Mapping tree density at a global scale.

The global extent and distribution of forest trees is central to our understanding of the terrestrial biosphere. We provide the first spatially continuous map of forest tree density at a global scale. This map reveals that the global number of trees is approximately 3.04 trillion, an order of magnitude higher than the previous estimate. Of these trees, approximately 1.39 trillion exist in tropical and subtropical forests, with 0.74 trillion in boreal regions and 0.61 trillion in temperate regions. Biome-level trends in tree density demonstrate the importance of climate and topography in controlling local tree densities at finer scales, as well as the overwhelming effect of humans across most of the world. Based on our projected tree densities, we estimate that over 15 billion trees are cut down each year, and the global number of trees has fallen by approximately 46% since the start of human civilization.

Urban soil health: A city-wide survey of chemical and biological properties of urban agriculture soils.

The integration of urban green spaces into modern city planning is seen as a promising tool to offset the drawbacks of ever-expanding cities. Urban agriculture is a common method to implement such strategies and to increase urban sustainability with a special focus on food security. Due to their location, urban farms are highly influenced by past and present anthropogenic activities which can threaten both soil health and food safety. This study includes 12 urban agriculture sites in the metropolitan area of Adelaide, Australia. It is the first of its kind to focus on soil health in urban agriculture systems with a further emphasis on mycorrhizal fungi. Descriptive information about each site, the biodiversity of the selected plots and soil samples from different depths and locations were collected and analysed for chemical and biological parameters. Seven metals, total and plant-available (Colwell) phosphorus and available nitrogen were measured in soils. A glasshouse bioassay was also conducted to determine the abundance of beneficial arbuscular mycorrhizal fungi in the soils and the change of root colonization after inoculation with the mycorrhizal fungus Rhizophagus irregularis. Results showed a generally high biodiversity of plants that correlated with site activity (commercial or community garden) and which could potentially be used for urban biodiversity conservation. Metal concentrations in soils were below national guidelines levels for all samples, although sites with previous industrial history showed elevated levels when compared to sites without industrial history. The use of raised beds with introduced soils eliminated differences in previous land-use history, thereby providing a good option to support cleaner production. Gardening soils were considered highly fertile, with plant-available (Colwell) P concentrations exceeding recommended levels for most horticultural crops, while soils were adequately supplied with nitrogen. Most plant nutrients were derived from freely available urban waste streams and integrated via composting. Various urban waste streams could be used to counter-act imbalanced soil nutrients. Arbuscular mycorrhizal fungi were present in all sites, indicating that the practiced soil management is sustainable from a microbial perspective. Given their important role in supporting plant nutrition, and potential to reduce the need for external nutrient inputs, they provide an important focal point for achieving clean and sustainable urban food production. The results were incorporated into a framework for the management of urban soil health.

General practitioner and nurse prescriber experiences of prescribing antibiotics for respiratory tract infections in UK primary care out-of-hours services (the UNITE study).

Background: Interventions are needed to reduce unnecessary antibiotic prescribing for respiratory tract infections (RTIs). Although community antibiotic prescribing appears to be decreasing in the UK, figures for out-of-hours (OOH) prescribing have substantially increased. Understanding the factors influencing prescribing in OOH and any perceived differences between general practitioner (GP) and nurse prescriber (NP) prescribing habits may enable the development of tailored interventions promoting optimal prescribing in this setting. Objectives: To explore UK GP and NP views on and experiences of prescribing antibiotics for RTIs in primary care OOH services. Methods: Thirty semi-structured interviews were conducted with GPs and NPs working in primary care OOH services. Inductive thematic analysis was used to analyse data. Results: The research shows that factors particular to OOH influence antibiotic prescribing, including a lack of patient follow-up, access to patient GP records, consultation time, working contracts and implementation of feedback, audit and supervision. NPs reported perceptions of greater accountability for their prescribing compared with GPs and reported they had longer consultations during which they were able to discuss decisions with patients. Participants agreed that more complex cases should be seen by GPs and highlighted the importance of consistency of decision making, illness explanations to patients as well as a perception that differences in clinical training influence communication with patients and antibiotic prescribing decisions. Conclusions: Environmental and social factors in OOH services and a mixed healthcare workforce provide unique influences on antibiotic prescribing for RTIs, which would need to be considered in tailoring interventions that promote prudent antibiotic prescribing in OOH services.

