Anomalies in the pseudogap phase of the cuprates: competing ground states and the role of umklapp scattering.

Over the past two decades, advances in computational algorithms have revealed a curious property of the two-dimensional Hubbard model (and related theories) with hole doping: the presence of close-in-energy competing ground states that display very different physical properties. On the one hand, there is a complicated state exhibiting intertwined spin, charge, and pair density wave orders. We call this 'type A'. On the other hand, there is a uniform d-wave superconducting state that we denote as 'type B'. We advocate, with the support of both microscopic theoretical calculations and experimental data, dividing the high-temperature cuprate superconductors into two corresponding families, whose properties reflect either the type A or type B ground states at low temperatures. We review the anomalous properties of the pseudogap phase that led us to this picture, and present a modern perspective on the role that umklapp scattering plays in these phenomena in the type B materials. This reflects a consistent framework that has emerged over the last decade, in which Mott correlations at weak coupling drive the formation of the pseudogap. We discuss this development, recent theory and experiments, and open issues.

The impact of timing of maternal influenza immunization on infant antibody levels at birth.

Pregnant women and infants are at an increased risk of severe disease after influenza infection. Maternal immunization is a potent tool to protect both these at-risk groups. While the primary aim of maternal influenza vaccination is to protect the mother, a secondary benefit is the transfer of protective antibodies to the infant. A recent study using the tetanus, diphtheria and acellular pertussis (Tdap) vaccine indicated that children born to mothers immunized in the second trimester of pregnancy had the highest antibody titres compared to children immunized in the third trimester. The aim of the current study was to investigate how the timing of maternal influenza immunization impacts infant antibody levels at birth. Antibody titres were assessed in maternal and cord blood samples by both immunoglobulin (Ig)G-binding enzyme-linked immunosorbent assay (ELISA) and haemagglutination inhibition assay (HAI). Antibody titres to the H1N1 component were significantly higher in infants born to mothers vaccinated in either the second or third trimesters than infants born to unvaccinated mothers. HAI levels in the infant were significantly lower when maternal immunization was performed less than 4 weeks before birth. These studies confirm that immunization during pregnancy increases the antibody titre in infants. Importantly, antibody levels in cord blood were significantly higher when the mother was vaccinated in either trimesters 2 or 3, although titres were significantly lower if the mother was immunized less than 4 weeks before birth. Based on these data, seasonal influenza vaccination should continue to be given in pregnancy as soon as it becomes available.

Antibody responses to Bordetella pertussis and other childhood vaccines in infants born to mothers who received pertussis vaccine in pregnancy - a prospective, observational cohort study from the United Kingdom.

The maternal Tdap (tetanus, diphtheria and acellular pertussis) vaccination programme in the United Kingdom has successfully reduced cases of pertussis in young infants. In addition to prevention of pertussis cases, it is also important to investigate the persistence of maternal antibodies during infancy and the possible interference of maternal antibodies with infant responses to vaccines. We recruited mother-infant pairs from vaccinated and unvaccinated pregnancies and measured concentrations of immunoglobulin (Ig)G against pertussis toxin (PTx), filamentous haemagglutinin (FHA), pertactin (Prn), diphtheria toxin (DTx), tetanus toxoid (TTx) Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae in mothers and infants at birth, and in infants at 7 weeks and at 5 months. Thirty-one mother-infant pairs were tested. Tdap-vaccinated women had significantly higher antibody against Tdap antigens, compared to unvaccinated women (DTx, P = 0·01; PTx, FHA, Prn and TTx, P < 0·001). All antibodies were actively transferred to the infants (transfer ratio  > 1) with higher transfer of DTx (P = 0·04) and TTx (P = 0·02) antibody in Tdap-vaccinated pregnancies compared to unvaccinated pregnancies. Infants from Tdap-vaccinated pregnancies had significantly elevated antibodies to all antigens at birth (P < 0.001) and at 7 weeks (FHA, Prn, TTx, P < 0·001; DTx, P = 0.01; PTx, P = 0·004) compared to infants from unvaccinated pregnancies. Infants from Tdap-vaccinated and -unvaccinated pregnancies had comparable antibody concentrations following primary pertussis immunization (PTx, P = 0·77; FHA, P = 0·58; Prn, P = 0·60; DTx, P = 0·09; TTx, P = 0·88). These results support maternal immunization as a method of protecting vulnerable infants during their first weeks of life.

