Formula modifications to the Crohn's disease exclusion diet do not impact therapy success in paediatric Crohn's disease.

OBJECTIVES: The Crohn's disease exclusion diet (CDED) + partial enteral nutrition (PEN) is an emerging diet used to induce clinical remission in children with active Crohn's disease (CD). This study aims to determine the effectiveness of using the CDED+PEN to induce clinical remission in an Australian group of children with active CD using different PEN formulas and incorporating patient dietary requirements. METHODS: We retrospectively collected data from children (both newly diagnosed and with existing CD while on therapy) with active CD (Paediatric Crohn's Disease Activity Index [PCDAI] ≥10) and biochemical evidence of active disease (elevated C-reactive protein [CRP], erythrocyte sedimentation rate [ESR] or faecal calprotectin [FC]) who completed at least phase 1 (6 weeks) of the CDED+PEN to induce clinical remission. Data were collected at baseline, Week 6 and Week 12. The primary endpoint was clinical remission at Week 6 defined as PCDAI < 10. RESULTS: Twenty-four children were included in phase 1 analysis (mean age 13.8 ± 3.2 years). Clinical remission at Week 6 was achieved in 17/24 (70.8%) patients. Mean PCDAI, CRP, ESR and FC decreased significantly after 6 weeks (p < 0.05). Formula type (cow's milk based, rice based, soy based) did not affect treatment efficacy. A greater than 50% decrease in FC was achieved in 14/21 (66.7%) patients who completed phase 1 and 12/14 (85.7%) patients who completed phase 2 of the CDED+PEN. CONCLUSIONS: Formula modifications to the CDED+PEN do not impact the expected treatment efficacy in Australian children with active luminal CD.

The mediating effect of going concern and corporate reporting in the relationship between corporate governance and investor confidence in financial institutions.

This study investigates the mediating role of going concern and corporate reporting on the relationship between corporate governance and investor confidence in financial institutions. The study employed Partial Least Squares Structural Equation Modeling (PLS-SEM) in SmartPLS 3 to analyze the data. The data for the study was collected from financial statements of selected commercial banks in Ghana, Nigeria and South Africa. The results indicate that corporate reporting partially mediates the interrelationships between corporate governance, going concern, and investor confidence. Conversely, there is neither mediation effect of going concern on the association between corporate reporting and investor confidence, nor between corporate governance and investor confidence. The results of the study have practical implications for financial institutions looking to maintain investor confidence and promote financial stability. The results also have policy implications for policymakers and regulators that oversee financial institutions. Knowledge in the field of corporate reporting and governance theoretically also is extended by highlighting the importance of transparency and disclosure in corporate reporting practices. In all, this study contributes to the literature on corporate governance and reporting by providing new insights into the mechanisms by which corporate reporting and going concern impact corporate governance and investor confidence in financial institutions.

Paediatric Gastrointestinal, Hepatic and Pancreatic Inflammatory Myofibroblastic Tumours, A Single Centre Experience.

ABSTRACT: Inflammatory myofibroblastic tumours (IMTs) are rare soft tissue tumours. Reports of gastrointestinal tract, liver and pancreas tumours are limited. The objective of this study is to identify presenting features, contributing prognostic / etiological factors and any variability in outcomes in the context of different historical treatments. We retrospectively reviewed the records of seven children treated at our hospital between 2006 and 2019 and assessed the demographic, presentation, treatment, immunohistochemistry, and outcomes of their tumours. Age range at presentation was 4 months-15 years with a male predominance. Presentations were typically due to local mass effect or incidental discovery. Systemic symptoms were rare. Outcomes were good with six out of seven stable or in remission irrespective of treatment. Surgical resection where possible is the treatment of choice. Medical therapy had good outcomes with chemotherapy acting as first line treatment when required. The only negative prognostic factor identified was local spread at the time of presentation.

Will we ever wash our hands of lubrication theory?

