OFF-FARM EMPLOYMENT DECISIONS BY MASSACHUSETTS FARM HOUSEHOLDS

The off-farm labor participation and supply decisions of Massachusetts farm families were estimated in a model which allows for joint decisions. The hypothesis of joint off-farm participation decisions by operators and spouses was rejected. However, there was some evidence that the hours supplied by the farm operator was dependent upon the decision by the spouse to work off-farm. Farm operators were found to respond to both family and farm characteristics in making participation and supply decisions. Spouses respond to the characteristics of the farm and family in participation decisions while family characteristics determined hours worked by the spouse.Consumer/Household Economics,

Mitochondrial heat-shock protein hsp60 is essential for assembly of proteins imported into yeast mitochondria

A nuclear encoded mitochondrial heat-shock protein hsp60 is required for the assembly into oligomeric complexes of proteins imported into the mitochondrial matrix. hsp60 is a member of the 'chaperonin' class of protein factors, which include the Escherichia coli groEL protein and the Rubisco subunit-binding protein of chloroplast

Estimation of Dietary Iron Bioavailability from Food Iron Intake and Iron Status

Currently there are no satisfactory methods for estimating dietary iron absorption (bioavailability) at a population level, but this is essential for deriving dietary reference values using the factorial approach. The aim of this work was to develop a novel approach for estimating dietary iron absorption using a population sample from a sub-section of the UK National Diet and Nutrition Survey (NDNS). Data were analyzed in 873 subjects from the 2000–2001 adult cohort of the NDNS, for whom both dietary intake data and hematological measures (hemoglobin and serum ferritin (SF) concentrations) were available. There were 495 men aged 19–64 y (mean age 42.7±12.1 y) and 378 pre-menopausal women (mean age 35.7±8.2 y). Individual dietary iron requirements were estimated using the Institute of Medicine calculations. A full probability approach was then applied to estimate the prevalence of dietary intakes that were insufficient to meet the needs of the men and women separately, based on their estimated daily iron intake and a series of absorption values ranging from 1–40%. The prevalence of SF concentrations below selected cut-off values (indicating that absorption was not high enough to maintain iron stores) was derived from individual SF concentrations. An estimate of dietary iron absorption required to maintain specified SF values was then calculated by matching the observed prevalence of insufficiency with the prevalence predicted for the series of absorption estimates. Mean daily dietary iron intakes were 13.5 mg for men and 9.8 mg for women. Mean calculated dietary absorption was 8% in men (50th percentile for SF 85 µg/L) and 17% in women (50th percentile for SF 38 µg/L). At a ferritin level of 45 µg/L estimated absorption was similar in men (14%) and women (13%). This new method can be used to calculate dietary iron absorption at a population level using data describing total iron intake and SF concentration

Spin-orbit coupling and electron spin resonance for interacting electrons in carbon nanotubes

We review the theoretical description of spin-orbit scattering and electron spin resonance in carbon nanotubes. Particular emphasis is laid on the effects of electron-electron interactions. The spin-orbit coupling is derived, and the resulting ESR spectrum is analyzed both using the effective low-energy field theory and numerical studies of finite-size Hubbard chains and two-leg Hubbard ladders. For single-wall tubes, the field theoretical description predicts a double peak spectrum linked to the existence of spin-charge separation. The numerical analysis basically confirms this picture, but also predicts additional features in finite-size samples.Comment: 19 pages, 4 figures, invited review article for special issue in J. Phys. Cond. Mat., published versio

Sensitivity of the ocean state to the vertical distribution of internal-tide-driven mixing

Author Posting. © American Meteorological Society, 2013. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 43 (2013): 602–615, doi:10.1175/JPO-D-12-055.1.The ocean interior stratification and meridional overturning circulation are largely sustained by diapycnal mixing. The breaking of internal tides is a major source of diapycnal mixing. Many recent climate models parameterize internal-tide breaking using the scheme of St. Laurent et al. While this parameterization dynamically accounts for internal-tide generation, the vertical distribution of the resultant mixing is ad hoc, prescribing energy dissipation to decay exponentially above the ocean bottom with a fixed-length scale. Recently, Polzin formulated a dynamically based parameterization, in which the vertical profile of dissipation decays algebraically with a varying decay scale, accounting for variable stratification using Wentzel–Kramers–Brillouin (WKB) stretching. This study compares two simulations using the St. Laurent and Polzin formulations in the Climate Model, version 2G (CM2G), ocean–ice–atmosphere coupled model, with the same formulation for internal-tide energy input. Focusing mainly on the Pacific Ocean, where the deep low-frequency variability is relatively small, the authors show that the ocean state shows modest but robust and significant sensitivity to the vertical profile of internal-tide-driven mixing. Therefore, not only the energy input to the internal tides matters, but also where in the vertical it is dissipated.This work is a component of the Internal- Wave Driven Mixing Climate Process Team funded by the National Science Foundation Grant OCE-0968721 and the National Oceanic and Atmospheric Administration, U.S. Department of Commerce, Award NA08OAR4320752.2013-09-0

