Method for routine density measurement of sublimating solid carbon dioxide (dry ice) for cold-chain quality control

With recent development of vaccines and biologics, interest in dry ice for cold chain shipping has increased. However, understanding of how dry ice properties relate to performance is not well understood. This study introduces a simple method for measuring a key property of dry ice that has been shown to correlate to performance. The method involves a variant of the water displacement method for determining volume, where dense solid particles are used in place of water for volume determination. Three particle types (sieved sand, glass beads, and stainless-steel shot) were tested for suitability with the particle displacement method. Items of known mass and volume were used to validate the method. Direct volume measurements of dry ice cut samples using digital calipers were conducted in parallel for relative comparison. Results showed that the proposed particle displacement method using sieved sand produced density readings with an accuracy of 97-99%, whereas digital calipers underestimated density values. The sand and glass particles were less successful due to high thermal conductivity (stainless-steel shot), which led to errors due to condensation, and particles that were too fine and not sufficiently dense to prevent fluidization doe to sublimation gas flow. Sieved sand provided a good combination of particle size, density, thermal conductivity, and heat capacity for routine measurement of density of dry ice regardless of shape

Variability in Pesticide Deposition and Source Contributions to Snowpack in Western US National Park.

Fifty-six seasonal snowpack samples were collected at remote alpine, subarctic, and arctic sites in eight Western U.S. national parks during three consecutive years (2003-2005). Four current-use pesticides (CUPs) (dacthal (DCPA), chlorpyrifos, endosulfans, and gamma-hexachlorocyclohexane (HCH)) and four historic-use pesticides (HUPs) (dieldrin, alpha-HCH, chlordanes, and hexachlorobenzene (HCB)) were commonly measured at all sites, during all years. The mean coefficient of variation for pesticide concentrations was 15% for site replicate samples, 41% for intrapark replicate samples, and 59% for interannual replicate samples. The relative pesticide concentration profiles were consistent from year to year but unique for individual parks, indicating a regional source effect. HUP concentrations were well-correlated with regional cropland intensity when the effect of temperature on snow-air partitioning was considered. The mass of individual CUPs used in regions located one-day upwind of the parks was calculated using air mass back trajectories, and this was used to explain the distribution of CUPs among the parks. The percent of the snowpack pesticide concentration due to regional transport was high (\u3e75%) for the majority of pesticides in all parks. These results suggest that the majority of pesticide contamination in U.S. national parks is due to regional pesticide use in North America

Use of Standardized Outcome Measures for People With Lower Limb Amputation: A Survey of Prosthetic Practitioners in the United States

Objective: To assess the clinical resources available for the assessment of health outcomes in people with lower limb amputation and to under-stand barriers and facilitators associated with use of standardized outcome measures in clinical practice. Design: Cross-sectional survey. Setting: General community (online). Participants: A volunteer sample of prosthetic practitioners was recruited through national professional organizations. Eligible participants were practitioners certified by a professional prosthetics organization and currently practicing as a prosthetist, prosthetist-orthotist, or prosthetic assistant. Interventions: Not applicable. Main Outcome Measures: A custom-designed online survey on clinical use of patient-reported and performance-based standardized outcome measures to assess patients with lower limb amputation. Results: A total of 375 participants completed the survey. Most participants (79%) reported that they are encouraged or required to administer standardized outcome measures in their clinic or facility. Most participants reported that use of patient-reported and performance-based outcome measures are within their scope of practice (88%) and that they have the knowledge required for outcomes measurement (84%). Few participants agreed that outcomes measurement is standardized across the profession (30%). Most participants had access to small spaces and equipment for outcomes measurement, such as short hallways (65%-94%), stairs (69%), and tablets with wireless internet connection (83%). Most participants reported that they would be willing to spend between 5 (36% of participants) and 10 (43% of participants) minutes on self-reported surveys, and between 10 (41% of participants) and 20 (28% of participants) minutes on performance-based tests. Conclusions: Outcomes measurement is encouraged or expected in contemporary prosthetic practice. Strategies to improve standardization and efficiency of administration are needed to facilitate routine use of outcome measures in clinical care. Archives of Physical Medicine and Rehabilitation 2022;103:1786-97 (c) 2022 by the American Congress of Rehabilitation Medicine

The Western Airborne Contaminant Assessment Project (WACAP): An Interdisciplinary Evaluation of the Impacts of Airborne Contaminants in Western US National Parks.

