bluuebunny/crossref_metadata_2025 huggingface dataset:
The metalloprotease Tolloid-related and its TGF-β-like substrate Dawdle regulateDrosophilamotoneuron axon guidance
Authors: Serpe Mihaela , O'Connor Michael B.
Published: November 2006

Proper axon pathfinding requires that growth cones execute appropriate turns and branching at particular choice points en route to their synaptic targets. Here we demonstrate that the Drosophila metalloprotease tolloid-related (tlr) is required for proper fasciculation/defasciculation of motor axons in the CNS and for normal guidance of many motor axons enroute to their muscle targets. Tlr belongs to a family of developmentally important proteases that process various extracellular matrix components, as well as several TGF-β inhibitory proteins and pro-peptides. We show that Tlr is a circulating enzyme that processes the pro-domains of three Drosophila TGF-β-type ligands, and, in the case of the Activin-like protein Dawdle (Daw), this processing enhances the signaling activity of the ligand in vitro and in vivo. Null mutants of daw, as well as mutations in its receptor babo and its downstream mediator Smad2, all exhibit axon guidance defects that are similar to but less severe than tlr. We suggest that by activating Daw and perhaps other TGF-β ligands, Tlr provides a permissive signal for axon guidance.
Bulk microphysics parametrization of ice fraction for application in climate models
Authors: Boudala Faisal S. , Isaac George A.
Published: November 2006

Using in situ aircraft measurements of cloud microphysical properties collected in extratropical stratiform clouds during several field programs, a parametrization of the ice‐particle spectrum that includes small ice particles has been developed. This parametrization has been tested using a single prognostic equation developed by Tremblay et al. (1996) for application in a regional model. The addition of small ice‐particles significantly increases the vapour deposition‐rate when the natural atmosphere is assumed to be water saturated, and thus enhances the glaciation of simulated mixed‐phase cloud via the Bergeron–Findeisen process without significantly affecting the other cloud microphysical processes such as riming and particle‐sedimentation rates. After the water vapour pressure in mixed‐phase cloud was modified, based on the scheme of Lord et al. (1984), by weighting the saturation water vapour pressure with ice fraction, it was possible to simulate a more stable mixed‐phase cloud. It was also noted that the ice‐particle concentration (maximum dimension L > 100 µm ) in mixed‐phase cloud is lower on average by a factor of three, and, consequently, the parametrization should be corrected for this effect. After accounting for this effect, the parametrized ice‐fraction agreed well with observation. Copyright © 2006 Royal Meteorological Society
Flow separation and rotor formation beneath two‐dimensional trapped lee waves
Authors: Vosper S. B. , Sheridan P. F. , Brown A.R.
Published: November 2006

Numerical simulations of trapped lee waves generated in flow over a two‐dimensional ridge are presented. It is shown that for sufficiently large amplitude waves flow separation occurs beneath the wave crests when a no‐slip lower boundary condition is applied. The occurrence of separation corresponds to rotor motion, or recirculation, under the wave crests. The dependence of the wave‐induced horizontal flow perturbations near the ground on the wave amplitude, wavelength and surface roughness is examined. It is shown that the normalized critical wave amplitude, above which rotors form, is a function of the ratio of the lee‐wave horizontal wavelength to the surface roughness length. This normalized wave amplitude is defined as the ratio of the lee‐wave pressure amplitude within the boundary layer, to the square of the friction velocity.

Linearized turbulent equations for motion beneath the wave crests are considered and numerical solutions to the linear problem are compared with results from the simulations. When the waves are of sufficiently small amplitude that flow separation does not occur, the linear flow perturbations are shown to agree closely with the results from the simulations. It is also shown that linear theory provides a useful prediction of the occurrence of rotor formation. © Crown copyright, 2006.
Automated tracking of dry intrusions on satellite water vapour imagery and model output
Authors: Michel Y. , Bouttier F.
Published: November 2006

A satellite image‐processing technique has been developed for the identification and tracking of upper‐tropospheric features related to midlatitude synoptic‐scale cyclogenesis. Persistent warm radiance features are detected on water vapour images using an adaptive thresholding technique, tracked using estimations of the motion of the features through displacement and cross‐correlation of successive images, and then screened using both image‐based and model‐based criteria. The aim is the characterization of jet dynamical features and dry intrusions of stratospheric air into the upper troposphere. On a selected sample of events, the resulting trajectories prove to be very consistent with the subjective identification of cyclogenesis events on imagery. In accordance with potential vorticity theory, the detected warm features are correlated with positive anomalies of potential vorticity. This identification technique can be applied to model output, which suggests future applications in forecast verification and data assimilation of midlatitude cyclones. Copyright © 2006 Royal Meteorological Society
Investigation into the wavelength dependence of the aerosol optical depth in the Athens area
Authors: Kaskaoutis D. G. , Kambezidis H. D.
Published: November 2006

