Secretion and mammary gland uptake of prolactin in dairy cows during lactogenesis

Mammary arteriovenous differences of prolactin concentration and net mammary uptake of prolactin from blood were quantified near parturition in 9 dairy cows. Six cows were milked once daily for at least 6 d before parturition, and prepartum lactogenesis occurred in 3 of 6 cows. Prepartum milking 2 or more d before parturition abruptly increased secretion of prolactin into blood, but milkings within 1 d before or after parturition did not increase prolactin secretion. Concentrations of prolactin in whole milk sampled over 8 d before parturition (64.5 ng/ml) were substantially greater than those occurring several days after parturition (19 ng/ml). Milk prolactin concentrations were unaffected by the successful induction of prepartum lactogenesis, which greatly increased prepartum yields of milk (2 to 8 kg/milking). Therefore, the alveolar lumenal content of prolactin was greatest in pregnant cows with prepartum lactogenesis. This enhanced content of intraalveolar prolactin before parturition was associated with an absence of mammary uptake of prolactin immediately prior to ejection of the prolactin-containing milk from the alveoli. However, prolactin uptake was quickly restored to about 2 micrograms/min per half udder shortly after milk ejection. During the prepartum period, an enhanced intraalveolar reservoir of 200 to 400 micrograms prolactin, due to induction of prepartum lactogenesis, appears to saturate temporarily all putative sites for uptake of prolactin from blood.     

The way ahead for London's bus priority at traffic signals

London has a long history of successful schemes for bus priority at traffic signals. Recently, transport for London (TfL) has procured a modern automatic vehicle location (AVL) system for bus fleet management, passenger information and bus priority. The new system is known as iBUS and is based on Global Positioning System (GPS) and supporting technologies for bus location. The system eliminates the need for on-street hardware for detecting buses and provides more flexibility and opportunity for using bus detectors. However, bus location based on this system is less accurate than location based on fixed infrastructure (e.g. beacons) and could result in reduced benefits from bus priority. This paper first summarises how bus priority at traffic signals works within iBUS, and then explores the effects of GPS locational errors on bus priority benefits. This is followed by a discussion of opportunities available in the context of iBUS to build an even more efficient and beneficial bus priority system by taking advantage of its cost-effective multiple detection capabilities. The paper is based on various studies carried out by the Transportation Research Group (TRG) at the University of Southampton for TfL.     

Intercomparison of the Realizations of the ITS-90 from 83.8058 K to 692.677 K among European NMIs

The EUROMET.T-K3 comparison is the regional extension of CCT-K3. The comparison involved the six European national metrology institutes (NMIs) previously involved in CCT-K3 (LNE-INM/CNAM, SMU, INRiM, NMi-VSL, NPL, PTB) and 18 additional European national laboratories. The comparison was divided into five different loops, each coordinated by a co-pilot chosen from the laboratories having participated in the CCT-K3 comparison. LNE-INM/CNAM played the role of pilot in linking the five loops. In each loop, an artifact in the form of a standard platinum resistance thermometer (SPRT, 25 Ω) was circulated among the participating laboratories. To have sufficient information about the possible drift of the SPRTs, the co-pilots performed a calibration over the full temperature range at the beginning and at the end of the loop. A EUROMET reference value (ERV), taking into account the whole comparison, was defined, and the differences (T _Lab − T _ERV) were calculated with the associated uncertainties. The method for establishing the link between the participants in CCT-K3 and in EUROMET.T-K3 is described. Institut National de Métrologie (BNM-INM/CNAM at the time of the comparison, LNE-INM/CNAM since 1 January 2005), Paris, France.     

Characterization of source power distributions in multimode fiber by a splice offset technique

Using a splice loss versus transverse offset technique in conjunction with a modal splice loss model, the power distribution created by a number of lasers and LED's in multimode fiber has been determined as a function of mode number. This technique provides a convenient way to characterize sources and to determine the mode power distribution they produce in multimode graded-index fibers.     

Southwest Oil Field Makes Breakthroughs in Natural Gas Exploration

Three structures in Northeast Sichuan 　　A series of breakthroughs have recently been made in natural gas exploration in the northeastern part of Sichuan basin. Dukouhe Gas Field, Luojiazhai gas-beating structure and Tieshan slope gasbearing structure are proven rich in natural gas resources. The main gas reservoir of those structuresFeixianguan oolitic shoal - is likely to become another largescale gas reservoir in Sichuan basin after Carboniferous.……     

The sympathetic nervous system''s role in regulating blood pressurevariability

This article focuses on how sympathetic nerve activity (SNA) contributes to the variability seen in blood pressure. Specifically, it examines the following questions: why do oscillations occur at certain frequencies, why do only certain frequencies of oscillations in SNA induce oscillations in the vasculature, and what may be the functional purpose of these oscillations     

Ipriflavone: an important bone-building isoflavone

Ipriflavone, an isoflavone synthesized from the soy isoflavone daidzein, holds great promise in the prevention and treatment of osteoporosis and other metabolic bone diseases. It has been widely studied in humans and found effective for inhibiting bone resorption and enhancing bone formation, the net result being an increase in bone density and a decrease in fracture rates in osteoporotic women. While ipriflavone appears to enhance estrogen's effect, it does not possess intrinsic estrogenic activity, making it an attractive adjunct or alternative to conventional hormone replacement therapy. Preliminary studies have also found ipriflavone effective in preventing bone loss associated with chronic steroid use, immobility, ovariectomy, renal osteodystrophy, and gonadotrophin hormone-releasing hormone agonists. In addition, it holds promise for the treatment of other metabolic diseases affecting the bones, including Paget's disease of the bone, hyperparathyroidism, and tinnitus caused by otosclerosis.     

The procedure used to assess the long range generation andtransmission resources in the Mid-Continent Area Power Pool

A study was undertaken by the Mid-Continent Area Power Pool to examine future power supply options from a regional perspective. The pool is modeled as a single utility, without regard to particular economic or operating characteristics of any individual utility or group of utilities. Extensive use is made of the generalized benders decomposition algorithm in the EPRI EGEAS computer program to model poolwide optimization of capacity additions. The selected methodology, which offers both computational efficiency and acceptable accuracy for such a large-scale study, is discussed. Finally, an overview of the analysis of results is given     

Cognitive functions and aging in the dog: acquisition of nonspatial visual tasks

Child welfare practice and substance abuse treatment have become overlapping areas for many human service professionals. This article stresses the importance of combining perspectives, calling for the child welfare and alcohol and other drug (AOD) abuse treatment systems to deal with both the mother's recovery and the child's well-being. Changes in attitudes, knowledge, and skills are required on the part of both the child welfare practitioner and the AOD abuse treatment worker.     

试论国有石油批发企业的规模经营

结合当前的实际情况,论述了石油批发企业规模经营的必要性,并对拓展规模经营中应注意的一些问题,提出了看法和意见。