Loop Corrections and Naturalness in a Chiral Effective Field Theory

The loop expansion is applied to a chiral effective hadronic lagrangian; with the techniques of Infrared Regularization, it is possible to separate out the short-range contributions and to write them as local products of fields that are already present in our lagrangian. (The appropriate field variables must be re-defined at each order in loops.) The corresponding parameters implicitly include short-range effects to all orders in the interaction, so these effects need not be calculated explicitly. The remaining (long-range) contributions that must be calculated are nonlocal and resemble those in conventional nuclear-structure calculations. Nonlinear isoscalar scalar $(\sigma)$ and vector $(\omega)$ meson interactions are included, which incorporate many-nucleon forces and nucleon substructure. Calculations are carried out at the two-loop level to illustrate these techniques at finite nuclear densities and to verify that the coupling parameters remain natural when fitted to the empirical properties of equilibrium nuclear matter. Contributions from the $\omega N$ tensor coupling are also discussed.Comment: 22 pages, 6 figure

Mental Health Needs Among Minority Aviation Students

Higher education, including science, technology, engineering, and mathematics (STEM) education, benefit our society and economic growth. However, overcoming gender disparity and increasing the retention of underrepresented minorities within these programs is challenging. Mental health across higher education has shown to be on the rise, and when it comes to the mental health needs of aviation students, research shows that underrepresented minorities experience unique challenges in achieving academic success. This paper focused on identifying aviation minority students\u27 unique challenges in a small STEM university. This mixed-methods action research study collected quantitative data using an adapted version of the Counseling Center Assessment of Psychological Symptoms-62 (CCAPS-62) and qualitative in-person focus groups. Essential elements evaluated were social support, psychological distress, and psychological well-being needed to thrive in the academic environment. The findings provide educational leaders with research-based strategies to meet the needs of underrepresented minority students and increase their retention in aviation education

Daniel D. McIntire requesting a certificate of [enlistment] for Charles H. McIntire

https://digitalmaine.com/arc_me_militia/1131/thumbnail.jp

An electrostatic mechanism for Ca(2+)-mediated regulation of gap junction channels.

Gap junction channels mediate intercellular signalling that is crucial in tissue development, homeostasis and pathologic states such as cardiac arrhythmias, cancer and trauma. To explore the mechanism by which Ca(2+) blocks intercellular communication during tissue injury, we determined the X-ray crystal structures of the human Cx26 gap junction channel with and without bound Ca(2+). The two structures were nearly identical, ruling out both a large-scale structural change and a local steric constriction of the pore. Ca(2+) coordination sites reside at the interfaces between adjacent subunits, near the entrance to the extracellular gap, where local, side chain conformational rearrangements enable Ca(2+)chelation. Computational analysis revealed that Ca(2+)-binding generates a positive electrostatic barrier that substantially inhibits permeation of cations such as K(+) into the pore. Our results provide structural evidence for a unique mechanism of channel regulation: ionic conduction block via an electrostatic barrier rather than steric occlusion of the channel pore

Acyclovir suppression to prevent recurrent genital herpes at delivery.

OBJECTIVE: To determine if suppressive acyclovir near term decreased the frequency of clinical recurrences at delivery in women with recurrent genital herpes simplex virus (HSV) infection. METHODS: We conducted a prospective, double-blind, randomized trial in 234 women with recurrent genital herpes. Women with genital infection of any frequency were enrolled. Patients received either suppressive oral acyclovir 400 mg three times daily or an identical placebo after 36 weeks' gestation. Clinical lesions were identified, and HSV cultures were obtained at delivery. The frequencies of clinical and subclinical HSV recurrences at delivery were evaluated. RESULTS: Six percent of patients treated with acyclovir, and 14% of patients treated with placebo had clinical HSV at delivery (p = 0.046). No patients in the acyclovir group had positive HSV cultures, compared with 6% of placebo-treated patients (p = 0.029). There was no significant difference in subclinical HSV shedding in the acyclovir group (0%) compared with the placebo-treated group (3%) (p = 0.102). CONCLUSIONS: Suppressive acyclovir therapy significantly decreased the incidence of clinical genital herpes and the overall incidence of HSV excretion at delivery in patients with previous herpes infection

Hydrologic Scales, Cloud Variability, Remote Sensing, and Models: Implications for Forecasting Snowmelt and Streamflow

Accurate prediction of available water supply from snowmelt is needed if the myriad of human, environmental, agricultural, and industrial demands for water are to be satisfied, especially given legislatively imposed conditions on its allocation. Robust retrievals of hydrologic basin model variables (e.g., insolation or areal extent of snow cover) provide several advantages over the current operational use of either point measurements or parameter-izations to help to meet this requirement. Insolation can be provided at hourly time scales (or better if needed during rapid melt events associated with flooding) and at 1-km spatial resolution. These satellite-based retrievals incorporate the effects of highly variable (both in space and time) and unpredictable cloud cover on estimates of insolation. The insolation estimates are further adjusted for the effects of basin topography using a high-resolution digital elevation model prior to model input. Simulations of two Sierra Nevada rivers in the snowmelt seasons of 1998 and 1999 indicate that even the simplest improvements in modeled insolation can improve snowmelt simulations, with 10%–20 % reductions in root-mean-square errors. Direct retrieval of the areal extent of snow cover may mitigate the need to rely entirely on internal calculations of this variable, a reliance that can yield large errors that are difficult to correct until long after the season is complete and that often leads to persistent underestimates or overestimates of the volumes of the water to operational reservoirs. Agencie

Postpartum sterilization choices made by HIV-infected women.