ß+ Gamow-Teller transition strengths from 46Ti and stellar electron-capture rates.

The Gamow-Teller strength in the ß(+) direction to (46)Sc was extracted via the (46)Ti(t,(3)He + γ) reaction at 115 MeV/u. The γ-ray coincidences served to precisely measure the very weak Gamow-Teller transition to a final state at 991 keV. Although this transition is weak, it is crucial for accurately estimating electron-capture rates in astrophysical scenarios with relatively low stellar densities and temperatures, such as presupernova stellar evolution. Shell-model calculations with different effective interactions in the pf shell-model space do not reproduce the experimental Gamow-Teller strengths, which is likely due to sd-shell admixtures. Calculations in the quasiparticle random phase approximation that are often used in astrophysical simulations also fail to reproduce the experimental Gamow-Teller strength distribution, leading to strongly overestimated electron-capture rates. Because reliable theoretical predictions of Gamow-Teller strengths are important for providing astrophysical electron-capture reaction rates for a broad set of nuclei in the lower pf shell, we conclude that further theoretical improvements are required to match astrophysical needs.

Nuclear structure towards N = 40 60Ca: in-beam γ-ray spectroscopy of 58,60Ti.

Excited states in the neutron-rich N = 38, 36 nuclei (60)Ti and (58)Ti were populated in nucleon-removal reactions from (61)V projectiles at 90 MeV/nucleon. The γ-ray transitions from such states in these Ti isotopes were detected with the advanced γ-ray tracking array GRETINA and were corrected event by event for large Doppler shifts (v/c ∼ 0.4) using the γ-ray interaction points deduced from online signal decomposition. The new data indicate that a steep decrease in quadrupole collectivity occurs when moving from neutron-rich N = 36, 38 Fe and Cr toward the Ti and Ca isotones. In fact, (58,60)Ti provide some of the most neutron-rich benchmarks accessible today for calculations attempting to determine the structure of the potentially doubly magic nucleus (60)Ca.

Cultivation can increase harvesting pressure on overexploited plant populations.

Captive breeding and cultivation of overharvested species is frequently proposed as a conservation strategy, yet there is little evidence under what conditions, if at all, the strategy is effective. We created a bioeconomic model to investigate the socioeconomic conditions favoring cultivation over wild harvesting and likely impacts on the wild population. We parameterize the model with the case study of illegal xaté palm (Chamaedorea ernesti-augusti) harvesting in Belize and Guatemala. We examine how changes in law enforcement, a price premium for cultivated leaf, land ownership, and alternative income might affect decisions to cultivate and the impact of cultivation on wild populations. We show that those switching to cultivation are largely not wild harvesters because of barriers such as land ownership. We also find that if harvesters do switch to cultivation, they may have a negative effect on the wild population through harvesting of material to set up plantations. We found increasing alternative income reduces harvesting pressure and suggests the provision of alternative livelihoods would more directly reduce pressure on the wild population. Although schemes to encourage cultivation seem an appealing conservation intervention, we urge caution in assuming that people will readily adopt cultivation of wild harvested species or that this would necessarily reduce impacts on wild populations.

Direct observation of long-lived isomers in 212Bi.

Long-lived isomers in (212)Bi have been studied following (238)U projectile fragmentation at 670 MeV per nucleon. The fragmentation products were injected as highly charged ions into a storage ring, giving access to masses and half-lives. While the excitation energy of the first isomer of (212)Bi was confirmed, the second isomer was observed at 1478(30) keV, in contrast to the previously accepted value of >1910 keV. It was also found to have an extended Lorentz-corrected in-ring half-life >30 min, compared to 7.0(3) min for the neutral atom. Both the energy and half-life differences can be understood as being due a substantial, though previously unrecognized, internal decay branch for neutral atoms. Earlier shell-model calculations are now found to give good agreement with the isomer excitation energy. Furthermore, these and new calculations predict the existence of states at slightly higher energy that could facilitate isomer deexcitation studies.

High-precision measurement of the 19Ne half-life and implications for right-handed weak currents.

