85 research outputs found
Age differences in night-time metabolic rate and body temperature in a small passerine
Spending the winter in northern climes with short days and cold ambient temperatures (Ta) can be energetically challenging for small birds that have high metabolic and heat loss rates. Hence, maintaining body temperature (Tb) in Ta below thermoneutrality can be energetically costly for a small bird. We still know little about how increased heat production below thermoneutrality affects the level at which Tb is maintained, and if these patterns are age specific. To test this, we measured subcutaneous body temperature (Ts) and resting metabolic rate (RMR) simultaneously in blue tits (Cyanistes caeruleus) during winter nights in Taâs ranging from 25 to â 15 °C. RMR increased below the lower critical temperature (LCT, estimated at 14 °C) and was 6% higher in young (birds in their first winter) compared to old birds (birds in their second winter or older). The higher RMR was also mirrored in higher Ts and thermal conductance (C) in young birds, which we suggest could be caused by age differences in plumage quality, likely driven by time constraints during moult. Reduction in nightly predicted Tb was modest and increased again at the coldest ambient temperatures, suggesting that either heat retention or heat production (or both) improved when Ta reached levels which are cold by the standards of birds in our population. Our results show that levels of heat production and Tb can be age specific. Further studies should address age-specific differences on quality, structure, and thermal conductivity of plumage more explicitly, to investigate the role of variation in insulation in age-linked metabolic phenotypes
Ăr du blind eller?!
Uppsatsens syfte Àr att belysa hur mÀnniskor med nedsatt syn upplever tillgÀngligheten tillkollektivtrafik i Malmö samt diskutera och problematisera det klassiska förhÄllningssÀttet gentemot begreppet tillgÀnglighet. Uppsatsens metod Àr av kvalitativ karaktÀr. Intervjuer genomfördes för att undersöka hur synskadade i Malmö upplever tillgÀnglighet till kollektivtrafiken. En dokumentstudie har genomförts för att undersöka hur Malmö stad och Region SkÄne definierar och tillÀmpar begreppet tillgÀnglighet i sitt arbete mot mer hÄllbar mobilitet. Slutligen har vi genomfört en kompletterande deltagande övning dÀr vi fick uppleva hur tillgÀnglig staden Àr utifrÄn blinda mÀnniskors perspektiv.
Vi har kommit fram till att mÀnniskor med nedsatt syn har behov som inte tillmötesgÄs av den allmÀnna kollektivtrafiken. En rad behov, exempelvis tillgÄng till information, Àr begrÀnsad till följd av kollektivtrafikens bristande teknisk funktion. Ytterligare behov, till exempel sjÀlvstÀndighet och spontanitet, Àr svÄra att tillmötesgÄ eftersom de Äterfinns
bortom det kvantifierbara. Dessa icke kvantifierbara behov kan inte kopplas till specifik kvalitet vilket pÄvisar svagheten i att definiera kollektivtrafikens tillgÀnglighet utifrÄn befintliga kvaliteter. Dokumentstudien pÄvisar att de tvÄ administrativa organen Region SkÄne och Malmö stad definierar och tillÀmpar tillgÀnglighet pÄ ett sÀtt som frÄnkopplar individen. Fokus finns pÄ mÀtbara indikatorer för att definiera tillgÀnglighet till kollektivtrafik. Dokumentstudien visar ocksÄ att Malmö stad försöker inkorporera den individuella resenÀren vilket uppenbaras dÄ kommunen genomför kvalitativa bedömningar av kollektivtrafikens tillgÀnglighet. Kvantifierbara indikatorers dominans i sammanhanget Äterspeglas dock dÄ Malmö stad utför kvantitativa undersökningar som indexerar kollektivtrafikens kvalitet och tillgÀnglighet varje Är och kvalitativa bedömningar vartannat Är.
Uppsatsens slutsats Àr att begreppet upplevd tillgÀnglighet kan bidra till en mer samtalsdriven planering dÀr mÀnniskans behov stÄr i fokus istÀllet för kollektivtrafikens kvalitet. Genom att planera med mÀnniskor skapas förutsÀttningar att inte missa behov som finns bortom det kvantifierbara. Om planering utförs med nuvarande och framtida brukare kan kollektivtrafiken bli mer tillgÀnglig för fler vilket Àr viktigt för den hÄllbara utvecklingen.The aim of this study is to illuminate how the visually impaired experience accessibility to the public transport in Malmö and to discuss and problematize the classic approach to the concept. We have used a qualitative approach to the studied phenomenon. Interviews were conducted i to examine how visually impaired in Malmö experience accessibility to public transport. We have also carried out a document study to examine how Malmö stad and
Region SkÄne defines and apply accessibility in their work for sustainable mobility. Finally we participated in a participation exercise where we got to experience how accessible thecity are from the perspective of the visually impaired.
