The effect of herbage allowance and concentrate supplementation on milk production performance and dry matter intake of spring-calving dairy cows in early lactation

The objective of this study was to determine the effect of daily herbage allowance (DHA) and concentrate level on milk production and dry matter intake of spring-calving dairy cows in early lactation. Seventy-two Holstein-Friesian dairy cows (mean calving date February 2) were randomly assigned across 6 treatments (n = 12) in a 2 × 3 factorial arrangement. The 6 treatments consisted of 2 DHA ( > 4 cm) and 3 concentrate levels: 13 kg of herbage dry matter/cow per d (low) or 17 kg of herbage dry matter/cow per d (high) DHA and unsupplemented, 3 kg, or 6 kg of dry matter concentrate/cow per d. The experimental period (period I) lasted 77 d and was followed by a carryover period (period II) during which animals were randomly reassigned across 2 grazing treatments offering 17 or 21 kg of herbage dry matter/cow per d. Increasing DHA significantly increased milk (+1.85 kg), solids-corrected milk, protein (+79.5 g), and lactose yields, protein concentration, and mean body weight (BW). Mean body condition score (BCS) and end-point BCS were also significantly higher with the high-DHA treatments. There was a linear response in milk yield, milk lactose concentration, and solids-corrected milk to concentrate supplementation. There was a significant difference in mean BW as concentrate increased from 0 to 3 kg (506 and 524 kg, respectively); there was no further increase in BW when 6 kg of concentrate was offered. Cows offered the low DHA had significantly lower grass dry matter intake (13.3 kg) and total dry matter intake (16.3 kg) than the high-DHA cows during period I. Concentrate supplementation significantly increased total dry matter intake. During period II, previous DHA continued to have a significant carryover effect on milk protein concentration, BW change, mean BCS, and end-point BCS. Concentrate supplementation during period I continued to have a significant carryover effect in period II on milk yield; milk fat, protein, and lactose yields; solids-corrected milk yield; BW; and mean BCS. Results from this study indicate that offering a medium level of DHA (17 kg of herbage dry matter) in early lactation will increase milk production. Offering concentrate will result in a linear increase in milk production. In an early spring feed-budgeting scenario, when grass supply is in deficit, offering 3 kg of dry matter concentrate with 17 kg of DHA has the additive effect of maintaining the grazing rotation at the target length as well as ensuring the herd is adequately fed.     

Management of psychiatric problems in a Kenyan mission hospital

Many psychiatric conditions are found in the rural general hospital in Kenya and are recognisable and manageable along standard Western lines. An essential element in management is the training of the nursing staff. The psychiatric patient should be actively managed and can benefit from the unsophisticated treatment possible at the mission hospital.     

Bile metabolites of polycyclic aromatic hydrocarbons (PAHs) in European eels Anguilla anguilla from United Kingdom estuaries

A total of 94 European eels (Anguilla anguilla) were collected from five estuaries in the UK. The deconjugated metabolites of polycyclic aromatic hydrocarbons (PAHs) in the bile of the eels were separated using HPLC. Six PAH metabolites were identified: 1-hydroxy (1-OH) metabolites of phenanthrene, pyrene and chrysene; and the 1-OH, 3-OH and 7,8 dihydrodiol metabolites of benzo[a]pyrene (BaP). The mean concentration of the six metabolites was greatest in eels from the Tyne (49 microM) followed by the Wear (33 microM), Tees (19 microM), Thames (4 microM) and Severn (2 microM) estuaries. Although 1-OH pyrene was always the dominant compound, there were significant differences (P<0.05) between sites and between estuaries for some metabolites. Normalising the molar concentration of the bile metabolites to the bile biliverdin absorbance reduced sample variation. When the metabolites identified were each expressed as a percentage of the total detected, the metabolite profile was characteristic for each estuary.     

