Tensile Properties of the Murine Ventral Vertical Midline Incision

In clinical surgery, the vertical midline abdominal incision is popular but associated with healing failures. A murine model of the ventral vertical midline incision was developed in order to study the healing of this incision type.The strength of the wild type murine ventral abdominal wall in the midline was contained within the dermis; the linea alba made a negligible contribution. Unwounded abdominal wall had a downward trend (nonsignificant) in maximal tension between 12 and 29 weeks of age. The incision attained 50% of its final strength by postoperative day 40. The maximal tension of the ventral vertical midline incision was nearly that of unwounded abdominal wall by postwounding day 60; there was no difference in unwounded vs. wounded maximal tension at postwounding day 120.After 120 days of healing, the ventral vertical midline incision in the wild type mouse was not significantly different from age-matched nonwounded controls. About half of the final incisional strength was attained after 6 weeks of healing. The significance of this work was to establish the kinetics of wild type incisional healing in a model for which numerous genotypes and genetic tools would be available for subsequent study

Substance use patterns and unprotected sex among street-involved youth in a Canadian setting: a prospective cohort study

BACKGROUND: Rates of sexually transmitted infections (STI) and unplanned pregnancy are high among youth. While the intersection between drug and alcohol use and unprotected sex is well recognized, few studies have examined the relationship between substance use patterns and unprotected sex among high risk-populations such as street-involved youth. METHODS: Data were derived from the At-Risk Youth Study (ARYS), a prospective cohort of street-involved youth from Vancouver, Canada. Generalized estimating equations (GEE) were used to examine substance use patterns that were independently associated with unprotected sex, defined as (vaginal or anal) sexual intercourse without consistent condom use. RESULTS: Between September 2005 and May 2013, 1,026 youth were recruited into the ARYS cohort and 75 % (n = 766) reported engaging in recent unprotected sex at some point during the study period. In a multivariable analysis, female gender (adjusted odds ratio [AOR] = 1.46, 95 % confidence interval [CI]: 1.18-1.81), Caucasian ancestry (AOR = 1.38, 95 % CI: 1.13-1.68), being in a stable relationship (AOR = 4.64, 95 % CI: 3.82-5.65), having multiple sex partners (AOR = 2.60, 95 % CI: 2.18-3.10) and the following substance use patterns were all independently associated with recent unprotected sex: injection or non-injection crystal methamphetamine use (AOR = 1.21, 95 % CI: 1.03-1.43), injection or non-injection cocaine use (AOR = 1.20, 95 % CI: 1.02-1.41), marijuana use (AOR = 1.23, 95 % CI: 1.02-1.49), ecstasy use (AOR = 1.23, 95 % CI: 1.01-1.48) and alcohol use (AOR = 1.31, 95 % CI: 1.11-1.55) (all p < 0.05). CONCLUSIONS: Unprotected sex was prevalent among street-involved youth in this setting, and independently associated with female gender and a wide range of substance use patterns. Evidence-based and gender-informed sexual health interventions are needed in addition to increased access to youth-centered addiction treatment services. STI testing and linkages to healthcare professionals remain important priorities for street-involved youth, and should be integrated across all health and social services

A search for bremsstrahlung solar axions using the Majorana low-background BEGe detector at Kimballton (MALBEK)

A low-background, high-purity germanium detector has been used to search for evidence of low-energy, bremsstrahlung-generated solar axions. An upper bound of $1.36\times 10^{-11}$ $(95$ is placed on the direct coupling of DFSZ model axions to electrons. The prospects for the sensitivity of the Majorana Demonstrator array of point-contact germanium detectors to solar axions are discussed in the context of the model-independent annual modulation due to the seasonal variation of the earth-sun distance

The Majorana Demonstrator neutrinoless double-beta decay experiment

The Majorana Demonstrator will search for the neutrinoless double-beta (β β 0 ) decay of the isotope Ge with a mixed array of enriched and natural germanium detectors. The observation of this rare decay would indicate that the neutrino is its own antiparticle, demonstrate that lepton number is not conserved, and provide information on the absolute mass scale of the neutrino. The Demonstrator is being assembled at the 4850-foot level of the Sanford Underground Research Facility in Lead, South Dakota. The array will be situated in a low-background environment and surrounded by passive and active shielding. Here we describe the science goals of the Demonstrator and the details of its design. © 2014 N. Abgrall et al

Background Model for the Majorana Demonstrator

The Majorana Collaboration is constructing a system containing 40 kg of HPGe detectors to demonstrate the feasibility and potential of a future tonne-scale experiment capable of probing the neutrino mass scale in the inverted-hierarchy region. To realize this, a major goal of the Majorana Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 cnt/(ROI-t-y) in the 4 keV region of interest around the Q-value at 2039 keV. This goal is pursued through a combination of a significant reduction of radioactive impurities in construction materials with analytical methods for background rejection, for example using powerful pulse shape analysis techniques profiting from the p-type point contact HPGe detectors technology. The effectiveness of these methods is assessed using simulations of the different background components whose purity levels are constrained from radioassay measurements

The {\sc Majorana Demonstrator} Neutrinoless Double-Beta Decay Experiment

The {\sc Majorana Demonstrator will search for the neutrinoless double-beta decay of the isotope Ge-76 with a mixed array of enriched and natural germanium detectors. The observation of this rare decay would indicate the neutrino is its own antiparticle, demonstrate that lepton number is not conserved, and provide information on the absolute mass scale of the neutrino. The {\sc Demonstrator} is being assembled at the 4850-foot level of the Sanford Underground Research Facility in Lead, South Dakota. The array will be situated in a low-background environment and surrounded by passive and active shielding. Here we describe the science goals of the {\sc Demonstrator} and the details of its design

The Majorana Demonstrator Neutrinoless Double-Beta Decay Experiment

The {\sc Majorana Demonstrator will search for the neutrinoless double-beta decay of the isotope Ge-76 with a mixed array of enriched and natural germanium detectors. The observation of this rare decay would indicate the neutrino is its own antiparticle, demonstrate that lepton number is not conserved, and provide information on the absolute mass scale of the neutrino. The {\sc Demonstrator} is being assembled at the 4850-foot level of the Sanford Underground Research Facility in Lead, South Dakota. The array will be situated in a low-background environment and surrounded by passive and active shielding. Here we describe the science goals of the {\sc Demonstrator} and the details of its design.The MAJORANA DEMONSTRATOR will search for the neutrinoless double-beta decay of the isotope Ge with a mixed array of enriched and natural germanium detectors. The observation of this rare decay would indicate that the neutrino is its own antiparticle, demonstrate that lepton number is not conserved, and provide information on the absolute mass scale of the neutrino. The DEMONSTRATOR is being assembled at the 4850-foot level of the Sanford Underground Research Facility in Lead, South Dakota. The array will be situated in a low-background environment and surrounded by passive and active shielding. Here we describe the science goals of the DEMONSTRATOR and the details of its design