Effects of omitting one udder quarter at one single milking

The aim of this study was to investigate if one single omitted milking on one udder quarter with or without re-sorting affects milk yield and udder health in cows in mid or late lactation. The study was carried out in an automatic milking rotary (AMR). It is an identified problem in automatic milking that one or more udder quarters are incompletely milked due to failed teat cup attachment or cows kicking teatcups off. At present, cows that are registered as incompletely milked on one udder quarter or more in the AMR used in this study are resorted for a second milking since it has been shown that extended milking intervals in early- and mid-lactation can lead to a decrease in milk yield and also cause an elevated somatic cell count (SCC) which is an indicator of impaired udder health. Resorting reduces the capacity of the AMR and for the individual cow resorting leads to more time away from feed and cubicles which can impair cow welfare or milk production or both. 36 cows of Swedish Holstein and Swedish Red Breed in day 167 to 376 in lactation were used in the experiment and were divided into two groups, control and treatment. All cows were subjected to one udder quarter being omitted at one milking. After the omitted milking, control cows were resorted back for a second milking while treatment cows were directed to exit. Composite milk and udder quarter milk sampling was performed for three days before and ten days after the treatment day and used for determination of SCC, lactose, milk fat and milk protein. In addition, milk yield was registered throughout the experiment period. Milk yield was 3.7kg lower on the treatment day but no negative long-term effect on milk yield or SCC was found. Furthermore, milk yield from the omitted teat was low on resorting, indicating that a resorting likely does not lead to a complete emptying of the omitted quarter. Therefore, it was concluded that a cow in mid or late lactation has no beneficial effects of being resorted for a second milking in an AMR. A cow can instead the allowed to return to feeding and cubicles after a single incomplete milking, allowing a higher capacity of the AMR. Effects of incomplete milking in early and peak lactation and repeated incomplete milking in any stage of lactation remain to be studied.Syftet med denna studie var att undersöka om och hur en överhoppad mjölkning på en juverdel med eller utan återsortering för ny mjölkning påverkar mjölkmängd och juverhälsa på kor i mitt- eller sen laktation i en automatiserad mjölkningskarusell. Ett identifierat problem i automatisk mjölkning är att en eller flera juverdelar blir ofullständigt mjölkande tack vare att spenkopparna sparkas av eller att påsättningen av spenkopparna misslyckas. När en ko registreras som ofullständigt mjölkad på en eller flera juverdelar blir hon i regel återsorterad för en andra mjölkning eftersom det har visats att förlängda mjölkintervall på kor i tidig och medellaktation påverkar mjölkproduktionen negativt och kan också orsaka en förhöjning av celltal vilket är en indikator på dålig juverhälsa. Återsortering sänker dock kapaciteten i robotkarusellen och en återsortering innebär att kon får spendera mer tid ifrån foder och liggbås vilket kan vara negativt för djurvälfärd och mjölkproduktion. 36 kor av Svensk Holstein och Svensk Röd Boskap i laktationsstadie från 167-376 dagar användes i experimentet och delades in i två grupper, kontroll och behandling. Efter den överhoppade mjölkningen på en juverdel som alla kor utsattes för, återsorterades kontrollkorna till en andra mjölkning medan behandlingskorna fick lämna karusellen och återvända till liggavdelning och foder. Helmjölk och juverfjärdedelsprover togs under tre dagar innan och tio dagar efter den överhoppade mjölkningen och analyserades med avseende på celltal och mjölkkomposition. Även mjölkmängd registrerades under hela försöksperioden. Mjölkmängden var 3.7kg lägre under 2 behandlingsdagen men inga långvariga negativa effekter på varken mjölkmängd eller celltal observerades. Den mjölkmängd som erhölls vid återsortering var också låg, vilket indikerar att en återsortering ändå inte leder till att juverdelen blir fullständigt mjölkad. Slutsatsen är därför att det inte finns någon anledning att återsortera en ko i mitt eller sen laktation till en andra mjölkning efter en enstaka ofullständig mjölkning. Om dessa kor istället får gå tillbaka till liggavdelning och foder upprätthålls kapaciteten i karusellen. Effekter av ofullständig mjölkning i tidig och topplaktation samt effekt av upprepade ofullständiga mjölkningar behöver utredas