We report a precise determination of the (19)Ne half-life to be T(1/2)=17.262±0.007 s. This result disagrees with the most recent precision measurements and is important for placing bounds on predicted right-handed interactions that are absent in the current standard model. We are able to identify and disentangle two competing systematic effects that influence the accuracy of such measurements. Our findings prompt a reassessment of results from previous high-precision lifetime measurements that used similar equipment and methods.

Spatiotemporal dynamics of soil health in urban agriculture.

There is a paucity of data on the state of urban agriculture soils. In order to develop efficient management practices, it is necessary to understand the seasonal dynamics of the soil health of these systems. This study sampled two community gardens, and one commercial urban agriculture site on a monthly basis over the span of one year. The dynamic analysis examined soil nutritional, chemical and microbial properties. Plant biodiversity was significantly higher in community gardens compared to commercial sites. Analysis of soil nutrients revealed fluctuations of mineral nitrogen with seasonal conditions and consistently high concentrations of plant-available phosphorus. We identified gradually decreasing soil total nitrogen and carbon concentrations throughout the year. Soils were abundant in arbuscular mycorrhizal fungi spores. Soil metabarcoding using 16S and ITS amplicons revealed a seasonal gradient of the microbial diversity and changes after the application of organic fertilizer. Soil-borne potential human pathogens were also detected in the soils. The results of this study provide relevant information about soil management principles in urban agriculture systems. These principles include mulching and the use of nutrient-balanced composts to counteract decreasing carbon pools and the excessive accumulation of phosphorus.

High-precision half-life measurement for the superallowed ß+ emitter ²6Al(m).

A high-precision half-life measurement for the superallowed ß+ emitter 26Al(m) was performed at the TRIUMF-ISAC radioactive ion beam facility yielding T 1/2 6346.54 ± 0.46(stat) ± 0.60 (syst) ms, consistent with, but 2.5 times more precise than, the previous world average. The 26Al(m) half-life and ft value, 3037.53(61) s, are now the most precisely determined for any superallowed ß decay. Combined with recent theoretical corrections for isospin-symmetry-breaking and radiative effects, the corrected Ft value for (26)Al(m), 3073.0(12) s, sets a new benchmark for the high-precision superallowed Fermi ß-decay studies used to test the conserved vector current hypothesis and determine the V(ud) element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix.

Factors that predict bleeding following endoscopic mucosal resection of large colonic lesions.

BACKGROUND AND STUDY AIMS: Endoscopic mucosal resection (EMR) for large colonic laterally spreading tumors (LSTs) is a safe, efficacious, and cost-effective treatment. The most common serious complication is delayed bleeding, which reduces these advantages, but consensus guidelines for large-polyp EMR do not exist. PATIENTS AND METHODS: Data from two large prospective intention-to-treat studies of EMR for colonic LSTs 20 mm or greater in size were analyzed. Data collection was comprehensive, and included patient and lesion characteristics. EMR technique and cessation of anticoagulant and antiplatelet therapy was standardized. Clinically significant delayed bleeding was defined as that requiring hospital admission. RESULTS: EMR was performed on 302 lesions in 288 patients. There was clinically significant delayed bleeding in 21 cases (7 %). Ten underwent colonoscopy. One required angiography. One required surgery after perforation following hemostatic clip placement. There were no deaths. Risk factors for bleeding on multivariate analysis were right colon location [adjusted odds ratio (OR) 4.4, P = 0.01], use of aspirin (OR 6.3, P = 0.005), and age (OR per decade of age 1.70). All bleeds occurred before aspirin was restarted. Patient characteristics, including ASA grade and co-morbidity type, were not predictive. Despite requiring more complex EMR, larger lesion size ( P = 0.2), multiple excisions rather than en bloc resection ( P = 0.1), polyp morphology ( P = 0.2), and previous attempts ( P = 0.5), were not associated with increased risk. CONCLUSIONS: Proximal lesion location is a highly significant risk for clinically significant delayed bleeding following colonic EMR, and this knowledge could form the basis of a targeted therapeutic trial. Recent aspirin use also increases bleeding risk--specific consensus guidelines in this area are required for colonic EMR.

Complete Barrett's excision by stepwise endoscopic resection in short-segment disease: long term outcomes and predictors of stricture.

