Book chapters will be unavailable on Saturday 24th August between 8am-12pm BST. This is for essential maintenance which will provide improved performance going forwards. Please accept our apologies for any inconvenience caused.
To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Experiments are presented on the deformation of free surface induced by water exit of axisymmetric bodies, particular at the moment before body detaching from water. A set of experimental apparatus is designed to provide driving force for the bodies. A high-speed camera is adopted to capture the motion and deformation of the free surface. Bodies of various shapes, including a stretched spheroid, a sphere, a circular cone and a combination of cylinder and circular cone, are lifted out of water with different velocities, by using a straight rod attached on the top of models. It is found that free-surface deformation is affected by the moving velocity a lot. Three wake flow or free-surface spike patterns are generated corresponding to different velocities. When the velocity is larger than a critical velocity, cavitation incepts and bubble is entrapped inside the water spike, which changes the flow pattern and shape of the spike. It is aimed to explore the spike phenomenon of free surface and explain the reasons behind it.
The oriental armyworm, Mythimna separata is an important crop pest in eastern Asia. Nocturnal insects, including nocturnal moths, have phototactic behavior to an artificial light source. Phototactic behavior in insects is species-specific in response to different wavelengths of light sources. Our previous study showed that green (520 nm) light emitting diode (LED) light resulted in a significantly higher phototactic behavior in M. separata moths compared to the other wavelength LED lights. The goal of the present study is to investigate the influence of green light illumination on biological characteristics of different developmental stages in M. separata. Our results revealed that when different developmental stages of M. separata were exposed to the green light illumination in a dark period, several biological characteristics in all developmental stages except for egg stage were positively changed, but those of F1 generation M. separata which are next generation of the adults exposed to the green light did not significantly change compared with the control level. These findings suggest that green light illumination at night (or dark period) has a positive effect on the development and longevity of M. separata.
The combustion instability characteristics in a model dump combustor with an exhaust nozzle were experimentally investigated. The first objective was to understand the effects of operating conditions and geometric conditions on combustion instability. The second objective was to examine more generalised parameters that affect the onset of combustion instability. Three different premixed gases consisting of air and hydrocarbon fuels (C2H4, C2H6, C3H8) were burnt in the dump combustor at various inlet velocity, equivalence ratio and combustion chamber length. Dynamic pressure transducer and photomultiplier tube with a bandpass filter were used to measure pressure fluctuation and CH* chemiluminescence data. Peak frequencies and their maximum power spectral densities of pressure fluctuations at same equivalence ratios showed different trends for each fuel. However, the dynamic combustion characteristics of pressure fluctuations displayed consistent results under similar characteristics chemistry times regardless of the used hydrocarbon fuels. The results showed that characteristic chemistry time and characteristic convection time influenced combustion instabilities. It was found that the convective-acoustic combustion instability could be prevented by increasing the characteristic chemistry time and characteristic convection time.
Latrophilin (LPH) is known as an adhesion G-protein-coupled receptor which involved in multiple physiological processes in organisms. Previous studies showed that lph not only involved the susceptibility to anticholinesterase insecticides but also affected fecundity in Tribolium castaneum. However, its regulatory mechanisms in these biological processes are still not clear. Here, we identified two potential downstream carboxylesterase (cce) genes of Tclph, esterase4 and esterase6, and further characterized their interactions with Tclph. After treatment of T. castaneum larvae with carbofuran or dichlorvos insecticides, the transcript levels of Tcest4 and Tcest6 were significantly induced from 12 to 72 h. RNAi against Tcest4 or Tcest6 led to the higher mortality compared with the controls after the insecticides treatment, suggesting that these two genes play a vital role in detoxification of insecticides in T. castaneum. Furthermore, with insecticides exposure to Tclph knockdown beetles, the expression of Tcest4 was upregulated but Tcest6 was downregulated, indicating that beetles existed a compensatory response against the insecticides. Additionally, RNAi of Tcest6 resulted in 43% reductions in female egg laying and completely inhibited egg hatching, which showed the similar phenotype as that of Tclph knockdown. These results indicated that Tclph affected fecundity by positively regulating Tcest6 expression. Our findings will provide a new insight into the molecular mechanisms of Tclph involved in physiological functions in T. castaneum.
