722 research outputs found
Innate lymphoid cell regulation of adaptive immunity
Innate lymphoid cells (ILCs) were identified principally as nonāTācell sources of key cytokines, able to provide rapid and early production of these molecules in the support of tissue homeostasis, repair and response to infection. As our understanding of these cells has developed, it has become evident that ILCs can impact on lymphocytes through a range of mechanisms. Hence, an exciting area of research has evolved in determining the extent to which ILCs may regulate adaptive immune responses. This review will focus initially on our current understanding of where ILC populations are located and what this means for potential cellular interactions. Mechanisms underpinning such interactions and how they may contribute to controlling adaptive immunity will then be considered
Metabolic Physiology of Euthermic and Torpid Lesser Long-Eared Bats, Nyctophilus geoffroyi (Chiroptera: Vespertilionidae)
Thermal and metabolic physiology of the Australian lesser long-eared bat, Nyctophilias geojfroyi, a small (ca. 8 g) gleaning insectivore, was studied using flow-through respirometry. Basal metabolic rate of N. geojfroyi (1.42 ml O2 gā1 hā1) was 70% of that predicted for an 8-g mammal but fell within the range for vespertilionid bats. N. geoffroyi was thermally labile, like other vespertilionid bats from the temperate zone, with clear patterns of euthermy (body temperature >32Ā°C) and torpor. It was torpid at temperatures ā¤25Ā°C, and spontaneously aroused from torpor at ambient temperatures ā„5Ā°C. Torpor provided significant savings of energy and water, with substantially reduced rates of oxygen consumption and evaporative water loss. Minimum wet conductance (0.39 ml O2 gā1 hā1 Ā°Cā1) of euthermic bats was 108% of predicted, and euthermic dry conductance was 7.2 J gā1 hā1 Ā°Cā1 from 5-25Ā°C. Minimum wet and dry conductances of bats that were torpid at an ambient temperature of 15-20Ā°C (0.06 ml O2 gā1 hā1 Ā°Cā1 and 0.60 J gā1 hā1 Ā°Cā1) were substantially less than euthermic values, but conductance of some torpid bats increased at lower ambient temperatures and approached values for euthermic bats. Metabolic rates of bats torpid at ambient temperatures >10Ā°C and bats euthermic in the thermoneutral zone indicated a metabolic Q10 of 3.9. That high Q10 suggested that there may have been an intrinsic reduction in metabolic rate during torpor, in addition to down-regulation of thermoregulation (which accounted for most of the reduction in metabolic rate) and the normal Q10 effec
MHC-II: A Mutual Support System for ILCs and T Cells?
Innate and adaptive immune cells form an ongoing partnership during an immune response. In this issue of Immunity, Oliphant etĀ al. (2014) show that MHC class II-peptide presentation by group 2 innate lymphoid cellsĀ is needed for reciprocal regulation of both cell types, resulting in effective antihelminth immunity
Improved Lower and Upper Bounds on the Tile Complexity of Uniquely Self-Assembling a Thin Rectangle Non-Cooperatively in 3D
We investigate a fundamental question regarding a benchmark class of shapes
in one of the simplest, yet most widely utilized abstract models of algorithmic
tile self-assembly. Specifically, we study the directed tile complexity of a thin rectangle in Winfree's abstract Tile Assembly Model, assuming
that cooperative binding cannot be enforced (temperature-1 self-assembly) and
that tiles are allowed to be placed at most one step into the third dimension
(just-barely 3D). While the directed tile complexities of a square and a
scaled-up version of any algorithmically specified shape at temperature 1 in
just-barely 3D are both asymptotically the same as they are (respectively) at
temperature 2 in 2D, the bounds on the directed tile complexity of a thin
rectangle at temperature 2 in 2D are not known to hold at temperature 1 in
just-barely 3D. Motivated by this discrepancy, we establish new lower and upper
bounds on the directed tile complexity of a thin rectangle at temperature 1 in
just-barely 3D. We develop a new, more powerful type of Window Movie Lemma that
lets us upper bound the number of "sufficiently similar" ways to assign glues
to a set of fixed locations. Consequently, our lower bound,
, is an asymptotic improvement over the
previous best lower bound and is more aesthetically pleasing since it
eliminates the that used to divide . The proof of our
upper bound is based on a just-barely 3D, temperature-1 counter, organized
according to "digit regions", which affords it roughly fifty percent more
digits for the same target rectangle compared to the previous best counter.
