bluuebunny/crossref_metadata_2025 huggingface dataset:
Wind generated by an attacking bat: anemometric measurements and detection by the praying mantis cercal system
Authors: Triblehorn Jeffrey D. , Yager David D.
Published: March 2006

The wind-sensitive cercal system, well-known for mediating terrestrial escape responses, may also mediate insect aerial bat-avoidance responses triggered by wind generated by the approaching bat. One crucial question is whether enough time exists between detection and capture for the insect to perform a successful evasive maneuver. A previous study estimated this time to be 16 ms, based on cockroach behavioral latencies and a prediction for the detection time derived from a simulated predator moving toward a simulated prey. However, the detection time may be underestimated since both the simulated predator and prey lacked certain characteristics present in the natural situation. In the present study, actual detection times are measured by recording from wind-sensitive interneurons of a tethered praying mantis that serves as the target for a flying, attacking bat. Furthermore, using hot-wire anemometry, we describe and quantify the wind generated by an attacking bat. Anemometer measurements revealed that the velocity of the bat-generated wind consistently peaks early with a high acceleration component(an important parameter for triggering wind-mediated terrestrial responses). The physiological recordings determined that the mantis cercal system detected an approaching bat 74 ms before contact, which would provide the insect with 36 ms to perform a maneuver before capture. This should be sufficient time for the mantis to respond. Although it probably would not have time for a full response that completely evades the bat, even a partial response might alter the mantid's trajectory enough to cause the bat to mishandle the insect,allowing it to escape.
Sperm selection and competition in pigs may be mediated by the differential motility activation and suppression of sperm subpopulations within the oviduct
Authors: Satake Nana , Elliott Roslyn M. A. , Watson Paul F. , Holt William V.
Published: March 2006

When spermatozoa from two or more boars are mixed and females inseminated,the resulting litters are often skewed in favour of one male but there is currently no satisfactory physiological explanation for this effect. However,to reach the oocytes, the spermatozoa must enter the oviduct where they are exposed to factors that modulate their activity. They either become sequestered within the oviductal sperm reservoir or bypass the reservoir and proceed towards the oocytes. The oviduct may therefore hold the key to mammalian sperm selection, thereby explaining why laboratory tests of sperm function, performed on whole ejaculates, are unable to account for the boar-specific skewing effects. We have previously shown that boar sperm motility is highly stimulated by bicarbonate, a naturally abundant component of oviductal fluid. Using motility-based sperm subpopulation analysis, we show here that the relative sizes of bicarbonate-responsive and unresponsive sperm subpopulations vary between individual boars. Proteins derived from oviduct epithelial plasma membranes suppress the activation response and modify sperm movement trajectories in a subpopulation-specific and dose-dependent manner. The suppression response varies between boars and some spermatozoa remain unsuppressed in the presence of oviductal proteins. When boars are ranked according to their susceptibility to bicarbonate-induced stimulation, rankings differ depending upon the presence or absence of oviductal proteins. The suppression response is not caused by inhibition of bicarbonate uptake; on the contrary this is enhanced by oviductal proteins. We suggest that the boar-specific and sperm subpopulation-specific interactions between sperm motility activation and suppression responses are likely to result in sperm selection before the spermatozoa meet the oocytes.
Source location encoding in the fish lateral line canal
Authors: Ćurčić-Blake Branislava , van Netten Sietse M.
Published: March 2006

The position of a hydrodynamic dipole source, as encoded in a linear array of mechano-detecting neuromasts in the fish lateral line canal, was electrophysiologically investigated. Measured excitation patterns along the lateral line were compared to theoretical predictions and were found to be in good agreement. The results demonstrate that information on the position of a vibrating source from a fish is linearly coded in the spatial characteristics of the excitation pattern of pressure gradients distributed along the lateral line canal. Several algorithms are discussed that could potentially be used by a fish to decode lateral line excitation patterns, in order to localise a source and its axis of vibration. Specifically, a wavelet transform of a 1-D excitation pattern is shown to reconstruct a 2-D image of dipole sources located within a distance comparable to the body length of a fish and with a close range spatial accuracy twice the inter-neuromast distance.
The postnatal development of neocortical neurons and glial cells in the Göttingen minipig and the domestic pig brain
Authors: Jelsing Jacob , Nielsen Rune , Olsen Aage Kristian , Grand Nanna , Hemmingsen Ralf , Pakkenberg Bente
Published: March 2006

The first mathematically unbiased estimates of neocortical cell numbers are presented from the developing pig brain, including a full description of tissue processing and optimal sampling for application of the stereological optical fractionator method in this species. The postnatal development of neocortical neurons and glial cells from the experimental Göttingen minipig was compared with the postnatal development of neocortical neurons in the domestic pig. A significant postnatal development was observed in the Göttingen minipig brain for both neuronal (28%; P=0.01) and glial cells (87%; P<0.01). A corresponding postnatal development of neurons was not detected in the domestic pig brain. The reason for this strain difference is not known. The mean total number of neocortical neurons is 324 million in the adult Göttingen minipig compared with 432 million in the domestic pig. The glial-to-neuron cell ratio is around 2.2 in the adult Göttingen minipig. Based on these results, the domestic pig seems to be a more suitable model for evaluating the effects of developmental insults on human brain growth and neuronal development than the Göttingen minipig.
Changes in composition of spider orb web sticky droplets with starvation and web removal, and synthesis of sticky droplet compounds
Authors: Townley Mark A. , Tillinghast Edward K. , Neefus Christopher D.
Published: March 2006

