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In this study, the thermal deformation of a machine tool structure due to the heat generated during operation was analyzed, and embedded cooling channels were applied to exchange the heat generated during the operation to achieve thermal error suppression. Then, the finite volume method was used to simulate the effect of cooling oil temperature on thermal deformation, and the effect of thermal suppression was experimentally studied using a feed system combined with a cooler to improve the positioning accuracy of the machine tool. In this study, the supply oil temperature in the structural cooling channels was found to significantly affect the position accuracy of the moving table and moving carrier. If the supply oil temperature in the cooling channels is consistent with the operational ambient temperature, the position accuracy of the moving table in the Y direction and the moving carrier in the X and Z directions has the best performance under different feed rates. From the thermal suppression experiments of the embedded cooling channels, the positioning accuracy of the feed system can be improved by approximately 25.5 % during the dynamic feeding process. Furthermore, when the hydrostatic guideway is cooled and dynamic feeding is conducted, positioning accuracy can be improved by up to 47.8 %. The machining accuracy can be improved by approximately 60 % on average by using the embedded cooling channels in this study. Therefore, thermal suppression by the cooling channels in this study can not only effectively improve the positioning accuracy but also enhance machining accuracy, proving that the method is effective for enhancing machine tool accuracy.
The Wisconsin Twin Project comprises multiple longitudinal studies that span infancy to early adulthood. We summarize recent papers that show how twin designs with deep phenotyping, including biological measures, can inform questions about phenotypic structure, etiology, comorbidity, heterogeneity, and gene–environment interplay of temperamental constructs and mental and physical health conditions of children and adolescents. The general framework for investigations begins with rich characterization of early temperament and follows with study of experiences and exposures across childhood and adolescence. Many studies incorporate neuroimaging and hormone assays.
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.
We present a variational optimization method that can identify the most efficient kinematic dynamo in a sphere, where efficiency is based on the value of a magnetic Reynolds number that uses enstrophy to characterize the inductive effects of the fluid flow. In this large-scale optimization, we restrict the flow to be steady and incompressible, and the boundary of the sphere to be no-slip and electrically insulating. We impose these boundary conditions using a Galerkin method in terms of specifically designed vector field bases. We solve iteratively for the flow field and the accompanying magnetic eigenfunction in order to find the minimal critical magnetic Reynolds number
for the onset of a dynamo. Although nonlinear, this iteration procedure converges to a single solution and there is no evidence that this is not a global optimum. We find that
is at least three times lower than that of any published example of a spherical kinematic dynamo generated by steady flows, and our optimal dynamo clearly operates above the theoretical lower bounds for dynamo action. The corresponding optimal flow has a spatially localized helical structure in the centre of the sphere, and the dominant components are invariant under rotation by
This study investigated the flow bifurcations of flows driven by a pressure gradient in a rectangular curved tube. When fluid flows within a curved tube, due to the centrifugal effect, secondary vortices can be induced in the cross section of the tube. The secondary flow states are dependent on the magnitude of the pressure gradient (q) and the aspect ratio (γ). In this study, the continuation method was applied to investigate the flow bifurcations in a curved tube with increasing pressure gradient (1 < q < 6000) and aspect ratio (0.9 < γ < 1.4).
The bifurcation diagrams are composed of solution branches, which are linked by limiting points or bifurcation points. The flow states in a solution branch belong to the same group. The ranges of the flow states and the relationship between the states can also be derived from the bifurcation diagrams. In this study, two types of bifurcation were found, one in the range of 0.9 < γ < 1.17, and another in the range of 1.18 < γ < 1.4. The ranges of stable flow solutions and the distributions of limit and bifurcation points in both pressure gradient and aspect ratio are derived in this study.
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.
Pigs living in commercial husbandry systems may experience both acute stress due to standard management procedures and chronic stress through limitations in their barren housing environment. This might influence their immune status, including antibody responses to neural and danger autoantigens. Levels of natural autoantibody (NAAb)-binding phosphorylcholine-conjugated bovine serum albumin (PC-BSA) and myelin basic protein (MBP) were measured over time in pigs that were kept in environmental enriched v. barren housing, and that underwent a regrouping test. In total, 480 pigs were housed in 80 pens in either barren or straw-enriched pens from 4 through 23 weeks of age. Blood samples were taken from pigs before (week 8), and 3 days after a 24 h regrouping test (week 9), and at 22 weeks of age. Phosphorylcholine-conjugated bovine serum albumin (PC-BSA) and MBP antibody titres in serum were measured using ELISA. Enriched-housed pigs had higher levels of IgM-binding MBP, and tended to have higher levels of IgG-binding MBP and IgA-binding PC-BSA than barren-housed pigs. Each NAAb measured in this study was affected by gender and litter. These results suggest that enriched housing conditions, as well as acute regrouping stress, have an influence on levels of serum NAAb-binding danger and neural antigens in pigs.