Ground‐based solar spectral irradiance measurements obtained by a spectroradiometer have been used to retrieve the aerosol optical depth, τα, and the Ångström wavelength exponent, α. These measurements were obtained in the Athens centre in May 1995. Exponent α is frequently computed from spectral measurements both from ground‐based photometers and satellite remote sensing retrievals. Although the retrieval of α has been the subject of many studies worldwide, its spectral variation is typically not considered. In this study we analyse the spectral measurements of ln τα versus ln λ, where λ is the wavelength, at six selected wavelengths which cover the spectrum from 340 to 870 nm. It is obvious that there is significant curvature in the ln ta versus ln λ relationship, and the reasons for this are examined. It was found that this curvature depends on both atmospheric turbidity and aerosol optical properties, and a second order polynomial fit provides excellent agreement. The curvature of the polynomial equation becomes greater as the aerosol loading alters from high to low. The curvature is characterized by the second derivative of α, which can be utilized in conjunction with α to characterize the spectral dependence of aerosol optical depth, and can also be used as an indicator of the relative influence of fine‐versus coarse‐mode particles. Copyright © 2006 Royal Meteorological Society
Microwave land emissivity and skin temperature for AMSU‐A and ‐B assimilation over land
Authors: Karbou Fatima , Gérard Élisabeth , Rabier Florence
Published: November 2006

AMSU‐A and ‐B measurements are still not extensively used over land surfaces for atmospheric applications. Recent studies have shown that it should now be possible to take advantage of the information content of these instruments provided land emissivity and skin temperature estimates are improved. This paper reports on comparisons between three land‐surface schemes using the Météo‐France four‐dimensional variational (4D‐Var) assimilation system. Firstly, a monthly mean estimated land emissivity atlas using AMSU data is used. A second land‐surface scheme based on direct emissivity calculations is developed to obtain dynamically emissivity values. The third approach is based on the first one with the addition of a dynamic skin temperature estimation based on one AMSU‐A or AMSU‐B window channel. The land‐surface schemes described above have been implemented within the 4D‐Var system and their results have been compared with those of the operational surface scheme (which uses emissivity models). All land schemes have been evaluated by examining the performances of the observation operator for sounding channels prior to the assimilation. With dynamically varying emissivities and/or skin temperatures or with averaged emissivities, the simulations are clearly improved compared with the operational model and many more data pass the quality‐control check. Copyright © 2006 Royal Meteorological Society
Implementation of 1D+4D‐Var assimilation of precipitation‐affected microwave radiances at ECMWF. II: 4D‐Var
Authors: Bauer Peter , Lopez Philippe , Salmond Deborah , Benedetti Angela , Saarinen Sami , Bonazzola Marine
Published: November 2006

This paper presents the operational implementation of a 1D+4D‐Var assimilation system of rain‐affected satellite observations at ECMWF performed on 28 June 2005. The first part describes the methodology and performance analysis of the 1D‐Var retrieval scheme in clouds and precipitation that uses Special Sensor Microwave/Imager (SSM/I) microwave radiance observations for the estimation of total‐column water vapour (TCWV). This part describes the technical implementation of the TCWV observations in 4D‐Var as well as the impact analysis.

The effect of the TCWV observations implied by precipitation on the 4D‐Var analyses is significant and the total information content is comparable to that of the SSM/I, High‐resolution InfraRed Sounder and Advanced Microwave Sounding Unit (AMSU‐B) radiances. Regions with systematic drying in the analysis persist throughout the forecast while moistening is removed by precipitation after 1–2 days. The corresponding divergence increments reflect the feedback between moisture and dynamics. Forecast evaluation using model analyses exhibits mostly positive relative‐humidity forecast scores, in particular at 700 hPa and in the Tropics. Some short‐term negative forecast scores are observed for geopotential near 1000 hPa and in the southern hemisphere between days 2–4. Wind scores vary greatly between regions and different forecast lengths. Tropical cyclone tracking forecasts are only slightly affected by a reduced location error spread through the rain assimilation. Comparison to dropsonde observations of wind and temperature shows improvement as does TCWV analysis validation against independent observations from Jason radiometer data. The system has been implemented operationally in June 2005 and will be further developed towards a direct 4D‐Var assimilation of radiances in clouds and precipitation. Copyright © 2006 Royal Meteorological Society
Educational Half Day
Authors: Nigwekar Sagar U. , Morse Diane S.
Published: November 2006

