Fixed-domain asymptotic properties of tapered maximum likelihood estimators

When the spatial sample size is extremely large, which occurs in many environmental and ecological studies, operations on the large covariance matrix are a numerical challenge. Covariance tapering is a technique to alleviate the numerical challenges. Under the assumption that data are collected along a line in a bounded region, we investigate how the tapering affects the asymptotic efficiency of the maximum likelihood estimator (MLE) for the microergodic parameter in the Mat\'ern covariance function by establishing the fixed-domain asymptotic distribution of the exact MLE and that of the tapered MLE. Our results imply that, under some conditions on the taper, the tapered MLE is asymptotically as efficient as the true MLE for the microergodic parameter in the Mat\'ern model.Comment: Published in at http://dx.doi.org/10.1214/08-AOS676 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Out-of-School Sports Time and Children\u27s Body Weight Status: Evidence From a Longitudinal Study

We used data from the Child Development Supplement (CDS) of the Panel Study of Income Dynamics in 2002 and 2007 to examine the relationship between the specific sport time spent during weekdays or weekends and American children’s body mass index (BMI). Time spent on out-of-school sports was recorded on a randomly selected weekday and a weekend day. Sports were further categorized as formal (organized sports such as sports games or lessons) or casual (any unorganized sports such as sports time in the neighborhood). Child’s height and weight were measured in person by interviewers. Body mass index was used to measure the child’s body weight status. We applied ordinary least square and fixed effects regressions to examine the cross-sectional and longitudinal relationships between out-of-school sports time and children’s body weight status. Children’s socio-demographics and parental socioeconomic status were controlled in the analyses. Double time spent on out-of-school sports during weekdays from 2002 to 2007 was associated with a reduction of BMI by 0.14 units, but the effects of time spent on out-of-school sports during weekends did not achieve statistical significance. For boys and girls, time spent on weekday casual (formal) sports was associated with a reduction of BMI by 0.18 and 0.17 units, respectively. Time spent on out-of-school sports during weekdays was more significant than during weekends in reducing BMI among US children

Pre-cold stress increases acid stress resistance and induces amino acid homeostasis in Lactococcus lactis NZ9000

Purpose: To investigate the effects of pre-cold stress treatments on subsequent acid stress resistance and the viability of Lactococcus lactis during acid fermentation.Methods: Bacterial strains were grown at 4 °C for 2 h pre-adaptation, and then subjected to various stresses including exposure to 4 °C, 1 mM hydrogen peroxide, 5 % sodium chloride, 7 % ethanol, and lactic acid (pH 5.5) to determine if any of these stress treatments could increase acid stress resistance and induce amino acid homeostasis during acid fermentation.Results: Among the different abiotic stresses investigated, pre-adaptation of lag-phase cultures to cold shock significantly enhanced cell survival during subsequent acid stress. The stress profile of L. lactis pre-adapted to cold stress revealed induction of amino acid homeostasis and energy balance; however, pre-adaptation responses are induced upon exposure to acid stress alone. Compared to exposure to acid stress only, pre-adaptation to cold stress decreased the redox balance ratio and the formation of hydroxyl radicals, indicating a change in aerobic respiration and oxidative state of the bacteria.Conclusion: Pre-adaptation to cold stress rescued L. lactis from the deleterious effects of subsequent acid exposure by modifying the amino acid metabolic pathway, leading to an improvement in redox mobility of acid stress response.Keywords: Pre-cold stress, Acis stress resistance, Lactococcus lactis, Redox balance, Amino acid homeostasi

BCL9 enhances the development of cervical carcinoma by deactivating CPEB3/EGFR axis