A continuation method, accompanied with a linear stability analysis, is employed to investigate the bifurcation diagram of the flow solutions, as well as the multiple flow states in a cavity with different aspect ratios for parallel motion of two facing lids. The Reynolds number proportional to the wall velocity is used as the continuation parameter, and the evolution of the bifurcation diagrams in cases with different aspect ratios is illustrated. The induced flow patterns are highly dependent upon both the aspect ratios and the moving velocity of the walls. Three different types of bifurcation diagrams and their corresponding flow states are classified according to the aspect ratios. One stable symmetric flow state and one stable asymmetric flow state are identified. The stable asymmetric flow state is obtained at a high aspect ratio and a low Reynolds number. Meanwhile, the regions of stable and unstable flows are distinguished according to the different aspect ratios.
Fatty acid synthase (FASN) is known as a crucial enzyme of cellular de novo fatty acid synthesis in mammary gland which has been proved as the main source of short and medium-chain fatty acids of milk. However, the regulatory role of FASN in goat-specific milk fatty acids composition remains unclear. We cloned and analyzed the full-length of FASN gene from the mammary gland of Capra hircus (Xinong Saanen dairy goat) (DQ 915966). Comparative gene expression analysis suggested that FASN is predominantly expressed in fat, small intestine and mammary gland tissues, and expresses higher level at lactation period. Inhibition of FASN activity by different concentrations (0, 5, 15, 25 and 35 μM) of orlistat, a natural inhibitor of FASN, resulted in decreased expression of acetyl-CoA carboxylase α (ACCα), lipoprotein lipase and heart-type fatty acid binding protein (H-FABP) in a concentration-dependent manner in goat mammary gland epithelial cells (GMEC). Similar results were also obtained by silencing of FASN. Additionally, reduction of FASN expression also led to apparent decline of the relative content of decanoic acid (C10:0) and lauric acid (C12:0) in GMEC. Our study provides a direct evidence for inhibition of FASN reduces cellular medium-chain fatty acids synthesis in GMEC.
Flexible electronics and microsystems are an emerging technology with a tremedous impact to the future electronics and information technology and widespread applications. Various devices and microsystems have been developed. Surface acoustic wave (SAW) devices are a type of essential device for electronics, microsensors and microsystems; however there is no activity on the development of flexible SAW devices yet. This paper reports the development of flexible SAW devices on cheap, bendable and disposable plastic films. Flexible SAW devices with resonant frequency of 198.1 MHz and 447 MHz for the Rayleigh and Lamb waves respectively have been obtained with a large transmission signal up to 18dB. The flexible SAW devices have also demonstrated their ability for acoustic streaming with a velocity up to 3.4 cm/s and for particle concentration. The results have clearly demonstrated that the flexible SAW devices have great potential for applications in electronics and microsystems.
We investigated the seasonality of tuberculosis (TB) in Wuhan, China, to evaluate the increased risk of disease transmission during each season and to develop an effective TB control strategy. We applied spectral analysis to the weekly prevalence data of sputum smear positive (SSP) and sputum smear negative (SSN) pulmonary TB reported from 2006 to 2010. Cases of both SSP and SSN feature 1·0- and 0·5-year periodic modes. The least squares method was used to fit curves to the two periodic modes for SSP and SSN data. The curves demonstrated dominant peaks in spring similar to cases reported previously for other locations. Notably for SSP, dominant peaks were also observed in summer. The spring peaks of SSP and SSN were explained in terms of poorly ventilated and humid rooms and vitamin D deficiency. For the summer peaks of SSP, summer influenza epidemics in Wuhan may contribute to the increase in TB prevalence.
We examine prospectively the influence of two separate but potentially inter-related factors in the etiology of post-traumatic stress disorder (PTSD): childhood maltreatment as conferring a susceptibility to the PTSD response to adult trauma and juvenile disorders as precursors of adult PTSD.
The Dunedin Multidisciplinary Health and Development Study (DMHDS) is a birth cohort (n = 1037) from the general population of New Zealand's South Island, with multiple assessments up to age 38 years. DSM-IV PTSD was assessed among participants exposed to trauma at ages 26–38. Complete data were available on 928 participants.
Severe maltreatment in the first decade of life, experienced by 8.5% of the sample, was associated significantly with the risk of PTSD among those exposed to adult trauma [odds ratio (OR) 2.64, 95% confidence interval (CI) 1.16–6.01], compared to no maltreatment. Moderate maltreatment, experienced by 27.2%, was not associated significantly with that risk (OR 1.55, 95% CI 0.85–2.85). However, the two estimates did not differ significantly from one another. Juvenile disorders (ages 11–15), experienced by 35% of the sample, independent of childhood maltreatment, were associated significantly with the risk of PTSD response to adult trauma (OR 2.35, 95% CI 1.32–4.18).