Internal medicine residents often come across substance use disorder (SUD) issues; however not all residency programs have curricula to educate residents on management of these issues. We hereby describe a curricular action plan incorporating an innovative method of Educational Half Day (EHD) to address SUD issues in small group settings. We believe that EHD is an effective way of addressing substance abuse issues in the residency curriculum and it has the potential to change the way residents manage their patients with SUD.
Evaluation of a Combined Online and in Person Training in the Use of Buprenorphine
Authors: Gunderson Erik W. , Levin Frances R. , Kleber Herbert D. , Fiellin David A. , Sullivan Lynn E.
Published: November 2006

To evaluate buprenorphine training methodology, we surveyed physicians who had completed a combined online and in person buprenorphine curriculum. Of 53/70 (76%) survey respondents, 57% were psychiatrists and 40% generalists. On a scale of 1 (very poor) to 7 (superlative), the overall training rated a mean of 5.8. The online course (5.0) rated lower than in person training components (p <.001) except for material that addressed the logistics of office practice. The in person patient interview received the highest rating (mean 6.3, p <.001). The 67% of physicians who intended to prescribe buprenorphine after the training were more likely than hesitant physicians to agree that the course provided enough information (p <.05) and that telephone access to experienced providers would improve their confidence (p <.05). Physicians hesitant to prescribe cited lack of experience as the main barrier (41%), with 24% concerned about induction difficulty and reimbursement. Overall, physicians preferred in person instruction and may benefit from additional experiential training and support after curriculum participation.
An Ethno‐Methodological Approach to Cannabis and Music Perception, with EEG Brain Mapping in a Naturalistic Setting
Authors: Fachner Jörg
Published: November 2006

Cannabis is known to change auditory perception and music appreciation as many musicians and music listeners report in narratives, interviews and biographies. An ethnographic pre/post study was conducted in a habituated naturalistic setting, combining qualitative and quantitative methods with four single case studies. Physiological results were gained with a mobile bedside EEG imaging machine in an authentic setting of the consumer's life‐world. Results represent explorative data of participants' spontaneous EEG‐activity, referable to results of psychological and medical studies.

Increasing Alpha‐signal strength in parietal association cortex and significant Theta band changes in temporal and on Alpha in occipital areas seem to represent an intraindividual constant EEG correlate of temporarily intensified attention ("high"), resulting in an altered music perception by hyperfocusing on acoustic space and broadened insight into the "space between the notes." THC has a measurable influence on cerebral music processing and seems to enhance acoustic perception temporarily.
“Tobacco Has a Purpose, Not Just a Past”: Feasibility of Developing a Culturally Appropriate Smoking Cessation Program for a Pan‐Tribal Native Population
Authors: Daley Christine Makosky , James Aimee S. , Barnoskie Randall S. , Segraves Marcia , Schupbach Ryan , Choi Won S.
Published: November 2006

Tobacco has long held spiritual significance to Native people of North America but, because of recreational use, it has become a health risk relatively recently. More Native people smoke than any other ethnic group (41 percent vs. 24 percent in whites and blacks), and death rates caused by tobacco‐related diseases are disproportionately high. However, no tested, culturally tailored smoking cessation programs exist for this group. We used a critical‐interpretive framework to understand the meaning of tobacco and the feasibility of smoking cessation interventions in a pan‐tribal population. In June 2004, the University of Kansas Medical Center (KUMC) and the Oklahoma Area Indian Health Service (IHS) collaborated on six focus groups with (IHS) patients. The patients served represent over 200 different nations. Our participants provided us with modifications to a currently untested program designed by the Muscogee Nation of Oklahoma's Tobacco Prevention Program to enhance cultural appropriateness, including (1) an emphasis on visual presentation and a “Native” look to program educational materials; (2) comprehensive information about tobacco, quitting, and coping among Native people; (3) an acknowledgment and incorporation of traditional tobacco use and its diversity; and (4) the use of talking circles and counseling with Native facilitators.
At the Back Stage of Prenatal Care: Japanese Ob‐Gyns Negotiating Prenatal Diagnosis
Authors: Ivry Tsipy
Published: November 2006

