bluuebunny/crossref_metadata_2025 huggingface dataset:
The sea urchin Lytechinus variegatus lives close to the upper thermal limit for early development in a tropical lagoon
Authors: Collin Rachel , Chan Kit Yu Karen
Published: July 2016

Thermal tolerance shapes organisms' physiological performance and limits their biogeographic ranges. Tropical terrestrial organisms are thought to live very near their upper thermal tolerance limits, and such small thermal safety factors put them at risk from global warming. However, little is known about the thermal tolerances of tropical marine invertebrates, how they vary across different life stages, and how these limits relate to environmental conditions. We tested the tolerance to acute heat stress of five life stages of the tropical sea urchin Lytechinus variegatus collected in the Bahía Almirante, Bocas del Toro, Panama. We also investigated the impact of chronic heat stress on larval development. Fertilization, cleavage, morula development, and 4‐armed larvae tolerated 2‐h exposures to elevated temperatures between 28–32°C. Average critical temperatures (LT50) were lower for initiation of cleavage (33.5°C) and development to morula (32.5°C) than they were for fertilization (34.4°C) or for 4‐armed larvae (34.1°C). LT50 was even higher (34.8°C) for adults exposed to similar acute thermal stress, suggesting that thermal limits measured for adults may not be directly applied to the whole life history. During chronic exposure, larvae had significantly lower survival and reduced growth when reared at temperatures above 30.5°C and did not survive chronic exposures at or above 32.3°C. Environmental monitoring at and near our collection site shows that L. variegatus may already experience temperatures at which larval growth and survival are reduced during the warmest months of the year. A published local climate model further suggests that such damaging warm temperatures will be reached throughout the Bahía Almirante by 2084. Our results highlight that tropical marine invertebrates likely have small thermal safety factors during some stages in their life cycles, and that shallow‐water populations are at particular risk of near future warming.
Fisheries and water level fluctuations in the world's largest desert lake
Authors: Gownaris Natasha J. , Pikitch Ellen K. , Aller Josephine Y. , Kaufman Les S. , Kolding Jeppe , Lwiza Kamazima M.M. , Obiero Kevin O. , Ojwang William O. , Malala John O. , Rountos Konstantine J.
Published: July 2016

Hydrological regimes are significant drivers of fisheries production in many African Lakes due to their influence on fish habitat and food availability, breeding success, and catchability. Lake Turkana, Kenya, will undergo substantial changes in hydrology due to water regulation and extraction along the Omo River in neighboring Ethiopia, which provides over 90% of its water. The objective of this study was to predict how the lake's fisheries, which provide an important livelihood and protein source in the region, will respond to hydrological change. While variations in fishing effort are poor predictors of fisheries catch in the lake, water levels and their fluctuations strongly influence fisheries production. Seasonal oscillations play a particularly important role, and with complete loss of these oscillations, the lake's predicted fisheries yield will decrease by over two thirds. The fishery is predicted to collapse at a lake level decline of 25 m, regardless of seasonal amplitude magnitude. The lake's total littoral habitat, where fisheries are currently concentrated, will increase in surface area with lake level declines of <25 m. However, the extent of productive, dynamic littoral habitat will decrease with dampening of the lake's seasonal oscillations. The most severe habitat loss will occur in the lake's Turkwel Sector, which hosts the region's highest human population densities, and North Sector, where inter‐tribal conflict over resources is common and likely to be exacerbated by lake level decline. The continued ecological functioning of Lake Turkana necessitates immediate efforts to develop and apply a water resource management plan rooted in science.
Applications of genetically encoded photosensitizer miniSOG: from correlative light electron microscopy to immunophotosensitizing
Authors: Souslova Ekaterina A. , Mironova Kristina E. , Deyev Sergey M.
Published: July 2016

Genetically encoded photosensitizers (PSs), e.g. ROS generating proteins, correspond to a novel class of PSs that are highly desirable for biological and medical applications since they can be used in combination with a variety of genetic engineering manipulations allowing for precise spatio‐temporal control of ROS production within living cells and organisms. In contrast to the commonly used chemical PSs, they can be modified using genetic engineering approaches and targeted to particular cellular compartments and cell types. Mini Singlet Oxygen Generator (miniSOG), a small flavoprotein capable of singlet oxygen production upon blue light irradiation, was initially reported as a high contrast probe for correlative light electron microscopy (CLEM) without the need of exogenous ligands, probes or destructive permeabilizing detergents. Further miniSOG was successfully applied for chromophore‐assisted light inactivation (CALI) of proteins, as well as for photo‐induced cell ablation in tissue cultures and in Caenorhabditis elegans. Finally, a novel approach of immunophotosensitizing has been developed, exploiting the specificity of mini‐antibodies or selective scaffold proteins and photo‐induced cytotoxicity of miniSOG, which is particularly promising for selective non‐invasive photodynamic therapy of cancer (PDT) due to the spatial selectivity and locality of destructive action compared to other methods of oncotherapy.

magnified image
7T MRI of distal radius trabecular bone microarchitecture: How trabecular bone quality varies depending on distance from end‐of‐bone
Authors: Griffin Lindsay M. , Honig Stephen , Chen Cheng , Saha Punam K. , Regatte Ravinder , Chang Gregory
Published: July 2016

Purpose

To use 7T magnetic resonance imaging (MRI) to determine how trabecular bone microarchitecture varies at the epiphysis, metaphysis, and diaphysis of the distal radius.