Severe maltreatment is associated with risk of PTSD response to adult trauma, compared to no maltreatment, and juvenile disorders, independent of earlier maltreatment, are associated with that risk. The role of moderate maltreatment remains unresolved. Larger longitudinal studies are needed to assess the impact of moderate maltreatment, experienced by the majority of adult trauma victims with a history of maltreatment.
We present chromospheric activities of late-type stars based on stellar spectrum survey of LAMOST (also called GuoShouJing telescope) in 2010-2013. Using the equivalent widths of the Hα line (larger than 1 Å), we have found 6391 active stars from 99741 M stars.
For the M active catalogue of Guoshoujing Telescope (LAMOST), 933 sources are presented in at least two exposures. We found that many M active stars show chromospheric variability in the Ca II H, Hα, Hβ, and Hγ lines on short or long timescales.
Current agricultural practices rely on crops with developmental phenologies adapted to local climate, photoperiods and soils; however, global climate change will alter some abiotic factors (e.g. temperature and precipitation). Previously adapted varieties may be poorly prepared for these changing conditions, if such conditions induce mismatched phenologies. Crops that depend on cross-pollination and synchronous flowering may be most susceptible, e.g. monoecious plants have separate male and female flowers, and changes in flowering synchrony may alter yield. Using genetically diverse (open-pollinated (OP)) and genetically homogeneous (hybrid) varieties of a monoecious crop, courgette, also known as zuchinni (Cucurbita pepo), phenological responses to experimentally manipulated moisture conditions were explored in an agricultural context. Under drier and wetter conditions, the hybrid courgette plants shifted towards a male-biased floral sex ratio due to the reduced production of female flowers. However, flowering synchrony and fruit production were unaffected by moisture treatment in both varieties. The hybrid and OP varieties differed in many traits related to floral sex ratios, phenology, synchrony and fruit production. Further, the OP variety displayed more phenotypic variation than the hybrid in many traits. Being in a population context rather than relying on self-pollination increased the availability of potential mates for a given female flower in both the hybrid and, particularly, the OP variety. Thus, the increased genetic diversity found in OP v. hybrid varieties may buffer the possible environmental effects on flowering synchrony within a cropping context. Finally, the likelihood of female flowers setting fruit increased with the number of male flowers within a population, and the rate of increase was higher in the hybrid variety. In summary, climate change is predicted to reduce investment in female function in some monoecious crops and genetically diverse varieties may play an important role in maintaining reproductive synchrony in altered environments.
Only a minority of trauma victims (<10%) develops post-traumatic stress disorder (PTSD), suggesting that victims vary in predispositions to the PTSD response to traumas. It is assumed that the influence of predispositions is inversely related to trauma severity: when trauma is extreme predispositions are assumed to play a secondary role. This assumption has not been tested. We estimate the influence of key predispositions on PTSD induced by an extreme trauma – associated with a high percentage of PTSD – (sexual assault), relative to events of lower magnitude (accidents, disaster, and unexpected death of someone close).
The National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) is representative of the adult population of the USA. A total of 34 653 respondents completed the second wave in which lifetime PTSD was assessed. We conducted three series of multinomial logistic regressions, comparing the influence of six predispositions on the PTSD effect of sexual assault with each comparison event. Three pre-existing disorders and three parental history variables were examined.
Predispositions predicted elevated PTSD risk among victims of sexual assault as they did among victims of comparison events. We detected no evidence that the influence of predispositions on PTSD risk was significantly lower when the event was sexual assault, relative to accidents, disasters and unexpected death of someone close.
Important predispositions increase the risk of PTSD following sexual assault as much as they do following accidents, disaster, and unexpected death of someone close. Research on other predispositions and alternative classifications of event severity would be illuminating.
The relationship between recurrent major depression (MD) in women and suicidality is complex. We investigated the extent to which patients who suffered with various forms of suicidal symptomatology can be distinguished from those subjects without such symptoms.
We examined the clinical features of the worst episode in 1970 Han Chinese women with recurrent DSM-IV MD between the ages of 30 and 60 years from across China. Student's t tests, and logistic and multiple logistic regression models were used to determine the association between suicidality and other clinical features of MD.
Suicidal symptomatology is significantly associated with a more severe form of MD, as indexed by both the number of episodes and number of MD symptoms. Patients reporting suicidal thoughts, plans or attempts experienced a significantly greater number of stressful life events. The depressive symptom most strongly associated with lifetime suicide attempt was feelings of worthlessness (odds ratio 4.25, 95% confidence interval 2.9–6.3). Excessive guilt, diminished concentration and impaired decision-making were also significantly associated with a suicide attempt.
This study contributes to the existing literature on risk factors for suicidal symptomatology in depressed women. Identifying specific depressive symptoms and co-morbid psychiatric disorders may help improve the clinical assessment of suicide risk in depressed patients. These findings could be helpful in identifying those who need more intense treatment strategies in order to prevent suicide.