Teneurin-3 regulates the generation of non-image-forming visual circuitry and responsiveness to light in the suprachiasmatic nucleus.

Visual system function depends upon the elaboration of precise connections between retinal ganglion cell (RGC) axons and their central targets in the brain. Though some progress has been made in defining the molecules that regulate RGC connectivity required for the assembly and function of image-forming circuitry, surprisingly little is known about factors required for intrinsically photosensitive RGCs (ipRGCs) to target a principal component of the non-image-forming circuitry: the suprachiasmatic nucleus (SCN). Furthermore, the molecules required for forming circuits critical for circadian behaviors within the SCN are not known. We observe here that the adhesion molecule teneurin-3 (Tenm3) is highly expressed in vasoactive intestinal peptide (VIP) neurons located in the core region of the SCN. Since Tenm3 is required for other aspects of mammalian visual system development, we investigate roles for Tenm3 in regulating ipRGC-SCN connectivity and function. Our results show that Tenm3 negatively regulates association between VIP and arginine vasopressin (AVP) neurons within the SCN and is essential for M1 ipRGC axon innervation to the SCN. Specifically, in Tenm3-/- mice, we find a reduction in ventro-medial innervation to the SCN. Despite this reduction, Tenm3-/- mice have higher sensitivity to light and faster re-entrainment to phase advances, probably due to the increased association between VIP and AVP neurons. These data show that Tenm3 plays key roles in elaborating non-image-forming visual system circuitry and that it influences murine responses to phase-advancing light stimuli.

Characterizing neural coding performance for populations of sensory neurons: comparing a weighted spike distance metrics to other analytical methods.

The identity of sensory stimuli is encoded in the spatio-temporal patterns of responses of the encoding neural population. For stimuli to be discriminated reliably, differences in population responses must be accurately decoded by downstream networks. Several methods to compare patterns of responses have been used by neurophysiologists to characterize the accuracy of the sensory responses studied. Among the most widely used analyses, we note methods based on Euclidean distances or on spike metric distances. Methods based on artificial neural networks and machine learning that recognize and/or classify specific input patterns have also gained popularity. Here, we first compare these three strategies using datasets from three different model systems: the moth olfactory system, the electrosensory system of gymnotids, and leaky-integrate-and-fire (LIF) model responses. We show that the input-weighting procedure inherent to artificial neural networks allows the efficient extraction of information relevant to stimulus discrimination. To combine the convenience of methods such as spike metric distances but leverage the advantages of weighting the inputs, we propose a measure based on geometric distances where each dimension is weighted proportionally to how informative it is. We show that the result of this Weighted Euclidian Distance (WED) analysis performs as well or better than the artificial neural network we tested and outperforms the more traditional spike distance metrics. We applied information theoretic analysis to LIF responses and compared their encoding accuracy with the discrimination accuracy quantified through this WED analysis. We show a high degree of correlation between discrimination accuracy and information content, and that our weighting procedure allowed the efficient use of information present to perform the discrimination task. We argue that our proposed measure provides the flexibility and ease of use sought by neurophysiologists while providing a more powerful way to extract relevant information than more traditional methods.

Phosphorus and iron-oxide transport from a hydrologically isolated grassland hillslope.

Dissolved reactive phosphorus (DRP) loss from agricultural soils can negatively affect water quality. Shallow subsurface pathways can dominate P losses in grassland soils, especially in wetter months when waterlogging is common. This study investigated the processes controlling intra- and inter-event and seasonal DRP losses from poorly drained permanent grassland hillslope plots. Temporal flow related water samples were taken from surface runoff and subsurface (in-field pipe) discharge, analysed, and related to the likelihood of anaerobic conditions and redoximorphic species including nitrate (NO3-) over time. Subsurface drainage accounted for 89% of total losses. Simple linear regression and correlation matrices showed positive relationships between DRP and iron and soil moisture deficit; and negative relationships between these three factors and NO3- concentrations in drainage. These data indicate that waterlogging and low NO3- concentrations control the release of P in drainage, potentially via reductive dissolution. The relationship between DRP and metal release was less obvious in surface runoff, as nutrients gathered from P-rich topsoil camoflaged redox reactions. The data suggest a threshold in NO3- concentrations that could exacerbate P losses, even in low P soils. Knowledge of how nutrients interact with soil drainage throughout the year can be used to better time soil N and P inputs via, for example, fertiliser or grazing to avoid to excessive P loss that could harm water quality.

