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51.
Butchart SH Resit Akçakaya H Chanson J Baillie JE Collen B Quader S Turner WR Amin R Stuart SN Hilton-Taylor C 《PloS one》2007,2(1):e140
The Red List Index uses information from the IUCN Red List to track trends in the projected overall extinction risk of sets of species. It has been widely recognised as an important component of the suite of indicators needed to measure progress towards the international target of significantly reducing the rate of biodiversity loss by 2010. However, further application of the RLI (to non-avian taxa in particular) has revealed some shortcomings in the original formula and approach: It performs inappropriately when a value of zero is reached; RLI values are affected by the frequency of assessments; and newly evaluated species may introduce bias. Here we propose a revision to the formula, and recommend how it should be applied in order to overcome these shortcomings. Two additional advantages of the revisions are that assessment errors are not propagated through time, and the overall level extinction risk can be determined as well as trends in this over time. 相似文献
52.
Aycan Akın Elçin Ekdal Yasemin Tuncer Arslanlar Mehmet Ayvacıklı Turgay Karalı Nurdoğan Can 《Luminescence》2015,30(6):830-834
Thermally stimulated luminescence glow curves of CaB4O7:Dy samples after β‐irradiation showed glow peaks at ~335, 530 and 675 K, with a heating rate of 2 K/s. The main peak at 530 K was analyzed using the Tmax–Tstop method and was found to be composed of at least five overlapping glow peaks. A curve‐fitting program was used to perform computerized glow curve deconvolution (CGCD) analysis of the complex peak of the dosimetric material of interest. The kinetic parameters, namely activation energy (E) and frequency factor (s), associated with the main glow peak of CaB4O7:Dy at 520 K were evaluated using peak shape (PS) and isothermal luminescence decay (ILD) methods. In addition, the kinetics was determined to be first order (b =1) by applying the additive dose method. The activation energies and frequency factors obtained using PS and ILD methods are calculated to be 0.72 and 0.72 eV and 8.76 × 105 and 1.44 × 106/s, respectively. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
53.
Summary. Various α/β amino acid derivatives 5 were attached to compounds 3 to yield 2,3-dihydro-1H-pyrrol-3-ones amino acids derivatives 6. This rare heterocyclic amino acid skeleton including the pyrrolo[1,2-b][1,3]oxazol moiety was also successfully prepared
in the esteric form. The structure of the new compounds was characterized by spectroscopic methods. 相似文献
54.
This is the very first report that suggests high pregnancy rates can be obtained with use of the Doublesynch protocol in anestrous dairy cows. Recently, a new synchronization method has been developed (Doublesynch) that resulted in synchronized ovulations both after the first and second gonadotropin-releasing hormone (GnRH) treatments. It was suggested that this protocol has the potential to increase the pregnancy rates in primiparous dairy cows. The aim of the current study was to confirm the success of the Doublesynch protocol and further to investigate the effect of this method on pregnancy rates in anestrous cows. Lactating primiparous Holstein (Bos taurus) cows (n = 165) between 60 and 172 d postpartum were monitored twice with 10-d intervals (on Days -10 and 0) by ultrasonography, and blood samples were collected. Cows were classified as anestrous if both blood samples had progesterone (P4) concentration <1 ng/mL and as cyclic if at least one of the two samples had P4 concentration ≥1 ng/mL. Cyclic cows were classified again as cyclic-high P4 (having an active corpus luteum) if the second blood samples had P4 concentrations ≥1 ng/mL and as cyclic-low P4 if P4 concentrations were <1 ng/mL on Day 0. Then, the cows classified as anestrous (n = 51), cyclic-high P4 (n = 63), or cyclic-low P4 (n = 51) were put into two treatment groups (Ovsynch or Doublesynch) randomly to establish six groups. Cows in the Ovsynch group were administered a GnRH (lecirelin 50 μg, im) on Day 0, PGF (Prostaglandin F2 alpha, D-cloprostenol 0.150 mg, im) on Day 7, and a second dose of GnRH 48 h later. Cows in the Doublesynch group were administered a PGF on Day 0, GnRH on Day 2, a second PGF on Day 9, and a second GnRH on Day 11. Timed artificial insemination (TAI) was performed 16 to 20 h after the second GnRH in both treatment groups. Pregnancy diagnosis was conducted (by ultrasonography) 45 ± 5 d after TAI. In anestrous cows and those with high and low progesterone concentration at treatment onset, Doublesynch treatment led to markedly increased pregnancy rates with respect to Ovsynch treatment (P < 0.05). On the overall analysis of data, it was revealed that the Doublesynch method increased pregnancy rates by 43 percentage units (29.8% vs. 72.8%, P < 0.0001) in relation to Ovsynch. Pregnancy rates of cows having small, medium, or large follicles at the day of second GnRH administration were similar in the Doublesynch group (70.4%, 85.2%, and 63.0%, respectively; P > 0.05), whereas pregnancy rates reduced dramatically as follicle size increased in the Ovsynch group, particularly in cows with follicles greater than 16 mm (45.5%, 28.1%, and 5.3%, respectively; P < 0.05). Our results confirm and support observations that the Doublesynch protocol increases the pregnancy rates in postpartum primiparous cows as reported previously. Our data also demonstrate that the Doublesynch method increases the pregnancy rates in anestrous cows. Thus, these data suggest that the Doublesynch protocol can be used to obtain satisfactory pregnancy rates after TAI in both anestrous and cycling primiparous dairy cows regardless of stage of estrous cycle. 相似文献
55.