Vision-Based Control of the Overhead Crane

Through the years, cranes have been used extensively for many different tasks. For example construction work, shipbuilding and cargo transportation. One of the tedious tasks that cranes perform is loading and unloading containers. This is a process which can be optimized with the aid of control theory. While moving cargo, the crane operator must make sure that crane motion does not cause the cargo to accelerate too quickly, as the cargo may then start to oscillate. Such motion may disrupt unsecured cargo and put unnecessary stress on secured cargo. Today the crane movement is directly controlled by the crane operator; this however severely limits the crane speed due to human inability to control the crane optimally. This thesis presents and investigates a method of controlling the crane movement. The method utilizes computer vision to determine cargo position which is used to control crane movement optimally

Ensilering, en jämförelse mellan olika ensileringssystem

Syftet med den här litteraturstudien är att gå igenom hur ensilering går till och vad som bör beaktas för att få ett hygieniskt och näringsrikt foder: vilka faktorer som är viktiga innan och efter materialet har ensilerats och vanliga problem i processen utvärderas. Slutligen beskrivs och jämförs vanliga ensileringssystem med dess för och nackdelar. Det är många faktorer som spelar in om ensileringen blir lyckad eller inte och det finns olika orosmoment i ensileringens olika faser. För att öka förutsättningarna för en bra ensilering förtorkas ofta grödan, det är också vanligt att tillsatsmedel används för att öka förutsättningarna till en ordentlig ensilering. Studien tar upp metoderna: balsilo, slangsilo, tornsilo och plansilo och jämför dessa i avseenden som är relevanta i jordbruket. Slutsatserna är att ett misstag i en del av ensileringen kan stjälpa hela processen, det är därför viktigt att alla moment utförs noggrant. Ensileringsmetoderna varierar i ts-halt vid lagring och därmed även i ts-förluster. Metoderna skiljer sig även i investeringskostnader och arbetsbehov, där torn- och plansilo har höga investeringskostnader samtidigt som de har hög kapacitet och rationalitet. Rundbal och slangsilo har sina fördelar i låga förluster och investeringskostnader samtidigt som de har stor flexibilitet i lagringskapacitet. Nackdelen med rundbal är den stora hanteringsgraden medans problemet i slangsilo utgörs av gropbildning som kan försvåra hanteringen. De olika ensileringsmetoderna varierar därför i lämplighet beroende på hur gårdens förutsättningar ser ut och det är svårt att dra slutsatsen om ett system är bättre än ett annat.The purpose of this report is to consider what happens during ensiling and what should be considered to achieve a hygienic and nutritious feed. Important processes before and after the material has been ensiled and common problems associated with them were evaluated. Finally, common ensiling methods are described and compared with its pros and cons. There are many factors that influence whether the ensiling is successful or not. The ensiling process faces various problems in the different ensiling stages. To increase the chances for a good ensiling the material is often wilted. The use of silage additives is another common practice to ensure a proper ensiling process. The study deals with methods such as: bale silo, tower silo, bag silo and bunker silo and compare them in a manner that is relevant to good agriculture practice. The conclusions of this report is that one mistake in one part of the process can ruin the entire process. It is therefore important that all stages are carefully managed. There is difference in suitable dry matter of crop ensiled in different ensiling methods, which consequently affects ensiling losses. The methods also differ in investment costs and labor requirement, where tower- and bunker silo has high investment costs simultaneously with high capacity and rationality. Bale and bag silo has its advantages in low dm losses and investment costs simultaneously with high flexibility in storage capacity. The disadvantage with bale silo is the large amount of handling meanwhile the problem in bag silo consists of pitting that can hamper the handling. The ensiling methods therefore vary depending on farm condition which makes it difficult to conclude that one system is better than another

Effects of Ligands on Unfolding of the Amyloid β-Peptide Central Helix: Mechanistic Insights from Molecular Dynamics Simulations

