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.
Objective: Deficits in the semantic learning strategy were observed in subjects with amnestic mild cognitive impairment (aMCI) in our previous study. In the present study, we explored the contributions of executive function and brain structure changes to the decline in the semantic learning strategy in aMCI. Methods: A neuropsychological battery was used to test memory and executive function in 96 aMCI subjects and 90 age- and gender-matched healthy controls (HCs). The semantic clustering ratio on the verbal learning test was calculated to evaluate learning strategy. Medial temporal lobe atrophy (MTA) and white matter hyperintensities (WMH) were measured on MRI with the MTA and Fazekas visual rating scales, respectively. Results: Compared to HCs, aMCI subjects had poorer performance in terms of memory, executive function, and the semantic clustering ratio (P < .001). In aMCI subjects, no significant correlation between learning strategy and executive function was observed. aMCI subjects with obvious MTA demonstrated a lower semantic clustering ratio than those without MTA (P < .001). There was no significant difference in the learning strategies between subjects with high-grade WMH and subjects with low-grade WMH. Conclusion: aMCI subjects showed obvious impairment in the semantic learning strategy, which was attributable to MTA but independent of executive dysfunction and subcortical WMH. These findings need to be further validated in large cohorts with biomarkers identified using volumetric brain measurements. (JINS, 2019, 25, 706–717)
The objective of the studies presented in this Research Communication was to investigate the association of single nucleotide polymorphisms present in the MAP4K4 gene with different milk traits in dairy cows. Based on previous QTL fine mapping results on bovine chromosome 11, the MAP4K4 gene was selected as a candidate gene to evaluate its effect on somatic cell count and milk traits in ChineseHolstein cows. Milk production traits including milk yield, fat percentage, and protein percentage of each cow were collected using 305 d lactation records. Association between MAP4K4 genotype and different traits and Somatic Cell Score (SCS) was performed using General Linear Regression Model of R. Two SNPs at exon 18 (c.2061T > G and c.2196T > C) with genotype TT in both SNPs were found significantly higher for somatic SCS. We found the significant effect of exon 18 (c.2061T > G) on protein percentage, milk yield and SCS. We identified SNPs at different location of MAP4K4 gene of the cattle and several of them were significantly associated with the somatic cell score and other different milk traits. Thus, MAP4K4 gene could be a useful candidate gene for selection of dairy cattle against mastitis and the identified polymorphisms might potentially be strong genetic markers.
In this paper we report a large-scale developmental study of early productive vocabulary acquisition by 928 Chinese-speaking children aged between 1;0 and 2;6, using the Early Vocabulary Inventory for Mandarin Chinese (Hao, Shu, Xing & Li, 2008). The results show that: (i) social words, especially words for people, are the predominant type of words in Chinese-speaking children's earliest productive vocabulary; (ii) overall, Chinese-speaking children's vocabulary contains greater proportions of nouns than other word categories, especially at the earliest vocabulary stage; and (iii) verbs tend to appear earlier for Chinese-speaking children as compared with English-speaking children at the same levels of vocabulary development. In addition, our study has identified the underlying variables that influence the age of acquisition of words, specifically, the interplay between the conceptual (imageability) and linguistic properties (word frequency, word length, and grammatical category) that jointly shape the development of Mandarin-speaking children's early vocabulary.
It is well known that extracellular signal-regulated kinase 8 (ERK8) plays pivotal roles in various mitotic events. But its physiological roles in oocyte meiotic maturation remain unclear. In this study, we found that although no specific ERK8 signal was detected in oocyte at the germinal vesicle stage, ERK8 began to migrate to the periphery of chromosomes shortly after germinal vesicle breakdown. At prometaphase I, metaphase I (MI), anaphase I, telophase I, and metaphase II (MII) stages, ERK8 was stably detected at the spindles. By taxol treatment, we clarified that the ERK8 signal was stained on the spindle fibers as well as microtubule asters in MI and MII oocytes. In fertilized eggs, the ERK8 signal was not observed in the two pronuclei stages. At prometaphase, metaphase, and anaphase of the first mitosis, ERK8 was detected on the mitotic spindle. ERK8 knock down by antibody microinjection and specific siRNA caused abnormal spindles, failed chromosome congression, and decreased first polar body extrusion. Taken together, our results suggest that ERK8 plays an important role in spindle organization during mouse oocyte meiotic maturation and early embryo cleavage.
The association of genetic polymorphism of mitochondrial aldehyde dehydrogenase 2 (ALDH2) and Alzheimer's disease (AD) has been controversial and has been investigated only in several small-sample studies. In the present study, we performed a meta-analysis to evaluate the cross-sectional association of ALDH2 variants and AD risk in East Asian populations.
Trials were retrieved through MEDLINE, EMBASE, J-STAGE and the China National Knowledge Internet databases (from January 1, 1994 to November 1, 2010) without any restriction on language. Data were abstracted by a standardized protocol.