Alkaptonuria (ochronosis) is a rare autosomal recessive disorder featuring a genetic error in the amino acid metabolism. A defect in the tyrosine metabolism results in the accumulation and deposition of homogentisic acid in connective tissue, causing a blue-black discolouration. Degenerative arthropathy of the spine, knee, and hip are common signs of ochronosis in older age. An association between ochronosis and depression has not previously been discussed in the literature. This case report describes a 69 year-old woman with diabetes mellitus, ochronosis, depression and chronic pain. 相似文献
56.
In traditional mixotrophic cultures of microalgae, all the inorganic nutrients and organic carbon sources are supplied in the medium before inoculation. In this study, however, an alternative approach was adopted in Haematococcus pluvialis Flotow, a microalga capable of growing mixotrophically on sodium acetate (Na-Ac). First, the cells were grown under 75 micromol photons m-2 s-1 phototrophically without Na-Ac until the stationary phase and then exposed to five different light regimes by the addition of Na-Ac, e.g., dark, 20, 40, 75 and 150 micromol photons m-2 s-1. Dry weight (DW), pigments and especially cell number in alternative mixotrophy (AM) were higher than traditional mixotrophy (TM). Cell number in AM almost doubled up from 21.7 to 42.9 x 104 cells mL-1 during 5 day exposure to Na-Ac, whereas the increase was only 1.2-fold in TM. Maximum cell density was reached in 75 micromol photons m-2 s-1 among the light intensities tested. We propose that Na-Ac in TM of H. pluvialis can not be utilized as efficient as in AM. With this respect, AM is of several advantages against TM such as a much higher cell density in a batch culture period and minimized risk of contamination due to the shorter exposure of cells to organic carbon sources. In consequence, this method may be used for other strains of the species, and even for the other microalgal species able to grow mixotrophically. 相似文献
57.
58.
Anterolateral thigh flap in the treatment of postburn flexion contractures of the knee 总被引:2,自引:0,他引:2
Yildirim S Avci G Akan M Misirlioğlu A Aköz T 《Plastic and reconstructive surgery》2003,111(5):1630-1637
The use of the anterolateral thigh fasciocutaneous flap in the reconstruction of soft-tissue defects around the knee among burn patients is described. The anterolateral thigh fasciocutaneous flap was used for eight patients (all male; mean age, 45 years; age range, 32 to 60 years). Flexion contracture was observed for seven patients with unhealed wounds and one patient with a healed burn wound. The anterolateral thigh flap was used as a free flap for six patients and as a distally based island flap for two patients. The flaps ranged from 8 to 17 cm in width and from 12 to 30 cm in length. Seven flaps were based on a musculocutaneous perforator, and two of them were thinned before transfer to the defect. A true septocutaneous perforator was observed in only one case. The mean follow-up period was 12.5 months (range, 3 to 23 months). Only one flap exhibited distal superficial necrosis, which did not compromise the final result. All patients returned to ambulatory status in 15 to 22 days. Extensor splints were applied to prevent mobilization of the skin graft at the flap donor site for only 7 days. The anterolateral thigh flap has many advantages for the reconstruction of postburn flexion contracture of the knee, as follows: (1) very large thin flaps can be elevated, (2) the two-team approach is possible, (3) color and texture matches are good, (4) the donor-site scar can be easily hidden, and (5) the technique allows early mobilization and patients can return to normal daily activity in a short time. Free or distally based anterolateral thigh flaps are a good choice, both aesthetically and functionally, for the reconstruction of soft-tissue defects of the knee region. 相似文献
59.
60.
We demonstrate the effect of uncertainty (resulting from lack of information or measurement error) on the assessment of human impact, with an analysis of the viability of the northern spotted owl throughout its range in the United States. We developed a spatially-explicit, stage-structured, stochastic metapopulation model of the northern spotted owl throughout its range in the United States. We evaluated the viability of the metapopulation using measures such as risk of decline and time to extinction. We incorporated uncertainty in the form of parameter ranges, and used them to estimate upper and lower bounds on the estimated viability of the species. We analysed the effect of this type of uncertainty on the assessment of human impact by comparing the species' viability under current conditions and under an assumed loss of spotted owl habitat in the next 100 years. The ranges of parameters were quite large and resulted in a wide range of risks of extinction. Despite this uncertainty, the results were sensitive to parameters related to habitat loss: under all assumptions and combinations of parameters, the model predicted that habitat loss results in substantially higher risks of metapopulation decline. This result demonstrated that even with relatively large uncertainties, risk-based model results can be used to assess human impact reliably. 相似文献