Materials and Methods

The distal radius of 24 females (mean age = 56 years, range = 24–78 years) was scanned on a 7T MRI using a 3D fast low‐angle shot sequence (0.169 × 0.169 × 1 mm). Digital topological analysis was applied at the epiphysis, metaphysis, and diaphysis to compute: total trabecular bone volume; trabecular thickness, number, connectivity, and erosion index (a measure of network resorption). Differences and correlations were assessed using standard statistical methods.

Results

The metaphysis and epiphysis had 83–123% greater total bone volume and 14–16% greater trabecular number than the diaphysis (both P < 0.0001). The erosion index was significantly higher at the diaphysis than the metaphysis and epiphysis (both P < 0.01). The most elderly volunteers had lower trabecular number (<66 years mean 0.29 ± 0.01; ≥66 years, 0.27 ± 0.02, P < 0.05) and higher erosion index (<66 years mean 1.18 ± 0.17; age ≥66 years, mean 1.42 ± 0.46, P < 0.05) at the epiphysis; differences not detected by total trabecular bone volume.

Conclusion

7T MRI reveals trabecular bone microarchitecture varies depending on scan location at the end‐of‐bone, being of overall higher quality distally (epiphysis) than proximally (diaphysis). Age‐related differences in trabecular microarchitecture can be detected by 7T MRI. The results highlight the potential sensitivity of 7T MRI to microarchitectural differences and the potential importance of standardizing scan location for future clinical studies of fracture risk or treatment response.

Level of Evidence: 3

J. Magn. Reson. Imaging 2017;45:872–878.
Vibration analysis of nanocomposite microplates integrated with sensor and actuator layers using surface SSDPT
Authors: Arani Ali Ghorbanpour , Jafari Gholamreza Soleimani , Kolahchi Reza
Published: July 2016

In the present work, nonlinear vibration analysis of polymeric nanocomposite microplates integrated with polyvinylidene fluoride (PVDF) layers as sensors and actuators is investigated. The middle layer is reinforced with carbon nanotubes (CNTs) and it's equivalent material properties are obtained by Mori–Tanaka approach. The nanocomposite and PVDF layers are subjected, respectively, to 2D magnetic and 3D electric fields. The system is rested on an elastic medium which is simulated with orthotropic Pasternak foundation. Based on the quasi‐3D sinusoidal shear deformation plate theory (SSDPT), the motion equations are derived considering surface effects using Gurtin–Murdoch theory. A partial‐differential (PD) controller is applied for the active control of the frequency through a closed‐loop control with bonded distributed PVDF sensors and actuators. Differential quadrature method (DQM) is applied in order to obtain the nonlinear frequency of microstructure. The detailed parametric study is conducted, focusing on the combined effects of the nonlocal parameter, magnetic field, surface stress, elastic medium, volume percent of CNTs, applied voltage, controller, and boundary conditions on the vibration behavior of microstructure. Results depict that applying the controller, the frequency significantly decreases. This investigation may be important for the design and smart control of microdevices. POLYM. COMPOS., 39:1936–1949, 2018. © 2016 Society of Plastics Engineers
Sensitivity of a continental night‐time stratocumulus‐topped boundary layer to varying environmental conditions
Authors: Leung W.‐Y. H. , Savre J. , Bender F. A.‐M. , Komppula M. , Portin H. , Romakkaniemi S. , Sedlar J. , Noone K. , Ekman A. M. L.
Published: July 2016

Large‐eddy simulation of a nocturnal stratocumulus‐topped boundary layer in a continental midlatitude environment has been performed to examine the sensitivity of the cloud to a number of different environmental parameters. The simulations showed that the stratocumulus cloud was strongly affected by the presence of an overlying free tropospheric cirrus cloud (FTC), in agreement with previous studies of marine nighttime stratocumulus. When introducing an FTC with an optical thickness of 2, stratocumulus liquid water path decreased by 30%. Enhancing the optical thickness of the FTC to 8 further decreased the liquid water path by almost 10%. The presence of an FTC decreased the cloud‐top radiative cooling which decreased the turbulent mixing in the boundary layer, so that the liquid water content and cloud depth were reduced. The sensitivity of the stratocumulus cloud to an overlying FTC was found to be affected by the moisture content in the free troposphere. When a clear positive or negative moisture gradient above the inversion was imposed, and an overlying FTC with an optical thickness of 8 was introduced, the stratocumulus cloud LWP decreased by more than 40%. Furthermore, the effect of changes in free tropospheric moisture content and an overlying FTC on the stratocumulus cloud properties was found to be nonlinear; the combined response was in general weaker than the two responses added together. The modeled response to changes in cloud condensation nuclei (CCN) concentrations was found to be non‐significant, unless the CCN concentrations were so low that drizzle was induced (∼50 cm−3).
An evaluation of parametric sensitivities of different meteorological variables simulated by the WRF model
Authors: Quan Jiping , Di Zhenhua , Duan Qingyun , Gong Wei , Wang Chen , Gan Yanjun , Ye Aizhong , Miao Chiyuan
Published: July 2016