Nottingham Health Profile and Short-Form 36 Health Survey questionnaires in patients with chronic lower limb ischemia: Before and after revascularization

AbstractObjective: The purpose of this study was to compare the usefulness of the Nottingham Health Profile (NHP) and the Short-Form 36 Health Survey (SF-36) as general outcome measures after vascular intervention for lower limb ischemia with respect to patients' quality of life, on the basis of validity, reliability, and responsiveness analyses. Patients and Methods: Eighty patients, 40 with claudication and 40 with critical ischemia, were assessed before and one month after revascularization by using comparable domains of the NHP and the SF-36 questionnaires. Results: The SF-36 scores were less skewed and were distributed more homogeneously than the NHP scores. Discriminate validity results showed that NHP was better than SF-36 in discriminating among levels of ischemia with respect to pain and physical mobility. For both questionnaires, the reliability standards were satisfactory in most respects. The NHP was more responsive than the SF-36 in detecting within-patient changes. All of the NHP domains not zero at baseline were improved significantly one month after hemodynamically successful revascularization for patients with claudication, whereas patients with critical ischemia showed significant abatement of pain and improvements in physical mobility and social isolation. The SF-36 scores indicated a significant decrease in bodily pain and improvements in physical functioning and vitality for patients with claudication, and decrease in bodily pain and improvement in physical functioning for patients with critical ischemia. Conclusions: The findings indicated that both NHP and SF-36 were reliable. The SF-36 scores were less skewed than the NHP scores, whereas NHP discriminated better among levels of ischemia and was more responsive in detecting quality-of-life changes over time than SF-36 in these particular patients. (J Vasc Surg 2002;36:310-7.

Detection of topological transitions by transport through molecules and nanodevices

We analyze the phase transitions of an interacting electronic system weakly coupled to free-electron leads by considering its zero-bias conductance. This is expressed in terms of two effective impurity models for the cases with and without spin degeneracy. We demonstrate using the half-filled ionic Hubbard ring that the weight of the first conductance peak as a function of external flux or of the difference in gate voltages between even and odd sites allows one to identify the topological charge transition between a correlated insulator and a band insulator.Comment: 4 pages, 5 figures, to appear in Phys. Rev. Let

APPLYING NEXT-GENERATION CANCER GENOME SEQUENCING APPROACHES TO OVARIAN CANCER

Ovarian cancer is the leading cause of death from gynecologic cancers. The ten year survival is less than 30% and has not improved significantly over the last 30 years. We employed next generation sequencing to address three common areas where previous studies have been lacking and insight into disease etiology would help improve survival and treatment of patients with ovarian cancer. Firstly, one of the challenges to improved diagnostic and therapeutic intervention in ovarian cancer has been a limited understanding of the natural history of the disease. It has been proposed that fallopian tube cancers may be precursors of high-grade serous ovarian carcinoma (HGSOC) but evolutionary evidence for this hypothesis has been limited. We performed whole exome sequence and copy number analyses of laser-capture microdissected fallopian tube lesions (p53 signatures, serous tubal intraepithelial carcinomas (STICs), and fallopian tube carcinomas), ovarian cancers, and metastases from nine patients. Secondly, to improve our understanding of ovarian cancer, we performed genome-wide analyses of 45 commonly used ovarian cancer cell lines. Lastly, endometrioid and mucinous ovarian cancers represent nearly a quarter of ovarian cancers and their molecular characteristics and pathologic origins are poorly understood. Whole exome sequencing analyses of HGSOC samples demonstrated that p53 signatures and STICs are precursors of ovarian carcinoma and identified a window of seven years between development of a STIC and initiation of ovarian carcinoma, with metastases following rapidly thereafter. Whole genome sequencing analyses of 45 ovarian cancer cell lines showed dose-response analyses to targeted therapies revealed unique molecular dependencies, including increased sensitivity of tumors with PIK3CA and PPP2R1A alterations to PI3K inhibitor GNE-493, MYC amplifications to PARP inhibitor BMN673, and SMAD3/4 alterations to MEK inhibitor MEK162. Finally, whole exome and genome sequencing analyses on less common ovarian cancer subtypes revealed ovarian and GI mucinous tumors were epigenetically distinct. In contrast, the number of alterations and affected genes in ovarian and uterine endometrioid cancers were not distinguishable, suggesting that these tumors may have a similar tissue of origin. Together these analyses provide insights into the etiology of ovarian cancer, have implications for prevention, early detection and therapeutic intervention of this disease