共查询到20条相似文献,搜索用时 31 毫秒
1.
Capsule Birds preferred stands with a particular density of trees, perhaps to avoid predation, and they selected aspects sheltered from prevailing winds. Aim To describe the nesting habitat and tree selection by crossbills in a restricted pinewood habitat in Scotland. Methods Scots Pines used by nesting crossbills were described and compared with randomly selected pines. Nest aspect was related to wind strength and direction. Results The crossbills selected trees at a density of 50–60 trees/ha. Such stands may be sufficiently dense to provide cover, yet occur at a low enough density to minimize being visited by potential arboreal predators, such as Red Squirrels and Pine Martens. Crossbills tended to nest on lateral branches on the northeast side of crowns. Tree crown development was not asymmetric, so the birds may choose the northeast side to shelter from the prevailing southerly to westerly winds. Conclusion Stands of pines at a low density need to be maintained for the benefit of crossbills. 相似文献
2.
R. Turnbull B.Sc. 《Plant Ecology & Diversity》2013,6(4):353-357
Background: Prescribed burning in peatlands is controversial due to concerns over damage to their ecological functioning, particularly regarding their key genus Sphagnum. However, empirical evidence is scarce.Aims: The aim of the article is to quantify Sphagnum recovery following prescribed burns.Methods: We completed nine fires at a raised bog in Scotland, achieving a range of fire severities by simulating drought in some plots. We measured Sphagnum cover and chlorophyll fluorescence Fv/Fm ratio (an estimate of photosynthetic capacity) up to 36 months post-fire.Results: Cover of dominant Sphagnum capillifolium was similar in unburnt and burnt plots, likely due to its high moisture content which prevented combustion. Burning decreased S. capillifolium Fv/Fm 5 months after fire from 0.67 in unburnt plots to 0.44 in low fire severity plots and 0.24 in higher fire severity (drought) plots. After 22 months, Fv/Fm in burnt plots showed a healthy photosynthetic capacity of 0.76 and no differences between severity treatments. Other Sphagnum species showed similar post-fire recovery though their low overall abundance precluded formal statistical analysis.Conclusions: S. capillifolium is resilient to low–moderate fire severities and the same may be true for a number of other species. This suggests that carefully applied managed burning can be compatible with the conservation of peatland ecosystem function. 相似文献
3.
PurposeThis study evaluated the dose distribution and homogeneity of four different types of intensity-modulated radiotherapy (IMRT) in comparison with standard wedged tangential-beam three-dimensional conformal radiotherapy (3DCRT) of the left breast in patients who had undergone lumpectomy.Materials and methodsFive radiotherapy treatment plans, including 3DCRT, forward-planned IMRT (for-IMRT), inverse IMRT (inv-IMRT), helical tomotherapy (HT) and volumetric-modulated arc therapy (VMAT), were created for 15 consecutive patients.ResultsAll modalities presented similar target coverage. Target max doses were reduced with for-IMRT compared to 3DCRT, and these doses were further reduced with inv-IMRT and HT. HT resulted in the lowest max doses delivered to the heart, left anterior descending artery (LAD), and ipsilateral lung, but had higher mean, max, and low doses delivered to contralateral breast. HT resulted in increased low doses to a large volume of healthy tissue. Compared to other techniques, all inverse-planned modalities significantly improved conformity number; however, VMAT had worse homogeneity. The for-IMRT plan significantly lowered monitor unit (MU) compared to the inverse-planned techniques.ConclusionAll modalities evaluated provide adequate coverage of the whole breast. For-IMRT improves target homogeneity compared with 3DCRT, but to a lesser degree than the inverse-planned inv-IMRT and HT. HT decreases the ipsilateral OAR volumes receiving higher and mean doses with an increase in the volumes receiving low doses, which is known to lead to an increased rate of radiation-induced secondary malignancies. 相似文献
4.
Arnoud B. van den Berg 《Zoology in the Middle East.》2013,59(1):12-15
Abstract A new record of the Grey-headed Woodpecker in north-eastern Turkey shows, together with published results, that the species apparently is distributed in low density over the whole Black Sea region of Turkey. 相似文献
5.
