•We present a new, transparent and replicable model-driven method to predict the onset of food crises across the world.•We apply the model to Malawi, a country with persistent chronic and acute food ...security problems.•Leveraging readily available data, our model substantially improves over the status quo global methods of prediction.•Our best forecasts predict the out-of-sample food security status for between 65 and 88 percent of village clusters.•Our analysis and results demonstrate the potential gains to real-time food security modeling.
Globally, over 800 million people are food insecure. Current methods for identifying food insecurity crises are not based on statistical models and fail to systematically incorporate readily available data on prices, weather, and demographics. As a result, policymakers cannot rapidly identify food insecure populations. These problems delay responses to mitigate hunger. We develop a replicable, near real-time model incorporating spatially and temporally granular market data, remotely-sensed rainfall and geographic data, and demographic characteristics. We train the model on 2010–2011 data from Malawi and forecast 2013 food security. Our model correctly identifies the food security status of 83 to 99% of the most food insecure village clusters in 2013, depending on the food security measure, while the prevailing approach correctly identifies between 0 and 10%. Our results show the power of modeling food insecurity to provide early warning and suggest model-driven approaches could dramatically improve food insecurity crisis response.
The initiation of growth cessation and dormancy represent critical life-history trade-offs between survival and growth and have important fitness effects in perennial plants. Such adaptive ...life-history traits often show strong local adaptation along environmental gradients but, despite their importance, the genetic architecture of these traits remains poorly understood.
We integrate whole genome re-sequencing with environmental and phenotypic data from common garden experiments to investigate the genomic basis of local adaptation across a latitudinal gradient in European aspen (Populus tremula). A single genomic region containing the PtFT2 gene mediates local adaptation in the timing of bud set and explains 65% of the observed genetic variation in bud set. This locus is the likely target of a recent selective sweep that originated right before or during colonization of northern Scandinavia following the last glaciation. Field and greenhouse experiments confirm that variation in PtFT2 gene expression affects the phenotypic variation in bud set that we observe in wild natural populations.
Our results reveal a major effect locus that determines the timing of bud set and that has facilitated rapid adaptation to shorter growing seasons and colder climates in European aspen. The discovery of a single locus explaining a substantial fraction of the variation in a key life-history trait is remarkable, given that such traits are generally considered to be highly polygenic. These findings provide a dramatic illustration of how loci of large-effect for adaptive traits can arise and be maintained over large geographical scales in natural populations.
Flexible airway endoscopy (FAE) is an accepted and frequently performed procedure in the evaluation of children with known or suspected airway and lung parenchymal disorders. However, published ...technical standards on how to perform FAE in children are lacking.
The American Thoracic Society (ATS) approved the formation of a multidisciplinary committee to delineate technical standards for performing FAE in children. The committee completed a pragmatic synthesis of the evidence and used the evidence synthesis to answer clinically relevant questions.
There is a paucity of randomized controlled trials in pediatric FAE. The committee developed recommendations based predominantly on the collective clinical experience of our committee members highlighting the importance of FAE-specific airway management techniques and anesthesia, establishing suggested competencies for the bronchoscopist in training, and defining areas deserving further investigation.
These ATS-sponsored technical standards describe the equipment, personnel, competencies, and special procedures associated with FAE in children.
The prevalences of asthma and obesity in children have increased significantly during the past 2 decades. The basis for the relationship between pediatric asthma and obesity is not well established.
...To explore the association between obesity and asthma severity in children and adolescents and to test whether obesity-induced inflammation, as characterized by serum C-reactive protein (CRP), is associated with increased severity of asthma.
Retrospective cohort analysis of interview, physical examination, and laboratory test data from participants younger than 20 years in 2 rounds of the National Health and Nutrition Examination Survey (2001-2002 and 2003-2004). We also performed generalized ordered logistic regression to evaluate the effect of body mass index (BMI) z score and CRP level on asthma severity, controlling for the impact of age, sex, race, income, insurance, and tobacco smoke exposure.
