Dry matter intake from parturition to midlactation

Six years of data from the Purina Research Center were summarized to quantitate relationships among DMI, DIM, BW, and 4% FCM. Cows were fed individually and housed in a tie-stall barn from parturition to 21 wk postpartum. Best overall equation predicting DMI was kg DMI = .008037 x kg BW + .3134 x kg 4% FCM + .2286 x DIM - .002176 x (DIM)2 + .00000705 x (DIM)3, R2 = .64, CV percentage = 11.1. Data were best fit when separate equations were developed for each week postpartum up to 6 wk and then for periods including 6 to 8, 9 to 13, and 14 to 20 wk. The commonly used equation, kg DMI = .02 x kg BW + .33 x kg 4% FCM, overestimated DMI until wk 10 but underestimated DMI thereafter. The NRC multifactor DMI estimates could be lower or higher than equations developed up to wk 8, depending on values chosen within range of several factors. At wk 8 and beyond, NRC estimates were lower than equations developed, even when highest level within range of several factors was chosen. Calculated energy balances resulted in greater and extended energy deficit for cows in their second or later lactation compared with first lactation. Loss of BW alone was a poor indicator of energy status in early lactation.     

The importance of oxytocin mechanisms in the control of mouse parturition

The role of oxytocin in parturition in mice was investigated. Pup birth profiles, blood samples and brains were collected from parturient mice observed under red light conditions in a reversed light:dark photoperiod. Peripheral administration of an oxytocin antagonist in a dose-dependent manner delayed the birth of subsequent pups, indicating that oxytocin is required for a normal pup birth profile. Oxytocin neurones were activated during birth as shown by both increased immediate early gene ( Fos) expression in oxytocin neurones in the supraoptic nucleus and increased plasma oxytocin concentrations during birth. In addition, the nucleus of the tractus solitarius and the olfactory bulbs, sites that process inputs to oxytocin neurones, become activated during parturition. Exposure to stress during parturition halted subsequent deliveries; at this stage plasma oxytocin concentrations were not higher than those of virgin mice, and birth was restored by administration of oxytocin. Administration of beta-adrenergic antagonist (propranolol) also restored stress-delayed birth, whereas administration of ritrodrine (beta-agonist) delayed birth in non-stressed mice, indicating that adrenergic mechanisms contribute to stress-delayed births in mice. Administration of morphine (mu-opioid agonist) delayed births transiently, but naloxone (opioid antagonist) did not prevent stress-delayed birth, indicating that endogenous opioids do not appear to contribute to neuroendocrine or uterine mechanisms that promote birth in mice. Therefore, despite evidence in oxytocin knockout mice that oxytocin is not essential for parturition in this species, the results of the present study indicate that oxytocin neurone activity and secretion contribute to the birth process in normal mice.     

A differential autophagic response to hyperglycemia in the developing murine embryo

Autophagy is critical to the process of development because mouse models have shown that lack of autophagy leads to developmental arrest during the pre-implantation stage of embryogenesis. The process of autophagy is regulated through signaling pathways, which respond to the cellular environment. Therefore, any alteration in the environment may lead to the dysregulation of the autophagic process potentially resulting in cell death. Using both in vitro and in vivo models to study autophagy in the pre-implantation murine embryo, we observed that the cells respond to environmental stressors (i.e. hyperglycemic environment) by increasing activation of autophagy in a differential pattern within the embryo. This upregulation is accompanied by an increase in apoptosis, which appears to plateau at high concentrations of glucose. The activation of the autophagic pathway was further confirmed by an increase in GAPDH activity in both in vivo and in vitro hyperglycemic models, which has been linked to autophagy through the activation of the Atg12 gene. Furthermore, this increase in autophagy in response to a hyperglycemic environment was observed as early as the oocyte stage. In conclusion, in this study, we provided evidence for a differential response of elevated activation of autophagy in embryos and oocytes exposed to a hyperglycemic environment.     

