Feedbacks on climate change so far identified are predominantly positive, enhancing the rate of change. Loss of sea-ice, increase in desert areas, water vapour increase, loss of tropical rain forest ...and the restriction of significant areas of marine productivity to higher latitude (thus smaller geographical zones) all lead to an enhancement of the rate of change. The other major feedback identified, changes in cloud radiation, will produce either a positive feedback, if high level clouds are produced, or a negative feedback if low level clouds are produced. Few significant negative feedbacks have been identified, let alone quantified. Here, we show that the loss of ice shelves and retreat of coastal glaciers around the Antarctic Peninsula in the last 50 years has exposed at least 2.4 x 10⁴ km² of new open water. We estimate that these new areas of open water have allowed new phytoplankton blooms containing a total standing stock of ~5.0 x 10⁵ tonnes of carbon to be produced. New marine zooplankton and seabed communities have also been produced, which we estimate contain ~4.1 x 10⁵ tonnes of carbon. This previously unquantified carbon sink acts as a negative feedback to climate change. New annual productivity, as opposed to standing stock, amounts to 3.5 x 10⁶ tonnes yr⁻¹ of carbon, of which 6.9 x 10⁵ tonnes yr⁻¹ deposits to the seabed. By comparison the total aboveground biomasses of lowland American tropical rainforest is 160-435 tonnes ha⁻¹. Around 50% of this is carbon. On this basis the carbon held in new biomass described here is roughly equivalent to 6000-17 000 ha of tropical rainforest. As ice loss increases in polar regions this feedback will become stronger, and eventually, over thousands to hundreds of thousands of years, over 50 Mtonnes of new carbon could be fixed annually in new coastal phytoplankton blooms and over 10 Mtonnes yr⁻¹ locked in biological standing stock around Antarctica.
Background: It is well recognized that amounts of trans and saturated fats should be minimized in Western diets; however, considerable debate remains regarding optimal amounts of dietary n−9, n−6, ...and n−3 fatty acids.Objective: The objective was to examine the effects of varying n−9, n−6, and longer-chain n−3 fatty acid composition on markers of coronary heart disease (CHD) risk.Design: A randomized, double-blind, 5-period, crossover design was used. Each 4-wk treatment period was separated by 4-wk washout intervals. Volunteers with abdominal obesity consumed each of 5 identical weight-maintaining, fixed-composition diets with one of the following treatment oils (60 g/3000 kcal) in beverages: 1) conventional canola oil (Canola; n−9 rich), 2) high–oleic acid canola oil with docosahexaenoic acid (CanolaDHA; n−9 and n−3 rich), 3) a blend of corn and safflower oil (25:75) (CornSaff; n−6 rich), 4) a blend of flax and safflower oils (60:40) (FlaxSaff; n−6 and short-chain n−3 rich), or 5) high–oleic acid canola oil (CanolaOleic; highest in n−9).Results: One hundred thirty individuals completed the trial. At endpoint, total cholesterol (TC) was lowest after the FlaxSaff phase (P < 0.05 compared with Canola and CanolaDHA) and highest after the CanolaDHA phase (P < 0.05 compared with CornSaff, FlaxSaff, and CanolaOleic). Low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol were highest, and triglycerides were lowest, after CanolaDHA (P < 0.05 compared with the other diets). All diets decreased TC and LDL cholesterol from baseline to treatment endpoint (P < 0.05). CanolaDHA was the only diet that increased HDL cholesterol from baseline (3.5 ± 1.8%; P < 0.05) and produced the greatest reduction in triglycerides (−20.7 ± 3.8%; P < 0.001) and in systolic blood pressure (−3.3 ± 0.8%; P < 0.001) compared with the other diets (P < 0.05). Percentage reductions in Framingham 10-y CHD risk scores (FRS) from baseline were greatest after CanolaDHA (−19.0 ± 3.1%; P < 0.001) than after other treatments (P < 0.05).Conclusion: Consumption of CanolaDHA, a novel DHA-rich canola oil, improves HDL cholesterol, triglycerides, and blood pressure, thereby reducing FRS compared with other oils varying in unsaturated fatty acid composition. This trial was registered at www.clinicaltrials.gov as NCT01351012.
The XO project’s first objective is to find hot Jupiters transiting bright stars (i.e.,
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) by precision differential photometry. Two XO cameras have been operating since 2003 September on the 10,000 foot Haleakala summit on Maui. Each XO camera consists of a 200 mm f/1.8 lens coupled to a
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pixel, thinned CCD operated by drift‐scanning. In its first year of routine operation, XO has observed 6.6% of the sky within six 7° wide strips scanned from 0° to +63° of declination and centered at R.A. = 0, 4, 8, 12, 16, and 20 hr. Autonomously operating, XO records 1 billion pixels per clear night, calibrates them photometrically and astrometrically, performs aperture photometry, archives the pixel data, and transmits the photometric data to the Space Telescope Science Institute for further analysis. From the first year of operation, the resulting database consists of photometry of ∼100,000 stars at more than 1000 epochs per star, with differential photometric precision better than 1% per epoch. Analysis of the light curves of those stars produces transiting‐planet candidates requiring detailed follow‐up, described elsewhere, culminating in spectroscopy to measure radial velocity variation in order to differentiate genuine planets from the more numerous impostors, primarily eclipsing binary and multiple stars.