Of the 77 million individuals younger than 20 years represented by this weighted sample, 19% met the study-defined criteria for asthma; most cases were defined as mild (11%) or moderate (6%); 2% had severe asthma. In multivariable models, elevated BMI z scores (odds ratio, 1.12; 95% confidence interval, 1.05-1.21) were associated with worse asthma severity. Elevated CRP level was associated with obesity (P < .001) and asthma severity (odds ratio, 1.33; 95% confidence interval, 1.16-1.52).
Higher BMI z scores and elevated serum CRP levels are associated with increased asthma severity. These findings highlight the importance of controlling for inflammation when considering the role of obesity and provide support for the hypothesis that obesity-induced inflammation may contribute to greater asthma severity.
Autumn senescence in aspen is not triggered by day length Michelson, Ingrid H.; Ingvarsson, Pär K.; Robinson, Kathryn M. ...
Physiologia plantarum,
January 2018, 2018-Jan, 2018-01-00, 20180101, 2018, Letnik:
162, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Autumn senescence in mature aspens, grown under natural conditions, is initiated at almost the same date every year. The mechanism of such precise timing is not understood but we have previously ...shown that the signal must be derived from light. We studied variation in bud set and autumn senescence in a collection of 116 natural Eurasian aspen (Populus tremula) genotypes, from 12 populations in Sweden and planted in one northern and one southern common garden, to test the hypothesis that onset of autumn senescence is triggered by day length. We confirmed that, although bud set seemed to be triggered by a critical photoperiod/day length, other factors may influence it. The data on initiation of autumn senescence, on the other hand, were incompatible with the trigger being the day length per se, hence the trigger must be some other light‐dependent factor.
Supermarkets, specialized wholesalers, processors, and agro-exporters are transforming the marketing channels into which smallholder farmers sell produce in low-income economies. We develop a ...conceptual framework with which to study contracting between smallholders and a commodity-processing firm. We then synthesize results from empirical studies of contract farming arrangements in five countries (Ghana, India, Madagascar, Mozambique, and Nicaragua). The resulting meta-narrative documents patterns of participation, the welfare gains associated with participation, reasons for nonparticipation, the significant extent of contract noncompliance, and the considerable dynamism of these value chains as farmers and firms enter and exit frequently.
Summary Paediatric haematopoietic cell transplantation has experienced significant advances in the last few decades. However, pulmonary complications are an important limitation to the efficacy of ...this intervention, contributing to post-transplantation morbidity and mortality. Such complications persist even in experienced centres and occur in adult and paediatric recipients. This review identifies the paediatric pulmonary complications that are commonly seen following haematopoietic cell transplantation and addresses both infectious and non-infectious aetiologies and their clinical manifestations, evaluation, and potential therapy. Ultimately, improvement in outcomes will require attention to immunosuppression as well as traditional diagnostic procedures and treatment. This article aims to review the current state of pulmonary complications post-transplantation, to examine the impact of our recent advances and changes in treatment, and to identify potential future therapies and hypothesise what role these might have on long-term survival.
1. We have developed a 19-compartment cable model of a guinea pig CA3 pyramidal neuron. Each compartment is allowed to contain six active ionic conductances: gNa, gCa, gK(DR) (where DR stands for ...delayed rectifier), gK(A), gK(AHP), and gK(C). THe conductance gCa is of the high-voltage activated type. The model kinetics for the first five of these conductances incorporate voltage-clamp data obtained from isolated hippocampal pyramidal neurons. The kinetics of gK(C) are based on data from bullfrog sympathetic neurons. The time constant for decay of submembrane calcium derives from optical imaging of Ca signals in Purkinje cell dendrites. 2. To construct the model from available voltage-clamp data, we first reproduced current-clamp records from a model isolated neuron (soma plus proximal dendrites). We next assumed that ionic channel kinetics in the dendrites were the same as in the soma. In accord with dendritic recordings and calcium-imaging data, we also assumed that significant gCa occurs in dendrites. We then attached sections of basilar and apical dendritic cable. By trial and error, we found a distribution (not necessarily unique) of ionic conductance densities that was consistent with current-clamp records from the soma and dendrites of whole neurons and from isolated apical dendrites. 3. The resulting model reproduces the Ca(2+)-dependent spike depolarizing afterpotential (DAP) recorded after a stimulus subthreshold for burst elicitation. 4. The model also reproduces the behavior of CA3 pyramidal neurons injected with increasing somatic depolarizing currents: low-frequency (0.3-1.0 Hz) rhythmic bursting for small currents, with burst frequency increasing with current magnitude; then more irregular bursts followed by afterhyperpolarizations (AHPs) interspersed with brief bursts without AHPs; and finally, rhythmic action potentials without bursts. 5. The model predicts the existence of still another firing pattern during tonic depolarizing dendritic stimulation: brief bursts at less than 1 to approximately 12 Hz, a pattern not observed during somatic stimulation. These bursts correspond to rhythmic dendritic calcium spikes. 6. The model CA3 pyramidal neuron can be made to resemble functionally a CA1 pyramidal neuron by increasing gK(DR) and decreasing dendritic gCa and gK(C). Specifically, after these alterations, tonic depolarization of the soma leads to adapting repetitive firing, whereas stimulation of the distal dendrites leads to bursting. 7. A critical set of parameters concerns the regulation of the pool of intracellular Ca2+ that interacts with membrane channels (gK(C) and gK(AHP)), particularly in the dendrites.