Cervical remodeling during pregnancy and parturition: molecular characterization of the softening phase in mice

Cervical remodeling during pregnancy and parturition is a single progressive process that can be loosely divided into four overlapping phases termed softening, ripening, dilation/labor, and post partum repair. Elucidating the molecular mechanisms that facilitate all phases of cervical remodeling is critical for an understanding of parturition and for identifying processes that are misregulated in preterm labor, a significant cause of perinatal morbidity. In the present study, biomechanical measurements indicate that softening was initiated between gestation days 10 and 12 of mouse pregnancy, and in contrast to cervical ripening on day 18, the softened cervix maintains tissue strength. Although preceded by increased collagen solubility, cervical softening is not characterized by significant increases in cell proliferation, tissue hydration or changes in the distribution of inflammatory cells. Gene expression studies reveal a potentially important role of cervical epithelia during softening and ripening in maintenance of an immunomucosal barrier that protects the stromal compartment during matrix remodeling. Expression of two genes involved in repair and protection of the epithelial permeability barrier in the gut (trefoil factor 1) and skin (serine protease inhibitor Kazal type 5) were increased during softening and/or ripening. Another gene whose function remains to be elucidated, purkinje cell protein 4, declines in expression as remodeling progressed. Collectively, these results indicate that cervical softening during pregnancy is a unique phase of the tissue remodeling process characterized by increased collagen solubility, maintenance of tissue strength, and upregulation of genes involved in mucosal protection.     

Estrous synchronization and establishment of pregnancy in bovine embryo transfer recipients

Characteristics of donors, embryos, recipients, and transfer procedures were examined for relationships with establishment of pregnancy. Data were from records of 1202 embryos transferred by the professional staff of a large embryo transfer company. Average pregnancy rate was 74.6%. Variables affecting establishment of pregnancy were service sire, embryo quality, stage of estrous cycle in recipient, quadratic effect of synchrony, and transfer quality. Because the direct or indirect effect of sire must be established at conception, these data demonstrate a latent effect of sire on pregnancy. One would expect the highest pregnancy rate among excellent quality embryos transferred with no delays or complications into recipients that had displayed estrus at the same time or prior to the donor yet were relatively early in their estrous cycles. There also was a tendency for pregnancy rate to decrease with advancing maturity of the embryo.     

Expression and regulation of stanniocalcin 1 and 2 in rat uterus during embryo implantation and decidualization

Stanniocalcin-1 (STC-1) is a recently discovered polypeptide hormone, while stanniocalcin-2 (STC-2) is a subsequently identified homologue of stanniocalcin-1. Although previous studies have shown that both STC-1 and -2 are involved in various physiological processes, such as ion transport, reproduction and development, their expression in the uterus and roles in implantation and early pregnancy are unclear. Here we have investigated the expression and regulation of both STC-1 and STC-2 in rat uterus during early pregnancy under various physiological conditions. We show that only basal levels of STC-1 and STC-2 mRNA were detected in the uterus from day one (D1) to day five (D5) of pregnancy. STC-2 immunostaining was gradually increased in the glandular epithelium from day two (D2), with a peak occurring on D5. High levels of both STC-1 and STC-2 mRNA were observed in the stoma cells at the implantation site on day six (D6) of pregnancy, whereas their immunostaining signals were also significant in the luminal epithelium. Basal levels of both STC-1 and STC-2 mRNA and STC-1 immunostaining were detected in the uterus with delayed implantation. After the delayed implantation was terminated by estrogen treatment, both STC-1 and STC-2 mRNA signals were significantly induced in the stroma underlying the luminal epithelium at the implantation site, and STC-2 immunostaining was also observed in the luminal epithelium surrounding the implanting blastocyst. Embryo transfer experiments further confirmed that STC-1 and STC-2 expression at the implantation sites was induced by the implanting blastocyst. Both STC-1 mRNA and immunostaining were seen in the decidualized cells from day seven (D7) to day nine (D9) of pregnancy. STC-2 mRNA was also found in the whole decidua from D7 to D9 of pregnancy; STC-2 protein, however, was strictly localized to the primary deciduas on D7 and D8, with a weak expression in the whole deciduas on D9. Consistent with the normal pregnancy process, strong STC-1 and STC-2 mRNA signals were detected in the decidualized cells under artificial decidualization, whereas only basal levels of STC-1 mRNA and immunostaining were observed in the control horn. These data suggest, for the first time, that STC-1 together with STC-2 may play important roles in the processes of implantation and decidualization in the rat.     