《Endocrine practice》2013,19(1):e17-e20
ObjectiveHypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome is an autosomal dominant disorder caused by a GATA3 gene mutation. Here we report a novel mutation of GATA3 in a patient diagnosed with HDR syndrome at the age of 58 with extensive intracranial calcification.MethodsA 58-year-old Japanese man showed severe hypocalcemia and marked calcification in the basal ganglia, cerebellum, deep white matter, and gray-white junction on computed tomography (CT). The serum intact parathyroid hormone level was relatively low against low serum calcium concentration. The patient had been diagnosed with bilateral sensorineural deafness in childhood and had a family history of hearing disorders. Imaging studies revealed no renal anomalies. The patient was diagnosed with HDR syndrome, and genetic testing was performed.ResultsGenetic analysis of GATA3 showed a novel nonsense mutation at codon 198 (S198X) in exon 3. The S198X mutation leads to a loss of two zinc finger deoxyribonucleic acid (DNA) binding domains and is considered to be responsible for HDR syndrome.ConclusionWe identified a novel nonsense mutation of GATA3 in an adult patient with HDR syndrome who showed extensive intracranial calcification. (Endocr Pract. 2013;19:e17-e20) 相似文献
6.
Wei-Yi Li Wei-Wei Ni Ya-Xi Ye Hai-Lian Fang Xing-Ming Pan Jie-Ling He 《Journal of enzyme inhibition and medicinal chemistry》2013,28(1):404-413
Abstract A urease inhibitor with good in vivo profile is considered as an alternative agent for treating infections caused by urease-producing bacteria such as Helicobacter pylori. Here, we report a series of N-monosubstituted thioureas, which act as effective urease inhibitors with very low cytotoxicity. One compound (b19) was evaluated in detail and shows promising features for further development as an agent to treat H. pylori caused diseases. Excellent values for the inhibition of b19 against both extracted urease and urease in intact cell were observed, which shows IC50 values of 0.16?±?0.05 and 3.86?±?0.10?µM, being 170- and 44-fold more potent than the clinically used drug AHA, respectively. Docking simulations suggested that the monosubstituted thiourea moiety penetrates urea binding site. In addition, b19 is a rapid and reversible urease inhibitor, and displays nM affinity to urease with very slow dissociation (k off=1.60?×?10?3 s?1) from the catalytic domain. 相似文献
7.
ABSTRACTIntroduction: Protein microarray is a powerful tool for both biological study and clinical research. The most useful features of protein microarrays are their miniaturized size (low reagent and sample consumption), high sensitivity and their capability for parallel/high-throughput analysis. The major focus of this review is functional proteome microarray.Areas covered: For proteome microarray, this review will discuss some recently constructed proteome microarrays and new concepts that have been used for constructing proteome microarrays and data interpretation in past few years, such as PAGES, M-NAPPA strategy, VirD technology, and the first protein microarray database. this review will summarize recent proteomic scale applications and address the limitations and future directions of proteome microarray technology.Expert opinion: Proteome microarray is a powerful tool for basic biological and clinical research. It is expected to see improvements in the currently used proteome microarrays and the construction of more proteome microarrays for other species by using traditional strategies or novel concepts. It is anticipated that the maximum number of features on a single microarray and the number of possible applications will be increased, and the information that can be obtained from proteome microarray experiments will more in-depth in the future. 相似文献
8.
ObjectivesTo examine the behaviour and attitudes related to smoking and contraband tobacco products among smokers in two socially deprived areas.DesignCross sectional study with qualitative semistructured interviews, augmented by smokers'' day grid.SettingTwo areas of socioeconomic deprivation in Edinburgh.Participants50 male and 50 female smokers aged 25-40 years randomly selected from general practitioners'' lists from two health centres, each located in an area of deprivation.ResultsMost smokers wanted to quit but felt unable to because of the importance of smoking in their daily routine and their addiction to nicotine. Strategies for maintaining consumption levels in the face of increasing cigarette prices and low income included purchasing contraband cigarettes and tobacco. Vendors were contacted through social networks, family, and friends as well as common knowledge of people and places, particularly pubs where contraband was available. Most users of contraband considered that smugglers were providing a valuable service. Purchasing contraband tobacco was viewed as rational in the face of material hardship. Many smokers criticised the government for its high tobacco taxation and the lack of local services to help them to stop smoking.ConclusionsSmokers in deprived areas perceive a lack of support to help them to stop smoking. Cigarette and tobacco smuggling is therefore viewed positively by low income smokers as a way of dealing with the increasing cost of cigarettes. Smokers in areas of deprivation may thus show little support for tackling smuggling until more action is taken to deal with the material and personal factors that make it difficult for them to quit.
