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Climate change will increase variability in temperature and precipitation on rangelands, impacting ecosystem services including livestock grazing. Facing uncertainty about future climate, managers must know if current practices will maintain rangeland sustainability. Herein, the future density of an invasive species, broom snakeweed, is estimated using a long-term ecological dataset and climate projections. We find that livestock stocking rates determined using a current method result in lower forage production, allowable stocking rate, and grazing value than an economically efficient stocking rate. Results indicate that using ecology and adaptive methods in management are critical to the sustainability of rangelands.
Background: High comorbidity rates among emotional disorders have led researchers to examine transdiagnostic factors that may contribute to shared psychopathology. Bifactor models provide a unique method for examining transdiagnostic variables by modelling the common and unique factors within measures. Previous findings suggest that the bifactor model of the Depression Anxiety and Stress Scale (DASS) may provide a method for examining transdiagnostic factors within emotional disorders. Aims: This study aimed to replicate the bifactor model of the DASS, a multidimensional measure of psychological distress, within a US adult sample and provide initial estimates of the reliability of the general and domain-specific factors. Furthermore, this study hypothesized that Worry, a theorized transdiagnostic variable, would show stronger relations to general emotional distress than domain-specific subscales. Method: Confirmatory factor analysis was used to evaluate the bifactor model structure of the DASS in 456 US adult participants (279 females and 177 males, mean age 35.9 years) recruited online. Results: The DASS bifactor model fitted well (CFI = 0.98; RMSEA = 0.05). The General Emotional Distress factor accounted for most of the reliable variance in item scores. Domain-specific subscales accounted for modest portions of reliable variance in items after accounting for the general scale. Finally, structural equation modelling indicated that Worry was strongly predicted by the General Emotional Distress factor. Conclusions: The DASS bifactor model is generalizable to a US community sample and General Emotional Distress, but not domain-specific factors, strongly predict the transdiagnostic variable Worry.
A distinctive feature of polar regions is the formation of ice clusters attached to the seabed, known as ‘anchor ice’. Anchor ice plays an important role in mobilizing bed sediments, and serves ecological roles providing habitats, or as an agent of disturbance creating potentially fatal environments to benthic fauna. The sublittoral zone associated with the landward margin represents the most likely environment for anchor ice formation, where conditions conducive to the advection of supercooled water from sub-ice-shelf cavities are favourable. We develop a framework to estimate the areal extent of anchor ice formation assuming a northerly flow of 75m deep supercooled water plumes from the Ross and McMurdo Ice Shelf cavities, Antarctica. In McMurdo Sound our results indicate that regions beneath the McMurdo Ice Shelf, extending along Brown Peninsula and White and Black Islands, are likely conducive to anchor ice formation. Anchor ice may also form along the Hut Point Peninsula and around Ross Island, and in pockets along the southern Victoria Land coast. The limitations of our approach include an imposed northerly flow of Ice Shelf Water, poorly constrained sub-ice-shelf bathymetry, and temporal variability in supercooled water depth production, particularly in the eastern Sound.
A high Ca intake has been recommended for osteoporosis prevention; however, little research has examined the relationship between dietary Ca and bone health in men. We examined associations between dietary Ca intake, bone mineral density (BMD) and change in BMD at the total body, hip and spine over 2 years in a cohort of men (mean age 57 years, BMI 26 kg/m2) from a trial. Data from the total cohort (n 323) were used in the analysis of Ca intake and BMD at baseline, and data from the placebo group (n 99) were used in the longitudinal analysis of Ca intake and change in BMD. Parathyroid hormone (PTH) and the markers of bone turnover serum total alkaline phosphatase activity, serum C-telopeptide and serum procollagen type-1 N-terminal propeptide were measured in a subset of participants at baseline (n 150), and associations with dietary Ca at baseline were examined. Mean Ca intake was 870 mg/d. Baseline BMD was not related to dietary Ca intake at any site, before or after adjustment for covariables. Similarly, bone loss over 2 years was not related to Ca intake at any site, before or after adjustment. Dietary Ca intake was inversely correlated with PTH at baseline (r −0·19, P=0·02), but was not associated with the markers of bone turnover. BMD and rates of bone loss were unrelated to Ca intake in these men. This suggests that strategies to increase Ca intake are unlikely to impact on the prevalence of and morbidity from male osteoporosis.