The interviews show that the visually impaired have needs which donât get meet by the public transport system in Malmö. Some of the needs, for example access to information, are limited as a result of deficient technical function in public transport. Other needs, for example the need to be independent or spontaneous, are harder to meet because they exist beyond the quantifiable. These non quantifiable needs canÂŽt be coupled with a specific quality in public transport which accentuates the weakness in the classical way of defining accessibility within transport planning. The document study demonstrates that the two administrative agencies Region SkĂ„ne and Malmö stad defines and practice accessibility in a way that decouples the individual. Focus is on measurable indicators to define accessibility to public transport. The document study also shows that Malmö stad are conducting qualitative assessment in the context of accessibility to public transport. Yet quantifiable
qualities are still dominating the work with accessibility which shows when quantifiable enquiries are executed more often than qualitative assessments.
The conclusion of the study is that the concept of perceived accessibility can contribute to a more discourse driven planning practise where the user stands in focus, not the quality of public transport. Planning with people generates better conditions to not undermine the needs that exists beyond the quantifiable. Planning with present and future users is key to create a more accessible public transport system, which is important for sustainable development
Experimental facilitation of heat loss affects work rate and innate immune function in a breeding passerine bird
The capacity to get rid of excess heat produced during hard work is a possible constraint on parental effort during reproduction [heat dissipation limit (HDL) theory]. We released hard-working blue tits (Cyanistes caeruleus) from this constraint by experimentally removing ventral plumage. We then assessed whether this changed their reproductive effort (feeding rate and nestling size) and levels of self-maintenance (change in body mass and innate immune function). Feather-clipped females reduced the number of feeding visits and increased levels of constitutive innate immunity compared with unclipped females but did not fledge smaller nestlings. Thus, they increased self-maintenance without compromising current reproductive output. In contrast, feather clipping did not affect the number of feeding visits or innate immune function in males, despite increased heat loss rate. Our results show that analyses of physiological parameters, such as constitutive innate immune function, can be important when trying to understand sources of variation in investment in self-maintenance versus reproductive effort and that risk of overheating can influence innate immune function during reproduction
Intact salicylic acid signalling is required for potato defence against the necrotrophic fungus Alternaria solani.
Background
In order to get global molecular understanding of one of the most important crop diseases worldwide, we investigated compatible and incompatible interactions between Phytophthora infestans and potato (Solanum tuberosum). We used the two most field-resistant potato clones under Swedish growing conditions, which have the greatest known local diversity of P. infestans populations, and a reference compatible cultivar.
Results
Quantitative label-free proteomics of 51 apoplastic secretome samples (PXD000435) in combination with genome-wide transcript analysis by 42 microarrays (E-MTAB-1515) were used to capture changes in protein abundance and gene expression at 6, 24 and 72 hours after inoculation with P. infestans. To aid mass spectrometry analysis we generated cultivar-specific RNA-seq data (E-MTAB-1712), which increased peptide identifications by 17%. Components induced only during incompatible interactions, which are candidates for hypersensitive response initiation, include a Kunitz-like protease inhibitor, transcription factors and an RCR3-like protein. More secreted proteins had lower abundance in the compatible interaction compared to the incompatible interactions. Based on this observation and because the well-characterized effector-target C14 protease follows this pattern, we suggest 40 putative effector targets.
Conclusions
In summary, over 17000 transcripts and 1000 secreted proteins changed in abundance in at least one time point, illustrating the dynamics of plant responses to a hemibiotroph. Half of the differentially abundant proteins showed a corresponding change at the transcript level. Many putative hypersensitive and effector-target proteins were single representatives of large gene families
Thyroid function and immune status in perch (Perca fluviatilis) from lakes contaminated with PFASs or PCBs
The environment contains a multitude of man-made chemicals, some of which can act as endocrine disruptors (EDCs), while others can be immunotoxic. We evaluated thyroid disruption and immunotoxic effects in wild female perch (Perca fluviatilis) collected from two contaminated areas in Sweden; one site contaminated with perand polyfluoroalkyl substances (PFASs) and two sites contaminated with polychlorinated biphenyls (PCBs), with one reference site included for each area. The hepatic mRNA expression of thyroid receptors alpha and beta, and the thyroid hormone metabolising iodothyronine deiodinases (dio1, dio2 and dio3) were measured using real-time PCR, while the levels of thyroid hormone T3 in plasma was analysed using a radioimmunoassay. In addition, lymphocytes, granulocytes, and thrombocytes were counted microscopically. Our results showed lower levels of T3 as well as lower amounts of lymphocytes and granulocytes in perch collected from the PFAS-contaminated site compared to reference sites. In addition, expressions of mRNA coding for thyroid hormone metabolising enzymes (dio2 and dio3) and thyroid receptor alpha (thra) were significantly different in these fish compared to their reference site. For perch collected at the two PCB-contaminated sites, there were no significant differences in T3 levels or in expression levels of the thyroid-related genes, compared to the reference fish. Fish from one of the PCB-contaminated sites had higher levels of thrombocytes compared with both the second PCB lake and their reference lake; hence PCBs are unlikely to be the cause of this effect. The current study suggests that lifelong exposure to PFASs could affect both the thyroid hormone status and immune defence of perch in the wild
