Effect of sodium bicarbonate and calcium magnesium carbonate supplementation on milk production of high producing Holstein cows

Sodium discharge from dairies in California has been identified as an important contributor to soil and water pollution. The Waste Discharge Requirements General Order For Existing Milk Cow Dairies (2007) aims to minimize the amount of fixed solids, including Na, that are discharged from dairies, aiming to maximise the useable lifespan of water resources. As sodium bicarbonate (SB) contains 270 g/kg Na, SB supplementation can substantially increase Na discharge from dairies. The aim of this study was to determine the effects of SB and a potentially alternative buffer that does not contribute to Na discharge and related negative impacts on soil and water quality, (i.e., calcium magnesium carbonate (CMC)), on the performance of high producing California dairy cows. This could help establish if CMC could substitute for SB while maintaining potential benefits of SB. It is well known that SB is a rumen buffer, but research indicates that its benefits are limited mainly to corn silage-based diets. Californian dairies use a wide range of forages, and tend not to base their diets solely or mainly on corn silage. Therefore, typical Californian lactation diets do not always conform to those reported in research publications involving SB. In addition, research parameters such as milk yield, DM intake and dietary ADF often differ substantially between reported studies and conditions present on commercial California dairies, and results are therefore not always practically applicable. Apart from its rumen buffering capacity, SB also has an influence on dietary cation anion difference (DCAD), and can therefore elicit a response via a change in blood acid base balance of cows. The experiment was a Latin square design with 3 treatments (i.e., control (C), SB and CMC), 3 pens of ~310 early lactation cows each, and 3 periods of 28 d. Sodium bicarbonate supplemented cows had elevated milk fat proportion, but a reduced milk yield, resulting in similar milk fat yield between SB supplemented and C cows. Based on a tendency for elevated faecal and in vitro rumen fluid pH, SB had a buffering effect on the gastrointestinal tract GIT, most likely in the rumen. However, it is likely that the difference in DCAD between the C and SB diets played a role in affecting milk yield and milk fat proportion, and a high intake of Na may have been the cause for a reduction in milk yield resulting in passive increase in milk fat proportion. There were no differences between C and CMC treatments, except for an elevated faecal pH of CMC cows. As CMC is not generally soluble at normal rumen pH, buffering likely occurred in the abomasum and small and large intestines. However, a lack of difference in productivity indicates that the buffering effect on the hindgut was not physiologically required. While there were no productive benefits of SB use, it likely substantially increased Na discharge, resulting in an increase in soil and water sodicity and the associated deterioration in soil and water quality. While CMC did not improve productivity or efficiency of cows, it also did not increase Na discharge from the dairy and therefore did not contribute to soil or water sodicity. It can be concluded that SB or CMC supplementation is not advisable for diets and conditions comparable to those present in this study, i.e., high producing dairy cows fed a diet with ‘normal’ aNDF levels and relatively low proportions of corn silage and starch (334.0, 104.0 and 160.3 g/kg DM, respectively, in our study). CopyrightDissertation (MSc(Agric))--University of Pretoria, 2012.Animal and Wildlife Sciencesunrestricte

Swiss Product Management 2013/14 : Von den Besten lernen

StudieIm Rahmen der Studie wurden 389 Entscheidungsträger zu ihrem Rollenverständnis, ihren Herausforderungen und den relevanten Trends im Product Management befragt. Das diesjährige Motto der Studie lautet "Von den Besten lernen" – es stellt sich die Frage: Was machen erfolgreiche Product Manager besser als ihre weniger erfolgreichen Kollegen

Enhanced accretion rates of stars on Super-massive Black Holes by star-disk interactions in galactic nuclei