The specification of model parameters in numerical weather prediction (NWP) models has great influence on model performance. However, how to specify model parameters properly is not a trivial task because a typical NWP model like the Weather Research and Forecasting (WRF) model contains many model parameters and many model outputs. This article presents the results of an investigation into the sensitivities of different WRF model outputs to the specification of its model parameters. Using a global sensitivity analysis method, the sensitivities are evaluated for surface meteorological variables such as precipitation, surface air temperature, humidity and wind speed, as well as for atmospheric variables such as total precipitable water, cloud cover, boundary‐layer height and outgoing long‐wave radiation at the top of the atmosphere, all simulated by the WRF model using different model parameters. The goal of this study is to identify the parameters that exert most influence on the skill of short‐range meteorological forecasts. The study was performed over the Greater Beijing Region of China. A total of 23 adjustable parameters from seven different physical parametrization schemes were considered. The results indicate that parameter sensitivities vary with different model outputs. However, some of the 23 model parameters considered are shown to be sensitive to all model outputs evaluated, while other parameters may be sensitive to a particular output. The sensitivity results from this research are a basis for further optimizations of the WRF model parameters.
Novel technique of robotic extralevator abdominoperineal resection with gracilis flap closure
Authors: Sieffert Michelle , Ouellette James , Johnson Michael , Hicks Todd , Hellan Minia
Published: July 2016

Background

The purpose of this paper is to introduce a robotic assisted approach to extralevator abdominoperineal excision in the modified Lloyd‐Davis position with reconstruction of the perineum using pedicled gracilis flaps, and to discuss outcomes in a cohort of six patients.

Methods

Data was collected by chart review on six patients who underwent extralevator excision with gracilis flap reconstruction from 10/2013 to 06/2015. Technical details, operative data, oncologic outcomes, and wound healing complications were evaluated.

Results

There were no instances of intraoperative perforation or positive circumferential resection margin, and one case of locoregional recurrence. Two patients experienced flap venous congestion and one patient developed a perineal abscess. All patients went on to complete healing.

Conclusions

The combination of a minimally invasive robotic assisted extralevator abdominoperineal excision performed in the modified Lloyd‐Davis position with reconstruction of the perineum with pedicled gracilis flaps has excellent oncologic outcomes and acceptable wound healing complications. Copyright © 2016 John Wiley & Sons, Ltd. StartCopTextCopyright © 2016 John Wiley & Sons, Ltd.
Enhancing Decoding Efficiency in Poor Readers via a Word Identification Game
Authors: van Gorp Karly , Segers Eliane , Verhoeven Ludo
Published: July 2016

The effects of a word identification game aimed at enhancing decoding efficiency in poor readers were tested. Following a pretest–posttest–retention design with a waiting control group, 62 poor‐reading Dutch second graders received a five‐hour tablet intervention across a period of five weeks. During the intervention, participants practiced reading words and pseudowords while doing semantic categorization and lexical decision exercises in a gaming context. Prior to, directly after, and five weeks following the intervention, word‐decoding efficiency was assessed using a standardized read‐aloud test consisting of six lists of untrained words and pseudowords with three levels of difficulty: consonant‐vowel‐consonant items, consonant cluster items, and disyllabic items. Significant increases as a result of the brief gaming intervention were found for decoding efficiency on all six word lists. The game, which included repetition, immediate corrective feedback, and a semantics task, elicited transfer and retention effects.
Hierarchical models for multiple, rare outcomes using massive observational healthcare databases
Authors: Shaddox Trevor R. , Ryan Patrick B. , Schuemie Martijn J. , Madigan David , Suchard Marc A.
Published: July 2016

Clinical trials often lack power to identify rare adverse drug events (ADEs) and therefore cannot address the threat rare ADEs pose, thus motivating the need for new ADE detection techniques. Emerging national patient claims and electronic health record databases have inspired post‐approval early detection methods like the Bayesian self‐controlled case series (BSCCS) regression model. Existing BSCCS models do not account for multiple outcomes, where pathology may be shared across different ADEs. We integrate a pathology hierarchy into the BSCCS model by developing a novel informative hierarchical prior linking outcome‐specific effects. Considering shared pathology drastically increases the dimensionality of the already massive models in this field. We develop an efficient method for coping with the dimensionality expansion by reducing the hierarchical model to a form amenable to existing tools. Through a synthetic study we demonstrate decreased bias in risk estimates for drugs when using conditions with different true risk and unequal prevalence. We also examine observational data from the MarketScan Lab Results dataset, exposing the bias that results from aggregating outcomes, as previously employed to estimate risk trends of warfarin and dabigatran for intracranial hemorrhage and gastrointestinal bleeding. We further investigate the limits of our approach by using extremely rare conditions. This research demonstrates that analyzing multiple outcomes simultaneously is feasible at scale and beneficial. © 2016 Wiley Periodicals, Inc. Statistical Analysis and Data Mining: The ASA Data Science Journal, 2016
Synthesis and Characterization of Diorganocobalt Chlorides by Aliphatic Vinylic C–Cl Bond Activation
Authors: Niu Qingfen , Zhang Shumiao , Li Xiaoyan , Sun Hongjian , Fuhr Olaf , Fenske Dieter
Published: July 2016

Three diorganocobalt chlorides [CoClMe(PMe3)2–{(C5H6)–CH=O}] (4), [CoClMe(PMe3)2–{(C6H8)–CH=O}] (5), and [CoClMe(PMe3)2–{(C6H7Memeta)–CH=O}] (6) were synthesized through cyclometalation reactions with aldehyde as an anchoring group involving aliphatic vinylic C–Cl bond activation. Complexes 4–6 were characterized by IR and NMR spectroscopy. The crystal and molecular structures of complexes 4 and 5 were determined by single‐crystal X‐ray diffraction. Complexes 4–6 are stable in solution at room temperature, but they decompose at above 30 °C affording C,C‐couplings products with the formation of [Co(PMe3)3Cl]. The results of this work will be important for people to deepen the understanding of the C–Cl bond activation mechanism.
Neurological soft signs in Chinese adolescents with schizophrenia and schizotypal personality traits
Authors: Wang Xin , Cai Lin , Li Lingyan , Yang Yanjie , Zhu Xiongzhao
Published: July 2016

Objective

Neurological soft signs (NSSs) may reflect neurodevelopmental anomalies in association with the spectrum of schizophrenia disorders. We examined NSSs in Chinese adolescents with schizophrenia and schizotypal personality traits.