BACKGROUND AND STUDY AIMS: Complete Barrett's excision (CBE) of short-segment Barrett's high grade dysplasia (HGD) and early esophageal adenocarcinoma by stepwise endoscopic resection is a precise staging tool, detects covert synchronous disease, and may produce a sustained treatment response. Esophageal stricture is the most commonly reported complication of CBE although risk factors have not yet been clearly defined. PATIENTS AND METHODS: Data were recorded prospectively on patients with limited co-morbidity and age ≤ 80 years undergoing CBE for histologically proven HGD or esophageal adenocarcinoma within ≤ C3M5 segments. Endoscopic resection was performed by standardized protocol every 6 - 8 weeks until CBE was achieved. Esophageal dilation was performed when patients reported dysphagia. Dysphagia scores were recorded at scheduled endoscopic surveillance or by telephone interview. RESULTS: By intention-to-treat analysis, complete eradication of neoplasia and intestinal metaplasia was achieved in 95 % and 82 %, respectively, in 77 patients undergoing a median of 2 resection sessions (interquartile range [IQR] 1 - 3). Esophageal dilation was required in 33 % (median 3 dilations, IQR 1 - 3.5) at median follow-up of 20 months (IQR 6 - 40). Independent risk factors for dilation requirement were the number of mucosal resections at the index procedure (odds ratio [OR] 1.3 per resection, 95 % confidence interval [CI] 1.0 - 1.9; P = 0.043) and maximal extent of the Barrett's segment (OR 2.2 per cm, 95 %CI 1.2 - 3.9; P = 0.009). CONCLUSIONS: Although CBE is highly effective in the treatment of Barrett's HGD and esophageal adenocarcinoma, the risk of post-CBE dysphagia increases with the maximal extent of the Barrett's segment and the number of mucosal resections at the index procedure. These data could be used to inform treatment decisions and identify those patients who may benefit from prophylactic therapies such as dilation.

Evaluation of commercial composts and potting mixes and their ability to support arbuscular mycorrhizal fungi with maize (Zea mays) as host plant.

The use of composts and potting mixes in food production systems is a promising way to counteract the effects of soil degradation and allows crop growth in soilless culture systems. Arbuscular mycorrhizal fungi (AMF) are a well-studied group of beneficial plant symbionts that have been shown to provide important ecosystem services. This study analysed the properties of nine commercial Australian potting mixes and composts and investigated whether they support colonization of maize plants with AMF in a plant growth bioassay. Physicochemical analyses showed highly variable properties between the substrates, with some extreme values that limited plant growth. DNA-based analysis revealed the presence of various plant pathogens, which was linked to inhibited plant growth in one substrate. Some substrates did not meet national quality standards, due to the concentrations of plant nutrients, heavy metals, or substrate maturity. Plant growth was mostly limited due to nitrogen immobilization, which required weekly fertilizer applications. Solid state 13C nuclear magnetic resonance spectroscopy gave insight into the decomposition state of the substrates. Plant roots in most substrates were well colonized with AMF (>60% root length), regardless of most substrate properties. Root colonization was negatively affected in only one substrate, likely due to ammonium toxicity. Results of this study show that not all commercial substrates adhered to national quality standards. Potting mixes and composts can support high mycorrhizal root colonization when plant growth is otherwise not limited.

Spatiotemporal expression of alpha(1), alpha(3) and beta(1) integrin subunits is altered in rat myometrium during pregnancy and labour.

Integrins are transmembrane extracellular matrix (ECM) receptors composed of alpha- and beta-subunits. Integrins can cluster to form focal adhesions and, because there is significant ECM remodelling and focal adhesion turnover in the rat myometrium during late pregnancy, we hypothesised that the expression of alpha(1), alpha(3) and beta(1) integrin subunits in the rat myometrium would be altered at this time to accommodate these processes. Expression of alpha(1) and beta(1) integrin subunit mRNA was significantly increased on Days 6-23 of pregnancy compared with non-pregnant (NP) and postpartum (PP) time points (P < 0.05). In contrast, alpha(3) integrin subunit mRNA expression was significantly increased on Days 14, 21 and 22 compared with NP, Day 10, 1 day PP and 4 days PP (P < 0.05). A relative gene expression study revealed that, of the integrins studied, the expression of beta(1) integrin mRNA was highest in pregnant rat myometrium. The alpha(1), alpha(3) and beta(1) integrin subunit proteins became immunolocalised to myocyte membranes in situ by late pregnancy and labour in both myometrial muscle layers. Increased alpha(1), alpha(3) and beta(1) integrin gene expression during gestation and the specific detection of these subunits in myocyte membranes during late pregnancy and labour may contribute to the cell-ECM interactions required for the development of a mechanical syncytium.