We investigate the dynamical interaction of a central star cluster surrounding a super-massive black hole and a central accretion disk. The dissipative force acting on stars in the disk leads to an enhanced mass flow towards the super-massive black hole and to an asymmetry in the phase space distribution due to the rotating accretion disk. The accretion disk is considered as a stationary Keplerian rotating disk, which is vertically extended in order to employ a fully self-consistent treatment of stellar dynamics including the dissipative force originating from star-gas ram pressure effects. The stellar system is treated with a direct high-accuracy N-body integration code. A star-by-star representation, desirable in N-body simulations, cannot be extended to real particle numbers yet. Hence, we carefully discuss the scaling behavior of our model with regard to particle number and tidal accretion radius. The main idea is to find a family of models for which the ratio of two-body relaxation time and dissipation time (for kinetic energy of stellar orbits) is constant, which then allows us to extrapolate our results to real parameters of galactic nuclei. Our model is derived from basic physical principles and as such it provides insight into the role of physical processes in galactic nuclei, but it should be regarded as a first step towards more realistic and more comprehensive simulations. Nevertheless, the following conclusions appear to be robust: the star accretion rate onto the accretion disk and subsequently onto the super-massive black hole is enhanced by a significant factor compared to purely stellar dynamical systems neglecting the disk. This process leads to enhanced fueling of central disks in active galactic nuclei and to an enhanced rate of tidal stellar disruptions. [Abridged]Comment: 17 pages, 6 figures (with 9 panels), 2 tables, accepted for publication in Ap

Practical IR extinction coefficients for water in commercial glasses determined by nuclear reaction analysis

For a number of commercial glasses with different chemical compositions the water contents were determined by nuclear reaction analysis (NRA) measurements. These results were used to deduce practical extinction coefficients by comparison with the measured IR absorbance values at 2.8 μm. For aluminosilicate and television glasses the practical molar extinction coefficients are given for the first time. Practical extinction coefficients are dependent upon glass composition. With increasing basicity of the glasses studied they decrease from 182 to 24 l/(mol cm)

Swiss Marketing Leadership Studie 2016 : digitale Transformation im Marketing

Die meisten Schweizer Unternehmen haben verstanden, dass die Digitale Transformation das Marketing grundlegend verändert. Doch vielerorts fehlt es an strategischer Verankerung, Systematik und Ressourcen. Das Institut für Marketing Management der ZHAW School of Management hat am 8. September im Rahmen des Swiss CRM Forum seine diesjährige Swiss Marketing Leadership Studie vorgestellt. Die Befragung von 646 Schweizer Unternehmen zeigt, dass hierzulande ein grundlegendes Verständnis für die Veränderungen im Marketing vorhanden ist, welche die Digitale Transformation mit sich bringt. Allerdings befinden sich viele Unternehmen noch am Anfang des Transformationsprozesses. Auch nicht alle Unternehmen sehen die Entwicklung vornehmlich als Chance. Bisweilen fürchtet man eine Bedrohung des Status quo. Insgesamt zeigt sich, dass hierzulande noch viele Herausforderungen zu meistern sind, will man weiterhin im internationalen Wettbewerb mithalten können.­­ Kundenbeziehungsmanagement als Treiber: Bei B2C-Unternehmen geniesst die Digitale Transformation einen signifikant höheren Stellenwert als im B2B-Bereich. Insbesondere das Kundenbeziehungsmanagement gilt vielerorts als Katalysator der Entwicklung. Weniger ausgeprägt ist das Verständnis für den Wandel hingegen im Produktmanagement, wo entsprechende Methoden und Tools noch eine untergeordnete Rolle spielen. Zudem zeigt sich, dass kaum ein Unternehmen bisher ein ganzheitliches, toolbasiertes Product-Lifecycle-Management betreibt. Fachleute verzweifelt gesucht: Gemäss Studie planen Schweizer Unternehmen mehr denn je, in das Kundenbeziehungsmanagement zu investieren. Allerdings zeigen sich dabei grosse Unterschiede: Je reifer das Unternehmen bezüglich Digitalisierung, desto grösser die Bereitschaft für Investitionen. Ausserdem gibt es grosse branchenspezifische Unterschiede. Trotz teilweise reger Aktivität fehlt es jedoch an strategischer Verankerung, Systematik und vor allem Ressourcen. Entsprechende Budgets sind zwar vielerorts vorhanden, doch die Rekrutierung geeigneter Mitarbeitenden stellt eine grosse Herausforderung dar. Die Studie wurde in Zusammenarbeit mit zahlreichen Partnern aus der Privatwirtschaft realisiert