Methiozolin is an isoxazoline herbicide being investigated for selective POST annual bluegrass control in managed turfgrass. Research was conducted to evaluate methiozolin efficacy for controlling two annual bluegrass phenotypes with target-site resistance to photosystem II (PSII) or enolpyruvylshikimate-3-phosphate synthase (EPSPS)-inhibiting herbicides (i.e., glyphosate), as well as phenotypes with multiple resistance to microtubule and EPSPS or PSII and acetolactate synthase (ALS)-inhibiting herbicides. All resistant phenotypes were established in glasshouse culture along with a known herbicide-susceptible control and treated with methiozolin at 0, 125, 250, 500, 1000, 2000, 4000, or 8000 g ai ha−1. Methiozolin effectively controlled annual bluegrass with target-site resistance to inhibitors of EPSPS, PSII, as well as multiple resistance to EPSPS and microtubule inhibitors. Methiozolin rates required to reduce aboveground biomass of these resistant phenotypes 50% (GR50 values) were not significantly different from the susceptible control, ranging from 159 to 421 g ha−1. A phenotype with target-site resistance to PSII and ALS inhibitors was less sensitive to methiozolin (GR50=862 g ha−1) than a susceptible phenotype (GR50=423 g ha−1). Our findings indicate that methiozolin is an effective option for controlling select annual bluegrass phenotypes with target-site resistance to several herbicides.
We aimed to explore how individually experienced disaster-related stressors and collectively experienced community-level damage influenced perceived need for mental health services in the aftermath of Hurricane Sandy.
In a cross-sectional study we analyzed 418 adults who lived in the most affected areas of New York City at the time of the storm. Participants indicated whether they perceived a need for mental health services since the storm and reported on their exposure to disaster-related stressors (eg, displacement, property damage). We located participants in communities (n=293 census tracts) and gathered community-level demographic data through the US Census and data on the number of damaged buildings in each community from the Federal Emergency Management Agency Modeling Task Force.
A total of 7.9% of participants reported mental health service need since the hurricane. Through multilevel binomial logistic regression analysis, we found a cross-level interaction (P=0.04) between individual-level exposure to disaster-related stressors and community-level building damage. Individual-level stressors were significantly predictive of individual service needs in communities with building damage (adjusted odds ratio: 2.56; 95% confidence interval: 1.58-4.16) and not in communities without damage.
Individuals who experienced individual stressors and who lived in more damaged communities were more likely to report need for services than were other persons after Hurricane Sandy. (Disaster Med Public Health Preparedness. 2016;10:428–435)
A new method to perform X-ray absorption correction for spherical particles in quantitative energy-dispersive X-ray spectroscopy in the scanning transmission electron microscope is presented. An absorption correction factor is derived and simulated data is presented encompassing a range of X-ray absorption conditions. Theoretical calculations are compared with experimental data of X-ray counts from Au nanoparticles to verify the derived methodology. The effect of detector elevation angle is considered and a comparison with thin-film absorption correction is included.
A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), and included 842,951 height and BMI measurements from twins aged 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Similarly, a greater mean BMI of up to 0.3 kg/m2 in childhood and adolescence and up to 0.2 kg/m2 in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast, the variance of BMI was significantly higher in DZ than in MZ twins, particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes.
Fluridone has been used to successfully manage Eurasian watermilfoil since the late 1980s. However, recent documentation of hybrid watermilfoils and the resulting potential for reduced herbicide sensitivity necessitate the need for an assay to determine individual population response to fluridone. A known fluridone-resistant hybrid watermilfoil population from Townline Lake in Michigan was compared to 11 Eurasian and hybrid watermilfoil populations in laboratory experiments to develop a method for determining response to fluridone. Apical shoot tips were exposed to increasing concentrations of fluridone (0 to 48 μg L−1) for 3, 5, and 7 d. Chlorophyll fluorescence (Fv/Fm) was evaluated using a pulse-amplitude modulated fluorometer at each interval along with pigment analysis of chlorophyll and β-carotene at the 7-d interval. Fv/Fm and pigment analysis yielded the same results. A fluridone concentration of 12 μg L−1 and an analysis interval of 7 d were found to be optimal in determining invasive watermilfoil response to fluridone. Use of such small-scale assays can provide resource managers a rapid tool to cost-effectively evaluate invasive watermilfoil response to fluridone.
For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m2) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes.
Ca supplements, but not dietary Ca, have been associated with increased cardiovascular risk. This difference could be related to differences in their acute effects on serum Ca. We therefore examined the effects of Ca from different sources on serum Ca and phosphate in a randomised, cross-over trial of ten women (mean age of 69 years). Fasting participants received a single dose of 500 mg of Ca as citrate, citrate with a meal, fortified juice or a dairy product meal, with at least 6 d between each intervention. Blood was sampled before and 1, 2, 4 and 6 h after each intervention was ingested. Serum ionised and total Ca increased significantly from baseline over 6 h. Using calcium citrate fasting as a comparator, the elevations in ionised and total Ca were similar after fortified juice, delayed after calcium citrate with a meal and smaller after a dairy product meal. Serum phosphate and calcium–phosphate product increased from baseline after calcium citrate with a meal and after a dairy product meal, and they declined after calcium citrate fasting and after fortified juice. The elevations in serum Ca in the present study were only slightly different from those observed after the administration of 1000 mg of Ca in a previous study. These data indicate that different sources of Ca have different acute effects on serum Ca and support recommendations that dietary Ca might be safer than supplements. Whether these differences contribute to differences in cardiovascular risk requires further study.
Although evidence exists for abnormal brain function across various
anxiety disorders, direct comparison of neural function across diagnoses
is needed to elicit abnormalities common across disorders and those
distinct to a particular diagnosis.