Precise calorimetric reconstruction of 5–50 MeV electrons in liquid argon time projection chambers (LArTPCs) will enable the study of astrophysical neutrinos in DUNE and could enhance the physics ...reach of oscillation analyses. Liquid argon scintillation light has the potential to improve energy reconstruction for low-energy electrons over charge-based measurements alone. Here we demonstrate light-augmented calorimetry for low-energy electrons in a single-phase LArTPC using a sample of Michel electrons from decays of stopping cosmic muons in the LArIAT experiment at Fermilab. Michel electron energy spectra are reconstructed using both a traditional charge-based approach as well as a more holistic approach that incorporates both charge and light. A maximum-likelihood fitter, using LArIAT's well-tuned simulation, is developed for combining these quantities to achieve optimal energy resolution. A sample of isolated electrons is simulated to better determine the energy resolution expected for astrophysical electron-neutrino charged-current interaction final states. In LArIAT, which has very low wire noise and an average light yield of 18 pe / MeV , an energy resolution of σ / E ≃ 9.3 % / √ E ⊕ 1.3 % is achieved. Samples are then generated with varying wire noise levels and light yields to gauge the impact of light-augmented calorimetry in larger LArTPCs. At a charge-readout signal-to-noise of S / N ≃ 30 , for example, the energy resolution for electrons below 40 MeV is improved by ≈ 10 % , ≈ 20 % , and ≈ 40 % over charge-only calorimetry for average light yields of 10 pe / MeV , 20 pe / MeV , and 100 pe / MeV , respectively.
Piezoelectric tube scanners are employed in high-resolution positioning applications such as scanning probe microscopy and nanofabrication. Much research has proceeded with the aim of reducing ...hysteresis and vibration-the two foremost problems associated with piezoelectric tube scanners. In this paper, two simple techniques are proposed for simultaneously reducing hysteresis and vibration: 1) A new dc accurate charge amplifier is shown to significantly reduce hysteresis while avoiding characteristic voltage drift. 2) Piezoelectric shunt damping, a technique previously resident in the field of smart structures, has been applied to damp tube vibration. By attaching an LCR impedance to a single tube electrode, the first mechanical mode is reduced in magnitude by more than 20 dB.
To examine seasonality and long-term trends in the incidence and prevalence of gout.
A retrospective study (1994-2007) using routinely collected surveillance data from the Royal College of General ...Practitioners Weekly Returns Service sentinel general practice network in England and Wales. New cases and acute attacks of gout per 10,000 population were calculated for age groups 0-44, 45-64, 65-74 and > or =75 years. Long-term trends of annual incidence were assessed by regression analysis. Seasonality indices were calculated using 4-weekly data, and the relative risk of gout incidence during the summer was estimated. Annual prevalence was estimated from the consulting patient population (2001-7) and from prescribing data on defined daily doses (DDD) of allopurinol (2003-7).
The annual incidence rate of new gout cases was stable over the period 1998-2007; acute attacks decreased on average 4% per annum. New gout cases and acute attacks combined into 4-weekly incidence rates peaked during the "summer" period of each year. There was an increased risk of gout diagnosis during summer months (late April to mid-September; odds ratio 1.22, 95% CI 1.18 to 1.26). The annual prevalence of gout in 2001-7 was 0.46%, with highest rates in men > or =75 years (2.57%). Estimated prevalence based on a DDD of 400 mg allopurinol was 0.37%.
The incidence of gout is seasonal. This has implications for the management of patients who currently have gout, and for those who are at risk of future attacks. The decreasing trend in the incidence of acute attacks suggests that patient management is improving.
Acoustic signaling is widespread in bark beetles (Scolytinae), although little is known about the physical characteristics of signals, how they are transmitted, and how they differ among behavioural ...contexts. Signals were studied in the male mountain pine beetle (Dendroctonus ponderosae Hopkins, 1902) during stress, male-female, and male-male interactions. Sounds are broadband with significant energy in the ultrasound (peaks between 15 and 26 kHz) and low amplitude (55 and 47 dB SPL at 2 and 4 cm, respectively), indicating that signaling functions at close range. Signal trains vary among contexts primarily in the proportions of chirp types. Chirps were categorized as being simple or interrupted, with the former having significantly lower tooth strike rates and shorter chirp durations. Stress chirps are predominantly simple with characteristics resembling other insect disturbance signals. Male-female interactions begin with the male producing predominantly interrupted chirps prior to gallery entrance, followed by simple chirps. Male-male (rivalry) chirps are predominantly simple, with evidence of antiphonal calling. Substrate-borne vibrations were detectable with a laser-doppler vibrometer at short distances (1-3 cm), suggesting that sensory organs could be tuned to either air or substrate-borne vibrations. These results have important implications for future research on the function and reception of acoustic signals in bark beetles.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Novel oils high in monounsaturated fatty acids (MUFAs) and low in saturated fatty acids (SFAs) are an alternative to partially hydrogenated oils high in trans-unsaturated fatty acids. There is ...widespread use of high-MUFA oils across the food industry; however, limited knowledge of their cardiovascular impact exists.