OBJECTIVE: To assess if HIV-infected women made different choices for postpartum sterilization after implementation of the Pediatric AIDS Clinical Trials Group protocol 076 (November 1, 1994) compared to before implementation. STUDY DESIGN: A retrospective cohort study in which medical records were reviewed to obtain demographic, obstetric and HIV-related data from January 1993 through December 2002. HIV-infected women who completed a pregnancy by birth or abortion were divided into two comparison groups: "Pre-076" and "Post-076". The primary outcome was sterilization by postpartum tubal ligation.Results. Forty-two women (74%) in the Pre-076 group chose sterilization compared to 139 of 310 women (45%) in the Post-076 group (unadjusted OR 3.44, 95% CI 1.83, 6.47). Seventy-one percent of women younger than 21 years of age in the Pre-076 Group chose sterilization compared with only 35% of women younger than 21 years in the Post-076 group (p = 0.0136). Similarly, 78% of primiparous women chose sterilization after their first pregnancy in the Pre-076 group, compared to 14% in the Post-076 group (p < 0.001). CONCLUSIONS: Since the implementation of PACTG 076 protocol in November 1994, fewer HIV-infected women chose postpartum sterilization. The typical woman who now chooses postpartum sterilization is less likely to be young or primiparous than those who chose sterilization before PACTG Protocol 076 implementation

Risk Factors Associated with False Positive HIV Test Results in a Low-Risk Urban Obstetric Population

Objective. To examine risk factors for false positive HIV enzyme immunoassay (EIA) testing at delivery. Study Design. A review of pregnant women who delivered at Parkland Hospital between 2005 and 2008 was performed. Patients routinely received serum HIV EIA testing at delivery, with positive results confirmed through immunofluorescent testing. Demographics, HIV, hepatitis B surface antigen (HBsAg), and rapid plasma reagin (RPR) results were obtained. Statistical analyses included Pearson's chi-square and Student's t-test. Results. Of 47,794 patients, 47,391 (99%) tested negative, 145 (0.3%) falsely positive, 172 (0.4%) positive, and 86 (0.2%) equivocal or missing HIV results. The positive predictive value of EIA was 54.3%. Patients with false positive results were more likely nulliparous (43% versus 31%, P < 0.001) and younger (23.9 ± 5.7 versus 26.2 ± 5.9 years, P < 0.001). HIV positive patients were older than false positive patients and more likely positive for HBsAg and RPR. Conclusion. False positive HIV testing at delivery using EIA is associated with young maternal age and nulliparity in this population

Sensitivity and threshold dynamics of Pinus strobus and Quercus spp. in response to experimental and naturally-occurring severe droughts

Increased drought frequency and severity are a pervasive global threat, yet the capacity of mesic temperate forests to maintain resilience in response to drought remains poorly understood. We deployed a throughfall removal experiment to simulate a once in a century drought in New Hampshire, USA, which coupled with the region-wide 2016 drought, intensified moisture stress beyond that experienced in the lifetimes of our study trees. To assess the sensitivity and threshold dynamics of two dominant northeastern tree genera (Quercus and Pinus), we monitored sap flux density (Js), leaf water potential and gas exchange, growth, and intrinsic water use efficiency (iWUE) for one pretreatment year (2015) and two treatment years (2016-17). Results showed that Js in pine (P. strobus) declined abruptly at a soil moisture threshold of 0.15 m3m-3 , while oak’s (Q. rubra and Q. velutina) threshold was 0.11 m3m-3 — a finding consistent with pine’s more isohydric strategy. Nevertheless, once oaks’ moisture threshold was surpassed, Js declined abruptly, suggesting that while oaks are well-adapted to moderate drought, they are highly susceptible to extreme drought. The radial growth reduction in response to the 2016 drought was more than twice as great for pine than for oaks (50% vs. 18% respectively). Despite relatively high precipitation in 2017, the oaks’ growth continued to decline (low recovery), whereas pine showed neutral (treatment) or improved (control) growth. iWUE increased in 2016 for both treatment and control pines, but only in treatment oaks. Notably, pines exhibited a significant linear relationship between iWUE and precipitation across years, whereas the oaks only showed a response during the driest conditions, further underscoring the different sensitivity thresholds for these species. Our results provide new insights into how interactions between temperate forest tree species’ contrasting physiologies and soil moisture thresholds influence their responses and resilience to extreme drought

Acyclovir Suppression to Prevent Clinical Recurrences at Delivery After First Episode Genital Herpes in Pregnancy: An Open-Label Trial

Objective: To continue evaluation of the use of acyclovir suppression in late pregnancy after first episode genital herpes simplex virus (HSV) infection, using an open-label study design. Methods: Ninety-six women diagnosed with genital herpes for the first time in the index pregnancy were prescribed suppressive acyclovir 400 mg orally three times daily from 36 weeks until delivery in an open-label fashion. Herpes cultures were obtained when patients presented for delivery. Vaginal delivery was permitted if no clinical recurrence was present; otherwise a Cesarean delivery was performed. NeonatalHSV cultures were obtained and infants were followed clinically. Rates of clinical and asymptomatic genital herpes recurrences and Cesarean delivery for genital herpes were measured, and 95% confidence intervals were calculated. Results: In 82 patients (85%) compliant with therapy, only 1% had clinical HSV recurrences at delivery. In an intent to treat analysis of the entire cohort, 4% had clinical recurrences (compared with 18–37% in historical controls). Asymptomatic shedding occurred in 1% of women without lesions at delivery. Two of the four clinical recurrences were HSV-culture positive. No significant maternal or fetal side-effects were observed. Conclusions: In clinical practice the majority of patients are compliant with acyclovir suppression at term. The therapy appears to be effective at reducing clinical recurrences after a first episode of genital herpes complicating a pregnancy