大豆胚芽油的提取及组成分析

以大豆胚芽出油率为指标,石油醚为脱脂溶剂,通过单因素和正交试验对大豆胚芽索氏提取工艺进行了研究,并用气相色谱对胚芽油的脂肪酸组成进行了分析。结果表明,大豆胚芽制油的最佳提取工艺为:粒度30目、料液比1:12、回流时间5h,在此条件下,大豆胚芽出油率为10.50%,其主要组成为亚麻酸20.73%、亚油酸52.21%、油酸10.51%、棕榈酸为13.47%。     

Efficacy of timed embryo transfer with fresh and frozen in vitro produced embryos to increase pregnancy rates in heat-stressed dairy cattle

Our objective was to determine whether pregnancy rates in heat-stressed dairy cattle could be enhanced by timed embryo transfer of fresh (nonfrozen) or frozen-thawed in vitro-derived embryos compared to timed insemination. Ovulation in Holstein cows was synchronized by a GnRH injection followed 7 d later by PGF2 alpha and a second treatment with GnRH 48 h later. Control cows (n = 129) were inseminated 16 h (d 0) after the second GnRH injection. On d 7, a fresh (n = 133) or frozen-thawed (n = 142) in vitro-derived embryo was transferred to cows assigned for timed embryo transfer after categorizing the corpus luteum by palpation per rectum as 3 (excellent), 2 (good or fair), 1 (poor), and 0 (nonpalpable). Response to the synchronization treatment, determined by plasma progesterone concentration (ng/ml) < or = 1.5 on d 0 and > or = 2.0 on d 7, was 76.2%. Mean plasma progesterone concentration on d 7 increased as the quality of corpus luteum improved from category 0 to 3. Concentrations of progesterone in plasma were elevated (> or = 2.0 ng/ml) at 21 d in 64.7 (fresh embryo), 40.3 (frozen embryo), and 41.4 +/- 0.1% (timed insemination) of cows, respectively. Cows that received a fresh embryo had a greater pregnancy rate at 45 to 52 d than did cows that received a frozen-thawed embryo or timed insemination (14.3 > 4.8, 4.9 +/- 2.3%). Body condition (d 0) of cows influenced the pregnancy rate and plasma progesterone concentrations. In summary, timed embryo transfer with fresh in vitro-produced embryos in heat-stressed dairy cattle improved pregnancy rate relative to timed insemination.     

Effect of a single dose of ibuprofen lysinate before embryo transfer on pregnancy rates in cows

Embryo implantation is a critical step in both cows and humans. The use of ibuprofen lysinate to enhance implantation has been investigated in cattle with the specific aim of improving pregnancy rates after embryo transfer. In this study, heifers (n = 100) were assigned randomly to one of two groups: one group was treated i.m. with 5 mg ibuprofen lysinate kg(-1) body weight 1 h before embryo transfer and a control group received vehicle only. A single embryo was transferred into each recipient cow. There was a significant difference in the number of pregnancies after embryo transfer between cows in the treated (41 of 50; 82%) and control (28 of 50; 56%) groups (P < 0.05). These data indicate that ibuprofen lysinate may be an effective adjunctive treatment for assisted reproduction in cattle. Further studies are needed to clarify whether this effect is associated with the reduction of cyclooxygenase enzyme isoforms during embryo transfer or whether other mechanisms are involved.     

完全多部图的拉普拉斯特征多项式

研究拉普拉斯整图的存在性问题.用A(G)表示有n个顶点的简单图G的邻接矩阵,D(G)表示图G的顶点度对角矩阵.图G的拉普拉斯矩阵为L(G)=D(G)-A(G).通过研究完全多部图Kp1,p2,…,pr的拉普拉斯特征多项式,得到了所有的完全多部图Kp1,p2.…pr都是拉普拉斯整图.     

Activity of lysosomal enzymes in murine mammary tissue through pregnancy, lactation, and involution

Murine mammary tissue homogenates obtained during pregnancy, lactation, and involution were assayed for activities of two lysosomal marker enzymes, acid phosphatase, and N-acetyl-beta-D-glucosaminidase. Acid phosphatase activity per milligram protein was relatively constant through pregnancy and lactation, although a decrease was detected at parturition. Acid phosphatase activity per milligram deoxyribonucleic acid was also stable through pregnancy and lactation except for a peak of activity during lactogenesis. Acid phosphatase activity per gram wet weight also remained stable during pregnancy and lactation, but activity was significantly higher during lactation than pregnancy. Glucosaminidase activity, whether expressed as milligrams deoxyribonucleic acid of milligrams protein, tended to decrease during pregnancy, decreased further with lactogenesis, and remained significantly lower throughout lactation. Glucosaminidase activity per gram wet weight increased as pregnancy progressed and slowly decreased through lactogenesis to midpregnancy levels, which remained stable throughout the remainder of lactation. Both acid phosphatase and glucosaminidase activities were slightly higher at the end of lactation, and both decreased within 24 h of weaning. Significant increases in activities of both enzymes were observed from d 1 to 4 of involution.     