The National Park Service Organic Act of 1916 (1) required protection of the national parks for perpetuity by tasking the National Park Service (NPS) to maintain these lands “...unimpaired for the enjoyment of future generations.” Near the close of the last century, the NPS became aware of a new body of research describing a potential ecosystem threat that could not be ignored. Toxic airborne contaminants were increasingly being found in the world’s most pristine alpine and polar ecosystems, far from where such chemicals were produced or used, and the risks to the national parks of the western U.S. were unknown. Airborne contaminants present a broad range of potential risks to these ecosystems, largely due to bioaccumulation and or biomagnification of toxicants in biota, particularly vertebrates, that can result in loss of fecundity, unfit offspring, maladaptive behavior, and even death. As an outgrowth of these concerns, the Western Airborne Contaminants Assessment Project (WACAP) was initiated in 2002 to determine the risk from airborne contaminants to ecosystems and food webs in national parks of the U.S. The specific objectives that guided design and implementation of WACAP were the following: 1. Determine if contaminants were present in western national parks. 2. If contaminants were present, determine in what way and where they were accumulating (geographically and by elevation). 3. If contaminants were present, determine which ones posed an ecological threat. 4. Determine which indicators appeared to be the most useful for assessing contamination. 5. If contaminants were present, determine the source of the air masses most likely to have transported contaminants to the national park sites

Correlation of Chromosomal Instability, Telomere Length and Telomere Maintenance in Microsatellite Stable Rectal Cancer: A Molecular Subclass of Rectal Cancer

<div><p>Introduction</p><p>Colorectal cancer (CRC) tumor DNA is characterized by chromosomal damage termed chromosomal instability (CIN) and excessively shortened telomeres. Up to 80% of CRC is microsatellite stable (MSS) and is historically considered to be chromosomally unstable (CIN+). However, tumor phenotyping depicts some MSS CRC with little or no genetic changes, thus being chromosomally stable (CIN-). MSS CIN- tumors have not been assessed for telomere attrition. </p> <p>Experimental Design</p><p>MSS rectal cancers from patients ≤50 years old with Stage II (B2 or higher) or Stage III disease were assessed for CIN, telomere length and telomere maintenance mechanism (telomerase activation [TA]; alternative lengthening of telomeres [ALT]). Relative telomere length was measured by qPCR in somatic epithelial and cancer DNA. TA was measured with the TRAPeze assay, and tumors were evaluated for the presence of C-circles indicative of ALT. p53 mutation status was assessed in all available samples. DNA copy number changes were evaluated with Spectral Genomics aCGH. </p> <p>Results</p><p>Tumors were classified as chromosomally stable (CIN-) and chromosomally instable (CIN+) by degree of DNA copy number changes. CIN- tumors (35%; n=6) had fewer copy number changes (<17% of their clones with DNA copy number changes) than CIN+ tumors (65%; n=13) which had high levels of copy number changes in 20% to 49% of clones. Telomere lengths were longer in CIN- compared to CIN+ tumors (p=0.0066) and in those in which telomerase was not activated (p=0.004). Tumors exhibiting activation of telomerase had shorter tumor telomeres (p=0.0040); and tended to be CIN+ (p=0.0949).</p> <p>Conclusions</p><p>MSS rectal cancer appears to represent a heterogeneous group of tumors that may be categorized both on the basis of CIN status and telomere maintenance mechanism. MSS CIN- rectal cancers appear to have longer telomeres than those of MSS CIN+ rectal cancers and to utilize ALT rather than activation of telomerase. </p> </div

Clone gains/losses by ALT activity.

<p>Tumors that were ALT- exhibited significantly more chromosomal gains/losses than ALT+ rectal cancer (p=0.0091).</p

Histology, C-circle dot blot and aCGH summary for a MSS CIN- ALT + rectal cancer without activation of telomerase and MSS CIN+ ALT - rectal cancer with activation of telomerase.

<div><p>Panel A. Hematoxylin and Eosin tissue sections from an MSS CIN- , ALT+,Telomerase- rectal cancer (left) and from MSS CIN+, ALT-, Telomerase + rectal cancer. Both are moderately differentiated adenocarcinomas. The gland-to-stroma ratio is higher in the ALT+/tel- case, and it has less desmoplastic stroma.</p> <p>Panel B. Dot/blot showing presence of C-circles. C circles, extrachromosomal telomeric DNA, are strongly associated with ALT. Assessed in tumor DNA with isothermic amplification of C-circle complementary strand and hybridization with ³²P-(CCCTAA)₃ probe by Capital Biosciences (Capital Biosciences, Maryland, U. S. A. ), a sample was called ALT+ if C-circles were detected. The presence of C-circles are illustrated by the presence of radioactive tracer in the image on the left, and the absence of radioactivity in the blot on the right indicates absence of C-circles in the ALT- tumor. </p> <p>Panel C. Ideograms summarizing chromosomal gains and losses across all chromosomes evaluated by aCGH. The ALT+, telomerase negative tumor on the left had <10% of BAC clones showing aberrant hybridization and is classified as a CIN- tumor. The ALT-,,telomerase positive tumor on the right had 40% of clones with aberrant hybridization and is classified as a CIN+ tumor. </p> <p>Panel D. aCGH results of raw data for chromosome 17 for each tumor corresponding to the ideograms in Panel C. </p></div