1. Intracellular recordings were obtained from pyramidal, granule and hilar cells in transverse slices of guinea-pig hippocampus
to examine synaptic interactions between GABAergic neurones. 2. In the ...presence of the convulsant compound 4-aminopyridine
(4-AP), after fast excitatory amino acid (EAA) neurotransmission was blocked pharmacologically, large amplitude inhibitory
postsynaptic potentials (IPSPs) occurred rhythmically (every 4-8 s) and synchronously in all principal cell populations (triphasic
synchronized IPSPs). In the presence of the GABAA receptor blocker picrotoxin (PTX), a large amplitude IPSP continued to occur
spontaneously in all principal cells simultaneously (monophasic synchronized IPSP). 3. Burst firing occurred simultaneously
in a group of hilar neurones (synchronized bursting neurones) coincident with triphasic synchronized IPSPs in principal cells.
After PTX was added, the bursts and the underlying depolarizing synaptic potentials were completely suppressed in some of
the synchronized bursting neurones (type I hilar neurones), while others (type II hilar neurones) continued to fire in bursts
coincident with monophasic synchronized IPSPs in principal cells. Intense hyperpolarization blocked burst firing and revealed
underlying attenuated spikes of less than 10 mV, but did not uncover any underlying depolarizing synaptic potentials. 4. In
type II hilar neurones, during sufficient hyperpolarization, spontaneous activity consisted of attenuated spikes. With depolarization,
the small spikes began to trigger full size action potentials. These data suggest the presence of electrotonically remote
spike initiation sites. 5. The morphology of synchronized bursting neurones was revealed by intracellular injection of the
fluorescent dye Lucifer Yellow. Attempts to inject dye into one type II hilar neurone often resulted in the labelling of two
to four cells (dye coupling). Dye coupling was not observed in type I hilar neurones. 6. These findings indicate that excitatory
interactions synchronizing the firing of GABAergic neurones can occur in the absence of fast EAA neurotransmission. GABAergic
neurones can become synchronized via their recurrent collaterals through the depolarizing action of synaptically activated
GABAA receptors. In addition, a subpopulation of GABAergic neurones can become synchronized by a mechanism probably involving
electrotonic coupling.
Undernutrition is common in cystic fibrosis (CF) and is correlated with long-term outcomes, yet current nutritional interventions have not demonstrated consistent improvements in energy intake, and ...subsequently, growth. Development of novel nutritional interventions to increase energy intake is essential to improve clinical outcomes of individuals with CF. Ready-to-use supplemental food (RUSF) is a modifiable, inexpensive, palatable, safe, and nutrient-dense food for treatment or prevention of acute malnutrition in developing countries. Utilizing a linear-programming tool we identified 6 RUSF formulations with sufficient nutrient density (495 kcal/100 g), protein, and fat for children with CF. Palatability was established by a taste-trial and affirmed by a 2-wk tolerability assessment that demonstrated consistent consumption and tolerance of the RUSF. Although preliminary, this study demonstrates the potential for developing RUSF as a nutritional supplement for increasing energy intake in children with CF.
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