Lubrication theory is used to investigate how weakly bound particles can be transported away from the vicinity of the wall when two spatially periodic rough surfaces are sheared relative to one another at constant velocity U while immersed in fluid. The aim is to model what could be an important process during decontamination of hands by washing and is motivated by Mittal et al. ["The flow physics of COVID-19," J. Fluid Mech. 894, F2 (2020)] who remark "Amazingly, despite the 170+ year history of hand washing in medical hygiene, we were unable to find a single published research article on the flow physics of hand washing." Under the assumption that the roughness wavelength 2 π / k is large compared with the spacing of the surfaces, a, the lubrication approximation permits closed-form expressions to be found for the time-varying velocity components. These are used to track the motion of a particle that is initially trapped in a potential well close to one of the surfaces, and experiences a drag force proportional to the difference between its velocity and that of the surrounding fluid. Complications such as particle-wall hydrodynamic interactions, finite size effects, and Brownian motion are ignored for now. Unsurprisingly, particles remain trapped unless the flow driven by the wall motion is strong compared to the depth of the trapping potential well. Perhaps less obvious is that for many starting positions the process of escape to large distances from the wall takes place over a large number of periods 2 π / k U , essentially because the no-slip boundary condition means that fluid velocities relative to the wall are small close to the wall, and thus the velocities of particles along or away from the wall are also small. With reasonable estimates for the various dimensional parameters, the escape times in these cases are found to be comparable in magnitude to the washing times recommended in hand washing guidelines.

Multichannel impedance monitoring for distinguishing nonerosive reflux esophagitis with minor changes on endoscopy in children.

OBJECTIVES: There are reports describing the relationship between baseline impedance level and esophageal mucosal integrity at endoscopy, such as erosive and nonerosive reflux esophagitis. However, many children with symptoms of gastroesophageal reflux disease have normal findings or minor changes on esophagogastroduodenoscopy. We aimed to examine whether modest changes at esophagogastroduodenoscopy can be evaluated and correlated with esophageal multichannel intraluminal impedance monitoring. METHODS: Patients (ages 0-17 years) with upper gastrointestinal symptoms who underwent combined esophagogastroduodenoscopy and multichannel intraluminal impedance monitoring at the Women's and Children's Hospital, Adelaide, Australia, between 2014 and 2016 were retrospectively studied and the following data were collected and used for analysis: demographics, multichannel intraluminal impedance data, included baseline impedance. Endoscopic findings were classified by modified Los Angeles grading, Los Angeles N as normal, Los Angeles M as with minimal change such as the erythema, pale mucosa, or friability of the mucosa following biopsy. Patients on proton pump inhibitor were excluded. RESULTS: Seventy patients (43 boys; 61%) were enrolled with a mean age of 7.9 years (range 10 months to 17 years). Fifty-one patients (72.9%) were allocated to Los Angeles N, while Los Angeles M was evident in 19 patients (27.1%). Statistically significant differences were observed in the following parameters: frequency of acid and nonacid reflux and baseline impedance in channels 5 and 6. The median values of the data were 18.3 episodes, 16.0 episodes, 2461.0 Ω, 2446.0 Ω in Los Angeles N, 36.0 episodes, 31.0 episodes, 2033.0 Ω, 2009.0 Ω in Los Angeles M, respectively. CONCLUSION: Lower baseline impedance is helpful in predicting minimal endoscopic changes in the lower esophagus. A higher frequency of acid and nonacid reflux episodes was also predictive of minimal endoscopic change in the lower esophagus.

Intestinal stem cells promote crypt fission during postnatal growth of the small intestine.

OBJECTIVE: Wnt-ß-catenin signalling is essential for intestinal stem cells. Our aim was to investigate the relationship between intestinal stem cells and crypt fission which peaks during infancy. DESIGN: Duodenal biopsies were obtained during endoscopy to assess the severity of reflux oesophagitis of 15 infants, children and teenagers, which would not affect the duodenum. Samples of small intestine were also obtained from rats 7-72 days of life. Crypt fission was assessed using microdissection of 100 whole crypts and recording the percentage of bifid crypts. Intestinal LGR5+ stem cells were identified by in situ hybridisation. Rats were treated with Dickkopf to block Wnt-ß-catenin signalling. RESULTS: Crypt fission peaked during infancy before declining after 3-4 years in humans and after 21 days of life in rats. Occasional mitotic figures were seen in bifid crypts during early fission. Stem cells were elevated for a greater period during infancy and childhood in humans. Clustering of Paneth cells was present around the stem cells at the crypt base. Dickkopf reduced the number of stem cells and crypt fission to 45% and 29%, respectively, of control values, showing dependence of both crypt fission and Lgr5+ stem cells on Wnt signalling. However, Dickkopf did not decrease mitotic count per crypt, indicating a difference in signalling between stem cells and their progeny in the transit amplifying zone. CONCLUSION: Crypt fission peaks during infancy and is dependent on intestinal stem cells. This is relatively hidden by 'a cloak of invisibility' due to the low proliferation of stem cells.