The sticky spiral of araneoid spider orb webs consists of silk fibers coated with adhesive droplets. The droplets contain a variety of low-molecular-mass compounds (LMM). Within a species, a fairly consistent ratio of LMM is often observed, but substantial variability can exist. To gain insight into factors influencing LMM composition, spiders of three araneid species were starved and LMM from their webs were analyzed for changes in composition. To determine if these changes were consistent with the spider's ability to synthesize the different organic LMM, synthetic capacities were estimated following the feeding of radiolabeled metabolites. Some changes in droplet composition were broadly consistent with differing synthetic capacities: molar percentages of less readily synthesized compounds (e.g. choline, isethionate, N-acetyltaurine) typically declined with starvation, at least during a portion of the imposed fast, while more readily synthesized compounds (e.g. GABamide, glycine) tended to increase. Most striking was the apparent partial substitution of N-acetylputrescine by the more readily synthesized GABamide in fasting Argiope trifasciata. However, departures from expected compositional shifts demonstrated that synthetic capacity alone does not adequately predict sticky droplet compositional shifts with starvation. Moreover, feeding controls exhibited some changes in composition similar to starving spiders. As the webs of both feeding and starving spiders were removed for chemical analysis and could not be recycled, the loss of LMM contained in these webs likely contributed to similarities between treatments. In addition, feeding spiders molted, oviposited and/or built heavier webs. The added metabolic demands of these activities may have contributed to changes in composition similar to those resulting from starvation.
Sweet problems: insect traits defining the limits to dietary sugar utilisation by the pea aphid,Acyrthosiphon pisum
Authors: Douglas A. E. , Price D. R. G. , Minto L. B. , Jones E. , Pescod K. V. , François C. L. M. J. , Pritchard J. , Boonham N.
Published: March 2006

Plant phloem sap is an extreme diet for animals, partly because of its high and variable sugar content. The physiological and feeding traits of the pea aphid Acyrthosiphon pisum that define the upper and lower limits to the range of dietary sucrose concentrations utilised by this insect were determined principally using chemically defined diets containing 0.125–1.5 mol l–1 sucrose. On the diets with 0.125 mol l–1 and 1.5 mol l–1 sucrose, the aphids died as larvae within 8 and 14 days of birth, respectively. On the other diets,60–96% of aphids developed to adulthood, and the 0.5 mol l–1 and 0.75 mol l–1 diets supported the highest fecundity. The diet with 0.125 mol l–1 sucrose was ingested at 36% of the rate of the 0.25 mol l–1 sucrose diet,but >90% of ingested sucrose-carbon was assimilated on both diets. This suggests that the lower limit is dictated by the aphid feeding response,specifically, a requirement for a minimal concentration of sucrose for sustained feeding. The haemolymph osmotic pressure of aphids on diets with 0.125–1.5 mol l–1 sucrose was up to 68% higher than on 0.125–1.0 mol l–1 sucrose diets, but diet consumption and sucrose-carbon assimilation was not reduced on the very high sucrose diets relative to 1.0 mol l–1 sucrose. This suggests that failure of the osmoregulatory capacity of the insects on high sucrose diets may define the upper limit to the range of dietary sucrose utilised by the aphids. The mean haemolymph osmotic pressure of aphids on plants with phloem sap containing 0.37–0.97 mol l–1 sucrose was 1.61±0.063 MPa (mean ± s.e.m.), not significantly different from that (1.47±0.059 MPa) on diets with 0.25–1.0 mol l–1 sucrose. It is concluded that the osmoregulatory response of aphids to diets and plants are comparable, and, more generally, that the feeding and osmoregulatory capabilities of the aphids are compatible with the phloem sugar levels commonly encountered by aphids feeding on plants.
Effects of temperature on maximum acceleration, deceleration and power output during vertical running in geckos
Authors: Bergmann Phillip , Irschick Duncan J.
Published: March 2006

We studied performance and kinematics of the diurnal gekkonid lizard Phelsuma dubia while running vertically on a smooth surface at different temperatures. Trials were conducted at 5°C intervals from 15°C to 35°C. High-speed video recordings and digitization were used to obtain measures of instantaneous velocity, acceleration, deceleration and mass-specific power output and maximal values for each were taken as performance measures. Kinematic variables were also obtained from high-speed video recordings and included stride length and duration, step (stance phase)length and duration, and duty factor. Maximal instantaneous velocity,acceleration and deceleration increased by a factor of approximately 1.7 between 15°C and 25°C, and less so (∼1.2×) between 25°C and 35°C. Mass-specific power output was more temperature-sensitive,increasing 2.5× up to 25°C and a further 1.4× above that temperature. Stride length increased 1.5× over the entire temperature interval studied, while stride duration decreased by a factor of 1.9,suggesting that velocity is modulated by changes in both stride length and duration in P. dubia. Duty factor was not significantly influenced by temperature. Stride length was the only kinematic measure to be influenced by stride number, with second steps from a standstill being longer than first steps. We discuss the significance of velocity and acceleration being affected in a similar manner by temperature, and that speed is modulated by both changes in stride length and duration.
Honeybee odometry and scent guidance
Authors: Vladusich Tony , Hemmi Jan M. , Zeil Jochen
Published: March 2006