Purpose: To investigate the differential expression of BCL9 in cervical carcinoma samples, analyze its biological functions in regulating malignant phenotypes of cervical carcinoma cells, and to explore its potential molecular mechanism.Methods: Expression levels of BCL9 in 58 pairs of cervical carcinoma tissues and paracancerous tissues were determined using quantitative real time-polymerase chain reaction (qRT-PCR). Kaplan- Meier curves were used to analyze the prognostic potential of BCL9 in cervical carcinoma. After knockdown using BCL9 by lentivirus transfection, proliferative and migratory changes in Siha and HeLa cells were determined by CCK-8, colony formation and Transwell assays. Cytoplasmic polyadenylation element binding protein 3 (CPEB3), the potential downstream target of BCL9, was confirmed via dualluciferase reporter assay. Western blot analyses were conducted to determine the protein levels of CPEB3, EGFR, AKT and p21 in Siha and HeLa cells with BCL9 knockdown. The co-regulation of BCL9 and CPEB3 on phenotypes of cervical carcinoma cell was investigated.Results: BCL9 was upregulated in cervical carcinoma tissues. The high level of BCL9 was predicted by the tumor size, advanced stage and poor prognosis. The knockdown of BCL9 significantly weakened proliferative and migratory abilities of Siha and HeLa cells (p < 0.05). CPEB3 was the downstream target of BCL9, and was lowly expressed in cervical carcinoma tissues. The knockdown of BCL9 upregulated CPEB3, and downregulated EGFR, AKT and p21 (p < 0.05). The knockdown of CPEB3 also reversed the influence of silenced BCL9 in regulating its proliferative and migratory abilities in cervical carcinoma cells (p < 0.05).Conclusion: BCL9 drives the deterioration of cervical carcinoma by inhibiting the CPEB3/EGFR axis.Thus, BCL9 may be a novel molecular target for cervical carcinoma treatment

Protective Effects of Berberine on Isoproterenol-Induced Acute Myocardial Ischemia in Rats through Regulating HMGB1-TLR4 Axis

Berberine, an isoquinoline alkaloid originally isolated from the Chinese herb Coptis chinensis (Huanglian), has been shown to display a wide array of pharmacological activities. The present study was to investigate the effects of berberine against myocardial ischemia produced in rats by isoproterenol. 50 male Sprague-Dawley rats were randomized equally into five groups: a control group, an untreated model group, berberine (30, 60 mg/kg) treatment, or propranolol (30 mg/kg). Rats were treated for 12 days and then given isoproterenol, 85 mg/kg for 2 consecutive days by subcutaneous injection. ST-segment elevation was measured after the last administration. Serum levels of creatine kinase isoenzyme (CK-MB), lactate dehydrogenase (LDH), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were measured after the rats were sacrificed. The hearts were excised for determining heart weight index, microscopic examination, high mobility group box 1 (HMGB1), toll-like receptor (TLR4), prodeath protein (Bax), antideath protein (Bcl-2), and tumor necrosis factor (TNF-α) protein were determined by western blot. Berberine decreased the ST elevation induced by acute myocardial ischemia, and decreased serum levels of CK-MB, LDH, TNF-α, and IL-6. Berberine increased total superoxide dismutase (T-SOD) activity and decreased malondialdehyde (MDA) content in myocardial tissue. Berberine can regulate HMGB1-TLR4 axis to protect myocardial ischemia

The Effect of Fertilizer on Seed Production of \u3cem\u3eMelilotoides ruthenica\u3c/em\u3e

M. ruthenica is very important legume forage, which has drought resistance, winter-hardness and high protein characteristics, and is thus adaptable wide environmental range, but low seed yield limited its widely extension and utilization. Fertilizer is the necessary nutrition for plant growth and production, Alfalfa production positively correlated with soil content of P and K (Attoe and Troug, 1950), and its seed yield can be increased 20.87%～31.37% by splashing B and Mo during the florescence (Haby and Keonaro, 1998). This study discussed the effect of fertilizer of N, P, K and microelements Mo, B, Cu, Zn on the seed production of M. ruthenic

Influence of Different Phenolic Fractions on Red Wine Astringency Based on Polyphenol/Protein Binding

The presence of phenolic compounds can make a great contribution to the perception of astringency in red wines based on their interactions with proteins. Human salivary protein and bovine serum albumin were used in this study to investigate the relationship between astringency and polyphenol composition.  The interactions between polyphenols and proteins were analysed by means of electrophoresis and fluorescence spectra, and they were further confirmed by sensory analysis. The results indicate that a positive correlation existed among the percentage of polymeric proanthocyanidins and the total phenols.  Additionally, astringent wine was generally identified as having a high percentage of polymeric fragments.  In comparison with other fractions, polymeric fractions exhibited the highest affinity for protein, and thus the highest astringency