Efficient Suppression of Minority Drug-Resistant HIV Type 1 (HIV-1) Variants Present at Primary HIV-1 Infection by Ritonavir-Boosted Protease Inhibitor-Containing Antiretroviral Therapy

Background. Selection of preexisting minority variants of drug-resistant human immunodeficiency virus type 1 (HIV-1) can lead to virological failure in patients who receive antiretroviral therapy (ART) with low genetic resistance barriers. We studied treatment response and dynamics of minority variants during the first weeks of ART containing a ritonavir-boosted protease inhibitor (PI) and 2 nucleoside reverse-transcriptase inhibitors (NRTIs), which is a regimen with a high genetic resistance barrier. Methods. Plasma samples obtained prior to initiation of ART from 109 patients with primary HIV infection and samples obtained during viral decay during early ART from 17 of these 109 patients were tested by allelespecific polymerase chain reaction for K103N and M184V variants. Results. K103N and/or M184V mutations were detected in 15 (13.8%) of 109 patients prior to ART asminority variants. No selection of these variants was observed within the first weeks of ART in 7 of 15 patients with preexisting drug resistance mutations, nor was any selection observed in 10 patients without preexisting drug resistance mutations. Most patients received ART immediately after diagnosis of HIV-1 infection, showed a rapid decrease in viral load, and experienced sufficient suppression of viremia for ⩽48 months. Conclusions. Minority variants, in particular viruses harboring the M184V mutation, were efficiently suppressed in patients with acute infection who received a ritonavir-boosted PI and 2 NRTIs (most regimens included lamivudine). Under this high genetic resistance barrier regimen, the M184V was not further selecte

Infrequent Replication of Parvovirus B19 and Erythrovirus Genotypes 2 and 3 among HIV-Infected Patients with Chronic Anemia

We investigated the role that erythroviruses (parvovirus B19 and erythrovirus genotypes 2 and 3) play in the lives of immunosuppressed HIV-infected patients with chronic anemia. We screened the serum samples of 428 patients by specific ultrasensitive real-time polymerase chain reaction assay. Sixteen patients had circulating DNA, with no apparent clinical impact. Erythrovirus-associated anemia is an extremely rare event in HIV-infected patient

Incidence and Risk Factors for Chronic Elevation of Alanine Aminotransferase Levels in HIV-Infected Persons without Hepatitis B or C Virus Co-Infection

Background. Chronic liver disease in human immunodeficiency virus (HIV)-infected patients is mostly caused by hepatitis virus co-infection. Other reasons for chronic alanine aminotransferase (ALT) elevation are more difficult to diagnose. Methods. We studied the incidence of and risk factors for chronic elevation of ALT levels (greater than the upper limit of normal at ⩾2 consecutive semi-annual visits) in participants of the Swiss HIV Cohort Study without hepatitis B virus (HBV) or hepatitis C virus (HCV) infection who were seen during the period 2002-2008. Poisson regression analysis was used. Results. A total of 2365 participants were followed up for 9972 person-years (median age, 38 years; male sex, 66%; median CD4+ cell count, 426/µL; receipt of antiretroviral therapy [ART], 56%). A total of 385 participants (16%) developed chronic elevated ALT levels, with an incidence of 3.9 cases per 100 person-years (95% confidence interval [CI], 3.5-4.3 cases per 100 person-years). In multivariable analysis, chronic elevated ALT levels were associated with HIV RNA level >100,000 copies/mL (incidence rate ratio [IRR], 2.23; 95% CI, 1.45-3.43), increased body mass index (BMI, defined as weight in kilograms divided by the square of height in meters) (BMI of 25-29.9 was associated with an IRR of 1.56 [95% CI, 1.24-1.96]; a BMI ⩾30 was associated with an IRR of 1.70 [95% CI, 1.16-2.51]), severe alcohol use (1.83 [1.19-2.80]), exposure to stavudine (IRR per year exposure, 1.12 [95% CI, 1.07-1.17]) and zidovudine (IRR per years of exposure, 1.04 [95% CI, 1.00-1.08]). Associations with cumulative exposure to combination ART, nucleoside reverse-transcriptase inhibitors, and unboosted protease inhibitors did not remain statistically significant after adjustment for exposure to stavudine. Black ethnicity was inversely correlated (IRR, 0.52 [95% CI, 0.33-0.82]). Treatment outcome and mortality did not differ between groups with and groups without elevated ALT levels. Conclusions. Among patients without hepatitis virus co-infection, the incidence of chronic elevated ALT levels was 3.9 cases per 100 person-years, which was associated with high HIV RNA levels, increased BMI, severe alcohol use, and prolonged stavudine and zidovudine exposure. Long-term follow-up is needed to assess whether chronic elevation of ALT levels will result in increased morbidity or mortalit

