Effects of Bull Exposure and Gonadotropin Releasing Hormone on Postpartum Interval and Fertility in Beef Cowsa

Spring calving beef cows were utilized in a study to determine the effects of bull exposure (BE) and Gonadotropin Releasing Hormone (GnRH) administration on return to estrus and reproductive efficiency. Cows were either exposed to an epididectomized bull soon after calving until the breeding season or not exposed to bulls (NE). All cows were synchronized with Synchro-Mate B (SMB). One-half of the BE and NE cows were implanted with GnRH at SMB implant removal in 1987 or given an injection of GnRH at breeding in 1988. Each year, 20 cows were bled hourly for 80 consecutive hours after SMB removal. There was no difference (P\u3e.05) in days from calving to first estrus, calving date, number of cows cycling before breeding or conception rate to the synchronized estrus between BE or NE cow groups. In 1987 GnRH implants reduced (P\u3c.05) the time from SMB removal to the pre-ovulatory LH peak by 23.5 hours. However, there was no difference (P\u3e.05) in LH peak levels, duration of Luteinizing Hormone (LH) peak or conception rate. Bull exposure and GnRH implants had little effect on the interval from calving to first estrus or reproductive performance

Effects of Bull Exposure on Post-partum Interval and Reproductive Performance in Beef Cows

Spring calving beef cows were utilized to study the effect of bull exposure early postpartum on return to estrus and fertility. In the spring of 1985 and 1986, cows were randomly exposed to epididectomized bulls 3 to 7 days after calving until beginning of the breeding season or not exposed to bulls. Cows were observed for estrus twice daily beginning approximately 4 weeks after the start of calving until synchronization. I n 1986, blood samples were collected weekly by jugular venipuncture during heat detection and serum progesterone concentrations were determined. ALL cows were synchronized with Synchro-Mate B and inseminated 48 hours after implant removal. Calves were removed for 48 hours following implant removal. Each year a group of cows was selected from the two treatment groups and cannulated at estrus following Synchro-Mate B implant removal. Blood samples were collected at 15-minute intervals for 2 hours and every 2 hours for 46 hours for determination of luteinizing hormone concentration. Bull exposed cows had a shorter (Pa.09) interval to first estrus in 1985 and there was no difference (P\u3e.05) in 1986. The percentage exhibiting estrus prior to synchronization was greater (P\u3e.01) for bull exposed than nonexposed in 1985 and there was no difference (P\u3e.05) in 1986. There was no difference (P\u3e.05) in conception rates to the timed insemination in 1985 and 1986 and the total percentage pregnant did not differ (P\u3e.05) in either year. Bull exposure may reduce the interval from calving to first estrus and increase the percentage cycling prior to breeding, but conception rates are not influenced

Runway paving: taking a different approach

Hot Mix Asphalt (HMA) paving of airport runways mostly requires multiple paving teams, multiple pavers, and a wide array of other equipment. The runway paving projects are typically renowned for the logistical effort and the tight margins for overruns, often requiring a relatively large part of the contractor’s resources. Due to the nature of airport operations the projects are of a fast-track nature and planned meticulously. The large-scale nature of the projects raise the attention of the media and contractors often use them as showcases. Although their project characteristics are well known and often appeal to the imagination, the projects have little attention in scientific journals from a process and operations management perspective. We present research ideas on operational matters, process and quality control issues relevant for runway HMA paving construction. It builds on our research experience in the area of highway asphalt paving. We describe the current state of the asphalt paving process and provide a brief overview of the sparse publications in the area. Based on a limited oral inquiry amongst Dutch experts – we present a first list of issues typical for runway asphalt paving operations. We hone in on variability encountered during HMA paving operations and operational strategies necessary for consistent paving and compaction. Lastly, we present technologies and approaches to improve the operational control and subsequent quality consistency during runway HMA paving operations

Monitoring Hot Mix Asphalt Temperature to Improve Homogeneity and Pavement Quality

This paper describes how controlled compaction practices lead to better quality asphalt. Therefore, it is important that during compaction operations the mixture is at a suitable temperature in order to achieve the specified degree of compaction. The University of Twente’s Asphalt Paving Research and Innovation unit’s main aim is to professionalize the road construction industry. One of the focus research issues is developing a deeper understanding of the Hot Mix Asphalt (HMA) cooling process and the variation in the mix temperature during compaction and laydown operations. Temperature measurement has become easier over the last decade due to the development of new infrared cameras, line scanners and sensors. The authors used this new technology to study asphalt temperature characteristics on test sections constructed in 2007 and 2008. It provided several insights into the cooling and variation in temperature of some asphalt mixtures used in The Netherlands. This paper presents and discusses the temperature measuring equipment used and the techniques applied to analyze and visualize the temperature data. The trials show that asphalt surface temperature is a good indicator of temperature homogeneity and process control. Also, that contractors will pay more attention to enhanced integration of HMA temperature as operational parameter in the compaction process given that the measurement technology is now easily within their reach. In the future, the authors expect a revival of research into cooling processes of HMA