In this article, I explore the reluctance of Japanese ob‐gyns to discuss prenatal diagnosis (PND) tests with pregnant women. The analysis focuses on the culturally specific ways in which ob‐gyns formulate their cautiousness and criticism toward PND while invoking a local moral economy. Analyzing ob‐gyns' accounts, I show how the ambiguities of PND are constituted in a specific moment in Japanese culture, history, disability politics, and national reproductive policies and are formulated through local paradigms of thinking about pregnant women, their fetuses, and the process of becoming a person in Japanese society. Finally, I show how PND in Japan is pushed to a “back‐stage” realm in which the diagnosis for fetal anomalies is practiced in secrecy.
Care for Infibulated Women Giving Birth in Norway: An Anthropological Analysis of Health Workers' Management of a Medically and Culturally Unfamiliar Issue
Authors: Johansen R. Elise B.
Published: November 2006

The focus of this article is on Norwegian health care workers' experience and management of birth care of women who have undergone infibulation. Because infibulation is the most extensive form of female genital cutting, infibulated women experience a higher risk of birth complications, and health workers generally experience delivery care for this group as challenging. Infibulated women, who come from recently arrived immigrant groups, are a challenge to the predominant Norwegian birth philosophy of “natural childbirth” and the positive evaluation of everything considered natural. The challenges relate to a mixture of technical know‐how and a complex set of interpretations of central cultural elements of gender, nature, health, and gender equity. The findings suggest that a combination of taboo, silence, limited knowledge, and emotional difficulty along with a wish to be culture sensitive may at times prove counterproductive to giving the best help. Health care workers often seem to impose “imagined” cultural values on infibulated women, rather than clarifying them through personal communication.
A Game Theoretic Approach to Swarm Robotics
Authors: Givigi S. N. , Schwartz H. M.
Published: November 2006

In this article, we discuss some techniques for achieving swarm intelligent robots through the use of traits of personality. Traits of personality are characteristics of each robot that, altogether, define the robot′s behaviours. We discuss the use of evolutionary psychology to select a set of traits of personality that will evolve due to a learning process based on reinforcement learning. The use of Game Theory is introduced, and some simulations showing its potential are reported.
Permanent Magnetic System Design for the Wall‐Climbing Robot
Authors: Shen W. , Gu J. , Shen Y.
Published: November 2006

This paper presents the design and analysis of the permanent magnetic system for a wall‐climbing robot with permanent magnetic tracks. Based on the behaviour of gecko lizards, the architecture of the robot was designed and built, including the structure of the adhesion mechanism, the mechanical architecture and the anti‐toppling mechanism. The permanent magnetic adhesion mechanism and the tracked locomotion mechanism were employed in this kind of wall‐climbing robot. Through static and dynamic force analysis of the robot under different situations, design requirements for the adhesion mechanism were derived. Two different types of structures were put forward for the permanent magnetic units and are further discussed in this paper. These two types of structures are also analysed in detail. In addition, a finite‐element method was used to verify the results of magnetic units. Finally, two wall‐climbing robots, equipped with different magnetic systems described previously, are explained and their applications are discussed in this paper.
A Vision‐Based Method for Autonomous Landing of a Rotor‐Craft Unmanned Aerial Vehicle
Authors: Yuan Z. , Gong Z. , Chen J. , Wu J.
Published: November 2006

This article introduces a real‐time vision‐based method for guided autonomous landing of a rotor‐craft unmanned aerial vehicle. In the process of designing the pattern of landing target, we have fully considered how to make this easier for simplified identification and calibration. A linear algorithm was also applied using a three‐dimensional structure estimation in real time. In addition, multiple‐view vision technology is utilized to calibrate intrinsic parameters of camera online, so calibration prior to flight is unnecessary and the focus of camera can be changed freely in flight, thus upgrading the flexibility and practicality of the method.
Pneumatic Artificial Muscles Based on Biomechanical Characteristics of Human Muscles
Authors: Saga N. , Nagase J. , Saikawa T.
Published: November 2006