Scanning Small-Angle X-ray Scattering of Injection-Molded Polymers: Anisotropic Structure and Mechanical Properties of Low-Density Polyethylene
Injection molding is known to create a layered anisotropicmorphologyacross the sample thickness due to varying shear and cooling ratesduring the manufacturing process. In this study, scanning small-angleX-ray scattering was used to visualize and quantify the distributionof hierarchical structures present in injection-molded parts of low-densitypolyethylene (LDPE) with varying viscosities. By combining scatteringdata with results from injection molding simulations and tensile testing,we find that oriented shish-kebab structures, as well as elongatedspherulite structures consisting of semicrystalline ellipsoids, contributeto high ultimate tensile strength along the flow direction. Furthermore,we show that a higher degree of orientation is found close to theinjection gate and in LDPE with higher viscosity, consequently fromelevated shear and cooling rates present during the injection moldingprocess
Chronic fatigue syndromes: real illnesses that people can recover from
The âOslo Chronic Fatigue Consortiumâ consists of researchers and clinicians who question the current narrative that chronic fatigue syndromes, including post-covid conditions, are incurable diseases. Instead, we propose an alternative view, based on research, which offers more hope to patients. Whilst we regard the symptoms of these conditions as real, we propose that they are more likely to reflect the brain's response to a range of biological, psychological, and social factors, rather than a specific disease process. Possible causes include persistent activation of the neurobiological stress response, accompanied by associated changes in immunological, hormonal, cognitive and behavioural domains. We further propose that the symptoms are more likely to persist if they are perceived as threatening, and all activities that are perceived to worsen them are avoided. We also question the idea that the best way to cope with the illness is by prolonged rest, social isolation, and sensory deprivation. Instead, we propose that recovery is often possible if patients are helped to adopt a less threatening understanding of their symptoms and are supported in a gradual return to normal activities. Finally, we call for a much more open and constructive dialogue about these conditions. This dialogue should include a wider range of views, including those of patients who have recovered from them
Teasing, storytelling and categorizations : On friendship and romance in children's relational talk
This thesis focuses on how middle school children organize peer group relationships through various forms of so-called relational talk (Evaldsson, 2007), while they also negotiate and more generally make sense of friendships and romantic relationships. Prior micro-sociological research has demonstrated how children in everyday language practices through, for example, teasing, assessments, and storytellingâarticulate and manage social relationships and behaviors, moral views, and shared cultural knowledge, thereby constructing their emerging social worlds (see Goodwin & Kyratzis, 2011, for an overview). Several ethnographic studies have also shown how children in everyday peer group interactions construct gendered cultures, encompassing gender hierarchies and heteronormative ordering, while managing social relationships (Renold, 2005). This study is a continued exploration into these areas, building on ethnographic fieldwork, including participant observations, video recordings, and focus group interviews with friendship groups among children in two fifth grade classes in a Swedish school setting. The analysis draws on an ethnomethodological multimodal interactional approach to talk-in- interaction (Goodwin, 1990), combined with membership categorization work (Stokoe, 2010) and ethnographic knowledge of the local culture (Evaldsson, 2021; Goodwin, 2014).The analysis shows that humor-oriented language practices, such as teasing and joking, function as a resource for children to address potentially sensitive and/or embarrassing aspects of social relationships, where humor and collective laughter work as a de-dramatizing resource while building local peer group relationships (cf. Eder, 1991). Moreover, the results show that childrenâs way of articulating and making sense of their views on friendship and romance through storytelling, assessments, and jocular play is related to a moral dimension, as they index and negotiate (un)acceptable behaviors. This dimension becomes visible through their invocation and management of membership categorizations, person descriptions, and evaluative comments in their local identity work. Simultaneously, the analysis demonstrates how ethnographic knowledge of childrenâs social life is central in understanding how wider social dynamics become part of the local peer cultures of preteen children (Evaldsson, 2005a; Goodwin, 2011), especially regarding how the negotiation of local categories and their embedded meanings is related to wider social categorizations of gender, social class, and age. Overall, this thesis demonstrates how children as social actors use a variety of interactional resources (i.e., talk, laughter, loud voices, facial expressions, smiles, and gestures) to organize local peer group relationships, while collectively staging, negotiating, and making sense of both romance and friendship
Gastropod intrashell chemical profiles (d18=,d13C,Mg/Ca,Sr/Ca) as indicators of paleogene and recent environmental and climatic conditions
Body temperature data on great- and blue tits
Field data on body temperature in great- and blue tits together with all parameters used in the analyses. Sheet 1: great tit data, Sheet 2: blue tit data, Sheet 3: metadata, description of column heading
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