Characterization of Upper Gastrointestinal Motility in Infants With Persistent Distress and Non-IgE-mediated Cow's Milk Protein Allergy.

BACKGROUND: Persistent crying in infancy is common and may be associated with gastroesophageal reflux disease (GERD) and/or non-IgE-mediated cow's milk protein allergy (CMPA). We aimed to document upper gastrointestinal motility events in infants with CMPA and compare these to findings in infants with functional GERD. METHODS: Infants aged 2 to 26 weeks with persistent crying, GERD symptoms and possible CMPA were included. Symptoms were recorded by 48-hour cry-fuss chart and validated reflux questionnaire (infant GERD questionnaire [IGERDQ]). Infants underwent a blinded milk elimination-challenge sequence to diagnose CMPA. GERD parameters and mucosal integrity were assessed by 24-hour pH-impedance monitoring before and after cow's milk protein (CMP) elimination. C-octanoate breath testing for gastric emptying dynamics, dual-sugar intestinal permeability, fecal calprotectin, and serum vitamin D were also measured. RESULTS: Fifty infants (mean age 13 ±â€Š7 weeks; 27 boys) were enrolled. On the basis of CMP elimination-challenge outcomes, 14 (28%) were categorized as non-IgE-mediated CMPA, and 17 (34%) were not allergic to milk; 12 infants with equivocal findings, and 7 with incomplete data were excluded. There were no baseline differences in GERD parameters between infants with and without CMPA. In the CMPA group, CMP elimination resulted in a significant reduction in reflux symptoms, esophageal acid exposure (reflux index), acid clearance time, and an increase in esophageal mucosal impedance. CONCLUSIONS: In infants with persistent crying, upper gastrointestinal motility parameters did not reliably differentiate between non-IgE-mediated CMPA and functional GERD. In the group with non-IgE-mediated CMPA, elimination of CMP significantly improved GERD symptoms, esophageal peristaltic function, and mucosal integrity.

Cerebellar transcranial magnetic stimulation: The role of coil type from distinct manufacturers.

BACKGROUND: Stimulating the cerebellum with transcranial magnetic stimulation is often perceived as uncomfortable. No study has systematically tested which coil design can effectively trigger a cerebellar response with the least discomfort. OBJECTIVE: To determine the relationship between perceived discomfort and effectiveness of cerebellar stimulation using different coils: MagStim (70 mm, 110 mm-coated, 110-uncoated), MagVenture and Deymed. METHODS: Using the cerebellar-brain inhibition (CBI) protocol, we conducted a CBI recruitment curve with respect to each participant's maximum tolerated-stimulus intensity (MTI) to assess how effective each coil was at activating the cerebellum. RESULTS: Only the Deymed double-cone coil elicited CBI at low intensities (-20% MTI). At the MTI, the MagStim (110 mm coated/uncoated) and Deymed coils produced reliable CBI, whereas no CBI was found with the MagVenture coil. CONCLUSION: s: The Deymed double-cone coil was most effective at cerebellar stimulation at tolerable intensities. These results can guide coil selection and stimulation parameters when designing cerebellar TMS studies.

High-resolution esophageal manometry in pediatrics: Effect of esophageal length on diagnostic measures.

BACKGROUND: High-resolution esophageal manometry (HREM), derived esophageal pressure topography metrics (EPT), integrated relaxation pressure (IRP), and distal latency (DL) are influenced by age and size. Combined pressure and intraluminal impedance also allow derivation of metrics that define distension pressure and bolus flow timing. We prospectively investigated the effects of esophageal length on these metrics to determine whether adjustment strategies are required for children. METHODS: Fifty-five children (12.3 ± 4.5 years) referred for HREM, and 30 healthy adult volunteers (46.9 ± 3.8 years) were included. Studies were performed using the MMS system and a standardized protocol including 10 × 5 mL thin liquid bolus swallows (SBM kit, Trisco Foods) and analyzed via Swallow Gateway (www.swallowgateway.com). Esophageal distension pressures and swallow latencies were determined in addition to EGJ resting pressure and standard EPT metrics. Effects of esophageal length were examined using partial correlation, correcting for age. Adult-derived upper limits were adjusted for length using the slopes of the identified linear equations. KEY RESULTS: Mean esophageal length in children was 16.8 ± 2.8 cm and correlated significantly with age (r = 0.787, P = .000). Shorter length correlated with higher EGJ resting pressure and 4-s integrated relaxation pressures (IRP), distension pressures, and shorter contraction latencies. Ten patients had an IRP above the adult upper limit. Adjustment for esophageal length reduced the number of patients with elevated IRP to three. CONCLUSIONS & INFERENCES: We prospectively confirmed that certain EPT metrics, as well as potential useful adjunct pressure-impedance measures such as distension pressure, are substantially influenced by esophageal length and require adjusted diagnostic thresholds specifically for children.

