Age and Huddling as Determinants of Metabolic Rate in Grasshopper Mice (Onychomys leucogaster)

The metabolic rates of grasshopper mice (Onychomys leucogaster) were determined every third day from birth to adulthood. Metabolic rates were quantitated by measuring oxygen consumption in an open circuit system. There was a rapid fall in oxygen consumption from the third day after birth until the ninth day. Mice which were housed separately assumed a constant metabolic rate at an earlier age than mice which were kept with litter-mates. The greatest increases in metabolism occurred when immature mice were separated from litter-mates for oxygen consumption determinations. It is concluded that huddling plays an important role in reducing the metabolic rate of young grasshopper mice

Recent Developments in the Law of the Sea V: A Synopsis

Each year, as part of the San Diego Law Review\u27s symposium on law of the sea, a student article is dedicated to a synopsis of recent events in the field. The function of such as article is to provide the reader with a broadly circumscribed report of recent developments presented under the topic headings of conservation, fishing, pollution, seabed resources, shipping and sovereignty. This year\u27s compendium covers the period between January 1, 1973 and December 31, 1973. A myriad of sources are represented including the United States Code Congressional and Administrative News, the Environmental Reporter, International Legal Materials, the United Nations Chronicle, the Congressional Record and the New York Times

A needs analysis of maritime helicopter flight instructor training

1 online resource (iv, 30 p.) : col. ill.Includes abstract.Includes bibliographical references (p. 30).The purpose of this project is to conduct a training needs analysis of the Maritime Helicopter Flight Instructor Course at 406 Maritime Operational Training Squadron. This analysis will be a modified approach combining the academic process of the needs analysis with the Canadian Forces Individual Training and Education System approach training development. This project will determine the current and required training of Maritime Helicopter Flight Instructors in order to address a performance gap that was identified following a flight safety accident. Finally, the end state of the project will be the development and implementation of a Flight Instructor Course Training Plan. This will set the conditions for the elimination of the performance gap in instructional capability through realignment with superior training guidance, subordinate documentation amendments and training adjustments

Strain shielding in trabecular bone at the tibial cement-bone interface

Item does not contain fulltextAseptic loosening of the tibial component remains the leading cause for revision surgery in total knee arthroplasty (TKA). Understanding the mechanisms leading to loss of fixation can offer insight into preventative measures to ensure a longer survival rate. In cemented TKA, loosening occurs at the cement-trabecular interface probably due to a stress-shielding effect of the stiffer implant material in comparison with bone. Using finite element models of lab-prepared tibial cement-trabeculae interface specimens (n=4) based on micro-CT images, this study aims to investigate the micromechanics of the interlock between cement and trabecular bone. Finite element micromotion between cement and trabeculae and bone strain were compared in the interdigitated trabeculae as well as strain in the bone distal to the interface. Lab-prepared specimens and their FE models were assumed to represent the immediate post-operative situation. The cement layer was removed in the FE models while retaining the loading conditions, which resulted in FE models that represented the pre-operative situation. Results showed that micromotion and bone strain decrease when interdigitation depth increases. Bone-cement micromotion and bone strain at the distal interdigitated region showed a dependence on bone volume fraction. Comparing the immediate post-operative and pre-operative situations, trabeculae embedded deep within the cement generally showed the highest level of strain-shielding. Strain shielding of interdigitated bone, in terms of reduction in compressive strains, was found to be between 35 and 61 % for the four specimens. Strain adaptive remodeling could thus be a plausible mechanism responsible for loss of interdigitated bone

Preprocessing Among the Infalling Galaxy Population of EDisCS Clusters

We present results from a low-resolution spectroscopic survey for 21 galaxy clusters at $0.4 < z < 0.8$ selected from the ESO Distant Cluster Survey. We measured spectra using the low-dispersion prism in IMACS on the Magellan Baade telescope and calculate redshifts with an accuracy of $\sigma_z = 0.007$. We find 1763 galaxies that are brighter than $R = 22.9$ in the large-scale cluster environs. We identify the galaxies expected to be accreted by the clusters as they evolve to $z = 0$ using spherical infall models and find that $\sim30\%$ to $\sim70\%$ of the $z = 0$ cluster population lies outside the virial radius at $z \sim 0.6$. For analogous clusters at $z = 0$, we calculate that the ratio of galaxies that have fallen into the clusters since $z \sim 0.6$ to those that were already in the core at that redshift is typically between $\sim0.3$ and $1.5$. This wide range of ratios is due to intrinsic scatter and is not a function of velocity dispersion, so a variety of infall histories is to be expected for clusters with current velocity dispersions of $300 \lesssim\sigma\lesssim 1200$ km s$^{-1}$. Within the infall regions of $z \sim 0.6$ clusters, we find a larger red fraction of galaxies than in the field and greater clustering among red galaxies than blue. We interpret these findings as evidence of "preprocessing", where galaxies in denser local environments have their star formation rates affected prior to their aggregation into massive clusters, although the possibility of backsplash galaxies complicates the interpretation.Comment: Accepted for publication in Ap