We found four studies of 821AD patients and 1380 healthy controls that qualified for the analysis. The variant ALDH2 genotype GA/AA was not associated with increased AD risk (odds ratio (OR) = 1.35; 95% confidence interval (CI) = 0.75-2.42; p = 0.32), even after stratification for the status of apolipoprotein E epsilon 4 allele. However, in the subgroup analyses, the association was significant for men (OR = 1.72; 95% CI = 1.10-2.67; p = 0.02).
This study adds to the evidence that ALDH2 GA/AA genotype increases the risk of AD among East Asian men, although the effect size is moderate.
A new method for the acceleration of MD (molecular dynamics) simulation of ion implantation into crystalline targets is presented, named REACE (Rare Event Algorithm with Cascade Effect). This method can speed up the MD simulation of ion implantation with cascade processes. As a result, the time required to perform a simulation with high precision and dose effect is drastically reduced. And many details producing statistical noise in the simulation are simulated in the REACE and help it to be more reasonable and reliable.
Nanometer-sized intermetallic Mg-Ni and Mg-Cu compound powders were prepared by a physical vapor deposition method (arc discharge) and characterized by means of x-ray diffraction and transmission electron microscopy. Based on an empirical specific heat equation, the effective heat of formation and its temperature dependence were calculated to explain phase formation in nanoscale powders of the binary Mg-Ni and Mg-Cu systems. It is shown that theoretic calculations are in good agreement with the experimental observations.
This paper presents a novel approach, which is based on integrated
(automatic/interactive) knowledge acquisition, to rapidly develop
knowledge-based systems. Linguistic rules compatible with heuristic
expert knowledge are used to construct the knowledge base. A fuzzy
inference mechanism is used to query the knowledge base for problem
solving. Compared with the traditional interview-based knowledge
acquisition, our approach is more flexible and requires a shorter
development cycle. The traditional approach requires several rounds of
interviews (both structured and unstructured). However, our method
involves an optional initial interview, followed by data collection,
automatic rule generation, and an optional final interview/rule
verification process. The effectiveness of our approach is demonstrated
through a benchmark case study and a real-life manufacturing
Growing yellow cattle (Bos taurus, n 30, 1·0–3·5 years old and 75–240 kg) from their native altitude (2000–2800 m) were used to evaluate the effects of altitude, ambient temperature (Ta) and solar radiation on the basal energy metabolism in this large mammal. Fasting heat production (FHP) was measured at altitudes of 2260, 3250 and 4270 m on the Tibetan plateau both in the summer and winter respectively, after a 90 d adaptation period at each experimental site. The gas exchanges of the whole animal were determined continuously for 3 (2260 and 3250 m) or 2 (4270 m) d after a 96 (2260 and 3250 m) or 48 (4270 m) h starvation period, using closed-circuit respiratory masks. Increasing altitude from 2260 to 3250 m at similar Ta in the summer significantly elevated FHP for all animals (P<0·01), and from 3250 to 4270 m for young cattle (P<0·05); increasing altitude from 2260 to 3250 m in the winter also significantly elevated FHP (P<0·05), but the increase was mainly due to the decrease of Ta and the increase in wind speed. No results were obtained at 4270 m in the winter, due to the problems of the animals, adaptating to the altitude. The magnitude of FHP elevation caused by increasing altitude was greater with summer sunshine or winter wind than without them. Increase of Ta from 10·0 to 22·0°C, in the presence of solar radiation, slightly (2260 m) or significantly (3250 and 4270 m, P<0·01) elevated FHP, but slightly reduced it in the absence of solar radiation; decrease of Ta from 0·0 to −30·0°C linearly increased FHP. At 3250 and 4270 m, FHP at the same Ta was higher with summer sunshine or winter wind (3250 m) than without them, but this did not occur at 2260 m. In conclusion, high altitude elevates FHP in yellow cattle in the warm season, and the summer solar radiation and winter wind at high altitude significantly increase metabolic rate. It may be also concluded that the effects of solar radiation on metabolic rate depend on the altitude and the environmental temperature.