Polymerization of the amyloid β-peptide (Aβ), a process which requires that the helical structure of Aβ unfolds beforehand, is suspected to cause neurodegeneration in Alzheimer's disease. According to recent experimental studies, stabilization of the Aβ central helix counteracts Aβ polymerization into toxic assemblies. The effects of two ligands (Dec-DETA and Pep1b), which were designed to bind to and stabilize the Aβ central helix, on unfolding of the Aβ central helix were investigated by molecular dynamics simulations. It was quantitatively demonstrated that the stability of the Aβ central helix is increased by both ligands, and more effectively by Pep1b than by Dec-DETA. In addition, it was shown that Dec-DETA forms parallel conformations with β-strand-like Aβ, whereas Pep1b does not and instead tends to bend unwound Aβ. The molecular dynamics results correlate well with previous experiments for these ligands, which suggest that the simulation method should be useful in predicting the effectiveness of novel ligands in stabilizing the Aβ central helix. Detailed Aβ structural changes upon loss of helicity in the presence of the ligands are also revealed, which gives further insight into which ligand may lead to which path subsequent to unwinding of the Aβ central helix

Garbage collector interface

The purpose of the presented garbage collector interface is to provide a universal interface for many different implementations of garbage collectors. This is to simplify the integration and exchange of garbage collectors, but also to support incremental, non-conservative, and thread safe implementations. Due to the complexity of the interface, it is aimed at code generators and preprocessors. Experiences from ongoing implementations indicate that the garbage collector interface successfully provides the necessary functionality in an efficient way

Precipitation regime controls bryosphere carbon cycling similarly across contrasting ecosystems

In arctic and boreal ecosystems, ground bryophytes play an important role in regulating carbon (C) exchange between vast belowground C stores and the atmosphere. Climate is changing particularly fast in these high-latitude regions, but it is unclear how altered precipitation regimes will affect C dynamics in the bryosphere (i.e. the ground moss layer including senesced moss, litter and associated biota) and the closely associated upper humus layer, and how these effects will vary across contrasting environmental conditions. Here, we set up a greenhouse experiment in which mesocosms were assembled containing samples of the bryosphere, dominated by the feather moss Hylocomium splendens, and the upper humus layer, that were collected from across a boreal forest chronosequence in northern Sweden which varies strongly in nutrient availability, productivity and soil biota. We tested the effect of variation in precipitation volume and frequency on CO2 exchange and dissolved organic carbon (DOC) export, and on moss growth. As expected, reduced precipitation volume and frequency lowered net CO2 efflux, DOC export and moss growth. However, by regulating moisture, the lower bryosphere and humus layers often mediated how precipitation volume and frequency interacted to drive C dynamics. For example, less frequent precipitation reduced moss growth only when precipitation volume was low. When volume was high, high moisture content of the humus layer helped avoid moss desiccation. Variation in precipitation regime affected C cycling consistently in samples collected across the chronosequence, despite large environmental variation along the sequence. This suggests that the bryosphere exerts a strong buffering effect on environmental variation at the forest floor, which leads to similar responses of C cycling to external perturbations across highly contrasting ecosystems. As such, our study indicates that projected increases in droughts and ground evapotranspiration in high-latitude regions resulting from climate change will consistently reduce C losses from moss-dominated ecosystems

Investigating psychometric properties and dimensional structure of an educational environment measure (DREEM) using Mokken scale analysis - A pragmatic approach

© 2018 The Author(s). Background: Questionnaires and surveys are used throughout medical education. Nevertheless, measuring psychological attributes such as perceptions of a phenomenon among individuals may be difficult. The aim of this paper is to introduce the basic principles of Mokken scale analysis (MSA) as a method for the analysis of questionnaire data and to empirically apply MSA to a real-data example. Methods: MSA provides a set of statistical tools for exploring the relationship between items and latent traits. MSA is a scaling method of item selection algorithms used to partition an array of items into scales. It employs various methods to probe the assumptions of two nonparametric item response theory models: the monotone homogeneity model and the double monotonicity model. The background and theoretical framework underlying MSA are outlined in the paper. MSA for polytomous items was applied to a real-life data example of 222 undergraduate students who had completed a 50-item self-administered inventory measuring the educational environment, the Dundee Ready Educational Measure (DREEM). Results: A pragmatic and parsimonious approach to exploring questionnaires and surveys from an item response theory (IRT) perspective is outlined. The use of MSA to explore the psychometric properties of the Swedish version of the DREEM failed to yield strong support for the scalability and dimensional structure of the instrument. Conclusions: MSA, a class of simple nonparametric IRT models - for which estimates can be easily obtained and whose fit to data is relatively easily investigated - was introduced, presented, and tested. Our real-data example suggests that the psychometric properties of DREEM are not adequately supported. Thus, the empirical application depicted a potential and feasible approach whereby MSA could be used as a valuable method for exploring the behavior of scaled items in response to varying levels of a latent trait in medical education research

