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This paper reviews the effects of extended lactation (EXT) as a strategy in dairy cattle on milk production and persistency, reproduction, milk quality, lifetime performance of the cow and finally the economic effects on herd and farm levels as well as the impact on emission of greenhouse gas at product level. Primiparous cows are able to produce equal or more milk per feeding day during EXT compared with a standard 305-d lactation, whereas results for multiparous cows are inconsistent. Cows managed for EXT can achieve a higher lifetime production while delivering milk with unchanged or improved quality properties. Delaying insemination enhances mounting behaviour and allows insemination after the cow’s energy balance has become positive. However, in most cases EXT has no effect or a non-significant positive effect on reproduction. The EXT strategy sets off a cascade of effects at herd and farm level. Thus, the EXT strategy leads to fewer calvings and thereby expected fewer diseases, fewer replacement heifers and fewer dry days per cow per year. The optimal lifetime scenario for milk production was modelled to be an EXT of 16 months for first parity cows followed by an EXT of 10 months for later lactations. Modelling studies of herd dynamics indicate a positive effect of EXT on lifetime efficiency (milk per dry matter intake), mainly originating from benefits of EXT on daily milk yield in primiparous cows and the reduced number of replacement heifers. Consequently, EXT also leads to reduced total meat production at herd level. For the farmer, EXT can give the same economic return as a traditional lactation period. At farm level, EXT can contribute to a reduction in the environmental impact of dairy production, mainly as a consequence of the reduced production of beef. A wider dissemination of the EXT concept will be supported by methods to predict which cows may be most suitable for EXT, and clarification of how milking frequency and feeding strategy through the lactation can be organised to support milk yield and an appropriate body condition at the next calving.
The transition period is the most critical period in the lactation cycle of dairy cows. Extended lactations reduce the frequency of transition periods, the number of calves and the related labour for farmers. This study aimed to assess the impact of 2 and 4 months extended lactations on milk yield and net partial cash flow (NPCF) at herd level, and on greenhouse gas (GHG) emissions per unit of fat- and protein-corrected milk (FPCM), using a stochastic simulation model. The model simulated individual lactations for 100 herds of 100 cows with a baseline lactation length (BL), and for 100 herds with lactations extended by 2 or 4 months for all cows (All+2 and All+4), or for heifers only (H+2 and H+4). Baseline lactation length herds produced 887 t (SD: 13) milk/year. The NPCF, based on revenues for milk, surplus calves and culled cows, and costs for feed, artificial insemination, calving management and rearing of youngstock, was k€174 (SD: 4)/BL herd per year. Extended lactations reduced milk yield of the herd by 4.1% for All+2, 6.9% for All+4, 1.1% for H+2 and 2.2% for H+4, and reduced the NPCF per herd per year by k€7 for All+2, k€12 for All+4, k€2 for H+2 and k€4 for H+4 compared with BL herds. Extended lactations increased GHG emissions in CO2-equivalents per t FPCM by 1.0% for All+2, by 1.7% for All+4, by 0.2% for H+2 and by 0.4% for H+4, but this could be compensated by an increase in lifespan of dairy cows. Subsequently, production level and lactation persistency were increased to assess the importance of these aspects for the impact of extended lactations. The increase in production level and lactation persistency increased milk production of BL herds by 30%. Moreover, reductions in milk yield for All+2 and All+4 compared with BL herds were only 0.7% and 1.1% per year, and milk yield in H+2 and H+4 herds was similar to BL herds. The resulting NPCF was equal to BL for All+2 and All+4 and increased by k€1 for H+2 and H+4 due to lower costs for insemination and calving management. Moreover, GHG emissions per t FPCM were equal to BL herds or reduced (0% to −0.3%) when lactations were extended. We concluded that, depending on lactation persistency, extending lactations of dairy cows can have a positive or negative impact on the NPCF and GHG emissions of milk production.
Victimisation by the police is purported to be widespread in cities in the USA, but there is limited data on police–public encounters from community samples. This is partly due to an absence of measures for assessing police violence exposure from the standpoint of civilians. As such, the demographic distribution and mental health correlates of police victimisation are poorly understood. The aims of this study were to present community-based prevalence estimates of positive policing and police victimisation based on assessment with two novel measures, and to test the hypotheses that (1) exposure to police victimisation would vary across demographic groups and (2) would be associated with depression and psychological distress.