Six new species and one new subspecies of noctuid moths from western United States of America and Mexico (Lepidoptera, Noctuidae).

Six new species and one new subspecies of Noctuidae are described from western United States of America and Baja California, Mexico: Dolocuculliapoolei Crabo & Hammond, sp. n. (Cuculliinae), Plagiomimicusyakama Crabo & Wikle, sp. n., Plagiomimicusyakamamojave Wikle & Crabo, ssp. n., Plagiomimicusincomitatus Mustelin, sp. n. (Amphipyrinae), Sympistisferrirena Crabo, sp. n. (Oncocnemidinae), Aseptisharpi Crabo & Mustelin, sp. n., and Hypotrixlactomellis Wikle & Crabo, sp. n. (Noctuinae). The adults and genitalia of these species are described, illustrated, and compared to similar related moths. The larvae of the Plagiomimicustepperi species group, unknown previously, are reported to feed on several species of Brickellia Ell. (Asteraceae). The early stages of Plagiomimicusyakamamojave are described and late instars are illustrated.

Phenological responses of 215 moth species to interannual climate variation in the Pacific Northwest from 1895 through 2013.

Climate change has caused shifts in the phenology and distributions of many species but comparing responses across species is challenged by inconsistencies in the methodology and taxonomic and temporal scope of individual studies. Natural history collections offer a rich source of data for examining phenological shifts for a large number of species. We paired specimen records from Pacific Northwest insect collections to climate data to analyze the responses of 215 moth species to interannual climate variation over a period of 119 years (1895-2013) during which average annual temperatures have increased in the region. We quantified the effects of late winter/early spring temperatures, averaged annually across the region, on dates of occurrence of adults, taking into account the effects of elevation, latitude, and longitude. We assessed whether species-specific phenological responses varied with adult flight season and larval diet breadth. Collection dates were significantly earlier in warmer years for 36.3% of moth species, and later for 3.7%. Species exhibited an average phenological advance of 1.9 days/°C, but species-specific shifts ranged from an advance of 10.3 days/°C to a delay of 10.6 days/°C. More spring-flying species shifted their phenology than summer- or fall-flying species. These responses did not vary among groups defined by larval diet breadth. The highly variable phenological responses to climate change in Pacific Northwest moths agree with other studies on Lepidoptera and suggest that it will remain difficult to accurately forecast which species and ecological interactions are most likely to be affected by climate change. Our results also underscore the value of natural history collections as windows into long-term ecological trends.

Effect of donepezil on transcranial magnetic stimulation parameters in Alzheimer's disease.

INTRODUCTION: There is a need for a reliable, noninvasive biomarker for Alzheimer's disease (AD). We assessed whether short-latency afferent inhibition (SAI), a transcranial magnetic stimulation paradigm that assesses cholinergic circuits of the brain, could become such a biomarker. METHODS: Nineteen patients with AD underwent four SAI testing sessions. The timing of their usual donepezil dose was altered to create different cholinergic states for each session. This was compared to the SAI results from 20 healthy subjects. RESULTS: SAI was not able to distinguish the different cholinergic states assessed in our study. There appeared to be a diurnal variation in cholinergic function in the control group, which was not present in the AD cohort. DISCUSSION: SAI does not appear to have a role in diagnosis and assessment of AD patients. The loss of diurnal variation, however, warrants further investigation as it may provide further biochemical insights about AD.

TMS of primary motor cortex with a biphasic pulse activates two independent sets of excitable neurones.