Sub-acute herpes simplex virus myelitis in a patient with esophageal cancer on chemo-radiation with 5-fluorouracil: a case report.

No reported cases to date describe herpes simplex virus (HSV) myelitis in association with cancer and chemo-radiation. We report a case of sub-acute HSV myelitis in a 54-year-old man receiving chemo-radiation with 5-flourouracil for esophageal cancer who presented to the emergency department with increasing numbness in both lower limbs that gradually spread to waist level. Magnetic resonance imaging with gadobutrol contrast 1 week later showed transverse myelitis involving the dorsal columns. Radiation-induced myelitis was suspected, and the patient was initially treated with dexamethasone; however, CSF analysis revealed HSV myelitis. Treatment with antivirals resolved much of the numbness. HSV myelitis can be confused with complications of radiation or malignancy in patients presenting with focal neurological deficits.

Routine HIV Screening in Cancer Patients in the Emergency Department.

Treatment of human immunodeficiency virus(HIV) in cancer patients improves outcomes and reduces transmission of this oncogenic virus. HIV testing rates of cancer patients are similar to the general population (15-40%), despite the association with cancer. Our aim was to increase HIV screening in the Emergency Department(ED) of a comprehensive cancer center through a quality initiative. Testing increased significantly during the intervention (p<0.001; 0.15/day to 2.69/day). Seropositive HIV rate was 1.4% (12/852), with incidence of 0.3%. All patients were linked to care. Incident cases were between 36 and 55 years of age. Barriers encountered included confusion regarding the need for written consent for HIV testing, failure to consider ordering the test, and concerns regarding linkage to care.

Genome-wide association studies suggest sex-specific loci associated with abdominal and visceral fat.

BACKGROUND: To identify loci associated with abdominal fat and replicate prior findings, we performed genome-wide association (GWA) studies of abdominal fat traits: subcutaneous adipose tissue (SAT); visceral adipose tissue (VAT); total adipose tissue (TAT) and visceral to subcutaneous adipose tissue ratio (VSR). SUBJECTS AND METHODS: Sex-combined and sex-stratified analyses were performed on each trait with (TRAIT-BMI) or without (TRAIT) adjustment for body mass index (BMI), and cohort-specific results were combined via a fixed effects meta-analysis. A total of 2513 subjects of European descent were available for the discovery phase. For replication, 2171 European Americans and 772 African Americans were available. RESULTS: A total of 52 single-nucleotide polymorphisms (SNPs) encompassing 7 loci showed suggestive evidence of association (P<1.0 × 10(-6)) with abdominal fat in the sex-combined analyses. The strongest evidence was found on chromosome 7p14.3 between a SNP near BBS9 gene and VAT (rs12374818; P=1.10 × 10(-7)), an association that was replicated (P=0.02). For the BMI-adjusted trait, the strongest evidence of association was found between a SNP near CYCSP30 and VAT-BMI (rs10506943; P=2.42 × 10(-7)). Our sex-specific analyses identified one genome-wide significant (P<5.0 × 10(-8)) locus for SAT in women with 11 SNPs encompassing the MLLT10, DNAJC1 and EBLN1 genes on chromosome 10p12.31 (P=3.97 × 10(-8) to 1.13 × 10(-8)). The THNSL2 gene previously associated with VAT in women was also replicated (P=0.006). The six gene/loci showing the strongest evidence of association with VAT or VAT-BMI were interrogated for their functional links with obesity and inflammation using the Biograph knowledge-mining software. Genes showing the closest functional links with obesity and inflammation were ADCY8 and KCNK9, respectively. CONCLUSIONS: Our results provide evidence for new loci influencing abdominal visceral (BBS9, ADCY8, KCNK9) and subcutaneous (MLLT10/DNAJC1/EBLN1) fat, and confirmed a locus (THNSL2) previously reported to be associated with abdominal fat in women.

Recommendations for pathologic staging (pTNM) of cancer of the esophagus and esophagogastric junction for the 8th edition AJCC/UICC staging manuals.