We report on a striking asymmetry in search behaviour observed in honeybees trained to forage alternately at one of two feeder sites in a narrow tunnel. Bees were trained by periodically switching the position of a sucrose reward between relatively short and long distances in the tunnel. Search behaviour was examined in the training tunnel itself and in a fresh tunnel devoid of scent cues deposited by bees during training. Bees tested in the fresh tunnel exhibited a bias towards the shorter site, while bees tested in the training tunnel searched closer to the longer site. In additional experiments, we manipulated the position of scent cues, relative to the training location, in the testing tunnel. Bees generally searched at the site to which they were trained rather than at the position of the scent. Our data argue strongly against the hypothesis that bees rely exclusively on deposited scent to accurately localise a food source in natural foraging environments. We instead conclude that odometry and scent guidance contribute to honeybee food search in a manner reflecting the significance and relative reliability of sensory information.
Odours detected by rhinophores mediate orientation to flow in the nudibranch mollusc,Tritonia diomedea
Authors: Wyeth Russell C. , Willows A. O. Dennis
Published: March 2006

Tritonia diomedea is a useful neuroethological model system that can contribute to our understanding of the neural control of navigation. Prior work on both sensory and locomotory systems is complemented by recent field experiments, which concluded that these animals primarily use a combination of odours and water flow as guidance cues. We corroborate these field results by showing similar navigation behaviours in a flow tank. Slugs crawled upstream towards both prey and conspecifics, and turned downstream after crawling into a section of the flow tank downstream of a predator. Controls without upstream odour sources crawled apparently randomly. We then tested whether these behaviours depend on odours detected by the rhinophores. Outflow from a header tank was used to generate prey, predator and unscented control odour plumes in the flow tank. Slugs with rhinophores crawled upstream towards a prey odour plume source, turned downstream in a predator odour plume, and showed no reaction to a control plume. Slugs without rhinophores behaved similarly to controls, regardless of odour plume type. Finally, we used extracellular recordings from the rhinophore nerve to demonstrate that isolated rhinophores are chemosensitive. Afferent activity increased significantly more after application of all three odour types than after unscented control applications. Responses were odour specific. We conclude that rhinophores mediate orientation to flow, and suggest that future work should focus on the integration of mechanosensation and chemosensation during navigation in T. diomedea.
Assimilation experiments with CHAMP GPS radio occultation measurements
Authors: Healy S. B. , Thépaut J.‐N.
Published: March 2006

A one‐dimensional bending‐angle observation operator for assimilating GPS radio occultation (RO) measurements has been integrated into the ECMWF four‐dimensional variational assimilation (4D‐Var) system. We have performed forecast impact experiments with 60 days of CHAMP RO measurements, in addition to the latest set of conventional and satellite data that are assimilated operationally, including radiances from the Atmospheric Infrared Sounder. It is demonstrated that the CHAMP measurements provide extremely good temperature information in the upper troposphere and lower stratosphere. In the southern hemisphere (SH), they produce a clear, statistically significant improvement in the r.m.s. forecast fit to radiosonde measurements over the day 1 to day 5 forecast range at 300, 200, 100 and 50 hPa. An improved r.m.s. fit to radiosondes is also evident at 100 hPa in the tropics. However, the observations degrade the 500 hPa geopotential height (500Z) field in the SH. This appears to be mainly caused by erroneous surface pressure increments in Antarctica. As a result, we have modified the GPS tangent‐linear and adjoint routines, prior to the evaluation of the model‐level pressures and geopotential heights, in order to remove the sensitivity of the model geopotential height values to the surface pressure. This improves the SH 500Z forecast scores, although a small degradation is still evident at the day 1 and day 2 forecast range.

A simple method for estimating the degrees of freedom for signal (DFS) of a large variational assimilation system is noted and applied to estimate the DFS of the CHAMP measurements assimilated during a 12‐hour assimilation window. The CHAMP measurements increase the total DFS of the 4D‐Var system by ∼4%, and the DFS per CHAMP bending‐angle profile is ∼34. Copyright © 2006 Royal Meteorological Society
Origins of the reversed flow over the windward Alpine foothills during MAP IOP3 and IOP8
Authors: Asencio N. , Stein J.
Published: March 2006