Evaluating connectivity risk of farm roadway runoff with waters - Development and sensitivity analysis of a semi quantitative risk model.

Farm roadways are an important sub-component of the nutrient transfer continuum (NTC) and roadway runoff (RR), leading to nutrient pressures in receiving waters at different times of the year at catchment scale. This study developed a semi-quantitative risk assessment model for dairy farms that once populated with data identifies roadway sections where RR enters waters. The model contains parameters that represent source, mobilisation and transport-connectivity stages of the NTC defined as continuous or categorical variables. Each parameter has a corresponding scoring system in terms of connectivity likelihood to waters (L) and the associated impact on water quality (I) from which field data can be converted to a risk score (RS). The connectivity or impact risk of any roadway section is a sum of all parameter scores, i.e. 'Total Risk Score' (TRS). The risk scores were classified into 5 categories (very low, low, moderate, high and very high). Field data from seven farms enabled five equal interval risk score classifications to be developed (very low (110-134), low (135-158), moderate (159-182), high (183-206), very high (207-230)). Fieldwork data showed differences between the number of mapped roadway sections ranging from 35 to 76, with the lowest and highest risk scores being 110 and 230, respectively. Out of all sections scored 25.9 %, 45.6 %, 20.4 %, 6.4 %, and 2 % were in very low, low, moderate, high and very high categories, respectively. In terms of management, only 8.4 % (i.e. high or very high scores) had all components of the NTC and required RR mitigation. An examination of the mobilisation parameter showed that the % of roadway sections needing mitigation is likely to increase if rainfall increases on these farms. An uncertainty assessment limiting the model to different levels of connectivity confirmed that all components of the NTC and those with greater than moderate risk should only be considered in future mitigation plans. Future work should concentrate on adapting this methodology to a wide range of farm enterprises.

Mineral fertiliser equivalent value of dairy processing sludge and derived biochar using ryegrass (Lolium perenne L.) and spring wheat (Triticumaestivum).

As supply chains of chemical fertilisers become more precarious, raw or derived bio-based fertilisers (herein referred to as bio-fertilisers) from the dairy processing industry could be good alternatives. However, their agronomic performance is relatively unknown, and where documented, the method to estimate this value is rarely presented. This pot study investigated aluminium-precipitated and calcium-precipitated dairy processing sludges (Al and Ca-DPS) and DPS-derived biochar as potential bio-fertilisers to grow ryegrass (Lolium perenne L.) and spring wheat (Triticum aestivum). The study aims were to examine how (1) application rate (optimal versus high) and (2) calculation methods (with and without chemical fertiliser response curves) can affect estimates of nitrogen and phosphorus mineral fertiliser equivalence value (N- and P-MFE) and associated agronomic advice. The results from both crops showed that for nitrogen application rates (125 or 160 kg ha-1 for ryegrass and 160 or 240 kg ha-1 for spring wheat) estimates of N-MFE increased for both Al-DPS and Ca-DPS as application rate increased. Dry matter yield response curves produced the highest % N-MFE results (e.g., ryegrass ∼50% and 70% for Al-DPS and Ca-DPS) with other calculation methods producing all similar results (e.g., ryegrass ∼20% for Al-DPS and Ca-DPS). For phosphorus application rates (40 or 80 kg ha-1 for ryegrass and 50 or 80 kg ha-1 for spring wheat), estimates of P-MFE did not increase with application rate. Negative P-MFE values obtained for Ca-DPS and DPS-biochar when growing ryegrass and spring wheat grain, respectively, indicated low plant available phosphorus. Overall, Al-DPS had better performance as a bio-fertiliser when compared to the other products tested. There was no significant difference between the two calculation methods of MFE, which suggests that the determination of MFE could be simplified by using one application as opposed to numerous application rates of fertilisers. Future work should focus on elucidating the N- and P-MFE of a wider range of DPS and STRUBIAS bio-fertilisers, and alternative methods should be investigated that enable a comparison across all bio-fertiliser types.

Daily changes in light influence mood via inhibitory networks within the thalamic perihabenular nucleus.