The present study aimed to compare the anti-biofilm activities of four commonly available antiseptic eardrops against biofilms from methicillin-resistant Staphylococcus aureus and quinolone-resistant Pseudomonas aeruginosa in vitro.
The anti-biofilm activities of 50 per cent Burow's solution, vinegar with water (1:1), 2 per cent acetic acid solution, and 4 per cent boric acid solution were evaluated using biofilm assays. Additionally, the anti-biofilm activities of the four antiseptic solutions against tympanostomy tube biofilms were compared using a scanning electron microscope.
The inhibition of biofilm formation from methicillin-resistant S aureus and quinolone-resistant P aeruginosa occurred after treatment with 4 per cent boric acid solution, 2 per cent acetic acid solution, and vinegar with water (1:1). However, 50 per cent Burow's solution did not exhibit effective anti-biofilm activity.
The results indicate that 4 per cent boric acid solution and vinegar with water (1:1) are potent inhibitors of biofilms from methicillin-resistant S aureus and quinolone-resistant P aeruginosa, and provide safe pH levels for avoiding ototoxicity.
The Latino population in the United States is rapidly growing and faces profound health disparities; however, engagement of Latinos in biomedical research remains low. Our community-based participatory research partnership has recruited 2083 Spanish-speaking Latinos into 21 studies over 15 years. We sought to identify and describe the strategies we have used to successfully recruit and retain Spanish-speaking Latinos in research.
We abstracted and analyzed data from archived study notes, progress reports, team meeting minutes, and in-depth interviews conducted annually from community-based participatory research partnership members. We used a nominal group process to refine and prioritize strategies.
Overall, 13 recruitment strategies and 12 retention strategies emerged. These strategies relied on the creativity and perseverance of the study team and partners.
It is essential that we develop and disseminate effective recruitment and retention strategies that engage Latinos in biomedical research to reduce health disparities and promote health equity.
We investigated the clinical predictors of methicillin-resistance and their impact on mortality in 371 patients with Staphylococcus aureus bacteraemia identified from two prospective multi-centre studies. Methicillin resistant S. aureus (MRSA) accounted for 42.2% of community-onset and 74.5% of hospital-onset cases. No significant clinical difference was found between patients infected with MRSA vs. methicillin-sensitive S. aureus (MSSA), except that the former were more likely to have had hospital-onset bacteraemia and received antibiotics in the preceding 90 days. After stratifying according to the acquisition site, prior antibiotic use was the only independent predictor of having MRSA in both community-onset and hospital-onset cases. The frequency of inappropriate empirical antibiotic therapy was higher in patients with MRSA than in those with MSSA bacteraemia. However, methicillin resistance was not a predictor of mortality in patients and the clinical characteristics and outcomes of both MRSA and MSSA bacteraemia were similar. This study indicates that there are no definitive clinical or epidemiological risk factors which could distinguish MRSA from MSSA cases with the exception of the previous use of antibiotics for having MRSA bacteraemia, which emphasises the prudent use of glycopeptide treatment of patients at risk for invasive MRSA infections.