Unsafe Sex and Increased Incidence of Hepatitis C Virus Infection among HIV-Infected Men Who Have Sex with Men: The Swiss HIV Cohort Study

Background. Data on the incidence of hepatitis C virus (HCV) infection among human immunodeficiency virus (HIV)-infected persons are sparse. It is controversial whether and how frequently HCV is transmitted by unprotected sexual intercourse. Methods. We assessed the HCV seroprevalence and incidence of HCV infection in the Swiss HIV Cohort Study between 1988 and 2004. We investigated the association of HCV seroconversion with mode of HIV acquisition, sex, injection drug use (IDU), and constancy of condom use. Data on condom use or unsafe sexual behavior were prospectively collected between 2000 and 2004. Results. The overall seroprevalence of HCV infection was 33% among a total of 7899 eligible participants and 90% among persons reporting IDU. We observed 104 HCV seroconversions among 3327 participants during a total follow-up time of 16,305 person-years, corresponding to an incidence of 0.64 cases per 100 person-years. The incidence among participants with a history of IDU was 7.4 cases per 100 person-years, compared with 0.23 cases per 100 person-years in patients without such a history (P < .001). In men who had sex with men (MSM) without a history of IDU who reported unsafe sex, the incidence was 0.7 cases per 100 person-years, compared with 0.2 cases per 100 person-years in those not reporting unsafe sex (P = .02), corresponding to an incidence rate ratio of 3.5 (95% confidence interval, 1.2-10.0). The hazard of acquiring HCV infection was elevated among younger participants who were MSM. Conclusions. HCV infection incidence in the Swiss HIV Cohort Study was mainly associated with IDU. In HIV-infected MSM, HCV infection was associated with unsafe se

Intra-articular glucocorticoid injections decrease the number of steroid hormone receptor positive cells in synovial tissue of patients with persistent knee arthritis

Objectives: To explore changes in the number of steroid hormone receptor positive cells in synovial tissue (ST) after intra-articular glucocorticoid injection, to correlate these changes with changes in clinical variables, and to evaluate whether the number of steroid hormone receptor positive cells predicted the clinical response to glucocorticoid injection. Methods: Fourteen patients with persistent knee arthritis despite at least two previous injections in an outpatient setting received an intra-articular injection with glucocorticoids, followed by 3 days of admission with bed rest. Clinical efficacy was assessed at 6 and 12 weeks. ST biopsies were performed 2 weeks before and 12 weeks after the injection. The presence of different cell types (T cells, macrophages, fibroblast-like synoviocytes) and numbers of glucocorticoid, androgen and oestrogen α and β receptor positive cells were evaluated by histochemistry. Results: Patients showed, despite previous failures, good clinical response to glucocorticoid injection, with significant improvement in erythrocyte sedimentation rate, visual analogue scale (VAS) for pain, and joint disability score. The number of steroid hormone receptor positive cells decreased markedly (p<0.05 for all four receptors). The decrease in oestrogen receptor α positive cells correlated significantly with the improvement in VAS for pain and joint disability score. The number of glucocorticoid, androgen and oestrogen α and β receptor positive cells before injection did not predict the effect of treatment. Conclusions: Intra-articular glucocorticoid injections followed by bed rest for persistent arthritis are clinically effective and significantly decrease the number of steroid hormone receptor positive cells in ST. The relevance of the latter needs further study