The giant eyes of giant squid are indeed unexpectedly large, but not if used for spotting sperm whales

© The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in BMC Evolutionary Biology 13 (2013): 187, doi:10.1186/1471-2148-13-187.We recently reported (Curr Biol 22:683–688, 2012) that the eyes of giant and colossal squid can grow to three times the diameter of the eyes of any other animal, including large fishes and whales. As an explanation to this extreme absolute eye size, we developed a theory for visual performance in aquatic habitats, leading to the conclusion that the huge eyes of giant and colossal squid are uniquely suited for detection of sperm whales, which are important squid-predators in the depths where these squid live. A paper in this journal by Schmitz et al. (BMC Evol Biol 13:45, 2013) refutes our conclusions on the basis of two claims: (1) using allometric data they argue that the eyes of giant and colossal squid are not unexpectedly large for the size of the squid, and (2) a revision of the values used for modelling indicates that large eyes are not better for detection of approaching sperm whales than they are for any other task. We agree with Schmitz et al. that their revised values for intensity and abundance of planktonic bioluminescence may be more realistic, or at least more appropriately conservative, but argue that their conclusions are incorrect because they have not considered some of the main arguments put forward in our paper. We also present new modelling to demonstrate that our conclusions remain robust, even with the revised input values suggested by Schmitz et al

Ротаційно–ударна обробка спіралей шнеків

Forskningsinriktningen vid den historiska avdelningen vid Linköpings universitet har sedan länge en stark socialhistorisk profil. kollektivens vardag studeras på en rad områden, på olika nivåer och över sinsemellan skilda tidsperioder. Det gäller inom såväl agrara som industriella miljöer, på samhällelig liksom på grupp-, familje- och individnivå samt över tid som omspänner senantiken till det sena 1900-talets historia. Hur identiteter skapas, tillägnas och förändras är en alltmer växande inriktning, liksom anknytningen till socialpolitiska ideer, normsystem, attityder, värderingar och mentaliteter. Även den  rättshistoriska och ekonomiskhistoriska forskningen ryms inom detta fält. Den historiska demografin utgör också traditionellt en stark del av det socialhistoriska fältet. Studier av arbeta och ohälsa, sjuklighet, dödlighet och hälsopolitik ligger långt framme. Bredden i den socialhistoriska profilen morsvaras av en mångfald melodologiska inslag. Skriftserien Socialhistoria i Linköping uppmärksammar denna profil och vilka uttryck den tar sig i grundutbildningen. I serien publiceras i första hand uppsatser skrivna på C- och D- nivå, men även bidrag från lärare och doktorander vid avdelningen förekommer. Detta nummer av Socialhistoria i Linköping är en specialutgåva till Svenska historikermötet i Linköping 23-25 april 199

Food plots as a habitat management tool: forage production and ungulate browsing in adjacent forest

A key challenge for wildlife management is to handle competing goals. High ungulate densities may be desirable from hunting and recreational perspectives, but may come in conflict with needs to limit or reduce browsing damage. Since browsing intensity is negatively related to forage availability it may be possible to mitigate damage on forest by increasing forage availability within the landscape. A commonly used method to increase the attractiveness of a localized part of the landscape is to establish food plots. In a multiyear setup using enclosures, wildlife observations, field surveys, and controlled biomass removal, we studied food plots to document forage production, utilization by ungulates, and browsing on adjacent forests in southern Sweden. The fenced parts of the food plots produced on average 2230 to 5810 kg ha. 1 marrow-stem kale, second-year clover mix or early-sown rapeseed. The biomass of target crops was generally higher within ungrazed (exclosures) compared to grazed (controls) quadrats on the food plots, which demonstrates that the crops were used as forage by ungulates. Browsing on deciduous trees in the adjacent forest was higher within 70-135 m from the food plots compared to areas further away. For wildlife management, our study shows that establishment of food plots provides substantial amounts of forage both during growing season and at the onset of the dormant season, and that a large share of this food is consumed. Finally, our study documents that forage availability for ungulates at the onset of the often-limiting dormant season can be increased by fencing food plots throughout the growing season