Influence of precursors on the morphology and performance of TiO2 photoanodes

The preparation of TiO₂ photoanodes for dye-sensitized electrochemical devices was investigated. TiO₂ precursors with different rates of hydrolysis were used to modify the microstructures of the resulting TiO₂ photoanodes. The photoelectrochemical quantum yield for electrodes prepared from citrate remained low. Acetate precursors gave rise to electrodes with high fill factors and high open circuit voltages. Titanium isopropoxide hydrolysed very rapidly, leaving a powderous, poorly compacted deposit. Photoanodes from TiCl₄ precursors exhibit high surface roughness, which is necessary for a high degree of dye adsorption. With high hydrolysis rates, isopropoxide precursors produced powdery, poorly coherent films. A composite electrode with an acetate-based substrate and TiCl₄-based surface layers appears to be a suitable compromise.     

The NPL InSb-based Radiation Thermometer for the Medium Temperature Range ( < 962°C)

Over the temperature range from 156 to 962°C, the NPL maintains a series of heatpipe blackbody sources for the calibration of customer sources, radiation thermometers, and thermal imagers. The temperature of each of the sources is determined using a calibrated platinum resistance thermometer or gold-platinum thermocouple placed close to the radiating surface at the back of the cavity. The integrity of such a blackbody source relies on it having good temperature uniformity, a high and well-known effective emissivity, and having the sensor in good thermal contact with the cavity. To verify the performance of the blackbody sources, it is necessary to use an infrared thermometer that has been independently calibrated to compare the radiance temperature of the source with the temperature measured by the contact sensor. Such verification of the NPL blackbodies has been carried out at short wavelengths: from 500 to 1,000°C using the NPL LP2 calibrated using the NPL gold point, and at 1.6 μm using an InGaAs-based radiation thermometer calibrated at a series of fixed-points from indium (156°C) to silver (962°C). Thermal imaging systems traditionally operate over the 3–5 μm waveband and are calibrated using NPL sources. Up until now, it has not been possible to verify the performance of the sources in this waveband except indirectly by cross-comparison of the sources where they overlap in temperature. A mid-infrared (nominally 3–5 μm) radiation thermometer has, therefore, been designed, constructed, and validated at NPL. The instrument was validated and calibrated using the fixed-point blackbody sources and then used to validate the heatpipe blackbodies over their temperature range of operation. The results of the instrument validation and blackbody measurements are given.     

Safety, tolerance, and pharmacokinetics of a small unilamellar liposomal formulation of amphotericin B (AmBisome) in neutropenic patients

The safety, tolerance, and pharmacokinetics of a small unilamellar liposomal formulation of amphotericin B (AmBisome) administered for empirical antifungal therapy were evaluated for 36 persistently febrile neutropenic adults receiving cancer chemotherapy and bone marrow transplantation. The protocol was an open-label, sequential-dose-escalation, multidose pharmacokinetic study which enrolled a total of 8 to 12 patients in each of the four dosage cohorts. Each cohort received daily doses of either 1.0, 2.5, 5.0, or 7.5 mg of amphotericin B in the form of AmBisome/kg of body weight. The study population consisted of patients between the ages of 13 and 80 years with neutropenia (absolute neutrophil count, <500/mm3) who were eligible to receive empirical antifungal therapy. Patients were monitored for safety and tolerance by frequent laboratory examinations and the monitoring of infusion-related reactions. Efficacy was assessed by monitoring for the development of invasive fungal infection. The pharmacokinetic parameters of AmBisome were measured as those of amphotericin B by high-performance liquid chromatography. Noncompartmental methods were used to calculate pharmacokinetic parameters. AmBisome administered as a 1-h infusion in this population was well tolerated and was seldom associated with infusion-related toxicity. Infusion-related side effects occurred in 15 (5%) of all 331 infusions, and only two patients (5%) required premedication. Serum creatinine, potassium, and magnesium levels were not significantly changed from baseline in any of the dosage cohorts, and there was no net increase in serum transaminase levels. AmBisome followed a nonlinear dosage relationship that was consistent with reticuloendothelial uptake and redistribution. There were no breakthrough fungal infections during empirical therapy with AmBisome. AmBisome administered to febrile neutropenic patients in this study was well tolerated, was seldom associated with infusion-related toxicity, was characterized by nonlinear saturation kinetics, and was effective in preventing breakthrough fungal infections.     