What is already known on this topic
Areas of deprivation have the highest rates of smoking and lowest levels of cessationAround 25-30% of cigarettes consumed in the United Kingdom are contrabandWe know little about the attitudes of smokers in these areas to smuggled cigarettes or whether and how they access themWhat this study adds
In such areas the easy availability of cheap tobacco products through contraband networks works against many smokers'' desire to quitGiven the perceived lack of support to help them to stop smoking, this smuggling network is viewed positively by low income smokers as a way of dealing with the increasing cost of cigarettesSmokers in areas of deprivation may thus show little support for tackling smuggling until more action is taken to address the material and personal factors that make it difficult for them to quit 相似文献9.
Max Seidy Saito André Luiz Lourenço Luiza Rosaria Sousa Dias Antônio Carlos Carreira Freitas Maíra Ingrid Vitorino Magaly Girão Albuquerque 《Journal of enzyme inhibition and medicinal chemistry》2016,31(6):1591-1601
Platelet aggregation is one of the main events involved in vascular thrombus formation. Recently, N′-substituted-phenylmethylene-3-methyl-1,6-diphenyl-1H-pyrazolo[3,4-b]pyridine-4-carbohydrazides were described as antiplatelet derivatives. In this work, we explore the properties of these antiplatelet agents through a series of pharmacological, biochemical and toxicological studies. The antiplatelet activity of each derivative was confirmed as 3a, 3b and 3?h significantly inhibited human platelet aggregation induced by arachidonic acid, with no detectable effect on clotting factors or healthy erythrocytes. Importantly, mice treated with derivative 3a showed a higher survival rate at an in vivo model of pulmonary thromboembolism with a lower bleeding risk in comparison to aspirin. The in silico studies pointed a series of structural parameters related to thromboxane synthase (TXS) inhibition by 3a, which was confirmed by tracking plasma levels of PGE2 and TXB2 through an in vitro enzyme immunoassay. Derivative 3a showed selective TXS inhibition allied with low bleeding risk and increased animal survival, revealing the derivative as a promising candidate for treatment of cardiovascular diseases. 相似文献
10.
11.
Capsule?Wing length and age independently predicted spring arrival timing in a long-distance migratory warbler, but there was no association with mass or tarsus length.Aims?To test a range of biometric features and other measures of fitness for their importance in determining spring arrival patterns in a long-distance migratory landbird, and to investigate why these features may be important.Methods?Fifty-one males with known spring arrival dates were caught and key biometrics were measured at breeding sites across Norfolk, UK, during April and May 2012. Blood samples were also taken in order to consider any effect of infection with blood parasites.Results?Early-arriving males were more likely to be adults and to have longer wings. Mass and tarsus length had no significant relationship with arrival timing. Haemosporidian prevalence was low (~10%) compared to other studies of this species, and so it was not possible to determine the effect of infection on arrival date with confidence.Conclusions?Wing length, rather than other measures that simply measure structural body size, is probably important in arrival timing due to either the advantage it confers by increasing flight efficiency or because it reflects past condition during feather growth. 相似文献
12.