This article reports the pneumatic artificial muscles based on biomechanical characteristics of human muscles. A wearable device and a rehabilitation robot that assist a human muscle should have characteristics similar to those of human muscle. In addition, since the wearable device and the rehabilitation robot should be light, an actuator with a high power to weight ratio is needed. At present, the McKibben type is widely used as an artificial muscle, but in fact its physical model is highly nonlinear. Therefore, an artificial muscle actuator has been developed in which high‐strength carbon fibres have been built into the silicone tube. However, its contraction rate is smaller than the actual biological muscles. On the other hand, if an artificial muscle that contracts axially is installed in a robot as compactly as the robot hand, big installing space is required. Therefore, an artificial muscle with a high contraction rate and a tendon‐driven system as a compact actuator were developed, respectively. In this study, we report on the basic structure and basic characteristics of two types of actuators.
Long-term Cognitive and Motor Deficits After Enterovirus 71 Brainstem Encephalitis in Children
Authors: Huang Mei-Chih , Wang Shih-Min , Hsu Yung-Wen , Lin Hui-Chen , Chi Chia-Yu , Liu Ching-Chuan
Published: November 2006

OBJECTIVES. Several large outbreaks of enterovirus 71 infections have occurred in Taiwan during the past decade. Brainstem encephalitis was the most common neurologic complication. This study was designed to determine the long-term cognitive and motor outcomes of children with enterovirus 71 brainstem encephalitis.

METHODS. We conducted a prospective follow-up study of children who met the case definition for enterovirus 71 brainstem encephalitis. Subjects were stratified into isolated brainstem encephalitis (stage II), autonomic nervous system dysregulation (stage IIIa), and pulmonary edema (stage IIIb). The subjects and their parents or guardians were interviewed using structured questionnaires and received comprehensive cognitive and neurologic examinations. Motor coordination, visual-motor skill, and intellectual ability were evaluated.

RESULTS. Follow-up studies were conducted in 63 previously healthy children with enterovirus 71 brainstem encephalitis (49 stage II, 7 stage IIIa, and 7 stage IIIb). The mean time to follow-up was 2.8 ± 1.0 years (range: 1.4–4.9 years). Boys outnumbered girls by 3 to 2. The mean age at diagnosis was 2.4 ± 1.4 years (range: 0.3–7.1 years). The most common abnormal neurologic findings on admission were altered consciousness (47.6%), followed by abnormal activities of daily living (52.4%), cerebellar dysfunction (17.5%), and cranial nerve palsy (15.9%). At follow-up, 51 of 63 children had no detectable deficits. Among the remaining 12 children, 3 died during the follow-up. The remaining 9 children (14.3%) had residual deficits. Two of these with stage IIIb disease continued to have severe motor and respiratory failure.

CONCLUSIONS. Residual defects were still present in a significant proportion of children with enterovirus 71 brainstem encephalitis at >2 years after their hospitalization. Children with stage II disease were most likely to have residual cerebellar defects. Those with stage IIIb disease continued to have severe respiratory and motor impairment. Long-term follow-up of this cohort is needed to determine the ultimate prognosis.
Effect of a Salt Crust on Evaporation from a Bare Saline Soil
Authors: Fujimaki Haruyuki , Shimano Takahiro , Inoue Mitsuhiro , Nakane Kazurou
Published: November 2006

Evaporation from the soil surface is a major cause of the salinization of irrigated soils in arid and semiarid regions. To optimize irrigation scheduling under saline conditions, it is essential to be able to accurately predict solute transport in soils and the evaporation rate. We conducted laboratory column experiments under constant meteorological conditions, except for radiation, which was automatically regulated such that the temperature of the soil remained the same as that of the air. The concentration of the initial soil solution and that of the inflowing water from the bottom of the 5.2‐cm‐long column were set at 3000 g m−3 The evaporation experiments were performed with three combinations of soil and solute. Although the soil surface was kept wet by maintaining a low suction at the bottom, the evaporation rate was found to decrease considerably with time. This decrease could not be explained by a decrease in osmotic potential alone, but rather was due also to the formation of a salt crust near the surface. The bulk transfer equation for evaporation was therefore modified to include a resistance to water vapor diffusion caused by the salt crust. The dependence of the salt crust resistance on the amount of accumulated salt was evaluated experimentally and theoretically. In our numerical analysis, we used independently estimated soil hydraulic and solute transport parameters. Results show that the convection–dispersion equation (CDE) tends to overestimate backward diffusion near an evaporating soil surface, thus significantly delaying salt accumulation at the soil surface and decreasing the evaporation rate. Since the CDE uses an analogy of Fick's law to describe mechanical dispersion, the dispersion term overestimated the downward transport of solutes against upward convective transport.
Evaluating the Moisture Conditions in the Fractured Rock at Yucca Mountain: The Impact of Natural Convection Processes in Heated Emplacement Drifts
Authors: Birkholzer J. T. , Webb S. W. , Halecky N. , Peterson P. F. , Bodvarsson G. S.
Published: November 2006