Methods

Eighty‐seven schizophrenic adolescents (SCH group), 85 adolescents with only schizotypal personality traits (SPT group), and 88 healthy controls (HC group) were enrolled. The NSS subscales of the Cambridge Neurological Inventory (CNI) were administered to all 260 participants.

Results

The NSS prevalence rates were higher in the SCH group than in the other two groups for both hands in the fist‐edge‐palm, Oseretsky, and graphesthesia tests. Relative to HCs, the SCH group also showed higher NSS prevalence rates in the right finger agnosia and right mirror movement of finger opposition tests. SCH > SPT > HC trends were observed for all NSS subscale scores and for the left, right, and total NSS scores.

Conclusions

To our knowledge, the present study is the first to examine NSSs in adolescents with schizophrenia and adolescents with schizotypal personality traits. These results provide preliminary findings suggesting that schizophrenia spectrum disorders may be characterized by developmental abnormalities in the central nervous system, and support the notion that NSSs may be schizophrenia spectrum disorder biomarkers.
Feeding behavior and dietary intake of male children and adolescents with autism spectrum disorder: A case‐control study
Authors: Castro Kamila , Faccioli Larissa Slongo , Baronio Diego , Gottfried Carmem , Perry Ingrid Schweigert , Riesgo Rudimar
Published: July 2016

Autism spectrum disorder (ASD) is a neurodevelopmental disorder associated with restrictive or repetitive behaviors and difficulties with verbal and interpersonal communication, in which some problems involving nutrition may be present. This study aims to evaluate dietary intake and identify feeding behavioral problems in male children and adolescents with ASD when compared to matched controls, as well as parents or caregivers' feelings about strategies for dealing with eating problems. A 3‐day food record was performed and nutrient intake was compared to the Dietary Reference Intake according to age. To evaluate children feeding behavior and parents or caregivers' feelings, the Behavior Pediatrics Feeding Assessment Scale (BPFA) was used. ASD patients consumed in average more calories than controls (though with a high patient's frequency above and below calorie range references), had a limited food repertoire, high prevalence of children with inadequate calcium, sodium, iron vitamin B5, folate, and vitamin C intake. BPFA scores were also higher in the ASD group when compared to controls for all frequencies (child behavior, parents and total). These findings lead us to endorse the importance of evaluating feeding problems in the clinical routine, considering also the singular features of the patients.
Demand forecasting and order planning for humanitarian logistics: An empirical assessment
Authors: van der Laan Erwin , van Dalen Jan , Rohrmoser Michael , Simpson Rob
Published: July 2016

Humanitarian aid organizations are most known for their short‐term emergency relief. While getting aid items to those in need can be challenging, long‐term projects provide an opportunity for demand planning supported by forecasting methods. Based on standardized consumption data of the Operational Center Amsterdam of Médecins Sans Frontières (MSF‐OCA) regarding nineteen longer‐term aid projects and over 2000 medical items consumed in 2013, we describe and analyze the forecasting and order planning process. We find that several internal and external factors influence forecast and order planning performance, be it indirectly through demand volatility and safety markup. Moreover, we identify opportunities for further improvement for MSF‐OCA, and for humanitarian logistics organizations in general.
Effects of 8-Year Treatment of Long-Acting Testosterone Undecanoate on Metabolic Parameters, Urinary Symptoms, Bone Mineral Density, and Sexual Function in Men with Late-Onset Hypogonadism
Authors: Permpongkosol Sompol , Khupulsup Kalayanee , Leelaphiwat Supatra , Pavavattananusorn Sarawan , Thongpradit Supranee , Petchthong Thanom
Published: July 2016

Introduction

The long-term effects of long-acting testosterone undecanoate (TU) and androgen receptor CAG repeat lengths in Thai men with late-onset hypogonadism (LOH) have not been reported.

Aim

To analyze the 8-year follow-up effects of intramuscular TU therapy on metabolic parameters, urinary symptoms, bone mineral density, and sexual function and investigate CAG repeat lengths in men with LOH.

Methods

We reviewed the medical records of 428 men with LOH who had been treated with TU and 5 patients were diagnosed with prostate cancer during TU therapy. There were 120 patients (mean age = 65.6 ± 8.9 years) who had 5 to 8 years of continuous TU supplementation and sufficiently completed records for analysis. Genomic DNA was extracted from peripheral blood and the CAG repeat region was amplified by polymerase chain reaction. Fragment analysis, sequencing, electropherography, and chromatography were performed.

Main Outcome Measures

The main outcome measure was dynamic parameter changes during testosterone supplementation.