The synoptic‐scale situations during the two Intensive Observing Periods (IOPs) of the Mesoscale Alpine Programme (MAP) characterized by persisting precipitation and down‐valley flow as observed by the Doppler on the wheel radar (DOW) over the two Alpine valleys (Toce and Ticino) were investigated. The first period (IOP3, 24–27 September 1999) was characterized by a south‐westerly flow and convective precipitation, whereas the second period (IOP8, 20–21 October 1999) by a down‐valley flow and stratiform precipitation. During IOP3, the down‐valley northerly flow over the north‐western part of the Po valley was confined within a thin layer of 200–300 m depth. During IOP8, the northerly flow extended from the Alps foothills to the Ligurian sea in a deep layer of 1–2 km height. The Meso‐NH numerical model with a 2.5 km horizontal mesh grid reproduced the characteristics of both cases from the valley scale to the meso‐β scale. Sensitivity experiments were, furthermore, performed in order to highlight the relationships between wet or dry drainage flow channelled by the Alpine orography, mesoscale upstream flow blocked by the Alps, and a regional cold pool at the foothills inside the Po valley. During IOP8, the diabatic processes were dominant at local scales in confirmation of Steiner results based on the DOW observations and they were significant at regional scales upstream of the Alps by maintaining a cold pool over the Po valley. The IOP3 low‐level flow reversal occurred as the flow began to cross over the Alps instead of turning around. A downslope flow is associated with the blocked‐regime period upstream of the Alps. Copyright © 2006 Royal Meteorological Society
Sensitivity studies of developing convection in a cloud‐resolving model
Authors: Petch J. C.
Published: March 2006

Cloud‐resolving models (CRMs) remain an important tool for providing detailed process information about convection. In this short paper I focus on the development of deep convection and consider what can be considered a minimum expense benchmark simulation for comparison with a numerical weather‐prediction model. To decide this a range of sensitivity studies are presented to aspects of the experimental set‐up which strongly impact the computational expense. Many of the sensitivities shown in these CRM experiments are quite different to those seen in previous papers which have tended to focus more on deep active convection. Here it is shown that for the case‐study presented a minimum expense benchmark simulation must be a 3D simulation. A 200 m horizontal grid length and a domain of 25 km are also required to capture the most important processes. Copyright © 2006 Crown copyright
Sound Insulation Evaluation Using Transfer Function Measurements
Authors: Venegas C. Rodolfo , Nabuco Marco , Massarani Paulo
Published: March 2006

The accepted methods for measurement of sound insulation between rooms, audiometric cabins and other adjacent closed spaces deal with average sound pressure measurements and random sound excitation. The acoustic field can be as diffuse as found in reverberation chambers or form well-determined stationary waves in rectangular rooms. The use of random noise excitation requires averages in time to reduce the expected inherent uncertainties. The use of techniques, such as MLS or swept sine excitation, can avoid time consuming averaging processes and reduce measurement. With the advent of new front-end devices and signal analyzers it is now relatively easy to obtain acoustic transfer functions between two points in space, which can be in adjacent enclosures. With these transfer functions, it is possible to obtain the level differences, required by the international standard, as suggested in a new draft ISO document. This paper presents results obtained for the insulation of a cabin, tested in a reverberation chamber, using random noise and swept sine excitation. An analysis is given of the viability of using fewer positions of sound sources when measuring the transfer function. Repeatability tests, for both methods, are also presented.
Novel aromatics blended with a σ-flavor
Authors: Komatsu Koichi
Published: March 2006

We present the results of our systematic study on the synthesis, structures, and electronic properties of a series of cyclic π-conjugated systems with monocyclic six- to eight-membered rings as well as polycyclic benzenoid aromatics, which are fully surrounded by rigid bicyclic σ-frameworks such as bicyclo[2.2.2]octene (BCO). The study has also been extended to sulfur-containing systems such as thiophene, 1,2- and 1,4-dithiins, and oligothiophene. Such a structural modification using bicyclic frameworks is effective in elevation of the highest occupied molecular orbital (HOMO) levels of neutral π-systems and in remarkable stabilization of the corresponding cationic systems by both σ-π conjugation and kinetic effects. This has led to various new cationic π-conjugated systems such as highly stable radical cations as well as closed-shell mono- and dications, which could have never been attained by any other conventional techniques. The properties of benzene and entirely planar cyclooctatetraene (COT) possessing a marked bond fixation caused by structural modification with a strained bicyclic system (i.e., bicyclo[2.1.1]hexene, BCH) are also described.
Self-assembling and spectroscopic properties of soluble linear acenes
Authors: Desvergne Jean-Pierre , Del Guerzo André , Bouas-Laurent Henri , Belin Colette , Reichwagen Jens , Hopf Henning
Published: March 2006

The gelling and spectroscopic properties of new soluble disubstituted acenes (anthracene, tetracene, pentacene) are reported. It is shown that the 2,3-alkoxy derivatives gel a large variety of organic solvents, a process that is related to the linear shape of the molecule. The gelation involves the formation of nanofibers through noncovalent interactions (van der Waals, π-π stacking), weaving a 3D supramolecular network or a deposit made of isolated fibers on surfaces (mica or graphite). Transport of photons through this type of nanostructure has been evidenced by the observation of an efficient energy transfer occurring from an anthracene light-harvesting matrix to a tetracene energy trap doping agent.
Ring carbo-mers: From questionable homoaromaticity to bench aromaticity
Authors: Zou Chunhai , Lepetit Christine , Coppel Yannick , Chauvin Remi
Published: March 2006