The energy output of the high‐level radioactive waste to be emplaced in the proposed geologic repository at Yucca Mountain, NV, will strongly affect the thermal–hydrological (TH) conditions in the near‐drift fractured rock. Heating of rock water to above‐boiling conditions will induce large water saturation changes and flux perturbations close to the waste emplacement tunnels (drifts) that will last several thousand years. Understanding these perturbations is important for the performance of the repository, because they could increase, for example, the amount of formation water seeping into the open drifts and contacting waste packages. Recent computational fluid dynamics analysis has demonstrated that the drifts will act as important conduits for gas flows driven by natural convection. As a result, vapor generated from boiling of formation water near elevated‐temperature sections of the drifts may effectively be transported to cooler end sections (where no waste is emplaced), where it would condense and subsequently drain into underlying rock units. Thus, natural convection processes have great potential for reducing the near‐drift moisture content in heated drift sections, which has positive ramifications for repository performance. To study these processes, we have developed a new simulation method that couples existing tools for simulating TH conditions in the fractured formation with modules that approximate natural convection and evaporation conditions in heated emplacement drifts. The new method is applied to evaluate the impact of in‐drift natural convection on the future TH conditions at Yucca Mountain in a three‐dimensional model domain comprising a representative emplacement drift and the surrounding fractured rock.
Gas Transport Parameters in the Vadose Zone: Gas Diffusivity in Field and Lysimeter Soil Profiles
Authors: Kawamoto Ken , Moldrup Per , Schjønning Per , Iversen Bo V. , Rolston Dennis E. , Komatsu Toshiko
Published: November 2006

The main soil‐gas transport parameters, gas diffusivity and air permeability, and their variations with soil type and air‐filled porosity play a key role in soil‐gas emission problems including volatilization of toxic chemicals at polluted sites and the production and emission of greenhouse gases. Only limited information on soil‐gas transport parameters across the vadose zone is available, especially for soil layers below the root zone. In a series of studies, we developed new data for the soil‐gas transport parameters in different soil profiles and tested existing and new predictive models. In this first study, we measured gas diffusivity at different soil‐water matric potentials on undisturbed soil samples for three lysimeter soil profiles down to 1.4‐m depth and for two field soil profiles down to 5.6‐m depth, representing a total of 22 different soil layers with soil texture ranging from sand to sandy clay loam. Five commonly used predictive gas diffusivity models were tested. The three‐porosity model (TPM) performed best for both shallow and deep soil layers. The tortuosity–connectivity parameter X in the TPM varied with soil texture and pore size distribution, and the TPM predicted well the depth distributions of measured soil‐gas diffusivities. The TPM also requires less detailed information on the soil‐water characteristic curve than other well‐performing predictive models, and is therefore recommended for predicting variations in soil‐gas diffusivity within the vadose zone.
Sensitivity Analysis of the Nonparametric Nearest Neighbor Technique to Estimate Soil Water Retention
Authors: Nemes A. , Rawls W. J. , Pachepsky Ya. A. , van Genuchten M. Th.
Published: November 2006

A k‐nearest neighbor (k‐NN) nonparametric algorithm variant was earlier applied successfully to estimate soil water retention. In this study, we tested the sensitivity of that k‐NN variant to different data and algorithm options, such as: (i) estimations made to soils with differing distribution of properties; (ii) the use of different sample weighting methods; (iii) the number of ensembles we developed; (iv) data density in the reference data set; (v) the presence of outliers in the reference data set; (vi) unequal weighting of input attributes; and (vii) the addition of locally specific data to the reference data set. We used a hierarchical set of input attributes and data set sizes to develop ensembles of predictions using multiple randomized subset selections. The k‐NN technique performed comparably well as neural network models developed on the same data. Using >50 ensemble members did not improve the results any further. The k‐NN technique showed little sensitivity to the choice of sample weighting methods and to suboptimal weighting of input attributes. Differences in data density in parts of the reference data set did not substantially impact estimation errors. Estimations substantially improved for locally specific data when some local samples were included in the reference data set, while estimations for other samples remained almost unaffected. The k‐NN technique shows a large degree of stability and insensitivity to different settings and options, can easily adopt new data without the need to redevelop equations, and is an effective alternative to other techniques to estimate soil water retention.
Equivalent Soil Pore Geometry to Determine Effective Water Permeability
Authors: Unsal E. , Dane J. H.
Published: November 2006