The Survey of Police–Public Encounters study surveyed adults residing in four US cities to examine the prevalence, demographic distribution and psychological correlates of police victimisation. Participants (N = 1615) completed measures of psychological distress (K-6 scale), depression (Patient Health Questionnaire 9) and two newly constructed measures of civilian-reported police–public encounters. Both measures were developed to assess police victimisation based on the WHO domains of violence, which include physical violence (with and without a weapon, assessed separately), sexual violence (inappropriate sexual contact, including public strip searches), psychological violence (e.g., threatening, intimidating, stopping without cause, or using discriminatory slurs) and neglect (police not responding when called or responding too late). The Police Practices Inventory assesses lifetime history of exposure to positive policing and police victimisation, and the Expectations of Police Practices Scale assesses the perceived likelihood of future incidents of police victimisation. Linear regression models were used to test for associations between police–public encounters and psychological distress and depression.
Psychological violence (18.6%) and police neglect (18.8%) were commonly reported in this sample and a substantial minority of respondents also reported more severe forms of violence, specifically physical (6.1%), sexual (2.8%) and physical with a weapon (3.3%). Police victimisation was more frequently reported by racial/ethnic minorities, males, transgender respondents and younger adults. Nearly all forms of victimisation (but not positive policing) were associated with psychological distress and depression in adjusted linear regression models.
Victimisation by police appears to be widespread, inequitably distributed across demographic groups and psychologically impactful. These findings suggest that public health efforts to both reduce the prevalence of police violence and to alleviate its psychological impact may be needed, particularly in disadvantaged urban communities.
Measles, mumps, rubella (MMR) and varicella zoster virus (VZV) infection can cause serious diseases and complications in the HIV-positive population. Due to successful vaccination programmes measles, mumps and congenital rubella syndrome has become neglected in Germany. However, recent outbreaks of measles have occurred from import-associated cases. In this cross-sectional study the serostatus for MMR and VZV in 2013 HIV-positive adults from three different university outpatient clinics in Bonn (n = 544), Cologne (n = 995) and Munich (n = 474) was analysed. Sera were tested for MMR- and VZV-specific immunglobulin G antibodies using commercial immunoassays. Seronegativity was found in 3% for measles, 26% for mumps, 11% for rubella and 2% for VZV. Regarding MMR, 35% of patients lacked seropositivity against at least one infectious agent. In multivariable analysis younger age was strongly associated with seronegativity against all four viruses, measles, mumps, rubella (P < 0·001, P < 0·001 and P = 0·001, respectively) and VZV (P = 0·001). In conclusion, there is high need for MMR and VZV vaccination in people living with HIV in Germany born in 1970 or later. Thus, systematic MMR and VZV antibody screening and vaccination should be implemented in the HIV-positive population to prevent serious disease and complications of vaccine-preventable diseases.
There is a growing body of literature describing the characteristics of patients who plan for the end of life, but little research has examined how caregivers influence patients' advance care planning (ACP). The purpose of this study was to examine how patient and caregiver characteristics are associated with advance directive (AD) completion among patients diagnosed with a terminal illness. We defined AD completion as having completed a living will and/or identified a healthcare power of attorney.
A convenience sample of 206 caregiver–patient dyads was included in the study. All patients were diagnosed with an advanced life-limiting illness. Trained research nurses administered surveys to collect information on patient and caregiver demographics (i.e., age, sex, race, education, marital status, and individual annual income) and patients' diagnoses and completion of AD. Multivariate logistic regression was employed to model predictors for patients' AD completion.
Over half of our patient sample (59%) completed an AD. Patients who were older, diagnosed with amyotrophic lateral sclerosis, and with a caregiver who was Caucasian or declined to report an income level were more likely to have an AD in place.
Significance of results:
Our results suggest that both patient and caregiver characteristics may influence patients' decisions to complete an AD at the end of life. When possible, caregivers should be included in advance care planning for patients who are terminally ill.
The evolution of low- and intermediate-mass stars (about 1 to 8 M⊙) from the asymptotic giant branch (AGB) to the planetary nebulae stage is characterized by intense stellar wind. AGB stars evolve on a very short time scale (several thousand years) via a phase, where the star is hidden from view by a dense dust shell, towards the post-AGB phase (an optically visible star surrounded by a cold dust/gas shell). The observational investigation of these shells is rather difficult due to their small angular extent. However, the resolution of current infrared telescopes is sufficient to resolve the warm dust of the inner part of the envelope.
