981 research outputs found
Constraints on convergence: hydrophobic hind legs allow some male pollinator fig wasps early access to submerged females
Pollinator fig wasps (Hymenoptera: Agaonidae) display numerous adaptations linked to their obligate association with fig trees (Ficus). Ceratosolen fig wasps pollinate figs that often fill temporarily with liquid, and one clade has males with unusually long hind legs. We investigated their morphology and behaviour. Scanning electron microscopy (SEM) revealed that the cuticle of their hind legs is highly modified and covered with numerous hydrophobic setae and microtrichia that can prevent blockage of the wasps’ large propodeal spiracles by liquids. In deep liquid, the males floated on the surface, but when only a thin layer of liquid was present, the legs allowed males to access females without the risk of drowning. Access to females was facilitated by an air bubble that forms between the hind legs and maintains a column of air between the spiracles and the centre of the figs. Sexual selection should favour males that can gain earlier access to mates, and the modified legs represent an adaptation to achieve this. Convergent adaptations are known in some unrelated non-pollinating fig wasps that develop in similar liquid-filled figs, but these species have enlarged hydrophobic peritremata at the ends of their metasoma to protect the spiracles located there. Unlike non-pollinating fig wasps, pollinator males need to insert their metasoma deep into females’ galls during mating. This difference in mating behaviour has constrained the extent of convergence
Overvåking av vannkvalitet og biologiske forhold i Begna-/Øystre Slidre-vassdraget i 2002
Årsliste 2003Rapporten gir en beskrivelse av vannkvaliteten og forurensningsgraden av næringssalter i Slidrefjorden, Øyangen og Strondafjorden samt i Vindavassdraget. Den oppsummerer også tidsutviklingen i vannkvaliteten fra 1980-tallet til 2002. Ut fra sesongmiddelverdiene av næringssalter og klorofyll-a kan Slidrefjorden og Øyangen betegnes som næringsfattige innsjøer. Konsentrasjonene av tarmbakterier var lave, og vannkvaliteten kan derfor karakteriseres som meget god i vekstsesongen. Observasjonene i Øyangen gav ingen indikasjoner på større utslipp fra Beito renseanlegg i vekstsesongen 2002. Vannkvaliteten i Strondafjorden har stort sett vært god de siste 8-9 årene med hensyn til næringssalter, algemengder og tarmbakterier. Bortsett fra en moderat algeoppblomstring høsten 2001, har det ikke vært observert markerte algeoppblomstringer i perioden 1994-02, og middelkonsentrasjonen av fosfor i 2002 var den laveste som er observert siden målingene startet i 1984. Såvel algemengdene som sammensetningen innen planteplanktonet viste likevel at innsjøen var noe mere påvirket av næringssalttilførsler enn Slidrefjorden og Øyangen. Resultatene fra overvåkingen i perioden 1984-93 samt algeoppblomstringen i 2001 viser også at små økninger i tilførslene av næringssalter i kombinasjon med pent og varmt vær lett kan føre til algeoppblomstringer og dermed problemer for brukerne av innsjøen. Vindavassdraget med tilløpselver hadde i hovedsak rentvannskarakter og en akseptabel tilstand ved undersøkelsen i 2002. Unntak fra dette var en strekning av Grytebekken som var noe påvirket av næringssaltforurensninger. Volbuelva var også noe påvirket av overgjødsling.Forenenigen til Bægnavassdragets Regulering Nord-Aurdal kommune Øystre Slidre kommune Vestre Slidre kommune Vang kommun
LysoPC acyltransferase/PC transacylase activities in plant plasma membrane and plasma membrane-associated endoplasmic reticulum
<p>Abstract</p> <p>Background</p> <p>The phospholipids of the plant plasma membrane are synthesized in the endoplasmic reticulum (ER). The majority of these lipids reach the plasma membrane independently of the secretory vesicular pathway. Phospholipid delivery to the mitochondria and chloroplasts of plant cells also bypasses the secretory pathway and here it has been proposed that lysophospholipids are transported at contact sites between specific regions of the ER and the respective organelle, followed by lysophospholipid acylation in the target organelle. To test the hypothesis that a corresponding mechanism operates to transport phospholipids to the plasma membrane outside the secretory pathway, we investigated whether lysolipid acylation occurs also in the plant plasma membrane and whether this membrane, like the chloroplasts and mitochondria, is in close contact with the ER.</p> <p>Results</p> <p>The plant plasma membrane readily incorporated the acyl chain of acyl-CoA into phospholipids. Oleic acid was preferred over palmitic acid as substrate and acyl incorporation occurred predominantly into phosphatidylcholine (PC). Phospholipase A<sub>2 </sub>stimulated the reaction, as did exogenous lysoPC when administered in above critical micellar concentrations. AgNO<sub>3 </sub>was inhibitory. The lysophospholipid acylation reaction was higher in a membrane fraction that could be washed off the isolated plasma membranes after repeated freezing and thawing cycles in a medium with lowered pH. This fraction exhibited several ER-like characteristics. When plasma membranes isolated from transgenic <it>Arabidopsis </it>expressing green fluorescent protein in the ER lumen were observed by confocal microscopy, membranes of ER origin were associated with the isolated plasma membranes.</p> <p>Conclusion</p> <p>We conclude that a lysoPC acylation activity is associated with plant plasma membranes and cannot exclude a PC transacylase activity. It is highly plausible that the enzyme(s) resides in a fraction of the ER, closely associated with the plasma membrane, or in both. We suggest that this fraction might be the equivalent of the mitochondria associated membrane of ER origin that delivers phospholipids to the mitochondria, and to the recently isolated ER-derived membrane fraction that is in close contact with chloroplasts. The <it>in situ </it>function of the lysoPC acylation/PC transacylase activity is unknown, but involvement in lipid delivery from the ER to the plasma membrane is suggested.</p
PDB72 Health economic evaluation of canagliflozin in the treatment of type 2 diabetes mellitus in Sweden
Smoking, diet, pregnancy and oral contraceptive use as risk factors for cervical intra-epithelial neoplasia in relation to human papillomavirus infection