Thirty growing yaks Bos grunniens or Poephagus grunniens, 1·0–3·5 years and 50–230kg, from their native altitudes (3000–4000m), were used to study the basal metabolism in this species and to evaluate the effects of high altitude and season on the energy metabolism. Fasting heat production (FHP) was measured at altitudes of 2260, 3250 and 4270m on the Tibetan plateau in both the summer and the winter, after a 90d adaptation period at each experimental site. Gas exchanges of the whole animals were determined continuously for 3d (4–5 times per d, 10–12 min each time) after a 96 h starvation period, using closed-circuit respiratory masks. Increasing altitude at similar ambient temperature (Ta) did not affect (P>0·10) FHP in the summer, but decreased (P<0·05) it at different Ta in the winter. However, the decrease of FHP in the winter was mainly due to the decrease of Ta instead of the increase of altitude. In the summer, the respiratory rate, heart rate and body temperature were unaffected by altitude, except for a decrease (P<0·05) in body temperature at 4270m; in the winter, they were decreased (P<0·05) by increasing altitude. In both seasons, the RER was decreased (P<0·05) by increasing altitude. At all altitudes for all groups, the daily FHP was higher (P<0·05) in the summer (Ta 6–24°C) than in the winter (Ta 0 to -30°C), and the Ta-corrected FHP averaged on 920 kJ/kg body weight0·52 at Ta 8–14°C and on 704 kJ/kg body weight0·52 at Ta -15°C respectively. We conclude that in the yak high altitude has no effect on the energy metabolism, whereas the cold ambient temperature has a significant depressing effect. The results confirm that the yak has an excellent adaptation to both high altitude and extremely cold environments.
Four steers, average body weight 260±15 kg, fitted with portal catheters were used in a 4×4 Latin Square design to evaluate the influence of dietary protein degradability in the rumen on peptide and amino acid fluxes across the gastrointestinal tract. Dietary protein degradability was regulated by using different protein sources and the diets were calculated to contain 130 g CP/kg and 9·62 MJ ME per kg DM. Plasma concentrations of amino acids were analysed before and after acid hydrolysis of samples first subjected to chemical deproteinization and physical ultrafiltration, and peptide amino acids (PAA) were calculated as the difference between total and free amino acids (FAA). Portal blood flow and arterial concentrations of FAA and PAA were not affected by protein degradability or by diet. Venoarterial concentration difference and net portal flux of FAA tended to increase (P < 0·10) with increase of degradable protein intake. Portal-arterial concentration difference (P < 0·05) and net portal flux (P < 0·10) of PAA increased linearly as dietary protein degradability increased. The proportion of PAA in total amino acid (FAA+PAA) net flux was not modified by dietary protein degradability or by diet, and the mean value as a proportion was 0·32. The major PAA absorbed were glutamate, leucine, aspartate and lysine for all diets, accounting in total for 0·50 of PAA flux. The results demonstrate that PAA may contribute significantly to AA flux across the portal-drained viscera (PDV) of steers, and both FAA and PAA net fluxes can be affected by degradable protein intake.
The present experiment was conducted to quantify the net fluxes of both free and peptide amino acids
across the mesenteric and stomach portions of the portal-drained viscera (PDV) of three yak cows
(172·3±18·6 kg, BW) fed a straw-concentrate diet at maintenance level. Yaks had been fitted with
sampling catheters in the portal vein, mesenteric artery and mesenteric vein prior to its convergence
with the gastrosplenic vein. Blood flow was determined by measuring the dilution of para-aminohippurate
(PAH) infused constantly into a distal mesenteric vein. Amino acids in the
deproteinized plasma were analysed before and after acid hydrolysis. The increased amino acids after
acid hydrolysis were considered as peptide-bound amino acids (PAA). The fluxes of free amino acids
(FAA) and PAA across PDV and mesenteric-drained viscera (MDV) were calculated as the product
of venoarterial differences and plasma flow. Flux across the stomach viscera (SDV) was calculated
as the difference between portal and mesenteric fluxes. Portal blood flow was 389 l/h or
2·32 l/h kg BW, of which 37% was contributed by the mesenteric vein. There was net appearance of
a large quantity of PAA across PDV, which accounted for 92% of the total nonprotein amino acid
flux. Net release of PAA and FAA in SDV accounted for 78% and 42% of the net release in PDV,
respectively. These results suggest that in yaks, peptide possibly is the primary form of amino acid
absorption, and that the stomach area probably is the major site of peptide absorption.
By integrating the truncated complex scalar gravitational motion equations for an anelastic, rotating, slightly elliptical Earth, the complex frequency dependent Earth transfer functions are computed directly. Unlike the conventional method, the effects of both oceanic loads and tidal currents are included via outer surface boundary conditions, all of which are expanded to second order in ellipticity. A modified ellipticity profile in second order accuracy for the non-hydrostatic Earth is obtained from Clairaut’s equation and the PREM Earth model by adjusting both the ellipticity of the core-mantle boundary and the global dynamical ellipticity to modern observations. The effects of different Earth models, anelastic models, and ocean models are computed and compared. The atmospheric contributions to prograde annual, retrograde annual and retrograde semiannual nutation are also included as oceanic effects. Finally, a complete new nutation series of more than 340 periods, including in-phase and out-of-phase parts of longitude and obliquity terms, for a more realistic Earth, is obtained and compared with other available nutation series and observations.
Email your librarian or administrator to recommend adding this to your organisation's collection.