羊绒散纤维染色小样及成品颜色的控制

由于染色后的散纤维经过纺纱颜色会发生变化,散纤维染色颜色控制成为生产中的难题。实践中通过对羊绒散纤维从小样→大样→纱线→成品各个环节颜色变化的分析研究,总结出颜色控制的一般规律。     

模糊控制在电子送经中的应用

在电子送经控制中，采用张力传感器检测经纱总张力，但由于开口、松经、送经的影响，经纱张力受到周期性的外界扰动影响，经典的PID调节器不能胜任。模糊控制理论已经很成熟，但在应用中往往受到软硬件平台的制约。德国KEB公司的COMBIVERT F5系列伺服驱动器通过可编程面板方式开放了内部编程接口平台，使得我们可以很方便地用C语言编程完成对张力信号的离散采样与控制，保证送经精度并使经纱保持恒定的张力，并已成功应用在喷气织机上。     

印刷企业精益成本管理的有效途径（上）

一个企业是否具备优势竞争力的显著特征,最终取决于企业在多大程度上能够对相对成本和收入有所作为。近年来,由于各种原辅材料成本上涨,劳动力成本增加以及国家政策调整导致的企业成本上升,印刷企业在价格战的尽头,控制成本的水平已成为衡量企业是否具有竞争优势的重要标准。精益成本管理有效地降低成本,在企业经营战略中已处于核心地位,从根本上决定着企业竞争力的强弱。     

Dynamic changes in leptin distribution in the progression from ovum to blastocyst of the pre-implantation mouse embryo

The hormone leptin, which is primarily produced by adipose tissue, is a critical permissive factor for multiple reproductive events in the mouse, including implantation. In the CD1 strain, maternally derived leptin from the oocyte becomes differentially distributed among the blastomeres of pre-implantation embryos to create a polarized pattern, a feature consistent with a model of development in which blastomeres are biased toward a particular fate as early as the two-cell stage. In this study, we have confirmed that embryonic leptin is of maternal origin and re-examined leptin distribution in two distinct strains in which embryos were derived after either normal ovulation or superovulation. A polarized pattern of leptin distribution was found in the majority of both CD1 and CF1 embryos (79.1 and 76.9% respectively) collected following superovulation but was reduced, particularly in CF1 embryos (29.8%; P<0.0001), after natural ovulation. The difference in leptin asymmetries in the CF1 strain arose between ovulation and the first cleavage division and was not affected by removal of the zona pellucida. The presence or absence of leptin polarization was not linked to differences in the ability of embryos to normally develop to blastocyst. In the early blastocyst, leptin was confined subcortically to trophectoderm, but on blastocoel expansion, it was lost from the cells. Throughout development, leptin co-localized with LRP2, a multi-ligand transport protein, and its patterning resembled that noted for the maternal-effect proteins OOEP, NLRP5, and PADI6, suggesting that it is a component of the subcortical maternal complex with as yet unknown significance in pre-implantation development.     

米胚日式米果的研制

利用丰富的稻谷加工副产物米胚芽研究米胚日式米果的生产工艺。利用糠片、胚芽和碎米之间比重和在空气中流化速度的不同,采用前后2个方向上倾斜振动筛振动分级和吹风风选相结合的办法,从糠粞中提取大米胚芽。以植酸降解率为指标,设计4因素3水平正交试验,优化米胚中植酸酶解条件。通过单因素试验确定浸米工艺和制粉工艺,进而确定米胚日式米果的生产工艺。     

A method to guide community planning and evaluation efforts in tobacco control using data on smoking during pregnancy

Background: Effective community based tobacco control programmes are critical for state and nationwide impact. However, there is little discussion in the literature of methods for setting local objectives which use locally collected data and account for historical variation in progress.

Objectives: To develop and illustrate a method that uses locally available birth certificate data to model trends in tobacco use during pregnancy among women giving birth, predict future prevalence, and use predictions to set community specific tobacco control objectives.

Data source: Vital statistics. Wisconsin standard birth certificates, 1990–2000, which record the smoking status of the mother during pregnancy.

Data analysis: Trends in the prevalence of smoking during pregnancy in Wisconsin statewide and in all counties (n = 72) were modelled using linear regression of log prevalence on year. Model fit was assessed using R². Regression slopes, indicating estimated relative annual percentage change in prevalence, were used to predict prevalence in 2005, and objectives were calculated as a 20% reduction from the predicted prevalence in 2005.

Conclusions: Modelling trends in the prevalence of smoking using locally collected data enables communities to set reasonable future tobacco control objectives that account for historical trends in progress.