Exposure to irregular lighting schedules leads to deficits in affective behaviors. The retino-recipient perihabenular nucleus (PHb) of the dorsal thalamus has been shown to mediate these effects in mice. However, the mechanisms of how light information is processed within the PHb remains unknown. Here, we show that the PHb contains a distinct cluster of GABAergic neurons that receive direct retinal input. These neurons are part of a larger inhibitory network composed of the thalamic reticular nucleus and zona incerta, known to modulate thalamocortical communication. In addition, PHbGABA neurons locally modulate excitatory-relay neurons, which project to limbic centers. Chronic exposure to irregular light-dark cycles alters photo-responsiveness and synaptic output of PHbGABA neurons, disrupting daily oscillations of genes associated with inhibitory and excitatory PHb signaling. Consequently, selective and chronic PHbGABA manipulation results in mood alterations that mimic those caused by irregular light exposure. Together, light-mediated disruption of PHb inhibitory networks underlies mood deficits.

Metagenomic assembled plasmids of the human microbiome vary across disease cohorts.

We compiled a human metagenome assembled plasmid (MAP) database and interrogated differences across multiple studies that were originally designed to investigate the composition of the human microbiome across various lifestyles, life stages and events. This was performed as plasmids enable bacteria to rapidly expand their functional capacity through mobilisation, yet their contribution to human health and disease is poorly understood. We observed that inter-sample ß-diversity differences of plasmid content (plasmidome) could distinguish cohorts across a multitude of conditions. We also show that reduced intra-sample plasmidome α-diversity is consistent amongst patients with inflammatory bowel disease (IBD) and Clostridioides difficile infections. We also show that faecal microbiota transplants can restore plasmidome diversity. Overall plasmidome diversity, specific plasmids, and plasmid-encoded functions can all potentially act as biomarkers of IBD or its severity. The human plasmidome is an overlooked facet of the microbiome and should be integrated into investigations regarding the role of the microbiome in promoting health or disease. Including MAP databases in analyses will enable a greater understanding of the roles of plasmid-encoded functions within the gut microbiome and will inform future human metagenome analyses.

An examination of maximum legal application rates of dairy processing and associated STRUBIAS fertilising products in agriculture.

The dairy industry produces vast quantities of dairy processing sludge (DPS), which can be processed further to develop second generation products such as struvite, biochars and ashes (collectively known as STRUBIAS). These bio-based fertilizers have heterogeneous nutrient and metal contents, resulting in a range of possible application rates. To avoid nutrient losses to water or bioaccumulation of metals in soil or crops, it is important that rates applied to land are safe and adhere to the maximum legal application rates similar to inorganic fertilizers. This study collected and analysed nutrient and metal content of all major DPS (n = 84) and DPS-derived STRUBIAS products (n = 10), and created an application calculator in MS Excel™ to provide guidance on maximum legal application rates for ryegrass and spring wheat across plant available phosphorus (P) deficient soil to P-excess soil. The sample analysis showed that raw DPS and DPS-derived STRUBIAS have high P contents ranging from 10.1 to 122 g kg-1. Nitrogen (N) in DPS was high, whereas N concentrations decreased in thermo-chemical STRUBIAS products (chars and ash) due to the high temperatures used in their formation. The heavy metal content of DPS and DPS-derived STRUBIAS was significantly lower than the EU imposed limits. Using the calculator, application rates of DPS and DPS-derived STRUBIAS materials (dry weight) ranged from 0 to 4.0 tonnes ha-1 y-1 for ryegrass and 0-4.5 tonnes ha-1 y-1 for spring wheat. The estimated heavy metal ingestion to soil annually by the application of the DPS and DPS-derived STRUBIAS products was lower than the EU guideline on soil metal accumulation. The calculator is adaptable for any bio-based fertilizer, soil and crop type, and future work should continue to characterise and incorporate new DPS and DPS-derived STRUBIAS products into the database presented in this paper. In addition, safe application rates pertaining to other regulated pollutants or emerging contaminants that may be identified in these products should be included. The fertilizer replacement value of these products, taken from long-term field studies, should be factored into application rates.

Quantifying citrate-enhanced phosphate root uptake using microdialysis.