BACKGROUND: Biphasic pulses produced by most commercially available TMS machines have a cosine waveform, which makes it difficult to study the interaction between the two phases of stimulation. OBJECTIVE: We used a controllable pulse TMS (cTMS) device delivering quasi-rectangular pulse outputs to investigate whether monophasic are more effective than biphasic pulses. METHODS: Temporally symmetric ("biphasic") or highly asymmetric ("monophasic") charge-balanced biphasic stimuli were used to target the hand area of motor cortex in the anterior-posterior (AP) or posterior-anterior (PA) initial current direction. RESULTS: We observed the lowest motor thresholds and shortest motor evoked potential (MEP) latencies with initial PA pulses, and highest thresholds and longest latencies with AP pulses. Increasing pulse symmetry tended to increase threshold with a PA direction whereas it lowered thresholds and shortened latencies with an AP direction. Furthermore, it steepened the MEP input-output curve with both directions. CONCLUSIONS: "Biphasic" TMS pulses can be viewed as two monophasic pulses of opposite directions, each stimulating a different set of interneurons with different thresholds (PA < AP). At threshold, the reverse phase of an initially PA pulse increases threshold compared with "monophasic" stimulation. At higher intensities, the reverse phase begins to activate AP-sensitive neurones and increase the effectiveness of stimulation above that of a "monophasic" PA pulse. "Biphasic" stimulation with initially AP pulses is dominated at threshold by activation produced by the lower threshold reverse (PA) phase. SIGNIFICANCE: The effects of biphasic stimulation are best understood as the summed output of two independent sets of directionally selective neural populations.

Pemphigus Vulgaris and Eosinophilic Esophagitis in a 13-Year-Old Boy: Case Report and Review of the Literature.

This case report presents a 13-year-old boy referred to the Department of Paediatric Dentistry, Women's and Children's Hospital, Adelaide, South Australia, Australia, with a 5-week history of severe oral ulcerations and significant weight loss of unknown origin. The diagnosis of pemphigus vulgaris was made after histologic and immunofluorescent examination of an intraoral deep incisional biopsy, with eosinophilic esophagitis also diagnosed during the initial upper gastrointestinal endoscopy. The association between pemphigus vulgaris and eosinophilic esophagitis in this case, although previously unreported, is explicable on the basis of dysregulation of desmoglein 1 (DSG1). This case report identifies a new clinical association that could help clinicians identify further such cases and provides insight into the pathogenesis of both conditions.

Plant diversity enhances moth diversity in an intensive forest management experiment.

Intensive forest management (IFM) promises to help satisfy increasing global demand for wood but may come at the cost of local reductions to forest biodiversity. IFM often reduces early seral plant diversity as a result of efforts to eliminate plant competition with crop trees. If diversity is a function of bottom-up drivers, theory predicts that specialists at lower trophic levels (e.g., insect herbivores) should be particularly sensitive to reductions in plant diversity. We conducted a stand-level experiment to test bottom-up controls on moth community structure, as mediated by degrees of forest management intensity. Using a dataset of 12,003 moths representing 316 moth species, moth richness decreased only slightly, if at all, as herbicide intensity increased (P = 0.062); the moderate treatment, which is most commonly applied in the northwestern USA, was estimated to have 4.72 (±2.14 SE, P = 0.039) fewer species than the control. Structural equation modeling revealed strong support for an effect of herbicide on plant abundance, which influenced plant species richness and subsequently moth species richness. Moth species richness was associated with plant species richness and followed a power law function (z = 0.42, P = 0.006), which is surprisingly consistent with a recent large-scale experiment in agricultural systems, and provides support for bottom-up drivers of moth community structure. Moth abundance was not influenced by the direct effects of silvicultural herbicide treatments. Site-level effects and variation in pre-harvest vegetation communities resulted in residual broadleaf and herbaceous vegetation in even the most intensive treatment. Even at low densities, these residual deciduous and herbaceous plants supported higher than expected moth abundance and richness. We conclude that forest management practices that retain early seral vegetation diversity are the most likely to conserve moth communities.

Five new species and three new subspecies of Erebidae and Noctuidae (Insecta, Lepidoptera) from Northwestern North America, with notes on Chytolita Grote (Erebidae) and Hydraecia Guenée (Noctuidae).