Multiple human immunodeficiency virus (HIV)-1 genotypes in China were first discovered in Yunnan Province before disseminating throughout the country. As the HIV-1 epidemic continues to expand in Yunnan, genetic characteristics and transmitted drug resistance (TDR) should be further investigated among the recently infected population. Among 2828 HIV-positive samples newly reported in the first quarter of 2014, 347 were identified as recent infections with BED-captured enzyme immunoassay (CEIA). Of them, 291 were successfully genotyped and identified as circulating recombinant form (CRF)08_BC (47.4%), unique recombinant forms (URFs) (18.2%), CRF01_AE (15.8%), CRF07_BC (14.4%), subtype C (2.7%), CRF55_01B (0.7%), subtype B (0.3%) and CRF64_BC (0.3%). CRF08_BC and CRF01_AE were the predominant genotypes among heterosexual and homosexual infections, respectively. CRF08_BC, URFs, CRF01_AE and CRF07_BC expanded with higher prevalence in central and eastern Yunnan. The recent common ancestor of CRF01_AE, CRF07_BC and CRF08_BC dated back to 1983.1, 1992.1 and 1989.5, respectively. The effective population sizes (EPS) for CRF01_AE and CRF07_BC increased exponentially during 1991–1999 and 1994–1999, respectively. The EPS for CRF08_BC underwent two exponential growth phases in 1994–1998 and 2001–2002. Lastly, TDR-associated mutations were identified in 1.8% of individuals. These findings not only enhance our understanding of HIV-1 evolution in Yunnan but also have implications for vaccine design and patient management strategies.
Over the last 40 years, many types of population genetic markers have been used to assess the population structure of the pest moth species Helicoverpa armigera. While this species is highly vagile, there is evidence of inter-continental population structure. Here, we examine Z-chromosome molecular markers within and between Chinese and Australian populations. Using 1352 polymorphic sites from 40 Z-linked loci, we compared two Chinese populations of moths separated by 700 km and found virtually no population structure (n = 41 and n = 54, with <1% of variation discriminating between populations). The levels of nucleotide diversity within these populations were consistent with previous estimates from introns in Z-linked genes of Australian samples (π = 0.028 vs. 0.03). Furthermore, all loci surveyed in these Chinese populations showed a skew toward rare variants, with ten loci having a significant Tajima's D statistic, suggesting that this species could have undergone a population expansion. Eight of the 40 loci had been examined in a previous study of Australian moths, of which six revealed very little inter-continental population structure. However, the two markers associated with the Cyp303a1 locus that has previously been proposed to be a target of a selective sweep, exhibited allele structuring between countries. Using a separate dataset of 19 Australian and four Chinese moths, we scanned the molecular variation distributed across the entire Z-chromosome and found distinct blocks of differentiation that include the region containing Cyp303a1. We recommend some of these loci join those associated with insecticide resistance to form a set of genes best suited to analyzing population structure in this global pest.
To observe the five-year efficacy of standardised specific subcutaneous immunotherapy for house dust mite allergy in monosensitised and polysensitised children with persistent allergic rhinitis.
From January 2007 to August 2009, 236 children with persistent allergic rhinitis were divided into 2 groups: 1 group received standardised specific subcutaneous immunotherapy using house dust mite extract; the other received pharmacotherapy with intranasal corticosteroids and oral antihistamines. A total of 193 patients (106 in the immunotherapy group and 87 in the pharmacotherapy group) completed treatment. Scores for symptoms, total medication and quality of life were evaluated.
The subcutaneous immunotherapy group demonstrated a significant reduction in visual analogue scale scores, Rhinoconjunctivitis Quality of Life Questionnaire scores and total medication scores (p < 0.05) compared with the pharmacotherapy group. No significant differences in the visual analogue scale and Rhinoconjunctivitis Quality of Life Questionnaire scores were found between the polysensitised and monosensitised subgroups (p > 0.05). No serious adverse events occurred.
Standardised subcutaneous immunotherapy has long-term efficacy for children with persistent allergic rhinitis. Single-allergen subcutaneous immunotherapy was appropriate for allergic rhinitis caused by multiple allergens, including house dust mites, in the paediatric population.
Nitrogen (N) application and irrigation to winter wheat may decrease leaf temperature and enhance photosynthesis: as a result, more photosynthates will be allocated to the grains, resulting in higher grain yields. To investigate this hypothesis, a 2-year field study was conducted with three levels of N fertilizer application (no fertilizer, N0; 240 kg N/ha, N1; 360 kg N/ha, N2) and two different water regimes (rainfed with no irrigation, R; irrigation at the over-wintering, stem elongation and grain filling stages, W). The results show that both N application and supplemental irrigation significantly increased grain yield with increases in both grain number/m2 and the 1000-grain weight, viz., WN2>WN1>WN0>RN2>RN1>RN0. In addition, application of N under both water regimes significantly increased flag leaf area, above-ground biomass and single stem productivity and decreased leaf temperature, which led to an increase in net photosynthesis rates and ribulose bisphosphate (RuBP) carboxylase activity. Moreover, analysis of the chlorophyll α fluorescence transient showed that N fertilizer application and supplemental irrigation significantly increased electron donor and acceptor performance of the photosystem II reaction centre.