To delineate common and distinct abnormalities within generalised anxiety
(GAD), panic and social anxiety disorder (SAD) during affective
Fifty-nine adults (15 with GAD, 15 with panic disorder, 14 with SAD, and
15 healthy controls) underwent functional magnetic resonance imaging
while completing a facial emotion matching task with fearful, angry and
Greater differential right amygdala activation to matching fearful
v. happy facial expressions related to greater
negative affectivity (i.e. trait anxiety) and was heightened across all
anxiety disorder groups compared with controls. Collapsing across
emotional face types, participants with panic disorder uniquely displayed
greater posterior insula activation.
These preliminary results highlight a common neural basis for clinical
anxiety in these diagnoses and also suggest the presence of
Invasive watermilfoils, specifically Eurasian watermilfoil and the interspecific hybrid of Eurasian watermilfoil × northern watermilfoil, continue to be problematic for water resource managers. Herbicides are often used to control these nuisance weeds and have been historically successful in controlling Eurasian watermilfoil. A population of hybrid watermilfoil from Townline Lake in Michigan has shown increased tolerance to the herbicide fluridone. The objective of this work is to determine if cross- and multiple tolerance have also developed in this population. Eurasian watermilfoil plants collected from multiple sites and plants from Townline Lake were treated with 0, 5, 10, 20, 40, or 80 µg L−1 of fluridone, norflurazon, or topramezone. Fluridone and norflurazon inhibit phytoene desaturase, whereas topramezone is a 4-hydroxyphenylpyruvate dioxygenase-inhibiting herbicide. Chlorophyll fluorescence (Fv/Fm) and pigment content was measured at 10 d after treatment. Townline Lake plants responded differently from susceptible plants when treated with fluridone, norflurazon, and topramezone at 40 µg L−1. These results indicate that the Townline population of hybrid watermilfoil has inherent tolerance to multiple herbicide modes of action. These results are especially significant as topramezone has recently been labeled for aquatic use. Screening of additional herbicides to determine potential herbicide tolerance of the Townline Lake population is recommended.
The high fat content in Western diets probably affects placental function during pregnancy with potential consequences for the offspring in the short and long term. The aim of the present study was to compare genome-wide placental gene expression between rat dams fed a high-fat diet (HFD) and those fed a control diet for 3 weeks before conception and during gestation. Gene expression was measured by microarray and pathway analysis was performed. Gene expression differences were replicated by real-time PCR and protein expression was assessed by Western blot analysis. Placental and fetal weights at E17.25 were not altered by exposure to the maternal HFD. Gene pathways targeting placental growth, blood supply and chemokine signalling were up-regulated in the placentae of dams fed the HFD. The up-regulation in messenger RNA expression for five genes Ptgs2 (fatty acid cyclo-oxidase 2; COX2), Limk1 (LIM domain kinase 1), Pla2g2a (phospholipase A2), Itga1 (integrin α-1) and Serpine1 was confirmed by real-time PCR. Placental protein expression for COX2 and LIMK was also increased in HFD-fed dams. In conclusion, maternal HFD feeding alters placental gene expression patterns of placental growth and blood supply and specifically increases the expression of genes involved in arachidonic acid and PG metabolism. These changes indicate a placental response to the altered maternal metabolic environment.
Gestational methyl donor deficiency (MDD) leads to growth retardation as well as to cognitive and motor disorders in 21-d-old rat pups. These disorders are related to impaired neurogenesis in the cerebral neurogenic areas. Olfactory bulbs (OB), the main target of neuronal progenitors originating from the subventricular zone, play a critical role during the postnatal period by allowing the pups to identify maternal odour. We hypothesised that growth retardation could result from impaired suckling due to impaired olfactory discrimination through imbalanced apoptosis/neurogenesis in the OB. Since neurosteroidogenesis modulates neurogenesis in OB, in the present study, we investigated whether altered neurosteroidogenesis could explain some these effects. Pups born to dams fed a normal diet (n 24) and a MDD diet (n 27) were subjected to olfactory tests during the lactation and weaning periods (n 24 and 20, respectively). We studied the markers of apoptosis/neurogenesis and the expression levels of the key neurosteroidogenic enzyme aromatase, the cholesterol-transfer protein StAR (steroidogenic acute regulatory protein) and the ERα oestrogen receptor and the content of oestradiol in OB. The 21-d-old MDD female pups displayed lower body weight and impaired olfactory discrimination when compared with the control pups. MDD led to greater homocysteine accumulation and more pronounced apoptosis, along with impaired cell proliferation in the OB of female pups. The expression levels of aromatase, StAR and ERα as well as the content of oestradiol were lower in the OB of the MDD female pups than in those of the control female pups. In conclusion, gestational MDD may alter olfactory discrimination performances by affecting neurogenesis, apoptosis and neurosteroidogenesis in OB in a sex-dependent manner. It may be involved in growth retardation through impaired suckling.