Results

TU did not improve all obesity parameters. A statistically significant decrease was found in waist circumference, percentage of body fat, glycated hemoglobin, cholesterol, low-density lipoprotein, and International Prostate Symptom Score (P < .05). TU did not produce differences in body mass index, high-density lipoprotein, triglyceride, or the Aging Male Symptoms score from baseline. However, a statistically significant increase was found in the level of testosterone, prostate-specific antigen, hematocrit, International Index of Erectile Function score, and vertebral and femoral bone mineral density (P < .05). No major adverse cardiovascular events or prostate cancer occurred during this study. The CAG repeat length was 14 to 28 and the median CAG length was 22. There was no association between CAG repeat length and any of the anthropometric measurements.

Conclusion

Long-term TU treatment in men with LOH for up to 8 years appears to be safe, tolerable, and effective in correcting obesity parameters.
Investigation of spherical and concentric mechanism of compound droplets
Authors: Liu Meifang , Su Lin , Li Jie , Chen Sufen , Liu Yiyang , Li Jing , Li Bo , Chen Yongping , Zhang Zhanwen
Published: July 2016

Polymer shells with high sphericity and uniform wall thickness are always needed in the inertial confined fusion (ICF) experiments. Driven by the need to control the shape of water-in-oil (W1/O) compound droplets, the effects of the density matching level, the interfacial tension and the rotation speed of the continuing fluid field on the sphericity and wall thickness uniformity of the resulting polymer shells were investigated and the spherical and concentric mechanisms were also discussed. The centering of W1/O compound droplets, the location and movement of W1/O compound droplets in the external phase (W2) were significantly affected by the density matching level of the key stage and the rotation speed of the continuing fluid field. Therefore, by optimizing the density matching level and rotation speed, the batch yield of polystyrene (PS) shells with high sphericity and uniform wall thickness increased. Moreover, the sphericity also increased by raising the oil/water (O/W2) interfacial tension, which drove a droplet to be spherical. The experimental results show that the spherical driving force is from the interfacial tension affected by the two relative phases, while the concentric driving force, as a resultant force, is not only affected by the three phases, but also by the continuing fluid field. The understanding of spherical and concentric mechanism can provide some guidance for preparing polymer shells with high sphericity and uniform wall thickness.
The Road to Rio: Medical and Scientific Perspectives on the 2016 Paralympic Games
Authors: Blauwet Cheri , Lexell Jan , Derman Wayne , Idrisova Guzel , Kissick James , Stomphorst Jaap , Wosornu Yetsa Tuakli , Van de Vliet Peter , Webborn Nick
Published: July 2016

In August and September of this year, the world will turn its attention to Rio de Janeiro, Brazil, for the 2016 Summer Olympic and Paralympic Games. Of interest to physiatrists, the Paralympic Games will take place from September 7 to 18, with an estimated total of 4 billion viewers. In the United States, for the first time in history, the Summer Games will be broadcast over a total of 66 hours on NBCUniversal. The Paralympic Games represent the pinnacle of elite sport for athletes with disabilities while also changing perceptions around the importance of grassroots sport and physical activity opportunities for the disability community more broadly.
Probing the ultrafast dynamics in nanomaterial complex systems by femtosecond transient absorption spectroscopy
Authors: Zhang Qun , Luo Yi
Published: July 2016

Over the past decade the integration of ultrafast spectroscopy with nanoscience has greatly propelled the development of nanoscience, as the key information gleaned from the mechanistic studies with the assistance of ultrafast spectroscopy enables a deeper understanding of the structure–function interplay and various interactions involved in the nanosystems. This mini-review presents an overview of the recent advances achieved in our ultrafast spectroscopy laboratory that address the ultrafast dynamics and related mechanisms in several representative nanomaterial complex systems by means of femtosecond time-resolved transient absorption spectroscopy. We attempt to convey instructive, consistent information regarding the important processes, pathways, dynamics, and interactions involved in the nanomaterial complex systems, most of which exhibit excellent performance in photocatalysis.
Geochron Laboratories, Inc. Radiocarbon Measurements II
Authors: Krueger Harold W. , Weeks C. Francis
Published: July 2016

The following list presents dates on a small fraction of the total number of measurements made during 1964 and 1965 as well as data on some samples previously dated but not published. Results not appearing have not been released by our clients.
Tartu Radiocarbon Dates I
Authors: Liiva A. , Ilves E. , Punning J. M.
Published: July 2016

Preparations for the development of a laboratory for the determination of absolute age by the radiocarbon method were started at the Geobiochemical Laboratory of the Institute of Zoology and Botany of the Academy of Sciences of the Estonian SSR in 1957. Dating of various carbon-containing specimens has been carried out since 1959.
Radiocarbon Dating at the University of Washington III
Authors: Fairhall A. W. , Schell W. R. , Young J. A.
Published: July 2016

This date list consists of those measurements made since 1962. The counter is one described previously (Fairhall and Schell, 1963). The results are computed using NBS oxalic acid as the standard and 5568 for the half-life of C14. Standard deviations are computed for each measurement, including the statistical error in the sample count and uncertainties in background and standard. In general, each sample is counted at least twice. The quoted error on the date is the standard deviation. A 2σ criterion is used to establish a lower limit to the age of very old samples with no detectable trace of C14. No correction for isotope fractionation has been made in any of the measurements.
Groningen Radiocarbon Dates VI
Authors: Vogel J. C. , Zagwijn W. H.
Published: July 2016