Macrosomia, not only is closely associated with short-term, birth-related problems, but also has long-term consequences for the offspring. We investigated the expression of long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) in the placenta of macrosomia births using a microarray profile. The data showed that 2929 lncRNAs and 4574 mRNAs were upregulated in the placenta of macrosomia births compared with the normal birth weight group (fold change ⩾2.0, P<0.05), and 2127 lncRNAs and 2511 mRNAs were downregulated (fold change ⩾2.0, P<0.05). To detect the function of the differentially expressed lncRNAs and their possible relationship with the differentially expressed mRNAs, we also performed gene ontology analysis and pathway analysis. The results demonstrated that the PI3K-AKT signalling pathway, the mitogen-activated protein kinase (MAPK) signalling pathway, the focal adhesion pathway, the B cell receptor signalling pathway, and the protein processing in endoplasmic reticulum and lysosome pathway were significantly differentially expressed in the macrosomia placenta. Four lncRNAs were randomly chosen from the differentially expressed lncRNAs to validate the microarray data by quantitative polymerase chain reaction (qPCR). The qPCR results were consistent with the microarray data. In conclusion, lncRNAs were significantly differentially expressed in the placenta of macrosomia patients, and may contribute to the pathogenesis of macrosomia.
Hepatitis C virus (HCV) infection is one of the leading causes of death and morbidity associated with liver disease. Risk factors identified for the transmission of HCV include contaminated blood products, intravenous drug use, body piercing, an infected mother at birth, sexual activity, and dental therapy, among others. However, the exact diversity of the HCV genotype and genetic variation among patients with low-risk factors is still unknown. In this study, we briefly described and analysed the genotype distribution and genetic variation of HCV infections with low-risk factors using molecular biology techniques. The results suggested that genotype 1b was predominant, followed by genotypes 2a and 1a. Genetic variations in the 5′ UTR sequences of HCV were identified, including point mutations, deletions, and insertions. The frequency of genetic variations in 1b was higher than in 2a. This study provides considerable value for the prevention and treatment of liver disease caused by HCV among patients with low-risk factors and for the development of HCV diagnostic reagents and vaccines.
Human cystic echinococcosis is a widespread, chronic, endemic, helminthic zoonosis caused by larval tapeworms of the species Echinococcus granulosus. At present, there is no rational and effective therapy for patients with echinococcosis. The present study evaluated whether the combination of alkaloids from Sophora moorcroftiana seeds (SMSa2) and Bacillus Calmette–Guérin (BCG) was effective in the treatment of experimental echinococcosis. After 20 weeks of secondary infection with protoscoleces, mice were randomly allocated to five groups and treated for 6 weeks by daily intragastric administration of albendazole (ABZ, 100 mg/kg), SMSa2 (100 mg/kg), BCG (abdominal subcutaneous injection at 5 × 106 CFU), SMSa2 + BCG (100 mg/kg SMSa2 and 5 × 106 CFU BCG) or normal saline (untreated group), respectively. The results indicated a significant reduction in the weight of hydatid cysts in the SMSa2 + BCG group compared with the untreated, SMSa2 and BCG groups. The rate of inhibition of hydatid cyst growth in the SMSa2 + BCG group (76.1%) was obviously increased compared with that in the SMSa2 (25.7%) and BCG (26.6%) groups, respectively. Compared with the untreated control, the SMSa2 + BCG group showed a non-significant increase in serum interleukin-4 (IL-4). Furthermore, the serum levels of interferon-γ (IFN-γ) between the untreated and SMSa2 + BCG groups were not statistically different. Therefore, the combination of alkaloids from S. moorcroftiana seeds and BCG can reduce cyst burden and is an effective therapeutic regimen against echinococcosis.