Several taxonomic issues in the moth families Erebidae and Noctuidae are addressed for Northwestern North America. Drasteria parallelaCrabo & Mustelin andCycnia oregonensis tristisCrabo in the Erebidae and Eudryas brevipennis bonneville Shepard & Crabo, Resapamea diluvius Crabo, Resapamea angelika Crabo, Resapamea mammuthus Crabo, Fishia nigrescens Hammond & Crabo, and Xestia perquiritata orcaCrabo & Hammond in the Noctuidae are described as new. The following new synonyms are proposed: Chytolita petrealis Grote with Herminea morbidalis Guenée; Gortyna columbia Barnes & Benjamin and Gortyna ximena Barnes & Benjamin with Gortyna obliqua Harvey; and Hydroecia pallescens Smith with Hydroecia medialis Smith. The type locality of Gortyna intermedia Barnes & Benjamin is restricted to Lundbreck, Municipality of Crowsnest Pass, Alberta, Canada.

4-aminobutyrate aminotransferase (ABAT): genetic and pharmacological evidence for an involvement in gastro esophageal reflux disease.

Gastro-esophageal reflux disease (GERD) is partly caused by genetic factors. The underlying susceptibility genes are currently unknown, with the exception of COL3A1. We used three independent GERD patient cohorts to identify GERD susceptibility genes. Thirty-six families, demonstrating dominant transmission of GERD were subjected to whole genome microsatellite genotyping and linkage analysis. Five linked regions were identified. Two families shared a linked region (LOD 3.9 and 2.0) on chromosome 16. We used two additional independent GERD patient cohorts, one consisting of 219 trios (affected child with parents) and the other an adult GERD case control cohort consisting of 256 cases and 485 controls, to validate individual genes in the linked region through association analysis. Sixty six single nucleotide polymorphism (SNP) markers distributed over the nine genes present in the linked region were genotyped in the independent GERD trio cohort. Transmission disequilibrium test analysis followed by multiple testing adjustments revealed a significant genetic association for one SNP located in an intron of the gene 4-aminobutyrate aminotransferase (ABAT) (P(adj) = 0.027). This association did not replicate in the adult case-control cohort, possibly due to the differences in ethnicity between the cohorts. Finally, using the selective ABAT inhibitor vigabatrin (γ-vinyl GABA) in a dog study, we were able to show a reduction of transient lower esophageal sphincter relaxations (TLESRs) by 57.3 ± 11.4 % (p = 0.007) and the reflux events from 3.1 ± 0.4 to 0.8 ± 0.4 (p = 0.007). Our results demonstrate the direct involvement of ABAT in pathways affecting lower esophageal sphincter (LES) control and identifies ABAT as a genetic risk factor for GERD.

Spontaneous imbibition of surfactant solution into an oil-wet capillary: wettability restoration by surfactant-contaminant complexation.

For a given type of rock, the effectiveness of oil recovery through wettability alteration is highly dependent upon the nature of the water-soluble surfactant used. Different mechanisms have been proposed by others to explain wettability alteration by surfactants, and understanding the process is crucial to improve recovery performance. Known mechanisms include (1) surfactant adsorption onto the oil-wet solid surface (coating mechanism) and (2) surfactant molecules complexing with contaminant molecules from the crude oil which are adsorbed on the rock surface so as to strip them off (cleaning mechanism). With the second mechanism, the wettability is restored by lifting the contaminant layer away, exposing the rock surface which was originally water-wet. We previously focused on the numerical modeling of the surfactant coating mechanism (Hammond and Unsal Langmuir2009, 25, 12591; 2010, 26, 6206), and we now present a numerical study for the cleaning process. Our new model shows that when a wettability altering surfactant solution is allowed to imbibe spontaneously and acts by the cleaning process, the meniscus advances more rapidly than when there was wettability alteration by coating alone. In our previous model there was a concentration threshold below which imbibition was not possible. That threshold arose because a finite amount of surfactant needs to be adsorbed onto the oil-wet surface to change the contact angle to a water-wet value, but the maximum amount that can be absorbed is limited by the requirement that it be in equilibrium with the surfactant concentration near the meniscus. In the new model, with the cleaning mechanism there is no such threshold, since the cleaning process is driven by the surfactant flux into the vicinity of the advancing meniscus rather than the surfactant concentration there. As long as there are surfactant molecules present in the aqueous solution, the flux is nonzero and molecule pairs can form and alter the wettability by removing the contaminant from the oil-wet surface. However, under very low surfactant concentrations, the process is extremely slow compared to at higher concentrations.