Step-By-Step Atomic Insights into Structural Reordering from 2D to 3D MoS2

Vertically stacked low-dimensional heterostructures are outstanding systems both for exploring fundamental physics and creating new devices. Due to nanometer-scale building blocks, atomic scale phenomena become for them of fundamental importance, including during device operation. These can be accessed in situ in aberration-corrected scanning transmission electron microscopy (STEM) experiments. Here, the dynamics of a graphene-MoS₂ heterostructure are studied under Joule heating, where the graphene serves as a high temperature atomically thin and electron transparent “hot plate” for the MoS₂. Structural dynamics and evolution of the system are shown at the atomic scale, demonstrating that at the highest temperatures (estimated to exceed 2000 K), the continuous 2D MoS₂ transforms into separated 3D nanocrystals, initiated by sulfur vacancy creation and migration followed by formation of voids and clustering at their edges. The resulting nanocrystals exhibit predominantly hexagonal shapes with the 2H and hybrid (2H/3R, 3R/TZ) polytypes. The observed morphology of the crystals is further discussed during and after the transformation, as well as their different edge configurations and stability under electron irradiation. These observations of MoS₂ at extreme temperatures provide insights into the operation of devices based on graphene/MoS₂ heterostructures and ultimately may help device fabrication techniques to create MoS₂-based nanostructures, for example, in hydrogen evolution reaction applications.     

Stamping of Flexible,Coplanar Micro‐Supercapacitors Using MXene Inks

The fast growth of portable smart electronics and internet of things have greatly stimulated the demand for miniaturized energy storage devices. Micro‐supercapacitors (MSCs), which can provide high power density and a long lifetime, are ideal stand‐alone power sources for smart microelectronics. However, relatively few MSCs exhibit both high areal and volumetric capacitance. Here rapid production of flexible MSCs is demonstrated through a scalable, low‐cost stamping strategy. Combining 3D‐printed stamps with arbitrary shapes and 2D titanium carbide or carbonitride inks (Ti₃C₂T_x and Ti₃CNT_x, respectively, known as MXenes), flexible all‐MXene MSCs with controlled architectures are produced. The interdigitated Ti₃C₂T_x MSC exhibits high areal capacitance: 61 mF cm^?2 at 25 µA cm^?2 and 50 mF cm^?2 as the current density increases by 32 fold. The Ti₃C₂T_x MSCs also showcase capacitive charge storage properties, good cycling lifetime, high energy and power densities, etc. The production of such high‐performance Ti₃C₂T_x MSCs can be easily scaled up by designing pad or cylindrical stamps, followed by a cold rolling process. Collectively, the rapid, efficient production of flexible all‐MXene MSCs with state‐of‐the‐art performance opens new exciting opportunities for future applications in wearable and portable electronics.     

All-optical synchronization of self-pulsating laser diodes with frequency multiplication and division

Abstract

We investigate optical synchronization with frequency multiplication and division of self-pulsating laser diodes. Using a simple rate equation model to describe self-pulsation we show that synchronization with frequency multiplication can be accompanied by large variations in the period of the emitted laser pulses over the injected pulse cycle. These variations are not obvious in the frequency domain treatment of synchronization. By applying a frequency division synchronizing signal to our model, we also show that the sensitivity of the phase difference between the injected signal and laser emission to power increases with increasing frequency division ratio and leads to the presence of power synchronization ranges.     

Layered PtSe2 for Sensing,Photonic, and (Opto‐)Electronic Applications

Since the first experimental discovery of graphene 16 years ago, many other 2D layered nanomaterials have been reported. However, the majority of 2D nanostructures suffer from relatively complicated fabrication processes that have bottlenecked their development and their uptake by industry for practical applications. Here, the recent progress in sensing, photonic, and (opto‐)electronic applications of PtSe₂, a 2D layered material that is likely to be used in industries benefiting from its high air‐stability and semiconductor‐technology‐compatible fabrication methods, is reviewed. The advantages and disadvantages of a range of synthesis methods for PtSe₂ are initially compared, followed by a discussion of its outstanding properties, and industrial and commercial advantages. Research focused on the broadband nonlinear photonic properties of PtSe₂, as well as reports of its use as a saturable absorber in ultrafast lasers, are then reviewed. Additionally, the advances that have been achieved in a range of PtSe₂‐based field‐effect transistors, photodetectors, and sensors are summarized. Finally, a conclusion on these results along with the outlook for the future is presented.