AIMS: Organic acid exudation by plant roots is thought to promote phosphate (P) solubilisation and bioavailability in soils with poorly available nutrients. Here we describe a new combined experimental (microdialysis) and modelling approach to quantify citrate-enhanced P desorption and its importance for root P uptake. METHODS: To mimic the rhizosphere, microdialysis probes were placed in soil and perfused with citrate solutions (0.1, 1.0 and 10 mM) and the amount of P recovered from soil used to quantify rhizosphere P availability. Parameters in a mathematical model describing probe P uptake, citrate exudation, P movement and citrate-enhanced desorption were fit to the experimental data. These parameters were used in a model of a root which exuded citrate and absorbed P. The importance of soil citrate-P mobilisation for root P uptake was then quantified using this model. RESULTS: A plant needs to exude citrate at a rate of 0.73 µmol cm-1 of root h-1 to see a significant increase in P absorption. Microdialysis probes with citrate in the perfusate were shown to absorb similar quantities of P to an exuding root. CONCLUSION: A single root exuding citrate at a typical rate (4.3 × 10-5 µmol m-1 of root h-1) did not contribute significantly to P uptake. Microdialysis probes show promise for measuring rhizosphere processes when calibration experiments and mathematical modelling are used to decouple microdialysis and rhizosphere mechanisms.

A management framework for phosphorus use on agricultural soils using sorption criteria and soil test P.

The variation in sorption and desorption of phosphorus (P) among soil types is not captured in current agronomic advice for agri-environmentally sustainable use of P. Phosphorus use is typically based on soil test P (STP) and soils are assumed to have the same rate of response to added P, regardless of sorption properties. The development of P sorption categories, coupled with STP information could improve fertiliser decision making, by making it more site specific and soil type specific. A framework for P sorption specific advice is proposed here integrating soil P sorption dynamics with STP for agronomic and environmental management, at farm and catchment scale. Using a national population of agricultural soils, laboratory measurement of Langmuir sorption maximum (Smax50, mg kg-1) and binding energy (k50, l mg-1), were coupled with STP (Morgan P) to derive novel categories for P management advice, specifically addressing the build-up and draw-down phases of P in soils. In addition to measured values, Smax50 and k50 were predicted from MIR spectroscopy and pedotransfer functions and used to allocate soils into these new sorption categories. The allocation of soils into a P management category using predicted values indicated that pedotransfer functions offered greater reliability (90% allocation accuracy using an independent test set), however MIR spectroscopy is faster and less resource intensive (67% allocation accuracy using an independent test set). Phosphorus sorption dynamics should be interpreted alongside soil test P and P Index information so that water quality policy can consider the difference between high and very high STP soils based on sorption information. In the absence of laboratory data on P sorption, soils can be classified into P management classes using predicted values from spectroscopy (rapid and cheap) or pedotransfer functions (greater reliability). Further development of the MIR methodology is recommended along with field validation.

Long-term cognitive and psychiatric outcomes of acute respiratory distress syndrome managed with Extracorporeal Membrane Oxygenation.

BACKGROUND: Cognitive dysfunction is often reported in patients who have experienced acute respiratory distress syndrome (ARDS). Extra Corporeal Membrane Oxygenation (ECMO) therapy is increasingly used to manage ARDS patients in ICU, transforming survival rates. However, few studies have examined cognitive outcomes. METHODS: We examined self-reported cognitive complaints, psychiatric outcomes and neuropsychological test performance in survivors of severe hypoxaemia managed with VV-ECMO, at 18-24 month follow-up, compared with a group of healthy controls. RESULTS: Over 70% of ECMO-treated patients (N = 46) complained of difficulty in at least one aspect of cognition on self-report measures (study 1). However, a much lower frequency of cognitive impairment was found on formal neuropsychological testing (study 2). Mean neuropsychological test scores of the ECMO group (N = 24) did not significantly differ from healthy controls (N = 23) after controlling for depression. Less than 30% of ECMO-treated patients showed impairments in anterograde memory, and deficits on general IQ or executive function were seen in <17% of patients. However, we observed high levels of self-reported anxiety and depression in the ECMO-treated patients. CONCLUSIONS: Cognitive outcomes in ECMO-treated patients were generally good, with preserved neuropsychological function in the majority of patients, despite severe hypoxaemia and high rates of self-reported difficulties. However, we saw high levels of mental health symptoms in these patients, highlighting a need for psychological support.

Nutrient sensing of gut luminal environment.