We investigated the effects of diets containing canola oil, high-oleic acid canola oil (HOCO), and a control oil blend (diet formulated to emulate a Western fat profile) on lipids, lipoproteins, and apolipoproteins (apos), as secondary outcomes of the trial.
In a multi-center, double-blind, randomized, 3-period crossover, controlled feeding trial, men (n = 44) and women (n = 75) with a mean age of 44 y, mean body mass index (BMI; in kg/m2) of 31.7, and an increased waist circumference plus ≥1 metabolic syndrome criteria consumed prepared, weight-maintenance diets containing canola oil 17.5% MUFAs, 9.2% polyunsaturated fatty acids (PUFAs), 6.6% SFAs, HOCO (19.1% MUFAs, 7.0% PUFAs, 6.4% SFAs), or control oil (10.5% MUFAs, 10.0% PUFAs, 12.3% SFAs) for 6 wk with ≥4-wk washouts. Fasting serum lipids were assessed at baseline and 6 wk. Diet effects were examined using a repeated measures mixed model.
Compared with the control, canola and HOCO diets resulted in lower endpoint total cholesterol (TC; −4.2% and −3.4%; P < 0.0001), LDL cholesterol (−6.6% and −5.6%; P < 0.0001), apoB (−3.7% and −3.4%; P = 0.002), and non-HDL cholesterol (−4.5% and −4.0%; P = 0.001), with no differences between canola diets. The TC:HDL cholesterol and apoB:apoA1 ratios were lower after the HOCO diet than after the control diet (−3.7% and −3.4%, respectively). There were no diet effects on triglyceride, HDL cholesterol, or apoA1 concentrations.
HOCO, with increased MUFAs at the expense of decreased PUFAs, elicited beneficial effects on lipids and lipoproteins comparable to conventional canola oil and consistent with reduced cardiovascular disease risk in adults with central adiposity. This trial was registered at www.clinicaltrials.gov as NCT02029833.
Trypanosoma vivax is one of the causative agents of Animal African Trypanosomosis in cattle, which is endemic in sub-Saharan Africa and transmitted primarily by the bite of the tsetse fly vector. The ...parasite can also be mechanically transmitted, and this has allowed its spread to South America. Diagnostics are limited for this parasite and in farm settings diagnosis is mainly symptom-based. We set out to identify, using a proteomic approach, candidate diagnostic antigens to develop into an easy to use pen-side lateral flow test device. Two related members the invariant surface glycoprotein family, TvY486_0045500 and TvY486_0019690, were selected. Segments of these antigens, lacking N-terminal signal peptides and C-terminal transmembrane domains, were expressed in E. coli. Both were developed into ELISA tests and one of them, TvY486_0045500, was developed into a lateral flow test prototype. The tests were all evaluated blind with 113 randomised serum samples, taken from 37 calves before and after infection with T. vivax or T. congolense. The TvY486_0045500 and TvY486_0019690 ELISA tests gave identical sensitivity and specificity values for T. vivax infection of 94.5% (95% CI, 86.5% to 98.5%) and 88.0% (95% CI, 75.7% to 95.5%), respectively, and the TvY486_0045500 lateral flow test prototype a sensitivity and specificity of 92.0% (95% CI, 83.4% to 97.0%) and 89.8% (95% CI, 77.8% to 96.6%), respectively. These data suggest that recombinant TvY486_0045500 shows promise for the development of a pen-side lateral flow test for the diagnosis of T. vivax animal African trypanosomosis.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The influenza virus continues to pose a significant threat to public health throughout the world. Current avian influenza outbreaks in humans have heightened the need for improved surveillance and ...planning. Despite recent advances in the development of vaccines and antiviral drugs, seasonal epidemics of influenza continue to contribute significantly to general practitioner workloads, emergency hospital admissions, and deaths. In this paper we review data produced by the Royal College of General Practitioners Weekly Returns Service, a sentinel general practice surveillance network that has been in operation for over 40 years in England and Wales. We show a gradually decreasing trend in the incidence of respiratory illness associated with influenza virus infection (influenza-like illness; ILI) over the 40 years and speculate that there are limits to how far an existing virus can drift and yet produce substantial new epidemics. The burden of disease caused by influenza presented to general practitioners varies considerably by age in each winter. In the pandemic winter of 1969/70 persons of working age were most severely affected; in the serious influenza epidemic of 1989/90 children were particularly affected; in the millennium winter (in which the NHS was severely stretched) ILI was almost confined to adults, especially the elderly. Serious confounders from infections due to respiratory syncytial virus are discussed, especially in relation to assessing influenza vaccine effectiveness. Increasing pressure on hospitals during epidemic periods are shown and are attributed to changing patterns of health-care delivery.
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