1The decrease of temperatures along an elevation gradient imposes physiological constraints on reptiles that ultimately determine their distribution ranges. Forest patterns are likely to interact with this process, but very few studies have examined their contribution in determining distribution limits.2We examined the role played by thermal physiology and forest cover in determining the elevational ranges of a lizard, Eutropis longicaudata. We integrated this species’ thermal traits in simulating its maximum activity time under different conditions of forest cover and elevation using a NicheMapR model. In addition, we evaluated the influence of winter temperatures on the range limit by examining the simulated soil temperatures at the occurrence sites.3Laboratory experiments showed that E. longicaudata has a high preferred body temperature and low cold tolerance. The model predicts that maximum activity time decreases with elevation and forest cover. Although unforested areas may provide longer active time in all simulated elevations, mountain areas in Taiwan are heavily forested and are predicted to allow only a very short period of activity above 1000 m elevation.4All sightings were indeed located in areas below 1000 m elevation, in which the predicted average soil temperature is above 10 °C in January in cold years.5Our results show that reptile physiological response does respond strongly to the change of microclimate induced by forest cover and elevation. Overall, this suggests that forest cover is a major determinant of some reptiles’ elevational range. 相似文献
13.
Camila B?tto-Menezes Azucena Bardají Giselane dos Santos Campos Silke Fernandes Kara Hanson Flor Ernestina Martínez-Espinosa Clara Menéndez Elisa Sicuri 《PLoS neglected tropical diseases》2016,10(3)
BackgroundInformation on costs associated with malaria in pregnancy (MiP) in low transmission areas where Plasmodium vivax predominates is so far missing. This study estimates health system and patient costs of MiP in the Brazilian Amazon.ConclusionDespite being an area of low risk malaria transmission, MiP is responsible for a significant economic burden in Manaus. Especially when multiple infections are considered, costs associated with P. vivax are higher than costs associated with P. falciparum. The information generated may help health policy decisions for the current control and future elimination of malaria in the area. 相似文献
14.
Background and aimsThis paper is about pollen ecophysiology, anther opening, pollen dispersal and the timing of the male and female phases in Parietaria judaica (Urticaceae).MethodsEcophysiological (effects of different relative humidities (RHs) and osmotic relationships) and cytological methods (stigmatic receptivity, pollen viability, histology and histochemistry) were used to determine pollen and pollination features during the long blooming period of this species.Key resultsPollen is dispersed by rapid uncurling of the filament and anther opening. The filament and anther lack cells with lignified wall thickenings, which are usually responsible for anther opening and ballistic pollen dispersal. Instead, dispersal is the result of the sudden movement of the filament. Pollen is of the partially hydrated type, i.e. with a water content greater than 30% at shedding, and readily loses water, and hence viability, at low RH. Pollen carbohydrate reserves differ with season. Starchless grains germinate quickly and are less subject to water loss. Flowers are protogynous, pollen release occurring only after complete cessation of the female phase within an inflorescence.ConclusionParietaria has partially hydrated pollen which differs from typical pollen of this type because of its reduced size and the absence of callose. Because of its low water content at the time of shedding it survives better at higher RH. Dispersal and pollination are adapted to pollen features. 相似文献
15.
Chen ZF Liu YC Peng Y Hong X Wang HH Zhang MM Liang H 《Journal of biological inorganic chemistry》2012,17(2):247-261
Abstract
Liriodenine, an oxoaporphine alkaloid with anticancer activity isolated from Zanthoxylum nitidum (rutaceous anticancer traditional Chinese medicine), was selected as a bioactive ligand to react with HAuCl4 and NaAuCl4 to afford [LH][AuCl4] (1) and [AuCl3L] (2), respectively (where L is liriodenine). The structures of 1 and 2 were characterized by IR spectroscopy, electrospray ionization mass spectrometry, 1H-NMR spectroscopy, and elemental analysis. The single-crystal X-ray diffraction analysis of 1 revealed that it is an ionic compound consisting of protonated liriodenine cation [LH]+ and [AuCl4]− anion. The spectroscopic analysis showed that 2 is a coordination compound, in which one liriodenine coordinates to gold via its 7-N donor. In aqueous solution, 1 is relatively stable, but 2 undergoes rapid hydrolysis. The in vitro cytotoxicity towards five human tumor cell lines shows that 1 and 2 manifest roughly similar biological behavior and appreciable antiproliferative properties, with IC50 values falling in the 2–16 μM range. The flow-cytometric analysis of 1 and 2 suggests that both compounds induced an S-phase arrest. Compounds 1 and 2 significantly poison topoisomerase I in vitro at low concentration (25 μM or less). DNA binding studies indicate that both 1 and 2 interact with DNA mainly via intercalation between the neighboring base pairs of the DNA double helix. Electrostatic interactions of 1 and 2 with the polyanionic DNA phosphate backbone may reinforce the intercalation because both 1 and 2 are composed of planar cationic species. 相似文献16.