Sensing of nutrients by chemosensory cells in the gastrointestinal tract plays a key role in transmitting food-related signals, linking information about the composition of ingested foods to digestive processes. In recent years, a number of G protein-coupled receptors (GPCR) responsive to a range of nutrients have been identified. Many are localised to intestinal enteroendocrine (chemosensory) cells, promoting hormonal and neuronal signalling locally, centrally and to the periphery. The field of gut sensory systems is relatively new and still evolving. Despite huge interest in these nutrient-sensing GPCR, both as sensors for nutritional status and targets for preventing the development of metabolic diseases, major challenges remain to be resolved. However, the gut expressed sweet taste receptor, resident in L-enteroendocrine cells and responsive to dietary sweetener additives, has already been successfully explored and utilised as a therapeutic target, treating weaning-related disorders in young animals. In addition to sensing nutrients, many GPCR are targets for drugs used in clinical practice. As such these receptors, in particular those expressed in L-cells, are currently being assessed as potential new pathways for treating diabetes and obesity. Furthermore, growing recognition of gut chemosensing of microbial-produced SCFA acids has led further attention to the association between nutrition and development of chronic disorders focusing on the relationship between nutrients, gut microbiota and health. The central importance of gut nutrient sensing in the control of gastrointestinal physiology, health promotion and gut-brain communication offers promise that further therapeutic successes and nutritional recommendations will arise from research in this area.

Toll-like receptor 9 expressed in proximal intestinal enteroendocrine cells detects bacteria resulting in secretion of cholecystokinin.

Toll-like receptors (TLRs) play a key role in the recognition of microbes via detection of specific and conserved microbial molecular features. TLRs, mainly expressed in immune cells, interact with intestinal microbiome. Little is known about mechanism(s) of sensing of bacteria by the intestinal surface enteroendocrine cells (EECs). We show here that TLR9 is expressed by the EECs of proximal intestine in a range of species and is co-expressed with the satiety hormone cholecystokinin (CCK). CCK secreted in excess induces emesis (vomiting). Using an EEC model cell line, STC-1, we demonstrate that in response to the TLR9 agonist, DNA containing unmethylated CpG dinucleotide motifs, STC-1 cells secrete CCK and that this secretion is inhibited by specific inhibitors of TLR9. Exposure of STC-1 cells to heat-inactivated pathogenic bacteria, Escherichia coli O55/H7, Shigella flexneri 2457T, Salmonella typhimurium ST4/74, and non-pathogenic Lactobacillus amylovorus GRL1112, results to an increase in CCK secretion compared to untreated control. The magnitudes of CCK release are higher in response to pathogenic bacteria and lowest in response to the non-pathogenic L. amylovorus. The pathogenic strains not only have substantially bigger genomes than L. amylovorus, they also have significantly higher numbers/frequency of RR/CG/YY stimulatory CpG hexamers in their genomic DNA. Pathogen-induced excessive secretion of the gut hormone CCK, provoking emesis can serve as a protective mechanism against development of enteric infections.

Organization of intensive cardiac care units in Europe: Results of a multinational survey.

BACKGROUND: The present survey aims to describe the intensive cardiac care unit organization and admission policies in Europe. METHODS: A total of 228 hospitals (61% academic) from 27 countries participated in this survey. In addition to the organizational aspects of the intensive cardiac care units, including classification of the intensive cardiac care unit levels, data on the admission diagnoses were gathered from consecutive patients who were admitted during a two-day period. Admission policies were evaluated by comparing illness severity with the intensive cardiac care unit level. Gross national income was used to differentiate high-income countries (n=13) from middle-income countries (n=14). RESULTS: A total of 98% of the hospitals had an intensive cardiac care unit: 70% had a level 1 intensive cardiac care unit, 76% had a level 2 intensive cardiac care unit, 51% had a level 3 intensive cardiac care unit, and 60% of the hospitals had more than one intensive cardiac care unit level. High-income countries tended to have more level 3 intensive cardiac care units than middle-income countries (55% versus 41%, p=0.07). A total of 5159 admissions were scored on illness severity: 63% were low severity, 24% were intermediate severity, and 12% were high severity. Patients with low illness severity were predominantly admitted to level 1 intensive cardiac care units, whereas patients with high illness severity were predominantly admitted to level 2 and 3 intensive cardiac care units. A policy mismatch was observed in 12% of the patients; some patients with high illness severity were admitted to level 1 intensive cardiac care units, which occurred more often in middle-income countries, whereas some patients with low illness severity were admitted to level 3 intensive cardiac care units, which occurred more frequently in high-income countries. CONCLUSION: More than one-third of the admitted patients were considered intermediate or high risk. Although patients with higher illness severity were mostly admitted to high-level intensive cardiac care units, an admission policy mismatch was observed in 12% of the patients; this mismatch was partly related to insufficient logistic intensive cardiac care unit capacity.