We report analytic and consensus processes that produced recommendations for pathologic stage groups (pTNM) of esophageal and esophagogastric junction cancer for the AJCC/UICC cancer staging manuals, 8th edition. The Worldwide Esophageal Cancer Collaboration provided data for 22,654 patients with epithelial esophageal cancers; 13,300 without preoperative therapy had pathologic assessment after esophagectomy or endoscopic treatment. Risk-adjusted survival for each patient was developed using random survival forest analysis to identify data-driven pathologic stage groups wherein survival decreased monotonically with increasing group, was distinctive between groups, and homogeneous within groups. The AJCC Upper GI Task Force, by smoothing, simplifying, expanding, and assessing clinical applicability, produced consensus pathologic stage groups. For pT1-3N0M0 squamous cell carcinoma (SCC) and pT1-2N0M0 adenocarcinoma, pT was inadequate for grouping; subcategorizing pT1 and adding histologic grade enhanced staging; cancer location improved SCC staging. Consensus eliminated location for pT2N0M0 and pT3N0M0G1 SCC groups, and despite similar survival, restricted stage 0 to pTis, excluding pT1aN0M0G1. Metastases markedly reduced survival; pT, pN, and pM sufficiently grouped advanced cancers. Stage IIA and IIB had different compositions for SCC and adenocarcinoma, but similar survival. Consensus stage IV subgrouping acknowledged pT4N+ and pN3 cancers had poor survival, similar to pM1. Anatomic pathologic stage grouping, based on pTNM only, produced identical consensus stage groups for SCC and adenocarcinoma at the cost of homogeneity in early groups. Pathologic staging can neither direct pre-treatment decisions nor aid in prognostication for treatment other than esophagectomy or endoscopic therapy. However, it provides a clean, single therapy reference point for esophageal cancer.

Worldwide Esophageal Cancer Collaboration: pathologic staging data.

We report data-simple descriptions of patient characteristics, cancer categories, and non-risk-adjusted survival-for patients with pathologically staged cancer of the esophagus and esophagogastric junction after resection or ablation with no preoperative therapy from the Worldwide Esophageal Cancer Collaboration (WECC). Thirty-three institutions from six continents submitted de-identified data using standard definitions: demographics, comorbidities, clinical cancer categories, and all-cause mortality from first management decision. Of 13,300 patients, 5,631 had squamous cell carcinoma, 7,558 adenocarcinoma, 85 adenosquamous carcinoma, and 26 undifferentiated carcinoma. Patients were older (62 years) men (80%) with normal body mass index (51%), little weight loss (1.8 kg), 0-2 ECOG performance status (83%), and a history of smoking (70%). Cancers were pT1 (24%), pT2 (15%), pT3 (50%), pN0 (52%), pM0 (93%), and pG2-G3 (78%); most involved distal esophagus (71%). Non-risk-adjusted survival for both squamous cell carcinoma and adenocarcinoma was monotonic and distinctive across pTNM. Survival was more distinctive for adenocarcinoma than squamous cell carcinoma when pT was ordered by pN. Survival for pTis-1 adenocarcinoma was better than for squamous cell carcinoma, although monotonic and distinctive for both. WECC pathologic staging data is improved over that of the 7th edition, with more patients studied and patient and cancer variables collected. These data will be the basis for the 8th edition cancer staging manuals following risk adjustment for patient, cancer, and treatment characteristics, and should direct 9th edition data collection. However, the role of pure pathologic staging as the principal point of reference for esophageal cancer staging is waning.

Worldwide Esophageal Cancer Collaboration: clinical staging data.