Autoimmune pancreatitis: an important diagnostic consideration in obstructive jaundice due to a pancreatic mass lesion.

Autoimmune or immunoglobulin G subtype (IgG4) pancreatitis is a newly recognised clinical entity and is an important differential diagnosis for patients presenting with obstructive jaundice. Knowledge of autoimmune pancreatitis (AIP) continues to evolve both for pathogenesis and management; however diagnosis is often not straightforward or even considered, therefore a high index of suspicion remains an important tool for the treating physician. The six cases presented illustrate both the difficulties in diagnosis as well as management of this condition.

The suction pseudopolyp technique: a novel method for the removal of small flat nonpolypoid lesions of the colon and rectum.

BACKGROUND AND STUDY AIMS: Small flat nonpolypoid lesions of the colorectum can be technically difficult to target and completely remove; techniques such as hot biopsy forceps electrocauterization are associated with serositis, delayed bleeding, and perforation. This study aimed to describe a novel technique for the removal of such lesions and demonstrate its safety and efficacy. PATIENTS AND METHODS: Patients aged 18 - 80 years with flat nonpolypoid lesions (Paris-Japanese classification 0-IIa and 0-IIb, measuring less than 10 mm) identified at colonoscopy were included in this prospective study. The lesions were removed by the suction pseudopolyp technique (SPT): the lesion is aspirated into the suction channel of the colonoscope and continuous suction applied for 5 seconds whilst the colonoscope is gently retracted. On release of the suction, the resulting pseudopolyp containing the lesion and a margin of normal tissue is easily ensnared and resected. The primary outcomes were endoscopic completeness of polyp resection and complication rate. RESULTS: Over a 12-month period, 1231 polyps were removed during 2656 colonoscopies; 126 polyps (in 101 patients) met inclusion criteria. Complete endoscopic resection was achieved in 100 % of the polyps, without immediate or delayed complication. Of the resected lesions, 57 % had malignant potential (adenomas 47 % and sessile serrated lesions 10 %); a higher proportion of lesions removed from the right colon had malignant potential compared with those from the left colon (75 % vs. 41 %, P = 0.0066). CONCLUSIONS: Diminutive flat lesions of the colorectum are predominantly adenomas and sessile serrated lesions. SPT is a safe, effective, and reproducible therapy for removal of these lesions.

Added dietary cobalt or vitamin B12, or injecting vitamin B12 does not improve performance or indicators of ketosis in pre- and post-partum Holstein-Friesian dairy cows.

Vitamin B12 is synthesised in the rumen from cobalt (Co) and has a major role in metabolism in the peri-paturient period, although few studies have evaluated the effect of the dietary inclusion of Co, vitamin B12 or injecting vitamin B12 on the metabolism, health and performance of high yielding dairy cows. A total of 56 Holstein-Friesian dairy cows received one of four treatments from 8 weeks before calving to 8 weeks post-calving: C, no added Co; DC, additional 0.2 mg Co/kg dry matter (DM); DB, additional 0.68 mg vitamin B12/kg DM; IB, intra-muscular injection of vitamin B12 to supply 0.71 mg/cow per day prepartum and 1.42 mg/cow per day post-partum. The basal and lactation rations both contained 0.21 mg Co/kg DM. Cows were weighed and condition scored at drying off, 4 weeks before calving, within 24 h of calving and at 2, 4 and 8 weeks post-calving, with blood samples collected at drying off, 2 weeks pre-calving, calving and 2, 4 and 8 weeks post-calving. Liver biopsy samples were collected from all animals at drying off and 4 weeks post-calving. Live weight changed with time, but there was no effect of treatment (P>0.05), whereas cows receiving IB had the lowest mean body condition score and DB the highest (P0.05) with mean values of 21.6 kg/day, 39.6 kg/day and 40.4 g/kg, respectively. Cows receiving IB had a higher plasma vitamin B12 concentration than those receiving any of the other treatments (P0.05) of treatment on homocysteine or succinate concentrations, although mean plasma methylmalonic acid concentrations were lower (P=0.019) for cows receiving IB than for Control cows. Plasma ß-hydroxybutyrate concentrations increased sharply at calving followed by a decline, but there was no effect of treatment. Similarly, there was no effect (P>0.05) of treatment on plasma non-esterified fatty acids or glucose. Whole tract digestibility of DM and fibre measured at week 7 of lactation were similar between treatments, and there was little effect of treatment on the milk fatty acid profile except for C15:0, which was lower in cows receiving DC than IB (P<0.05). It is concluded that a basal dietary concentration of 0.21 mg Co/kg DM is sufficient to meet the requirements of high yielding dairy cows during the transition period, and there is little benefit from additional Co or vitamin B12.