The title journey is undertaken at the levels of both theory and experiment. Since 1983, homoaromaticity has been shown to play at most a minor role in the stability of Scott's [N]pericyclyne hydrocarbons - the first ring carbo-mers of cycloalkanes. This statement has been systematically refined for N = 3-6 by using both classical theoretical tools and newly designed tools based on electron localization function (ELF) analysis. The compatibility of the [5]- and [6]-pericyclyne cores with vertex functionalities was established by the synthesis of 20 oxy (carbo-cyclitol) derivatives. The stereoisomeric resolution of two of them has been achieved. Hexaoxy-[6]pericyclynes are actually potential precursors of the carbo-benzenes. Criteria based on density functional theory (DFT) calculations (magnetic, energetic, structural/"electronic") show that the aromaticity of carbo-[N]annulenic species is comparable to that of their parent molecule. This has been challenged by the synthesis of several novel carbo-benzenic molecules with various substitution patterns. The theory-experiment interplay is pursued by considering ring carbo-mers of other conjugated ring systems such as radialenes. The second carbo-mers (butadiyndiyl-expanded rings) of [3]radialene and benzene are also envisioned. Hexaphenyl-carbo2-benzene has been observed by 1H and UV-vis spectroscopy.
New interesting molecular topologies by way of modern cross-coupling reactions
Authors: de Meijere Armin , Stulgies Baldur , Albrecht Karsten , Rauch Karsten , Wegner Hermann A. , Hopf Henning , Scott Lawrence T. , Eshdat Lior , Aprahamian Ivan , Rabinovitz Mordecai
Published: March 2006

Modern transition-metal-catalyzed cross-coupling reactions, especially of the Kumada, Heck, and Suzuki types, have provided facile access to various bridge-annelated [2.2]paracyclophane derivatives including trifoliaphane and its tribenzo analog. The reduction of trifoliaphane with potassium metal in [D8]-THF led to hexakis[p-benzyl]benzene anion, which could efficiently be trapped with various electrophiles. Highly efficient multifold Suzuki couplings were performed with hexabromobenzene, octabromonaphthalene, and hexabromotriphenylene. The obtained hexa- and octaalkenylarene derivatives disclose interesting molecular shapes. Eventually, a newly developed cascade coupling of bromoarenes containing peri-positioned C-H bonds has led to indeno-annelated polycyclic aromatic hydrocarbons including indenocorannulene as well as the tetrakis- and tris(tert-butylindeno)pyrene which disclose very interesting spectroscopic properties. In particular, tetrakis(tert-butylindeno)pyrene self-assembles in solution by way of π-stacking, and it can be reduced with potassium metal to a stable dianion, a readily dimerizing trianion radical, and a tetraanion.
Thyroglobulin (Tg) Recovery Testing with Quantitative Tg Antibody Measurement for Determining Interference in Serum Tg Assays in Differentiated Thyroid Carcinoma
Authors: Persoon Adrienne CM , Links Thera P , Wilde Juergen , Sluiter Wim J , Wolffenbuttel Bruce HR , van den Ouweland Johannes MW
Published: March 2006

Background: Thyroglobulin (Tg) measurements are complicated by interference from Tg autoantibodies (TgAbs) or heterophilic antibodies (HAMAs). We used a new automated immunochemiluminometric assay (ICMA) with Tg recovery (TgR) on the Nichols Advantage® platform to reassess the clinical utility of recovery testing in detecting interference in serum Tg measurement in patients with differentiated thyroid carcinoma.

Methods: We used 2 TgAb methods to detect Tg measurement interference with TgR and quantitative TgAb measurement in sera from 127 patients. In a limited number of samples, we used an RIA as comparison method because it appeared to be minimally affected by TgAb.

Results: Prevalence of TgAbs was 13% (17 of 127) in either 1 or both TgAb assays. A compromised TgR (<70%) corresponded with TgAb positivity in either TgAb assay for 10 of 11 samples (91%), whereas a normal TgR (≥70%) corresponded with TgAb negativity in both assays for 95 of 101 samples (94%). In 6 TgAb-positive sera with TgR within the reference interval, there were no discrepancies between RIA and ICMA results. We obtained discordant RIA and ICMA results for 6 of 9 TgAb-positive sera with decreased TgR. In 1 TgAb-negative sample, the Tg result was falsely increased because of interference by HAMAs, as shown by an overrecovery of 126%.

Conclusions: The Nichols Advantage TgR assay is a valuable complementary method to overcome the technical problem of interference by TgAbs or HAMAs in TgAb assays. Further studies are needed to confirm the potential added value of this TgR assay.
Durability Testing of Polyurethane Foam Sealant in the Window-Wall Interface
Authors: Braun RG , Garcia J
Published: March 2006

In late 1990, the National Research Council of Canada (NRC-CNRC) and the Canadian Construction Materials Centre of Canada (CCMC) set about developing a durability protocol for aerosol foam sealants. Major input for this effort was supplied by Dr. Mark Bomberg then on the NRC-CNRC staff. At that time a major manufacturer of aerosol foam sealant wished to address some developing concerns whether foam sealant used around the perimeter of windows and doors during their installation was really durable. The manufacturer completed the durability testing according to the established NRC protocol. Now the protocol is also part of a new Standard CAN/ULC-S710.1 and CAN/ULC-S711.1. This paper will describe that testing as it was completed at the third party laboratory, Air-Ins Inc., of Montreal, Canada using criteria from the 1995 National Building Code of Canada [1]. The data obtained also formed the basis for CCMC Evaluation report 13074-R [2].
Analysis of Surface Inertial Profiles Measured on Jointed Portland Cement Pavements
Authors: Gagarin N , Mekemson JR
Published: March 2006