To address uncertainty of whether clinical stage groupings (cTNM) for esophageal cancer share prognostic implications with pathologic groupings after esophagectomy alone (pTNM), we report data-simple descriptions of patient characteristics, cancer categories, and non-risk-adjusted survival-for clinically staged patients from the Worldwide Esophageal Cancer Collaboration (WECC). Thirty-three institutions from six continents submitted data using variables with standard definitions: demographics, comorbidities, clinical cancer categories, and all-cause mortality from first management decision. Of 22,123 clinically staged patients, 8,156 had squamous cell carcinoma, 13,814 adenocarcinoma, 116 adenosquamous carcinoma, and 37 undifferentiated carcinoma. Patients were older (62 years) men (80%) with normal body mass index (18.5-25 mg/kg2 , 47%), little weight loss (2.4 ± 7.8 kg), 0-1 ECOG performance status (67%), and history of smoking (67%). Cancers were cT1 (12%), cT2 (22%), cT3 (56%), cN0 (44%), cM0 (95%), and cG2-G3 (89%); most involved the distal esophagus (73%). Non-risk-adjusted survival for squamous cell carcinoma was not distinctive for early cT or cN; for adenocarcinoma, it was distinctive for early versus advanced cT and for cN0 versus cN+. Patients with early cancers had worse survival and those with advanced cancers better survival than expected from equivalent pathologic categories based on prior WECC pathologic data. Thus, clinical and pathologic categories do not share prognostic implications. This makes clinically based treatment decisions difficult and pre-treatment prognostication inaccurate. These data will be the basis for the 8th edition cancer staging manuals following risk adjustment for patient characteristics, cancer categories, and treatment characteristics and should direct 9th edition data collection.

Worldwide Esophageal Cancer Collaboration: neoadjuvant pathologic staging data.

To address uncertainty of whether pathologic stage groupings after neoadjuvant therapy (ypTNM) for esophageal cancer share prognostic implications with pathologic groupings after esophagectomy alone (pTNM), we report data-simple descriptions of patient characteristics, cancer categories, and non-risk-adjusted survival-for pathologically staged cancers after neoadjuvant therapy from the Worldwide Esophageal Cancer Collaboration (WECC). Thirty-three institutions from six continents submitted data using variables with standard definitions: demographics, comorbidities, clinical cancer categories, and all-cause mortality from first management decision. Of 7,773 pathologically staged neoadjuvant patients, 2,045 had squamous cell carcinoma, 5,686 adenocarcinoma, 31 adenosquamous carcinoma, and 11 undifferentiated carcinoma. Patients were older (61 years) men (83%) with normal (40%) or overweight (35%) body mass index, 0-1 Eastern Cooperative Oncology Group performance status (96%), and a history of smoking (69%). Cancers were ypT0 (20%), ypT1 (13%), ypT2 (18%), ypT3 (44%), ypN0 (55%), ypM0 (94%), and G2-G3 (72%); most involved the distal esophagus (80%). Non-risk-adjusted survival for yp categories was unequally depressed, more for earlier categories than later, compared with equivalent categories from prior WECC data for esophagectomy-alone patients. Thus, survival of patients with ypT0-2N0M0 cancers was intermediate and similar regardless of ypT; survival for ypN+ cancers was poor. Because prognoses for ypTNM and pTNM categories are dissimilar, prognostication should be based on separate ypTNM categories and groupings. These data will be the basis for the 8th edition cancer staging manuals following risk adjustment for patient, cancer, and treatment characteristics and should direct 9th edition data collection.

Factors associated with hepatitis C virus RNA levels in early chronic infection: the InC3 study.

Improved understanding of natural history of hepatitis C virus (HCV) RNA levels in chronic infection provides enhanced insights into immunopathogenesis of HCV and has implications for the clinical management of chronic HCV infection. This study assessed factors associated with HCV RNA levels during early chronic infection in a population with well-defined early chronic HCV infection. Data were from an international collaboration of nine prospective cohorts studying acute HCV infection (InC(3) study). Individuals with persistent HCV and detectable HCV RNA during early chronic infection (one year [±4 months] postinfection) were included. Distribution of HCV RNA levels during early chronic infection was compared by selected host and virological factors. A total of 308 individuals were included. Median HCV RNA levels were significantly higher among males (vs females; 5.15 vs 4.74 log IU/mL; P < 0.01) and among individuals with HIV co-infection (vs no HIV; 5.89 vs 4.86; P = 0.02). In adjusted logistic regression, male sex (vs female, adjusted odds ratio [AOR]: 1.93; 95%CI: 1.01, 3.69), interferon lambda 4 (IFNL4) rs12979860 CC genotype (vs TT/CT; AOR: 2.48; 95%CI: 1.42, 4.35), HIV co-infection (vs no HIV; AOR: 3.27; 95%CI: 1.35, 7.93) and HCV genotype G2 (vs G3; AOR: 5.40; 95%CI: 1.63, 17.84) were independently associated with high HCV RNA levels (>5.6 log IU/mL = 400 000 IU/mL). In conclusion, this study demonstrated that IFNL4 rs12979860 CC genotype, male sex, HIV co-infection and HCV genotype G2 are associated with high HCV RNA levels in early chronic infection. These factors exert their role as early as one year following infection.

