that undergraduate medical curricula are comparably delivered across distributed medical education (DME) sites, a common requirement for accreditation. However, few researchers have critically explored the role of videoconference technologies in day-to-day DME. The authors, therefore, conducted a three-year ethnographic study of a Canadian undergraduate DME program.

Method

Drawing on 108 hours of observations, 33 interviews, and analysis of 65 documents—all collected at two campuses between January 2013 and February 2015—the authors explored the question, “What is revealed when we consider videoconferencing for DME as a sociomaterial practice?”

Results

The authors describe three interconnected ways that videoconference systems operate as unintended “technologies of exposure”: visual, curricular, and auditory. Videoconferencing inadvertently exposes both mundane and extraordinary images and sounds, offering access to the informal, unintended, and even disavowed curriculum of everyday medical education. The authors conceptualize these exposures as sociomaterial practices, which add an additional layer of complexity for members of medical school communities.

Conclusions

This analysis challenges the assumption that videoconferencing merely extends the bricks-and-mortar classroom. The authors discuss practical implications and recommend more critical consideration of the ways videoconferencing shifts the terrain of medical education. These findings point to a need for more critically oriented research exploring the ways DME technologies transform medical education, in both intended and unintended ways.
Impact of Nicotine and Other Stimulants on Sleep in Young Adults
Authors: Caviness Celeste M. , Anderson Bradley J. , Stein Michael D.
Published: November 2018

Objectives:

Sleep problems can have long-term negative consequences. This study explored the relationship of commonly used stimulant substances to poor sleep quality in young adults.

Methods:

We surveyed 498 participants, aged 18 to 25, who reported recent alcohol or marijuana use. Stimulant substances measured included coffee, energy drinks, nonmedical prescription stimulants (NPS), cocaine, and nicotine. Sleep outcomes were measured using the Pittsburgh Sleep Quality Index (PSQI) and its components.

Results:

Participants averaged 21.3 (±2.07) years of age, 47.8% male, 65.5% non-Latino white, 10.8% African-American, 12.3% Latino, and 11.5% other ethnic origins. In the past 30 days, 24.9% had used cigarettes, 48.1% energy drinks, 17.3% NPS, 79.3% coffee, and 7.9% cocaine. Mean PSQI global score was 6.21 (±3.66, median = 5). After adjusting for background characteristics, PSQI global scores were positively and significantly associated with number of cigarettes/day (b = 0.16, 95% confidence interval 0.07 to 0.25, P < 0.001) and days of NPS (b = 0.10, 95% confidence interval 0.01 to 0.18, P = 0.030).

Conclusions:

NPS negatively affects sleep, but nicotine is particularly deleterious to sleep quality. Addressing smoking cessation to improve sleep may be a novel way to motivate young adult smokers to quit.