BackgroundOsteoporosis is caused by excessive bone resorption (by osteoclasts) over bone formation (by osteoblasts). Monocytes are important to osteoporosis by serving as progenitors of osteoclasts and produce cytokines for osteoclastogenesis.AimTo identify osteoporosis-related genes, we performed microarray analyses of monocytes using Affymetrix 1.0 ST arrays in 42 (including 16 pre- and 26 postmenopausal) high hip BMD (bone mineral density) vs. 31 (including 15 pre- and 16 postmenopausal) low hip BMD Caucasian female subjects. Here, high vs. low BMD is defined as belonging to top vs. bottom 30% of BMD values in population.MethodDifferential gene expression analysis in high vs. low BMD subjects was conducted in the total cohort as well as pre- and post-menopausal subjects. Focusing on the top differentially expressed genes identified in the total, the pre- and the postmenopausal subjects (with a p <5E-03), we performed replication of the findings in 3 independent datasets of microarray analyses of monocytes (total N = 125).ResultsWe identified (in the 73 subjects) and successfully replicated in all the 3 independent datasets 2 genes, DAXX and PLK3. Interestingly, both genes are apoptosis induction genes and both down-regulated in the low BMD subjects. Moreover, using the top 200 genes identified in the meta-analysis across all of the 4 microarray datasets, GO term enrichment analysis identified a number of terms related to induction of apoptosis, for which the majority of component genes are also down-regulated in the low BMD subjects. Overall, our result may suggest that there might be a decreased apoptosis activity of monocytes in the low BMD subjects.ConclusionOur study for the first time suggested a decreased apoptosis rate (hence an increased survival) of monocytes, an important osteoclastogenic cell, as a novel mechanism for osteoporosis. 相似文献
17.
Haisong Zhang Meng Yu Hailei Zhang Libin Bai Yonggang Wu Sujuan Wang 《Bioscience, biotechnology, and biochemistry》2016,80(8):1451-1458
Curcumin is a potential natural anticancer drug with low oral bioavailability because of poor water solubility. The aqueous solubility of curcumin is enhanced by means of modification with the carbohydrate units. Polymerization of the curcumin-containing monomer with carbohydrate-containing monomer gives the water-soluble glycopolymer bearing curcumin pendant residues. The obtained copolymers (P1 and P2) having desirable water solubility were well-characterized by infrared spectroscopy (IR), nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), UV–Vis absorption spectroscopy, and photoluminescence spectroscopy. The copolymer P2 with a molar ratio of 1:6 (curcumin/carbohydrate) calculated from the proton NMR results exhibits a similar anticancer activity compared to original curcumin, which may serve as a potential chemotherapeutic agent in the field of anticancer medicine. 相似文献
18.
Paleoecologic,temporal, and spatial analysis of early Silurian Reefs of the Chicotte Formation,Anticosti Island,Quebec, Canada 总被引:1,自引:0,他引:1
Summary Reefs of the Lower Silurian Chicotte Formation are the largest and most faunally diverse known on Anticosti Island, Quebec.
They reach up to 25 m in thickness and 250 m in diameter and are present predominantly at two intervals, forming a lower and
upper reef cluster. Remnants of bioherms are represented on the present-day wave-cut terrace as 60 to 100 m diameter, subcircular
erosional depressions known as Philip structures or as outcrop.