Response to treatment following recently acquired hepatitis C virus infection in a multicentre collaborative cohort.

Pegylated interferon therapy is highly effective in recently acquired HCV. The optimal timing of treatment, regimen and influence of host factors remains unclear. We aimed to measure sustained virological response (SVR) during recent HCV infection and identify predictors of response. Data were from five prospective cohorts of high-risk individuals in Australia, Canada, Germany and the United States. Individuals with acute or early chronic HCV who commenced pegylated interferon therapy were included. The main outcome was SVR, and predictors were assessed using logistic regression. Among 516 with documented recent HCV infection, 237 were treated (pegylated interferon n = 161; pegylated interferon/ribavirin n = 76) (30% female, median age 35 years, 56% ever injected drugs, median duration of infection 6.2 months). Sixteen per cent (n = 38) were HIV/HCV co-infected. SVR among those with HCV mono-infection was 64% by intention to treat; SVR was 68% among HCV/HIV co-infection. Independent predictors of SVR in HCV mono-infection were duration of HCV infection (the odds of SVR declined by 8% per month of infection, aOR 0.92, 95% CI 0.85-0.99, P = 0.033), IFNL4 genotype (adjusted OR 2.27, 95% CI 1.13-4.56, P = 0.021), baseline HCV RNA <400 000 IU/mL (aOR 2.06, 95% CI 1.03-4.12, P = 0.041) and age ≥40 years (vs <30: aOR 2.92, 95% CI 1.31-6.49, P = 0.009), with no difference by drug regimen, HCV genotype, symptomatic infection or gender. The effect of infection duration on odds of SVR was greater among genotype-1 infection. Interferon-based HCV treatment is highly effective in recent HCV infection. Duration of infection, IFNL4 genotype and baseline HCV RNA levels can predict virological response and may inform clinical decision-making.

Fat-free mass loss generated with weight loss in overweight and obese adults: What may we expect?

There is concern that intentional weight loss may generate excessive loss of fat-free mass (FFM). Idealists target minimal loss of FFM, while others consider that FFM loss of up to 25% of weight loss is acceptable. In a cross-sectional study of 275 weight-stable, overweight or obese adults, we used whole-body dual-energy X-ray absorptiometry to measure FFM. A range of models was used to estimate the expected ΔFFM/Δweight ratio required to attain the body composition of a weight-stable individual at a lower body mass index (BMI). Higher BMI was associated linearly with higher FFM in men and women. Proportional ΔFFM/Δweight was influenced by sex, BMI and age. Direct scatter plot analysis, quadratic curve fit modelling and linear FFM-BMI modelling provided similar estimates for each model of ΔFFM/Δweight ratio, with 40% for men and 33% for women. These results show that the 25% rule is inappropriate and our estimates are higher than those generally reported after intentional weight loss indicating favourable preservation of FFM.

Timed barium esophagram in achalasia types.

Relationships of timed barium esophagram (TBE) findings to achalasia types defined by high-resolution manometry (HRM) have not been elucidated. Therefore, we correlated preoperative TBE and HRM measurements in achalasia types and related these to patient symptoms and prior treatments. From 2006 to 2013, 248 achalasia patients underwent TBE and HRM before Heller myotomy. TBE height and width were recorded at 1 and 5 minutes; HRM measured lower esophageal sphincter mean basal pressure, integrated relaxation pressure (IRP), and mean esophageal body contraction amplitude. Achalasia was classified into types I (25%), II (65%), and III (9.7%). TBE height at 5 minutes was higher for I (median 8 cm; interquartile range 6-12) and II (8 cm; 8-11) than for III (1 cm; 0-7). TBE width at 5 minutes was widest (3 cm; 2-4), narrower in II (2 cm; 2-3), and narrowest in I (1 cm; 0-2), P < 0.001. Volume remaining at 1 and 5 minutes was lower in III (1 m(2) ; 0-16) than I (42 m(2) ; 17-106) and II (39 m(2) ; 15-60), highlighting poorer emptying of I and II. Increasing TBE width correlated with deteriorating morphology and function from III to II to I. Symptoms poorly correlated with TBE and HRM. Prior treatment was associated with less regurgitation, faster emptying, and lower IRP. Although TBE and HRM are correlated in many respects, the wide range of their measurements observed in this study reveals a spectrum of morphology and dysfunction in achalasia that is best characterized by the combination of these studies.