The feasibility of measuring slab curling using high-speed profilers was assessed by the Turner-Fairbank Highway Research Center of the Federal Highway Administration. The primary objectives of the study were to: (1) measure the surface profile of the concrete slabs using state-of-the-art profiling technology, (2) establish a standard procedure to identify warping and curling of the slabs using the measured surface profiles, (3) relate the changes in pavement surface profiles to the change in surface temperature, (4) determine the relationship between changes in pavement surface profile, roughness, premature transverse cracking, and construction condition, and (5) establish a standard procedure to analyze the condition of joints, including rotation and faulting, and determine the relationship between joint condition, and roughness. The paper discusses data mining on a database of 16 000 slabs measured during four time windows in a 24-h period. A visualization of all parameters and samples at all four times of the day show the groups of slabs which have cracked and are likely to crack shown by the divergence from the normal response measured in most slabs.
Wind Tunnel Evaluation of Drift Reduction Potential and Spray Characteristics with Drift Retardants at High Operating Pressure
Authors: Guler H , Zhu H , Ozkan E , Derksen R , Krause C
Published: March 2006

Although considerable research has been done on effectiveness of drift retardants for many years, answers to some questions are still unclear to applicators. Laboratory tests were conducted to evaluate drift potentials associated with off-target ground and airborne spray deposits discharged with a hollow cone nozzle spraying three different drift retardants at a high operating pressure and various wind velocities in a wind tunnel. Droplet sizes and spray widths were also determined with a laser imaging system and a portable spray patternator. At 1655 kPa pressure and 4.65 L/m flow rate, the volume median diameters of droplets from the hollow cone nozzle discharging spray mixtures containing water only, polyvinyl polymer, nonionic colloidal polymer and polyacrylamide polymer drift retardants were 201, 222, 239, and 210 μm, respectively. The major spray pattern width was not changed after drift retardants were added into the spray carrier. For the wind velocity from 1 to 5 m/s in the wind tunnel, the polyacrylamide drift retardant produced the highest airborne deposit among the three drift retardants, followed by polyvinyl, and then nonionic colloidal. Also, the polyacrylamide drift retardant produced the highest ground drift potential, followed by nonionic colloidal and then polyvinyl. According to the results from this laboratory study, both nonionic colloidal and polyvinyl polymer drift retardants reduced the drift potential compared to the spray carrier containing water only.
Investigation of Oxygen-Acetylene Flashback Reactions in Welding Hoses
Authors: Newton BE , Pryor D , Chiffoleau GJA , Beeson H
Published: March 2006

A common concern in the welding industry is the development of conditions wherein an oxygen-acetylene (i.e., oxyacetylene) flashback reaction can propagate into a welding hose causing it to burst due to the rapid localized pressurization associated with an oxygen-acetylene deflagration-to-detonation transition. The investigation of a recent welding hose fire resulted in testing to evaluate the conditions under which detonations could be generated within welding hoses and the conditions in which welding hoses would burst when exposed to these events. This paper reports on elements of the welding hose fire investigation, the conditions for flashback reactions to develop, and the analytical work performed during the accident reconstruction to characterize deflagration-to-detonation transition within typical welding hoses. This paper also suggests physical and chemical criteria that are characteristic to welding hose ruptures due to flashback detonations.
The Influence of Initial Crack Length on Critical Stress Intensity FactorK1
Authors: Abril ER
Published: March 2006

It is postulated that initial crack length always affects the critical propagation of a crack, except when absolutely elastic materials are considered. The reason for this statement is explained, and a new fracture mechanics theory is presented and experimentally justified, complementing previous works in which it was partially developed.

The main innovation presented in this paper is a new fracture mechanics method, called “Limit Line Replacement,” which is thought to be applicable to any type of structure, provided some experimental verification is made.

This basis of the method consists in the acceptance that the critical crack length of a cracked structure subjected to fatigue always can be obtained experimentally, if the maximum and the minimum fatigue loads are known.

From this critical crack length, the life of a structure can be estimated experimentally if under similar conditions, the number of required cycles is measured.
The Mental Health of Married, Cohabiting, and Non–Coresident Parents With Infants
Authors: DeKlyen Michelle , Brooks-Gunn Jeanne , McLanahan Sara , Knab Jean
Published: March 2006

Objectives. We compared recent parents (married, cohabiting, not cohabiting but romantically involved, and not romantically involved) to examine the association between mental health problems and relationship status.

Methods. We analyzed data from the Fragile Families and Child Wellbeing Study that followed a cohort of approximately 4900 births in large US cities. Our study included a large oversample of nonmarital births (n=3700) and interviews with both mothers and fathers. We used the Composite International Diagnostic Interview Short Form to assess depression and generalized anxiety 1 year after the birth. Self reports were used to measure heavy drinking, illicit drug use, incarceration, and partner violence.