Space Saving by Dynamic Algebraization

Dynamic programming is widely used for exact computations based on tree decompositions of graphs. However, the space complexity is usually exponential in the treewidth. We study the problem of designing efficient dynamic programming algorithm based on tree decompositions in polynomial space. We show how to construct a tree decomposition and extend the algebraic techniques of Lokshtanov and Nederlof such that the dynamic programming algorithm runs in time $O^*(2^h)$, where $h$ is the maximum number of vertices in the union of bags on the root to leaf paths on a given tree decomposition, which is a parameter closely related to the tree-depth of a graph. We apply our algorithm to the problem of counting perfect matchings on grids and show that it outperforms other polynomial-space solutions. We also apply the algorithm to other set covering and partitioning problems.Comment: 14 pages, 1 figur

Effects of Anabolic Implants on Reproductive Function, Carcass Characteristics and Performance in Postweaned Beef Bulls

Angus bulls averaging 620 lb were used to study the effects of implants on performance, carcass characteristics and reproductive parameters of intact males. Sixty-six bulls were randomly assigned to four treatments. These treatments were (1) nonimplanted, (2) implanted with 36 mg of Ralgro every 60 t o 70 days, (3) implanted with 220 mg of Synovex-S every 60 t o 70 days, (4) implanted with 24 mg of Compudose every 180 days. Body weights were taken a t the initiation of the trial and every 28 days. Blood samples were collected v i a jugular venipuncture weekly for 9 weeks and then monthly for 4 months with the f i n a l sample taken a t slaughter. Blood was evaluated f o r testosterone, luteinizing hormone and growth hormone levels . Bulls were on test 217 days. Final average weight and hip height were 1142 lb and 49.6 in ., respectively. Nonimplanted bulls had the largest final scrotal circumference of 39.6 cm compared to 38.8 cm for Ralgro-, 38.6 cm for Compudose- and 37.8 cm for Synovex-implanted bulls. Implanting postweaning had little effect on average daily gain, hip height, testicular weight, testosterone, luteinizing hormone levels and sperm chromatin structure. Synovex implanted bulls had the highest growth hormone levels. Compudose- and Synovex-implanted bulls had the heaviest (PC .01) carcass weights and dressing percentage. Also, the Synovex-implanted bulls had the greatest (P\u3c.01) fat thickness at the 12th rib and least desirable yield grade. No difference was present for longissimus muscle, and KPH fat

Pulmonary intralobar sequestration

Two cases of pulmonary intralobar sequestration are presented, with aortography and selective arteriography. These examinations are prerequisites for the diagnosis and management of a patient with suspected sequestration. There should be a high degree of suspicion in a case of a persistent left lower-lobe tumour.S. Afr. Med. J., 48, 171 (1974)

Professionalisering van de wegenbouw – Het effect van de verdichtingstemperatuur op kwaliteitsparameters en de consequenties voor wegenbouwprocessen

Als respons op velerlei veranderingen in de wegenbouw is het netwerk ASPARi gericht op de professionalisering van de sector. In ASPARi-verband is bij Ooms Nederland Holding bv onderzoek verricht naar het effect van de temperatuur waarbij een asfaltmengsel verdicht wordt op de uiteindelijk functionele mechanische eigenschappen. Deze relatie is van belang voor het ‘verdichtingsvenster’: De temperaturen waarbinnen idealiter de verdichting plaatsvindt. Dat de temperatuur van het asfaltmengsel en de verdichtingsprocedure belangrijk zijn voor de eindkwaliteit van de asfaltverharding is al langer algemeen bekend. Traditioneel wordt zo’n verdichtingvenster gebaseerd op de viscositeit in een temperatuurbereik en de dichtheid die bij een gegeven viscositeit behaald kan worden. De uitkomsten van dit onderzoek laten zien dat het verstandig is om te werken met verdichtingsvensters en deze te bepalen aan de hand van beoogde mechanische \ud eigenschappen van de asfaltverharding. Verder blijkt dat de temperatuur waarop een asfaltmengsel verdicht wordt, sterk van belang is voor de eindkwaliteit van de asfaltverharding. Verdichten buiten het temperatuurvenster kan een vermindering van de eindkwaliteit tot gevolg hebben, en dus levensduurverkorting. Een kortere levensduur en eerdere schades aan het wegdek leiden tot reparatie, extra kosten, verminderde beschikbaarheid en mogelijk discussie over de garantie en dus financiële afrekening van het werk. Daarom wordt in deze paper voorgesteld het klassieke principe aan te scherpen. Hierbij wordt voorgesteld het verdichtingsvenster niet alleen aan de hand van de \ud streefdichtheid vast te stellen, maar ook aan de hand van de beoogde mechanische eigenschappen die uiteindelijk behaald moeten worden. In lijn daarmee zijn vervolgstappen richting professionalisering wenselijk en noodzakelijk om de eindkwaliteit verder te kunnen verbeteren en om tijdens het proces tijdig te kunnen bijsturen. Deze paper geeft daartoe aanleiding en aanwijzingen.\u

An Ensemble Kalman-Particle Predictor-Corrector Filter for Non-Gaussian Data Assimilation

An Ensemble Kalman Filter (EnKF, the predictor) is used make a large change in the state, followed by a Particle Filer (PF, the corrector) which assigns importance weights to describe non-Gaussian distribution. The weights are obtained by nonparametric density estimation. It is demonstrated on several numerical examples that the new predictor-corrector filter combines the advantages of the EnKF and the PF and that it is suitable for high dimensional states which are discretizations of solutions of partial differential equations.Comment: ICCS 2009, to appear; 9 pages; minor edit