Gefitinib in definitive management of esophageal or gastroesophageal junction cancer: a retrospective analysis of two clinical trials.

The role of epidermal growth factor receptor inhibition in resectable esophageal/gastroesophageal junction (E/GEJ) cancer is uncertain. Results from two Cleveland Clinic trials of concurrent chemoradiotherapy (CCRT) and surgery are updated and retrospectively compared, the second study differing only by the addition of gefitinib (G) to the treatment regimen. Eligibility required a diagnosis of E/GEJ squamous cell or adenocarcinoma, with an endoscopic ultrasound stage of at least T3, N1, or M1a (American Joint Committee on Cancer 6th). Patients in both trials received 5-fluorouracil (1000 mg/m(2) /day) and cisplatin (20 mg/m(2) /day) as continuous infusions over days 1-4 along with 30 Gy radiation at 1.5 Gy bid. Surgery followed in 4-6 weeks; identical CCRT was given 6-10 weeks later. The second trial added G, 250 mg/day, on day 1 for 4 weeks, and again with postoperative CCRT for 2 years. Preliminary results and comparisons have been previously published. Clinical characteristics were similar between the 80 patients on the G trial (2003-2006) and the 93 patients on the no-G trial (1999-2003). Minimum follow-up for all patients was 5 years. Multivariable analyses comparing the G versus no-G patients and adjusting for statistically significant covariates demonstrated improved overall survival (hazard ratio [HR] 0.64, 95% confidence interval [CI] = 0.45-0.91, P = 0.012), recurrence-free survival (HR 0.61, 95% CI = 0.43-0.86, P = 0.006), and distant recurrence (HR 0.68, 95% CI = 0.45-1.00, P = 0.05), but not locoregional recurrence. Although this retrospective comparison can only be considered exploratory, it suggests that G may improve clinical outcomes when combined with CCRT and surgery in the definitive treatment of E/GEJ cancer.

Competing states in the t-J model: uniform D-wave state versus stripe state.

Variational studies of the t-J model on the square lattice based on infinite projected-entangled pair states confirm an extremely close competition between a uniform d-wave superconducting state and different stripe states. The site-centered stripe with an in-phase d-wave order has an equal or only slightly lower energy than the stripe with antiphase d-wave order. The optimal stripe filling is not constant but increases with J/t. A nematic anisotropy reduces the pairing amplitude and the energies of stripe phases are lowered relative to the uniform state with increasing nematicity.

Severe obesity and diabetes self-care attitudes, behaviours and burden: implications for weight management from a matched case-controlled study. Results from Diabetes MILES--Australia.

AIMS: To investigate whether diabetes self-care attitudes, behaviours and perceived burden, particularly related to weight management, diet and physical activity, differ between adults with Type 2 diabetes who are severely obese and matched non-severely obese control subjects. METHODS: The 1795 respondents to the Diabetes MILES--Australia national survey had Type 2 diabetes and reported height and weight data, enabling BMI calculation: 530 (30%) were severely obese (BMI ≥ 35 kg/m(2); median BMI = 41.6 kg/m(2)) and these were matched with 530 control subjects (BMI < 35 kg/m(2); median BMI = 28.2 kg/m(2)). Diabetes self-care behaviours, attitudes and burden were measured with the Diabetes Self-Care Inventory-Revised. Within-group and between-group trends were examined. RESULTS: The group with BMI ≥ 35 kg/m(2) was less likely to achieve healthy diet and exercise targets, placed less importance on diet and exercise recommendations, and found the burden of diet and exercise recommendations to be greater than the group with BMI < 35 kg/m(2). The group with BMI ≥ 35 kg/m(2) was more likely to be actively trying to lose weight, but found weight control a greater burden. These issues accentuated with increasing obesity and were greatest in those with BMI > 45 kg/m(2). There were no between-group differences in other aspects of diabetes self-care: self-monitoring of blood glucose, use of medications and smoking. Moderate-to-severe symptoms of depression were independently associated with reduced likelihood of healthy diet and physical activity, and with greater burden associated with diet, physical activity and weight management. CONCLUSIONS: Severely obese people with diabetes demonstrated self-care attitudes, behaviours and burdens that infer barriers to weight loss. However, other important diabetes self-care behaviours are supported equally by severely obese and non-severely obese individuals.