Results. Unmarried parents reported more mental health and behavioral problems than did married parents, and unmarried parents whose relationships ended before the birth reported more impairment compared with other groups of unmarried parents.

Conclusions. A substantial number of children are born to unmarried parents and are at risk for poor parenting and poor developmental outcomes. Government initiatives aimed at increasing marriage rates among low-income couples need to consider the mental health status of unmarried parents.
Associations of Maternal Age- and Parity-Related Factors With Trends in Low-Birthweight Rates: United States, 1980 Through 2000
Authors: Yang Quanhe , Greenland Sander , Flanders W. Dana
Published: March 2006

Objectives. We assessed the effects of changes in the maternal age–parity distribution and age-and parity-specific low-birthweight rates on low-birthweight trends in the United States.

Methods. We used natality file data from 1980 through 2000 to assess very-low-birthweight and low-birthweight rates among singleton live-born infants.

Results. Changes in age-and parity-specific low-birthweight rates were the main contributor to the overall trend in rates. However, changes in the age–parity distribution, primarily delayed childbearing, had a smaller but noticeable impact. The very-low-birthweight rate increased 27% among Black women, and changes in the age–parity distribution were associated with, on average, more than 20% of the increased rate during the 1990s. Among His-panic and non-Hispanic White women, on average, more than 10% of the rate increase observed during the 1990s was associated with changes in the age–parity distribution.

Conclusions. Assuming minimal changes in age-specific rates, delayed childbearing may play an increasingly important role in low-birthweight trends in the United States.
Asthma Prevalence Among US Adults, 1998–2000: Role of Puerto Rican Ethnicity and Behavioral and Geographic Factors
Authors: Rose Deborah , Mannino David M. , Leaderer Brian P.
Published: March 2006

Objectives. We analyzed asthma prevalence among US adults by age, gender, race, Puerto Rican ethnicity, and other demographic, behavioral, health, and geographic variables. We hypothesized that high prevalences would be observed among Puerto Ricans and in the Northeast census region.

Methods. We used data from the 1998 through 2000 US National Health Interview Surveys. Information on lifetime history of asthma and asthma in the past year was collected from 95615 adults. We calculated weighted prevalence estimates and odds ratios from logistic regression.

Results. Of US adults, 8.9% had ever been diagnosed with asthma, and 3.4% had experienced an episode in the past 12 months. Asthma diagnosis rates were highest among Puerto Ricans (17.0%) and lowest among Mexican Americans (3.9%); rates were 9.6% and 9.2% among non-Hispanic Blacks and non-Hispanic Whites, respectively. Geographically, asthma prevalence was highest in the West (10.5%) and lowest in the Northeast (8.6%). Puerto Ricans in all regions had high asthma rates.

Conclusions.final logistic regression model included race/ethnicity, obesity, poverty, female gender, and cigarette smoking. Higher asthma rates were confirmed among Puerto Ricans but not in the Northeast region.
A Nationwide Population-Based Study Identifying Health Disparities Between American Indians/Alaska Natives and the General Populations Living in Select Urban Counties
Authors: Castor Mei L. , Smyser Michael S. , Taualii Maile M. , Park Alice N. , Lawson Shelley A. , Forquera Ralph A.
Published: March 2006

Objectives. Despite their increasing numbers, little is known about the health of American Indians/Alaska Natives living in urban areas. We examined the health status of American Indian/Alaska Native populations served by 34 federally funded urban Indian health organizations.

Methods. We analyzed US census data and vital statistics data for the period 1990 to 2000.

Results. Disparities were revealed in socioeconomic, maternal and child health, and mortality indicators between American Indians/Alaska Natives and the general populations in urban Indian health organization service areas and nationwide. American Indians/Alaska Natives were approximately twice as likely as these general populations to be poor, to be unemployed, and to not have a college degree. Similar differences were observed in births among mothers who received late or no prenatal care or consumed alcohol and in mortality attributed to sudden infant death syndrome, chronic liver disease, and alcohol consumption.

Conclusions. We found health disparities between American Indians/Alaska Natives and the general populations living in selected urban areas and nationwide. Such disparities can be addressed through improvements in health care access, high-quality data collection, and policy initiatives designed to provide sufficient resources and a more unified vision of the health of urban American Indians/Alaska Natives.
Service Uptake and Characteristics of Injection Drug Users Utilizing North America’s First Medically Supervised Safer Injecting Facility
Authors: Wood Evan , Tyndall Mark W. , Qui Zhenguo , Zhang Ruth , Montaner Julio S. G. , Kerr Thomas
Published: March 2006

In 2003, the city of Vancouver, British Columbia, opened North America’s first government-sanctioned safer injecting facility, where injection drug users (IDUs) can inject preobtained illicit drugs under the supervision of nurses. Use of the service by IDUs was followed by measurable reductions in public drug use and syringe sharing. IDUs who are frequently using the program tend to be high-intensity cocaine and heroin injectors and homeless individuals.