Management and Outcome of Prosthetic Patch Infection after Carotid Endarterectomy: A Single-centre Series and Systematic Review of the Literature

AbstractObjectivesOutcomes following prosthetic patch infection after carotid endarterectomy (CEA).MethodsRetrospective audit and systematic review.Results22 patients were treated between January 1992 and April 2012, 5 having undergone their original CEA at another institution. The commonest infecting organism was Staphylococcus. One patient was treated by antibiotic irrigation, one was stented, while 20 underwent debridement and patch excision plus; carotid ligation (n = 3), vein patching (n = 3) or vein bypass (n = 14). There was one peri-operative stroke, but no peri-operative deaths. There were no reinfections at a median follow-up of 54 months.A systematic review identified 123 patients with prosthetic patch infection in the world literature. Thirty-six (29%) presented <2 months, 78 (63%) presented >6 months after the original CEA. Seventy-nine of/87 patients (91%) with a positive culture yielded Staphylococci or Streptococci. Seventy-four patients were treated by patch excision and autologous reconstruction. Four (5%) developed reinfection <30 days, but later reinfections have been reported. Seven of nine patients (78%) undergoing prosthetic reconstruction either died or suffered reinfection. Five patients were treated with a covered stent, none developing reinfection (median followup 12 months).ConclusionPatch infection following CEA is rare. Few have undergone stenting and long term data are awaited. For now, patch excision and autologous reconstruction remains the ‘gold standard’

The Perils of Recreational Marijuana Use: Relationships With Mental Health Among Emergency Department Patients

Abstract Introduction Marijuana is a commonly used drug in the United States. Many states have legalized the recreational use of marijuana. The effects of marijuana on mental health are unknown. Methods In this prospective survey study, eligible participants included ED patients age 18 and older, who had ever used recreational marijuana. A survey instrument was developed, piloted, and revised. Data collected included reasons for marijuana use, marijuana\u27s perceived effectiveness, and history of mental health conditions, including depression, anxiety, and suicidal thoughts. Results Among 303 participants (86% response rate), the median age of first marijuana use was 16 ([IQR 14, 19], range 6–65). The most commonly cited reasons for marijuana use included recreational use (70%; n = 211), to treat anxiety (30%; n = 89), to treat pain (25%; n = 74), and to treat depression (17%; n = 51). Mental health issues were common in the study population. A majority of patients reported anxiety in the last 30 days (59%; n = 176), and a significant minority of patients reported serious depression in the last 30 days (46%; n = 137). Some patients reported suicidal thoughts in the last 30 days (9%; n = 29). Participants who used marijuana more frequently reported more days of anxiety (median 15.5, compared to 1; P = 0.001). Among participants with mental health conditions, most began using marijuana before the onset of the mental health conditions (77%, n = 167). Earlier age of starting to use marijuana was correlated with higher number of years of anxiety or tension in lifetime (r = −0.11, P = 0.05, n = 301). Perceived effects of marijuana use on mental health were variable. Most participants stated that marijuana improved their mental health (62%; n = 163), and some reported that marijuana did not improve their mental health (37%; n = 98). Conclusions Many ED patients have used marijuana, either currently or in the past. Mental health conditions are also common, including anxiety, depression, and suicidal thoughts. Most participants reported marijuana use starting at an age under 18. Marijuana use preceded the onset of mental health conditions in the majority of participants

Neuropathological background of phenotypical variability in frontotemporal dementia

Frontotemporal lobar degeneration (FTLD) is the umbrella term encompassing a heterogeneous group of pathological disorders. With recent discoveries, the FTLDs have been show to classify nicely into three main groups based on the major protein deposited in the brain: FTLD-tau, FTLD-TDP and FTLD-FUS. These pathological groups, and their specific pathologies, underlie a number of well-defined clinical syndromes, including three frontotemporal dementia (FTD) variants [behavioral variant frontotemporal dementia (bvFTD), progressive non-fluent aphasia, and semantic dementia (SD)], progressive supranuclear palsy syndrome (PSPS) and corticobasal syndrome (CBS). Understanding the neuropathological background of the phenotypic variability in FTD, PSPS and CBS requires large clinicopathological studies. We review current knowledge on the relationship between the FTLD pathologies and clinical syndromes, and pool data from a number of large clinicopathological studies that collectively provide data on 544 cases. Strong relationships were identified as follows: FTD with motor neuron disease and FTLD-TDP; SD and FTLD-TDP; PSPS and FTLD-tau; and CBS and FTLD-tau. However, the relationship between some of these clinical diagnoses and specific pathologies is not so clear cut. In addition, the clinical diagnosis of bvFTD does not have a strong relationship to any FTLD subtype or specific pathology and therefore remains a diagnostic challenge. Some evidence suggests improved clinicopathological association of bvFTD by further refining clinical characteristics. Unlike FTLD-tau and FTLD-TDP, FTLD-FUS has been less well characterized, with only 69 cases reported. However, there appears to be some associations between clinical phenotypes and FTLD-FUS pathologies. Clinical diagnosis is therefore promising in predicting molecular pathology