Impact of P inputs on source-sink P dynamics of sediment along an agricultural ditch network.

Phosphorus (P) loss from intensive dairy farms is a pressure on water quality in agricultural catchments. At farm scale, P sources can enter in-field drains and open ditches, resulting in transfer along ditch networks and delivery into nearby streams. Open ditches could be a potential location for P mitigation if the right location was identified, depending on P sources entering the ditch and the source-sink dynamics at the sediment-water interface. The objective of this study was to identify the right location along a ditch to mitigate P losses on an intensive dairy farm. High spatial resolution grab samples for water quality, along with sediment and bankside samples, were collected along an open ditch network to characterise the P dynamics within the ditch. Phosphorus inputs to the ditch adversely affected water quality, and a step change in P concentrations (increase in mean dissolved reactive phosphorus (DRP) from 0.054 to 0.228 mg L-1) midway along the section of the ditch sampled, signalled the influence of a point source entering the ditch. Phosphorus inputs altered sediment P sorption properties as P accumulated along the length of the ditch. Accumulation of bankside and sediment labile extractable P, Mehlich 3 P (M3P) (from 13 to 97 mg kg-1) resulted in a decrease in P binding energies (k) to < 1 L mg-1 at downstream points and raised the equilibrium P concentrations (EPC0) from 0.07 to 4.61 mg L-1 along the ditch. The increase in EPC0 was in line with increasing dissolved and total P in water, demonstrating the role of sediment downstream in this ditch as a secondary source of P to water. Implementation of intervention measures are needed to both mitigate P loss and remediate sediment to restore the sink properties. In-ditch measures need to account for a physicochemical lag time before improvements in water quality will be observed.

Split phosphorus fertiliser applications as a strategy to reduce incidental phosphorus losses in surface runoff.

Organic soils have low sorption capacities for phosphorus (P), and may pose a risk of P loss to water if P applications to these soils coincide with runoff events. Little is known about the magnitude of exports of P in overland flow following application of P fertiliser onto these soils, or on the influence of the frequency on P losses and persistence. The number of P fertiliser applications was surveyed across 39 commercial farms to assess current practice and inform the design of a rainfall runoff experiment to evaluate the effect of frequency of P applications on losses and persistence across time. Superphosphate (16% P) was applied in single (equivalent to 30 and 55 kg P ha-1 applied at day 0) and split (equivalent to 15 and 27.5 kg P ha-1 applied in two doses at days 0 and 55) applications to an organic soil inclined at a slope of 6% in a rainfall simulator experiment. The surface runoff of dissolved reactive phosphorus (DRP) was measured in controlled 30-min rainfall simulations conducted intermittently over an 85-day period. The DRP losses in surface runoff after the first rainfall event were 44.6 and 97.8 mg L-1 for single applications of 30 and 55 kg ha-1, respectively, and 13.3 and 21.8 mg L-1 for the same rates split in two doses, indicating that single P applications had disproportionately bigger impacts on losses than split applications. This supports the idea that frequent, but smaller, P applications can minimise the impact of fertilisation on waters. Dissolved reactive P concentrations remained significantly higher than those from the control samples until the end the experiment for almost all the P treatments, highlighting the long-lasting effects of added P and the elevated risk of P losses on organic soils. For climates with frequent rainfall events, which are likely to coincide with fertiliser applications, smaller but more frequent P applications can reduce the risk of P transfer as opposed to one single application.

A Quantitative Self-Assessment of Seminarians' Response to a Curriculum Addition on Marriage, Sexuality, FertilityCare, and Naprotechnology: The Kenrick-Glennon Experience (2006-2015).