Spin density wave fluctuations and p-wave pairing in Sr2RuO4.

Recently, a debate has arisen over which of the two distinct parts of the Fermi surface of Sr(2)RuO(4) is the active part for the chiral p-wave superconductivity exhibited. Early theories proposed p-wave pairing on the two-dimensional γ band, whereas a recent proposal focuses on the one-dimensional (α, ß) bands whose nesting pockets are the source of the strong incommensurate spin density wave (SDW) fluctuations. We apply a renormalization group theory to study quasi-one-dimensional repulsive Hubbard chains and explain the form of SDW fluctuations, reconciling the absence of long-range order with their nesting Fermi surface. The mutual exclusion of p-wave pairing and SDW fluctuations in repulsive Hubbard chains favors the assignment of the two-dimensional γ band as the source of p-wave pairing.

High host density favors greater virulence: a model of parasite-host dynamics based on multi-type branching processes.

We use a multitype continuous time Markov branching process model to describe the dynamics of the spread of parasites of two types that can mutate into each other in a common host population. While most mathematical models for the virulence of infectious diseases focus on the interplay between the dynamics of host populations and the optimal characteristics for the success of the pathogen, our model focuses on how pathogen characteristics may change at the start of an epidemic, before the density of susceptible hosts decline. We envisage animal husbandry situations where hosts are at very high density and epidemics are curtailed before host densities are much reduced. The use of three pathogen characteristics: lethality, transmissibility and mutability allows us to investigate the interplay of these in relation to host density. We provide some numerical illustrations and discuss the effects of the size of the enclosure containing the host population on the encounter rate in our model that plays the key role in determining what pathogen type will eventually prevail. We also present a multistage extension of the model to situations where there are several populations and parasites can be transmitted from one of them to another. We conclude that animal husbandry situations with high stock densities will lead to very rapid increases in virulence, where virulent strains are either more transmissible or favoured by mutation. Further the process is affected by the nature of the farm enclosures.

Esophageal leiomyoma: experience from a single institution.

Esophageal leiomyomas are rare. We report the clinicopathologic features of one of the largest series of esophageal leiomyomas from a single institution. We retrospectively reviewed the Cleveland Clinic pathology database (1985-2010) for patients with a diagnosis of esophageal leiomyoma(s). Clinicopathologic features of 30 cases from 28 patients were analyzed. The group included 15 females and 13 males with a mean age at diagnosis of 56 years. These include 9 excisions, 9 esophagectomies, and 12 endoscopic biopsies. Only one partial esophagectomy was performed solely for a symptomatic 14-cm leiomyoma; the remainder of the resections (n= 8) were for other indications, including esophageal cancer (Barrett's esophagus-related adenocarcinoma and squamous cell carcinoma) and emergent esophageal perforation, with leiomyoma being an incidental finding. One patient (2.5%) had two synchronous leiomyomas (14 cm and 0.3 cm). Tumor size ranged from 0.1 to 14 cm (mean = 2.0 cm). Mean tumor size among symptomatic patients was 5.2 cm, as compared with 0.4 cm in asymptomatic patients. Dysphagia was the most common complaint in symptomatic patients (71.4%). Sixty-nine percent of the tumors were located in the distal and middle thirds of the esophagus, with most (69.6%) arising from muscularis propria. Histologically, these tumors were composed of bland spindle cells with low cellularity, no nuclear atypia, or mitotic activity. Only one case (14 cm) showed focal moderate cellularity and nuclear atypia, with low mitotic activity (<1/10 high power field). Immunohistochemical studies showed tumor cells were positive for smooth muscle actin, and negative for CD34 and CD117. Follow-up information was available for 22 patients (78.6%), and none had adverse events related to leiomyoma. In summary, esophageal leiomyoma is a rare benign tumor of the esophagus. Patients with larger tumors were more likely to have symptoms. The majority of the tumors were in the lower and mid-esophagus, and arose from muscularis propria. These tumors behave in a clinically benign fashion.