We investigated the long-term photometrical behaviour of the EXors V1118 Ori and V1143 Ori on the basis of the Sonneberg Plate Archive. About 2800 plates were checked for outbursts of these stars. We found several dozens of plates where the stars appeared to be distinctly brighter than the plate limit. To get magnitudes we have scanned those plates and applied a special method of brightness determination which is currently used at Sonneberg Observatory. Because of the small number of plates we were able to extract only crude estimates of some typical time scales of outburst and quiescent phases.
In this work, we present a detailed investigation of the growth of palladium-seeded GaAs nanowires. Nanowires grown on GaAs (111)B substrates consist of three different morphologies, denoted as curly (containing multiple kinks), inclined (relative to the substrate, such as 〈001〉), and vertical. We show that the relative yield of the different types is controllable by a combination of V/III ratio and temperature, where vertical and inclined nanowires are promoted by a high temperature and low V/III ratio. These growth conditions are expected to promote a higher Ga incorporation into the Pd particle, which is confirmed by energy dispersive x-ray analysis. We propose that the observed relationship between particle composition and nanowire morphology may be related to the particle phase, with liquid particles promoting straight nanowire growth. In addition, particles at the tips of nanowires are sometimes observed to be smaller than the initial particle size, suggesting that Pd has been lost during the growth process. Finally, we demonstrate the importance of initial particle size-control to interpret diameter changes after growth.
Our investigations with silane-modified TiO2 have revealed a beneficial effect of functionalization on the photoelectrochemical performance on spin-coated electrodes. However, in order to produce large area photoelectrodes, a more scalable manufacturing technology is required. Inkjet printing can fulfil this role and furthermore allow a finer control over coating morphologies. In this work, inkjet-printed photoelectrodes were prepared with silane-functionalized TiO2 nanoparticles, and investigated as electrodes for photoactivated water splitting. The catalyst layers, having thickness around 700 nm, were printed on FTO-coated glass supports, from cellulose stabilized dispersions. For comparison, electrodes of similar thicknesses were also prepared by spin-coating. After removing the stabilizer at 300 °C under air atmosphere, the electrodes were characterized in photoelectrochemical cells containing 0.5 M H2SO4 as electrolyte and a platinum ring as counter electrode. Under simulated sunlight, the best photocurrent densities for the oxygen evolution reaction were obtained for the inkjet-printed electrodes prepared with functionalized particles (up to 0.26 mA cm-2 at 1.2 V against the standard hydrogen electrode (SHE), compared to 0.18 mA cm-2 for spin coated). Microscopy of the printed electrodes shows structurally homogenous coatings with evenly distributed roughness. Under continuous illumination at 0.7 V (SHE), the electrodes showed no significant drop in photocurrent within five hours.
Kitagohaite, ideally Pt7Cu, is a new mineral from the Lubero
region of North Kivu, Democratic Republic of the Congo. The mineral occurs
as alluvial grains that were recovered together with other Pt-rich
intermetallic compounds and Au. Kitagohaite is opaque, greyish white and
malleable and has a metallic lustre and a grey streak. In reflected light,
kitagohaite is white and isotropic. The crystal structure of kitagohaite is
cubic, space group Fmm, of the Ca7Ge type, with a =
7.7891(3) Å, V = 472.57(5) Å3 and
Z = 4. The strongest diffraction lines
[d in Å(I)(hkl)] are: 2.246 (100)(222),
1.948(8)(004), 1.377 (77)(044), 1.174(27)(622), 1.123 (31)(444) and 0.893
(13)(662). The Vickers hardness is 217 kg mm−2
(VHN100), which is equivalent to a Mohs hardness of 3½ and the
calculated density is 19.958(2) g cm−3. Electron-microprobe
analyses gave a mean value (n = 13) of 95.49 wt.% Pt and
4.78 wt.%Cu, which corresponds to Pt6.93Cu1.07 on the
basis of eight atoms. The new mineral is named for the Kitagoha river, in
the Lubero region.