Using High-Throughput Phenotyping to Explore Growth Responses to Mycorrhizal Fungi and Zinc in Three Plant Species.

There are many reported benefits to plants of arbuscular mycorrhizal fungi (AMF), including positive plant biomass responses; however, AMF can also induce biomass depressions in plants, and this response receives little attention in the literature. High-throughput phenotyping (HTP) technology permits repeated measures of an individual plant's aboveground biomass. We examined the effect on AMF inoculation on the shoot biomass of three contrasting plant species: a vegetable crop (tomato), a cereal crop (barley), and a pasture legume (Medicago). We also considered the interaction of mycorrhizal growth responses with plant-available soil zinc (Zn) and phosphorus (P) concentrations. The appearance of a depression in shoot biomass due to inoculation with AMF occurred at different times for each plant species; depressions appeared earliest in tomato, then Medicago, and then barley. The usually positive-responding Medicago plants were not responsive at the high level of soil available P used. Mycorrhizal growth responsiveness in all three species was also highly interactive with soil Zn supply; tomato growth responded negatively to AMF inoculation in all soil Zn treatments except the toxic soil Zn treatment, where it responded positively. Our results illustrate how context-dependent mycorrhizal growth responses are and the value of HTP approaches to exploring the complexity of mycorrhizal responses.

A prospective randomized trial of cannulation technique in ERCP: effects on technical success and post-ERCP pancreatitis.

BACKGROUND AND STUDY AIMS: Inadvertent injection of contrast agent into the pancreatic duct is believed to be an important contributor to pancreatitis occurring after endoscopic retrograde cholangiopancreatography (post-ERCP pancreatitis, PEP). Our aim was to examine whether primary deep biliary cannulation with a guide wire is associated with a lower rate of PEP than conventional contrast-assisted cannulation. PATIENTS AND METHODS: From August 2003 to April 2006 all patients with an intact papilla who were referred for ERCP were eligible. Patients with pancreatic or ampullary cancer were excluded. Patients were randomized to undergo sphincterotomy biliary cannulation using either contrast injection or a guide wire. The ERCP fellow attempted initially for 5 minutes. If unsuccessful, the consultant attempted for 5 minutes using the same technique, followed by crossover to the other technique in the same sequence and then needle-knife sphincterotomy where appropriate. Patients were assessed clinically after the procedure, then followed up with telephone interviews after 24 hours and 30 days, and serum amylase and lipase tests after 24 hours. RESULTS: Out of 1654 patients undergoing ERCP, 413 were included in the study. PEP occurred in 29/413 (7.0 %): 16 in the guide-wire arm, 13 in the contrast arm ( P = 0.48). The overall cannulation success rate was 97.3 %. Cannulation was successful without crossover in 323/413 patients (78.2 %): 167/202 (81.4 %) in the guide-wire arm and 156/211 (73.9 %) in the contrast arm ( P = 0.03). Multivariate analysis demonstrated female sex (OR = 2.7, P = 0.04), suspected sphincter of Oddi dysfunction (OR = 5.5, P = 0.01), and complete filling of the pancreatic duct with contrast agent (OR = 3.5, P = 0.02) to be independently associated with PEP. The risk of PEP increased incrementally with each attempt at the papilla (OR 1.4 per attempt, P = 0.04) to greater than 10 % after four or more attempts. CONCLUSIONS: The guide-wire technique improves the primary success rate for biliary cannulation during ERCP but does not reduce the incidence of PEP compared to the conventional contrast technique. The incidence of PEP increases incrementally with each attempt at the papilla.