The bioherms were relatively low structures, with approximately 3 to 5 m maximum synoptic relief, some of which developed
on hardgrounds and possible paleokarst surfaces of crinoidal wackestone and packstone. Dominant skeletal framework builders
and sediment producers within all of the reefs are laminar to low domical stromatoporoids, colonial cerioid and fasciculate
rugose corals, colonial tabulate corals, and cryptostome bryozoans. Vertical zonation of reef biota is evident within well-exposed
reefs of the lower reef cluster. Three to four stages are recognizable:1) a low-diversity tabulate coral-dominatedpioneering community including large tabulate coral colonies (halysitids and favositids), and few stromatoporoids (clathrodictyids, ecclimadictyids),
fasciculate rugosans, large generally monotypic stalked crinoids, and shelly benthos (brachiopods, few ostracodes and trilobites);2) an intermediate- to high-diversity, mixed tabulate coral-stromatoporoid-dominatedreef-core community;3) a slightly lower diversity stromatoporoid-tabulate coral-dominatedclimax community with laminar coenitids and alveolitids; and,4) in a few localities, a capping, low-diversity tabulatecoral-dominated (alveolitid and coenitid), and stromatoporoid-bearing
community comprising laminar forms.
Amelioration of Early Silurian climates, following Late Ordovician glaciation, allowed gradual reestablishment of extensive
shallow-water reef growth, by mainly new and increasingly diverse genera and species of metazoans. Reef development within
the Chicotte Formation coincided with global, widespread development of latest Llandovery and earliest Wenlock reefs in subtropical
to tropical areas. Chicotte reefs have broad characteristics, in terms of overall biotic composition, vertical successions
recognized, and paleogeographic setting, similar to those of equivalent and slightly younger age from intracratonic settings
in Baltica (Gotland, Sweden and Estonia) and central and northern Laurentia (Midcontinent, U.S.A.; Hudson Bay, Canada; and
North Greenland, Denmark). 相似文献
19.
《Saudi Journal of Biological Sciences》2022,29(1):83-87
BackgroundAnemia in pregnancy is a globally health-related issue, that affects both mothers and their newborn. Anemia during pregnancy across the world involves approximately 38% of the world population. To evaluate the effect of gestational anemia on perinatal outcome in the population. The aim of present study is to evaluate the effect of gestational anemia on perinatal outcome in the population of Hyderabad, Sindh, Pakistan.MethodsA cross-sectional comparative analysis was conducted among pregnant mothers who were listed to give birth at Liaquat University of medical and health sciences Jamshoro/Hyderabad during the period of September 2018 to September 2019. The study population 400 were selected by convenient random sampling, and grouped into 2 on the basis of their Hb levels, with Hb < 11 gm% they were classified as anemic mothers, Hb ≥ 11 gm% were termed as non-anemic mothers, data was collected on the preformed questionnaire, and was analyzed on SPSS 21.ResultsThe prevalence of anemia was 51.5% in in total population out of which, the incidence of normocytic normochromic anemia was highest 52.4 %microcytic hypochromic anemia was found in 19.4%, Overall, extremely low Apgar was found in 53 anemics, and 8 non. anemic mother’s infants, LBW incidence was 47.5 %; in anemic mothers, and 15.4 % in non-anemic group, the term, small for gestational age infants were 14.5% in anemic mothers, and 3.6% in non-anemic mothers, there were 36 preterm births to anemic mothers and 10 in non-anemic mothers. The incidence of caesarian section is 53.3% in anemic mothers compared to 30.9% in non-anemic mothers.ConclusionsAnemia in pregnancy significantly increases risks of low Apgar, LBW, term SGA, preterm birth, and an increase incidence of caesarian section. 相似文献
20.
Three novel copper(II), cobalt(II), and nickel(II) complexes of lapachol (Lap) containing 110-phenanthroline (phen) ligand, [M(Lap)2(phen)] (M=Cu(II), 1, Co(II), 2, and Ni(II), 3), have been synthesized and characterized using, elemental analysis and spectroscopic studies. Their interactions with calf thymus DNA (CT DNA) were investigated using viscosity, thermal denaturation, circular dichorism, fluorescence quenching, and electronic absorption spectroscopy. The DNA cleavage abilities of 1–3 have been studied, where cleavage activity of copper complex 1 is more than the complexes 2 and 3. The in vitro cytotoxic potential of the complexes 1–3 against human cervical carcinoma (HeLa), human liver hepatocellular carcinoma (HepG-2), and human colorectal adenocarcinoma (HT-29) cells indicated their promising antitumor activity with quite low IC50 values in the range of .15–2.41 μM, which are lower than those of cisplatin. 相似文献