Auditory verbal hallucinations (AVHs) are one of the most common and severe symptoms of schizophrenia, but the neuroanatomical abnormalities underlying AVHs are not well understood. The present study aims to investigate whether AVHs are associated with cortical thinning.
Participants were schizophrenia patients from four centers across China, 115 with AVHs and 93 without AVHs, as well as 261 healthy controls. All received 3 T T1-weighted brain scans, and whole brain vertex-wise cortical thickness was compared across groups. Correlations between AVH severity and cortical thickness were also determined.
The left middle part of the middle temporal gyrus (MTG) was significantly thinner in schizophrenia patients with AVHs than in patients without AVHs and healthy controls. Inferences were made using a false discovery rate approach with a threshold at p < 0.05. Left MTG thickness did not differ between patients without AVHs and controls. These results were replicated by a meta-analysis showing them to be consistent across the four centers. Cortical thickness of the left MTG was also found to be inversely correlated with hallucination severity across all schizophrenia patients.
The results of this multi-center study suggest that an abnormally thin left MTG could be involved in the pathogenesis of AVHs in schizophrenia.
The performance of a circulation-control inlet guide vane that makes use of the Coanda effect was studied numerically in a high Mach number turbine cascade. The effect of different shapes (elliptic and circular) of the Coanda surface at the blade trailing edge was investigated by implementing both a Coanda jet and a counter-flow blowing. Under high subsonic flow conditions, with a total blowing ratio of 3% of the mainstream, the circulation control cascade can reach the same performance as the reference stator with a 13.5% reduction in the axial chord length, with minimal increase of the energy loss coefficient. The Coanda surfaces with small curvature are more efficient in entraining the mainstream flow, and they achieve better aerodynamic performance. The wall attachment of the Coanda jet is improved by employing counter-flow blowing, resulting in a slight increase of both the exit flow angle and the expansion ratio. Under supersonic flow conditions at the cascade exit, it is more difficult for the circulation control cascade to reach the appropriate flow turning due to a premature shock wave, which is absent in the original cascade until the very end of the suction surface.
Bacillary dysentery continues to be a major health issue in developing countries and ambient temperature is a possible environmental determinant. However, evidence about the risk of bacillary dysentery attributable to ambient temperature under climate change scenarios is scarce. We examined the attributable fraction (AF) of temperature-related bacillary dysentery in urban and rural Hefei, China during 2006–2012 and projected its shifting pattern under climate change scenarios using a distributed lag non-linear model. The risk of bacillary dysentery increased with the temperature rise above a threshold (18·4 °C), and the temperature effects appeared to be acute. The proportion of bacillary dysentery attributable to hot temperatures was 18·74% (95 empirical confidence interval (eCI): 8·36–27·44%). Apparent difference of AF was observed between urban and rural areas, with AF varying from 26·87% (95% eCI 16·21–36·68%) in urban area to −1·90% (95 eCI −25·03 to 16·05%) in rural area. Under the climate change scenarios alone (1–4 °C rise), the AF from extreme hot temperatures (>31·2 °C) would rise greatly accompanied by the relatively stable AF from moderate hot temperatures (18·4–31·2 °C). If climate change proceeds, urban area may be more likely to suffer from rapidly increasing burden of disease from extreme hot temperatures in the absence of effective mitigation and adaptation strategies.
Extended-spectrum β-lactamase (ESBL) production has been very rare in serotype K1 Klebsiella pneumoniae ST23 strains, which are well-known invasive community strains. Among 92 ESBL-producing strains identified in 218 isolates from nine Asian countries, serotype K1 K. pneumoniae strains were screened. Two ESBL-producing K. pneumoniae isolates from Singapore and Indonesia were determined to be serotype K1 and ST23. Their plasmids, which contain CTX-M-15 genes, are transferable rendering the effective transfer of ESBL resistance plasmids to other organisms.