Smoking, nutrition, parity and oral contraceptive use have been reported as major environmental risk factors for cervical cancer. After the discovery of the very strong link between human papillomavirus (HPV) infection and cervical cancer, it is unclear whether the association of these environmental factors with cervical cancer reflect secondary associations attributable to confounding by HPV, if they are independent risk factors or whether they may act as cofactors to HPV infection in cervical carcinogenesis. To investigate this issue, we performed a population-based case–control study in the Västerbotten county of Northern Sweden of 137 women with high-grade cervical intra-epithelial neoplasia (CIN 2–3) and 253 healthy age-matched women. The women answered a 94-item questionnaire on diet, smoking, oral contraceptive use and sexual history and donated specimens for diagnosis of present HPV infection (nested polymerase chain reaction on cervical brush samples) and for past or present HPV infections (HPV seropositivity). The previously described protective effects of dietary micronutrients were not detected. Pregnancy appeared to be a risk factor in the multivariate analysis (P< 0.0001). Prolonged oral contraceptive use and sexual history were associated with CIN 2–3 in univariate analysis, but these associations lost significance after taking HPV into account. Smoking was associated with CIN 2–3 (odds ratio (OR) 2.6, 95% confidence interval (CI) 1.7–4.0), the effect was dose-dependent (P = 0.002) and the smoking-associated risk was not affected by adjusting for HPV, neither when adjusting for HPV DNA (OR 2.5, CI 1.3–4.9) nor when adjusting for HPV seropositivity (OR 3.0, CI 1.9–4.7). In conclusion, after taking HPV into account, smoking appeared to be the most significant environmental risk factor for cervical neoplasia. © 2000 Cancer Research Campaig
The SOFIA Pilot Trial:A cluster-randomized trial of coordinated, co-produced care to reduce mortality and improve quality of life in people with severe mental illness in the general practice setting
Abstract Background People with severe mental illness (SMI) have an increased risk of premature mortality, predominantly due to somatic health conditions. Evidence indicates that primary and tertiary prevention and improved treatment of somatic conditions in patients with SMI could reduce this excess mortality. This paper reports a protocol designed to evaluate the feasibility of a coordinated co-produced care program (SOFIA model, a Danish acronym for Severe Mental Illness and Physical Health in General Practice) in the general practice setting to reduce mortality and improve quality of life in patients with severe mental illness. Methods The SOFIA pilot trial is designed as a cluster randomized controlled trial targeting general practices in two regions in Denmark. We aim to include 12 practices, each of which is instructed to recruit up to 15 community-dwelling patients aged 18 and older with SMI. Practices will be randomized by a computer in a ratio of 2:1 to deliver a coordinated care program or usual care during a 6-month study period. A randomized algorithm is used to perform randomization. The coordinated care program includes educational training of general practitioners and their clinical staff educational training of general practitioners and their clinical staff, which covers clinical and diagnostic management and focus on patient-centered care of this patient group, after which general practitioners will provide a prolonged consultation focusing on individual needs and preferences of the patient with SMI and a follow-up plan if indicated. The outcomes will be parameters of the feasibility of the intervention and trial methods and will be assessed quantitatively and qualitatively. Assessments of the outcome parameters will be administered at baseline, throughout, and at end of the study period. Discussion If necessary the intervention will be revised based on results from this study. If delivery of the intervention, either in its current form or after revision, is considered feasible, a future, definitive trial to determine the effectiveness of the intervention in reducing mortality and improving quality of life in patients with SMI can take place. Successful implementation of the intervention would imply preliminary promise for addressing health inequities in patients with SMI. Trial registration The trial was registered in Clinical Trials as of November 5, 2020, with registration number NCT04618250 . Protocol version: January 22, 2021; original versio
Electronic Coherence Dephasing in Excitonic Molecular Complexes: Role of Markov and Secular Approximations
We compare four different types of equations of motion for reduced density
matrix of a system of molecular excitons interacting with thermodynamic bath.
All four equations are of second order in the linear system-bath interaction
Hamiltonian, with different approximations applied in their derivation. In
particular we compare time-nonlocal equations obtained from so-called
Nakajima-Zwanzig identity and the time-local equations resulting from the
partial ordering prescription of the cummulant expansion. In each of these
equations we alternatively apply secular approximation to decouple population
and coherence dynamics from each other. We focus on the dynamics of intraband
electronic coherences of the excitonic system which can be traced by coherent
two-dimensional spectroscopy. We discuss the applicability of the four
relaxation theories to simulations of population and coherence dynamics, and
identify features of the two-dimensional coherent spectrum that allow us to
distinguish time-nonlocal effects.Comment: 14 pages, 8 figure
Clinical effectiveness of elective single versus double embryo transfer: meta-analysis of individual patient data from randomised trials
Objective To compare the effectiveness of elective single embryo transfer versus double embryo transfer on the outcomes of live birth, multiple live birth, miscarriage, preterm birth, term singleton birth, and low birth weight after fresh embryo transfer, and on the outcomes of cumulative live birth and multiple live birth after fresh and frozen embryo transfers
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