This increase in digit density results in an upper bound of
, that
is an asymptotic improvement over the previous best upper bound and roughly the
square of our lower bound
Physical characteristics and occurrence rates of meteoric plasma layers detected in the Martian ionosphere by the Mars Global Surveyor Radio Science Experiment
Low-altitude plasma layers are present in 71 of 5600 electron density profiles from the Martian ionosphere obtained by the Mars Global Surveyor Radio Science experiment. These layers are produced by the ablation of meteoroids and subsequent ionization of meteoric atoms. The mean altitude of the meteoric layer is 91.7 +/- 4.8 km. The mean peak electron density in the meteoric layer is (1.33 +/- 0.25) x 10(10) m(-3). The mean width of the meteoric layer is 10.3 +/- 5.2 km. The occurrence rate of meteoric layers varies with season, solar zenith angle, and latitude. Seasonal variations in occurrence rate are particularly strong, often exceeding an order of magnitude. Meteoric layer altitude, peak electron density, and width are all positively correlated, with correlation coefficients of 0.3-0.4. Other correlation coefficients between the physical characteristics of meteoric layers and atmospheric or observational properties, such as scale height, solar zenith angle, and solar flux, have absolute values that are significantly smaller, indicating lack of correlation. The photochemical lifetime of plasma in meteoric layers is similar to 12 days and depends on altitude
Life Cycle Assessment of Biofertilizer Production and Use Compared with Conventional Liquid Digestate Management
Handling of digestate produced by
anaerobic digestion impacts the
environment through emission of greenhouse gases, reactive nitrogen,
and phosphorus. Previous life cycle assessments (LCA) evaluating the
extraction of nutrients from digestate using struvite precipitation
and ammonia stripping did not relate synthetic fertilizer substitution
(SFS) to nutrient use efficiency consequences. We applied an expanded
LCA to compare the conventional management of 1 m<sup>3</sup> of liquid
digestate (LD) from food waste against the production and use of digestate
biofertilizer (DBF) extracted from LD, accounting for SFS efficacy.
Avoidance of CH<sub>4</sub>, N<sub>2</sub>O, and NH<sub>3</sub> emissions
from LD handling and enhanced SFS via more targeted use of nutrients
in the versatile DBF product could generate environmental savings
of up to 0.129 kg Sb eq, 4.16 kg SO<sub>2</sub> eq, 1.22 kg PO<sub>4</sub> eq, 33 kg CO<sub>2</sub> eq, and 20.6 MJ eq per m<sup>3</sup> LD, for abiotic resource depletion, acidification, eutrophication,
global warming, and cumulative energy demand burdens, respectively.
However, under worst-case assumptions, DBF extraction could increase
global warming and cumulative energy demand by 7.5 kg CO<sub>2</sub>e and 251 MJ eq per m<sup>3</sup> LD owing to processing inputs.
Normalizing these results against per capita environmental loadings,
we conclude that DBF extraction is environmentally beneficial
Simultaneous multiple allelic replacement in the malaria parasite enables dissection of PKG function.
Over recent years, a plethora of new genetic tools has transformed conditional engineering of the malaria parasite genome, allowing functional dissection of essential genes in the asexual and sexual blood stages that cause pathology or are required for disease transmission, respectively. Important challenges remain, including the desirability to complement conditional mutants with a correctly regulated second gene copy to confirm that observed phenotypes are due solely to loss of gene function and to analyse structure-function relationships. To meet this challenge, here we combine the dimerisable Cre (DiCre) system with the use of multiple lox sites to simultaneously generate multiple recombination events of the same gene. We focused on the Plasmodium falciparum cGMP-dependent protein kinase (PKG), creating in parallel conditional disruption of the gene plus up to two allelic replacements. We use the approach to demonstrate that PKG has no scaffolding or adaptor role in intraerythrocytic development, acting solely at merozoite egress. We also show that a phosphorylation-deficient PKG is functionally incompetent. Our method provides valuable new tools for analysis of gene function in the malaria parasite
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