This list contains dates related to the chronology of the last glaciation in Europe. Since several of the older results which already have appeared in print need correction or re-interpretation it was considered necessary to incorporate as many of them as possible into this list. Notably the dates published by de Vries (1958) are included here and reconsidered in the light of our present understanding of the climatic succession. It is noteworthy that, although the interpretation may have changed slightly, most of those measurements are still as valid today as they were eight years ago.
University of Kiel Radiocarbon Measurements II
Authors: Willkomm H. , Erlenkeuser H.
Published: July 2016

Most of the measurements reported here have been obtained with the 4.5-L CO2 counter previously described (Kiel I; Erlenkeuser, 1965). A few samples have been dated with a 3-L proportional counter. The copper counter is surrounded by 28 GM counters in the form of a double ring. The total assembly is shielded by 10 cm of old lead. Neither an inner lead shield between counter and anticoincidence ring nor screening of sensitive volume by a quartz tube-as in the 4.5-L counter-has been used. Background of the small counter is 17.20 cpm or The 0.95 x NBS value is 9.5 cpm at 400 torr. Within statistical error background does not depend on atmospheric pressure. The 3-L counter is placed under a concrete wall, 2.5 m in length and 9.4 m in height.
University of Pennsylvania Radiocarbon Dates X
Authors: Stuckenrath Robert
Published: July 2016

This date list includes those series of samples completed in this laboratory as of November, 1966. The B.P. ages are based upon A.D. 1950, and are calculated with a half-life value of 5568 yr. All samples were counted at least twice for periods of not less than 1000 min each. Errors quoted are derived from measurements of sample, background, and modern-age calibration, but do not include any half-life error. All samples were pretreated with 3N HCl, and some, where noted, received additional pretreatment with 2% NaOH for the removal of possible humic contaminants.
Louvain Natural Radiocarbon Measurements X
Authors: Gilot E.
Published: July 2016

The following list comprises measurements made during 1969–70. The method is essentially the same as previously described, using a 0.6 L proportional gas-counter at 3 atm CH4 pressure. Ages are calculated with a half-life of 5570 yr and quoted with 1σ experimental error. Descriptions and comments are based on information supplied by the submitters.
Lyon Natural Radiocarbon Measurements II
Authors: Evin J. , Longin R. , Marien G. , Pachiaudi Ch.
Published: July 2016

The Radiocarbon Dating Laboratory of the Department of Geology, University of Lyon, is going on with work since its foundation in 1965, in the basement of the Nuclear Physics Institute.
University of Tokyo Radiocarbon Measurements III
Authors: Sato Jun , Sato Tomoko , Matsui Yasuko , Suzuki Hisashi
Published: July 2016

Radiocarbon measurements in this list were made from Sept. to Dec., 1968. They are based on acetylene counting in an Oeschger-Houtermans-type proportional counter (1 L) at pressure 1 atm. All data are based on duplicated measurements. For calculation of ages, 95% activity of NBS oxalic acid is used as the modern standard and value of 5570 + 30 years is used for the half-life of C14. Dates are expressed in years B.P. (before A.D. 1950). Error corresponds to 1σ deviation of sample net counting rate as well as modern standard and background. Details of procedures are given in previous reports (R., 1968, v. 10, p. 144–148; 1969, v. 11, p. 509–514)
Institute of Geological Sciences Radiocarbon Dates II
Authors: Welin E. , Engstrand L. , Vaczy S.
Published: July 2016

This date list was compiled by the Institute of Geological Sciences (U.K.) incorporating data supplied under contract by E. Welin, Radioactive Dating Laboratory, Stockholm. Unless otherwise stated, age figures are in C14 years before A.D. 1950. The half-life of C14 is taken as 5568 and the standard error is given as a standard deviation of 1σ. Correction for C13/C12 has not been made.
Illinois State Geological Survey Radiocarbon Dates VI
Authors: Coleman Dennis D , Liu Chao Li
Published: July 2016

All samples processed from February 1973 through January 1974 at the Illinois State Geological Survey Radiocarbon Dating Laboratory are reported here. The benzene liquid scintillation technique was used. Laboratory procedures used were the same as those previously reported by Coleman (1973, 1974).
Belfast Radiocarbon Dates VIII
Authors: Pearson G W , Pilcher J R
Published: July 2016

Procedures of measurements and calculation remain as previously described. All samples are pretreated according to the methods described in R, 1971, v 13, p 103 and p 123 unless specified under the sample descriptions. Unless stated samples are from Ireland.
Lyon Natural Radiocarbon Measurements VI
Authors: Evin J , Marien G , Pachiaudi Ch
Published: July 2016

This list includes most of the samples measured during 1974 and most of those measured previously but not published in the preceding date list (R, 1975, v 17, p 4–34.)
Sydney University Natural Radiocarbon Measurements III
Authors: Gillespie R , Temple R B
Published: July 2016

This list describes samples dated in this laboratory between November 1972 and December 1974.
Sydney University Natural Radiocarbon Measurements IV
Authors: Gillespie Richard
Published: July 2016

The following list contains measurements made during the period 1972-5 which have not been previously published and which form part of a research project on marine shell dating (Gillespie, 1975). These sets of samples were measured to determine 1) “apparent age” of marine shells coll alive from Australian coastal waters before the advent of large-scale nuclear weapons testing, 2) the possibility of using post 1950 Australian marine shells as a modern reference, 3) “apparent age” of Australian marine shells in the past as shown by comparisons between stratigraphically equivalent charcoal and marine shell samples.
Tallinn Radiocarbon Dates IV
Authors: Punning J M , Rajamäe R , Ehrenpreis M , Sarv L
Published: July 2016