The facility has provided high-risk IDUs a hygienic space where syringe sharing can be eliminated and the risk of fatal overdose reduced. Ongoing evaluation will be required to assess its impact on overdose rates and HIV infection levels, as well as its ability to improve IDU contact with medical care and addiction treatment
Fertility Regulation and Reproductive Health in the Millennium Development Goals: The Search for a Perfect Indicator
Authors: Dixon-Mueller Ruth , Germain Adrienne
Published: March 2006

Although several key elements of sexual and reproductive health are included in the United Nations Millennium Development Goals, a measure of women’s capacity to regulate their fertility safely and effectively is missing. We considered the usefulness of 3 pairs of indicators in monitoring this component of reproductive health: contraceptive prevalence and total fertility; unmet need for contraception and unplanned births; and unsafe abortion and abortion mortality.

A single measure of contraceptive use is insufficient. The risks women face from unplanned births and unsafe abortion should also be incorporated into the monitoring process, either directly within the Millennium Development Goals framework or as a parallel effort by reporting governments and other agencies.
Newborn Screening: Complexities in Universal Genetic Testing
Authors: Green Nancy S. , Dolan Siobhan M. , Murray Thomas H.
Published: March 2006

Newborn screening (NBS)—in which each newborn infant is screened for up to 50 specific metabolic disorders for early detection and intervention—is the first program of populationwide genetic testing. As a public health intervention, NBS has greatly improved the lives of thousands of affected children.

New technologies and new economic and social forces pose significant ethical and clinical challenges to NBS. Two primary challenges concern (1) accommodating clinical and ethical standards to rapid technological developments in NBS and (2) preparing public health systems to respond to the medical advances and social forces driving expansion of NBS programs.

We describe and analyze these challenges through consideration of 3 disorders: phenylketonuria, medium-chain acyl-CoA dehydrogenase deficiency, and cystic fibrosis.
Patient Privacy and Conflicting Legal and Ethical Obligations in El Salvador: Reporting of Unlawful Abortions
Authors: McNaughton Heathe Luz , Mitchell Ellen M.H. , Hernandez Emilia G. , Padilla Karen , Blandon Marta Maria
Published: March 2006

Postabortion care providers who breach patient confidentiality endanger women’s health and violate ethics. A 1998 abortion ban in El Salvador likely spurred an increase in the number of women investigated, because many women were reported to legal authorities by health care providers.

Having analyzed safeguards of confidentiality in laws and ethical guidelines, we obtained information from legal records on women prosecuted from 1998 to 2003 and identified factors that may lead to reporting through a survey of obstetrician-gynecologists (n=110).

Although ethical and human rights standards oblige providers to respect patients’ privacy, 80% of obstetrician-gynecologists mistakenly believed reporting was required. Most respondents (86%) knew that women delay seeking care because of fear of prosecution, yet a majority (56%) participated in notification of legal authorities.
Life-Course Socioeconomic Position and Hypertension in African American Men: The Pitt County Study
Authors: James Sherman A. , Van Hoewyk John , Belli Robert F. , Strogatz David S. , Williams David R. , Raghunathan Trevillore E.
Published: March 2006

Objectives. We investigated the odds of hypertension for Black men in relationship to their socioeconomic position (SEP) in both childhood and adulthood.

Methods. On the basis of their parents’ occupation, we classified 379 men in the Pitt County (North Carolina) Study into low and high childhood SEP. The men’s own education, occupation, employment status, and home ownership status were used to classify them into low and high adulthood SEP. Four life-course SEP categories resulted: low childhood/low adulthood, low childhood/high adulthood, high childhood/low adulthood, and high childhood/high adulthood.

Results. Low childhood SEP was associated with a 60% greater odds of hypertension, and low adulthood SEP was associated with a 2-fold greater odds of hypertension. Compared with men of high SEP in both childhood and adulthood, the odds of hypertension were 7 times greater for low/low SEP men, 4 times greater for low/high SEP men, and 6 times greater for high/low SEP men.

Conclusions. Greater access to material resources in both childhood and adulthood was protective against premature hypertension in this cohort of Black men. Though some parameter estimates were imprecise, study findings are consistent with both pathway and cumulative burden models of hypertension.
Experiences of Hurricane Katrina Evacuees in Houston Shelters: Implications for Future Planning
Authors: Brodie Mollyann , Weltzien Erin , Altman Drew , Blendon Robert J. , Benson John M.
Published: March 2006

Objectives. To shed light on how the public health community can promote the recovery of Hurricane Katrina victims and protect people in future disasters, we examined the experiences of evacuees housed in Houston area shelters 2 weeks after the hurricane.

Methods. A survey was conducted September 10 through 12, 2005, with 680 randomly selected respondents who were evacuated to Houston from the Gulf Coast as a result of Hurricane Katrina. Interviews were conducted in Red Cross shelters in the greater Houston area.

Results. Many evacuees suffered physical and emotional stress during the storm and its aftermath, including going without adequate food and water. In comparison with New Orleans and Louisiana residents overall, disproportionate numbers of this group were African American, had low incomes, and had no health insurance coverage. Many had chronic health conditions and relied heavily on the New Orleans public hospital system, which was destroyed in the storm.

Conclusions. Our results highlight the need for better plans for emergency communication and evacuation of low-income and disabled citizens in future disasters and shed light on choices facing policymakers in planning for the long-term health care needs of vulnerable populations.