A special course on Marriage, the Family and Human Sexuality was established at Kenrick-Glennon Seminary in St. Louis so as to assist the seminarians in their better understanding of the Church's teaching relative to natural methods of family planning and women's health care. This article compares the response at the beginning of this three-credit semester course to the same seven-item questionnaire given at the conclusion of the course. The pre- and postcourse scores were calculated for each of the questions. The scores obtained after the course were all significantly higher than they were before the course with p values ranging from 0.01 to <0.0001. Four of the items showed marked improvement including an understanding of the church's teaching related to natural methods, current methods of natural family planning, the impact of a natural method on a couple's marriage, and also the impact of a natural method on family life. Statistically significant improvement was also seen in their understanding of the topic of natural family planning and the Creighton Model System and its relevance toward the seminarian's vocation, the use of the methods to either achieve or avoid pregnancy, and how contraception and abortion are linked. In these last three items, the level of statistical significance was quite high, although not as high as the other four items. There were 104 seminarians over an eight-year period of time, who provided answers to these questions, both before and after the course. This course was modeled after a course that was initiated at the Pope Paul VI Institute for the Study of Human Reproduction, which was for priests, seminarians, and Catholic leaders, titled Love & Life Unlimited. NONTECHNICAL SUMMARY: This is an evaluation of a ten-point, seven-question questionnaire that was utilized at the beginning of a course at Kenrick Seminary in Marriage, Sexuality, Creighton Model and NaProTECHNOLOGY. The same questionnaire was given to the students at the beginning of the course and then two to three months later at the conclusion of the three-credit course. The results show that there is a significant improvement in the seminarians' knowledge and general attitude about natural methods of family planning and suggests that such courses would be beneficial to establish in seminaries throughout the country.

The effect of root exudates on rhizosphere water dynamics.

Most water and nutrients essential for plant growth travel across a thin zone of soil at the interface between roots and soil, termed the rhizosphere. Chemicals exuded by plant roots can alter the fluid properties, such as viscosity, of the water phase, potentially with impacts on plant productivity and stress tolerance. In this paper, we study the effects of plant exudates on the macroscale properties of water movement in soil. Our starting point is a microscale description of two fluid flow and exudate diffusion in a periodic geometry composed from a regular repetition of a unit cell. Using multiscale homogenization theory, we derive a coupled set of equations that describe the movement of air and water, and the diffusion of plant exudates on the macroscale. These equations are parametrized by a set of cell problems that capture the flow behaviour. The mathematical steps are validated by comparing the resulting homogenized equations to the original pore scale equations, and we show that the difference between the two models is ≲7% for eight cells. The resulting equations provide a computationally efficient method to study plant-soil interactions. This will increase our ability to predict how contrasting root exudation patterns may influence crop uptake of water and nutrients.

Determination of macro-scale soil properties from pore scale structures: image-based modelling of poroelastic structures.

We show how a combination of X-ray computed tomography (X-CT) and image-based modelling can be used to calculate the effect of moisture content and compaction on the macroscopic structural properties of soil. Our method is based on the equations derived in Daly & Roose (2018 Proc. R. Soc. A474, 20170141. (doi:10.1098/rspa.2017.0141)), which we have extended so they can be directly applied to the segmented images obtained from X-CT. We assume that the soils are composed of air-filled pore space, solid mineral grains and a mixed phase composed of both clay particles and water. We considered three different initial soil treatments, composed of two different compaction levels and two different moisture contents. We found that the effective properties of the soils were unaffected by compaction over the range tested in this paper. However, changing the moisture content significantly altered the hydraulic and mechanical properties of the soils. A key strength of this method is that it enables the optimization or even design of soils composed from different constituents, with specific mechanical and hydraulic properties.

Determination of macro-scale soil properties from pore-scale structures: model derivation.

In this paper, we use homogenization to derive a set of macro-scale poro-elastic equations for soils composed of rigid solid particles, air-filled pore space and a poro-elastic mixed phase. We consider the derivation in the limit of large deformation and show that by solving representative problems on the micro-scale we can parametrize the macro-scale equations. To validate the homogenization procedure, we compare the predictions of the homogenized equations with those of the full equations for a range of different geometries and material properties. We show that the results differ by [Formula: see text] for all cases considered. The success of the homogenization scheme means that it can be used to determine the macro-scale poro-elastic properties of soils from the underlying structure. Hence, it will prove a valuable tool in both characterization and optimization.