The following list includes samples dated in 1975. The measurement of 14C activity was performed with 1-channel and 2-channel scintillation devices. Special attention was paid to the decrease of the background. The effectiveness of the measurement is ca 50% (Punning, Rajamäe, 1975). The “enriched standard” (Alekseejev et al, 1971) has been used as a contemporary reference standard of modern carbon. Age calculations are based on the 14C half-life of 5568 ± 30 yr, with 1950 as the standard year of reference. All samples are calculated to ± 1σ with respect to sample, standard and background after counting times of at least 2800 minutes. 13C/12C measurements and corrections have not been made for these samples.
University of Miami Radiocarbon Dates XV
Authors: Introne D S , Stipp J J
Published: July 2016

Radiocarbon measurements have been continued on a variety of projects and materials. Chemical and counting procedures remain the same as indicated in R, v 20, p 274-282. Dates are calculated using the Libby 14C half-life of 5568 years; errors are reported as one-standard deviation (1σ) based only on statistical counting uncertainties in background, modern standard, and sample activities. All samples for which 13C/12C ratios are available are corrected for isotopic fractionation by normalizing to —25‰. A 400 year reservoir age correction has been applied to marine carbonates.
Harwell Radiocarbon Measurements III
Authors: Otlet R L , Walker A J
Published: July 2016

The dates in this list follow on, approximately chronologically, from Harwell II (R, 1977, v 19, p 400-423) and refer principally to measurements carried out in the period 1975-6. Laboratory techniques have remained essentially unchanged from earlier reports but a full description of the setting-up philosophy and operating procedure of the liquid scintillation counting systems has now been published separately (Otlet and Warchal, 1977).
University of Lund Radiocarbon Dates XII
Authors: Håkansson Sören
Published: July 2016

Most of the 14C measurements reported here were made between October 1977 and October 1978. Equipment, measurement, and treatment of samples are as reported previously (R, 1968, v 10, p 36-37; 1976, v 18, p 290) except for some minor improvements of the electronic equipment.
GEOSECS Pacific Radiocarbon
Authors: Östlund H G , Stuiver Minze
Published: July 2016

In the preceding paper (Stuiver and Östlund, this issue), some of the general features of the Geochemical Ocean Section Study (GEOSECS) were outlined and results were listed for the Atlantic Ocean. This paper will deal with the second major cruise, which was described by Craig and Turekian (1976), covering the Pacific Ocean in 1973-74 (cf fig 1).
A high-precision calibration of the AD radiocarbon time scale
Authors: Stuiver Minze
Published: July 2016

A high-precision calibration curve, derived from the radiocarbon age determinations of 195 decade samples spanning the AD 1 to 1950 interval, is presented.

Though derived for the Pacific Northwest and California, the curve can be used for a large part of the northern hemisphere. This is proven by the radiocarbon ages of contemporaneous sample pairs which are, in most instances, identical within the quoted precision. Two sets of single-year data reveal no evidence for an 11-year cycle with an amplitude beyond the 12-year measuring precision. This indicates that the calibration curve is also applicable for single-year 14C samples.

Analysis of the Seattle data sets and comparison with those published by the Belfast, La Jolla, and Heidelberg laboratories show that the total variability in a radiocarbon age determination is often larger than that predicted from the quoted errors. Upper limits for the error multiplier (ie, the factor with which the quoted error has to be multiplied to obtain the overall laboratory variability) are estimated at 1.5 for Seattle and Belfast, 1.1 to 1.4 for La Jolla, and 2.0 for Heidelberg.

The comparisons with Belfast, La Jolla, and Heidelberg also reveal offsets with the Seattle calibration curve of, respectively, 4, 27 to 55, and 58 years. These offsets are most likely due to laboratory bias. An improvement of the present calibration curve by combining data sets from other laboratories will only be possible when offsets and error multipliers are precisely known through interlaboratory calibration.
Birbal Sahni Institute Radiocarbon Measurements III
Authors: Rajagopalan G , Vishnu-Mittre B Sekar , Mandal T K
Published: July 2016

The radiocarbon dates reported in this date list cover the measurements carried out in 1979 to 1980. Chemical and counting procedures are the same as reported earlier (R, 1978, v 20, p 398–404). Age calculations are based on the conventional 14C half-life (5570 yr) and on the contemporary value of 95% of the activity of NBS oxalic acid. Errors quoted correspond to 1σ value which takes into account the counting statistics, the uncertainty in the half-life, and the instability of the counting system. The ages are not corrected for isotopic fractionation in nature.
Lyon Natural Radiocarbon Measurements IX
Authors: Evin Jacques , Marechal Joelle , Marien Gerard
Published: July 2016

This list includes most of the measurements made in 1979 through 1981 and some values obtained during preceding years. The reporting of results, their calculation (half-life: 5570 ± 0, standard 13C correction only for bones), and the dilution ratios are as previously described in Lyon VIII (R, 1979, v 21, p 402–452).
Non-Concordance of Radiocarbon and Amino Acid Racemization Deduced Age Estimates on Human Bone
Authors: Taylor R E
Published: July 2016