The analysis of complex networks has so far revolved mainly around the role of nodes and communities of nodes. However, the dynamics of interconnected systems is often focalized on edge processes, and a dual edge-centric perspective can often prove more natural. Here we present graph-theoretical measures to quantify edge-to-edge relations inspired by the notion of flow redistribution induced by edge failures. Our measures, which are related to the pseudo-inverse of the Laplacian of the network, are global and reveal the dynamical interplay between the edges of a network, including potentially non-local interactions. Our framework also allows us to define the embeddedness of an edge, a measure of how strongly an edge features in the weighted cuts of the network. We showcase the general applicability of our edge-centric framework through analyses of the Iberian power grid, traffic flow in road networks, and the C. elegans neuronal network.
Multi-epoch, high-resolution (R ∼ 50 000) optical spectrosco-py of the O-type (O9 III – IV) star HD 152246 suggests that it is a triple system where a close inner pair (Aa–Ab) with a circular orbit and a period of 6 days is in a 53–d eccentric orbit (e = 0.68) with a third component Ac. The mass ratios for the inner and outer system are 0.10 and 0.96, respectively. The strengths of various He lines classify Aa and Ac as late O-type stars while Ab is invisible in our spectra.
We present the analysis of HD 181068 which is one of the first triply eclipsing triple system discovered. Using Kepler photometry, ground based spectroscopic and interferometric measurements, we determined the stellar and orbital parameters of the system. We show that the oscillations observed in the red giant component of the system are tidally forced oscillations, while one of the most surprising results is that it does not show solar-like oscillations.
We investigate the multiplicity as a function of stellar mass. For this purpose we have created three complete samples of O, B, and FGK stars and performed multi-epoch, high-resolution (R ∼ 50 000) optical spectroscopy. The current results for the O-type stars suggest a multiplicity fraction of more than 80%. Many O-type systems contain components of similar mass. The multiplicity fraction for B stars seems to decrease from 70% to 20%. We argue that this general decrease is most likely due to observational biases; however, similar-mass systems – like common for O-type stars – seem to vanish toward later B-types. Within the sample of F stars we observe an increasing multiplicity fraction with primary mass (∼50% – 80%); simultaneously there is a decrease of single stars toward the A-type regime. Closer inspection of spectroscopic binaries – either by spectral disentangling or by common proper motion studies – reveals higher-level systems in each mass range.
We carried out an extensive photometric and spectroscopic investigation of the SPB binary, HD 25558 (see Fig. 1 for the time and geographic distribution of the observations). The ~2000 spectra obtained at 13 observatories during 5 observing seasons, the ground-based multi-colour light curves and the photometric data from the MOST satellite revealed that this object is a double-lined spectroscopic binary with a very long orbital period of about 9 years. We determined the physical parameters of the components, and have found that both lie within the SPB instability strip. Accordingly, both components show line-profile variations consistent with stellar pulsations. Altogether, 11 independent frequencies and one harmonic frequency were identified in the data. The observational data do not allow the inference of a reliable orbital solution, thus, disentangling cannot be performed on the spectra. Since the lines of the two components are never completely separated, the analysis is very complicated. Nevertheless, pixel-by-pixel variability analysis of the cross-correlated line profiles was successful, and we were able to attribute all the frequencies to the primary or secondary component. Spectroscopic and photometric mode-identification was also performed for several of these frequencies of both binary components. The spectroscopic mode-identification results suggest that the inclination and rotation of the two components are rather different. While the primary is a slow rotator with ~6 d rotation period, seen at ~60° inclination, the secondary rotates fast with ~1.2 d rotation period, and is seen at ~20° inclination. Our spectropolarimetric measurements revealed that the secondary component has a magnetic field with at least a few hundred Gauss strength, while no magnetic field was detected in the primary.
The detailed analysis and results of this study will be published elsewhere.
The effect of the micro-porous layer (MPL) in polymer electrolyte fuel cells (PEFCs) was studied by a combination of in situ visualization of the liquid water distribution and advanced electrochemical analysis using helox and O2 pulses. Four cells with and without MPLs on the anode and cathode side were tested. Visualization studies showed that the significant changes in performance observed when using an MPL on the cathode side cannot be related to a reduction of the water content in the cathode side diffusion layer (GDL). The helox/O2 pulse analysis indicated that two different mechanisms are responsible for the performance loss without an MPL.