Radiocarbon determinations, employing both decay and direct counting, were obtained on various organic fractions of four human skeletal samples previously assigned ages ranging from 28,000 to 70,000 years on the basis of their D/L aspartic acid racemization values. In all four cases, the 14C values require an order of magnitude reduction in age.
La Jolla Natural Radiocarbon Measurements X
Authors: Linick T W
Published: July 2016

The following date list covers samples dated by the La Jolla (Mt Soledad) Radiocarbon Laboratory from January 1979 through August 1982. Most archaeologic, most geologic, and some geochemical samples measured during that period are included here. Results of 14C analyses of samples of tree rings, banded coral rings, and Antarctic seawater dissolved inorganic carbon measured during this period will be published elsewhere. Because of the cessation of all federal grant funding of this laboratory, this is the last date list to be published by it.
Recalibration of Heidelberg 14C Laboratory Data
Authors: Kromer Bernd
Published: July 2016

A sodium bicarbonate solution with a 10-fold activity compared to oxalic acid is used as a secondary standard in the Heidelberg 14C Laboratory. All routine checks and counter tests are greatly facilitated because of the high activity of the solution.
The Temporal Distribution of ‘Bomb’ 14C in a Forest Soil
Authors: Harkness D D , Harrison A F , Bacon P J
Published: July 2016

Patterns of 14C enrichment in the superficial plant debris and mineral soil horizons of an established woodland have been monitored at regular intervals during the past 15 years. These data are compared with a model evaluation of carbon turnover based on the recorded changes in atmospheric 14C concentration since AD 1900.

Leaf litter and decomposing plant debris are characterized by steady-state turnover values of ca 2 and ca 8 years, respectively. A two-component system of ‘fast’ (≤20 yr) and ‘slow’ (ca 350 yr) cycling carbon is indicated for the surface (0–5cm) soil humus; below 10cm, the “fast’ component is rare (<5%).

Selective microbal humification of leaf litter, branch, and root debris is proposed to explain a delay of several years in the peak transfer of ‘bomb’ 14C to the soil carbon pool.
A Study of Errors in14C Dates of Peat and Sediment
Authors: Olsson Ingrid U
Published: July 2016

It is a well-established fact that14C dates from lake sediments are usually too old because of contamination with allochthonous material and/or due to discrete reservoir effects. The latter can occur in soft water lakes and may be examined by the14C measurement of aqueous plants or the carbon dissolved and suspended in the water column.

Some plants assimilate CO2from the sediment. Their14C activity is then dependent on the sediment accumulation rate and nutrients stored in the root system may also contribute misleading results. If water is filtered through ultra-fine membranes and then treated chemically, several fractions can be isolated for dating. The present study shows that the14C activity of such fractions varies widely but with the weighted mean indicating an overall deficiency. Even the water from a raised bog evidences a14C deficiency relative to contemporary atmospheric CO2.

Charcoal from an archaeologic site and peat from corresponding layers in a nearby bog have yielded significantly different ages. The fact that theCladiumpeat was from a very calcareous area is significant. The risk of contamination by younger root material is also documented.
On the Initial 14C Activity of Karst Aquifers with Short Mean Residence Time
Authors: Krajcar-Bronić Ines , Horvatinčić Nada , Srdoč Dušan , Obelić Bogomil
Published: July 2016

The 14C activity of total dissolved inorganic carbon (DIC) as well as tritium activity and stable isotope content (13C, 2H, 18O) of spring water were measured for 3 consecutive years at 3 karst springs that feed Plitvice Lakes, NW Yugoslavia. The constant chemical and stable isotope composition and temperature indicated well mixed aquifers. A very short mean residence time of underground water (2–5 yr) was determined by tritium activity measurements. Measured C activities of 3 karst springs varied from 60.0% to 82.5%. The measured C activities were compared with calculated 14C activities based on various models using measured values of C activity of soil at different depths and 13C content of limestone, plants, and soils from the recharge area. Our measurements indicate that recharge systems in karst aquifers are open to the atmosphere. The atmospheric CO2 contributes to the 13C content and the C activity of ground water to an estimated extent which varies between 10 and 40% of DIC.
Validity of 14C Ages of Carbonates in Sediments
Authors: Chen Yijian , Polach Henry
Published: July 2016

This review is based on geologic surveys carried out in Australia and China as well as on more than 300 14C dates published in Radiocarbon, Evaluated are the origins and pathways of carbonate formation, stable isotopic composition, carbonate nodule growth rates and paleo-climatic effects. The three identified δ 13C abundance peaks are unrelated to environment and carbon source whilst 14C ages group themselves into periods corresponding to past humid warm climate. It is concluded that the major error in caliche dating is due to incorporation of old limestone whilst error on nodule dating is related to their slow growth rate, Thus, caliche antedates and nodules postdate the times of their deposition. Delta 13C values cannot be used to correct for limestone or atmospheric contamination effects.
14C Dating of Calcareous Tufa from Different Environments
Authors: Pazdur Anna , Pazdur Mieczysław F
Published: July 2016

14C dates of carbonate and organic matter fractions are compared with a series of calcareous tufa samples from selected sites representing different geochemical environments and associated with different bedrocks. Results obtained in this study indicate values of apparent age ranging from 940 ± 110 yr for calcareous tufas associated with Pleistocene sediments to 2000 ± 110 yr and even ca 4000 yr for tufas from sites associated with Jurassic or Cretaceous limestone. It was found also that within each of the investigated sites the value of apparent age does not change significantly with the age of the tufa layer.