Knowledge of hydraulic properties is essential for predicting flow and transport in porous media. Previously, Unsal et al. presented a procedure to determine an equivalent pore size distribution and pore geometry of a sandstone core using effective air permeability values as a function of volumetric water content in conjunction with a genetic algorithm for optimization purposes. They also showed how the obtained equivalent pore size distribution and geometry could be used to obtain the water retention curve. In this technical note, we extend their work to predict the effective water permeability as a function of volumetric water content from the same information. As a check for the theoretically obtained effective water permeability values, we compared the predicted value at saturation with the measured value at saturation and to the predicted and measured effective air permeability values for a dry core. The four values, referred to as intrinsic permeability, were sufficiently close to give confidence in the procedure.
Field Testing of a Soil Corer Air Permeameter (SCAP) in Desert Soils
Authors: Chief Karletta , Ferré Ty P. A. , Nijssen Bart
Published: November 2006

Measurements of air permeability are useful both directly, to assess gas phase movement through soils, and indirectly as a proxy for soil hydraulic conductivity. Several designs have been presented for field‐based air permeameters; however, none are suitable for use in gravelly desert soils. We designed an air permeameter compatible with a standard soil corer to facilitate insertion into desert soils. The soil corer air permeameter (SCAP) uses digital components to measure flow rates under low‐pressure gradients to improve accuracy, ease of use, and portability. The SCAP allows the extraction of undisturbed soil samples for laboratory analysis, providing direct comparisons of air permeability (ka) with other soil physical and hydraulic properties. The soil sample can be extracted before measuring ka, thus removing the need for a shape factor to account for divergent flow. In an analysis of the SCAP's performance, field testing showed that digital components operate well under field conditions; however, spanner wrench insertion holes must be sealed to provide correct ka measurements. The Jalbert and Dane shape factor for in situ ka is applicable for tilled, unstructured soils. However, significant soil‐specific variability exists in the shape factor, so we recommend measuring ex situ ka in the field, where possible. Ex situ field ka and laboratory hydraulic conductivity (Ksat) measurements were compared and air to water permeability ratios were calculated to determine structural changes due to water saturation. For soils that could be extracted with minimal structural change, we found good correlation between ka and Ksat and reasonable agreement with previously published results.
Tension Infiltrometer Measurements: Implications of Pressure Head Offset due to Contact Sand
Authors: Reynolds W. D.
Published: November 2006

The use of contact sand to achieve good hydraulic connection between the tension infiltrometer (TI) membrane and the soil is known to introduce an offset between the pressure head set on the bubble tower (h0) and the pressure head applied to the soil surface (hs). The nature and importance of the offset are poorly understood, however. Hence, the objectives of this study were to characterize the offset and to demonstrate its impacts on TI determinations of near‐saturated hydraulic conductivity, K(h), sorptive number, α*(h), flow‐weighted mean pore diameter, D(h), and number of flow‐weighted mean pores per unit area, N(h). The offset, Δh = hs − h0, consists of a constant elevation component and a variable head‐loss component. The elevation component increases hs relative to h0, and comprises most of the offset for low TI flux density, q(h0), and large contact sand hydraulic conductivity, Kcs The head‐loss component decreases hs relative to h0, and becomes more important as q(h0) increases or Kcs decreases. The offset has little effect on the accuracy of K(h), α*(h), D(h), and N(h) when these relationships are insensitive to changes in h0 When the relationships are sensitive to changing h0, the offset can change the shapes of the relationships; cause systematic overestimates of the K(h), α*(h), and D(h) values; and cause systematic underestimates of the N(h) values. The amount of overestimate and underestimate increases with increasing offset and should be corrected using a form of Darcy's law to prevent the introduction of systematic biases in TI results.
Effects of Land Use and Land Cover, Stream Discharge, and Interannual Climate on the Magnitude and Timing of Nitrogen, Phosphorus, and Organic Carbon Concentrations in Three Coastal Plain Watersheds
Authors: Lehrter John C.
Published: November 2006

In‐stream nitrogen, phosphorus, organic carbon, and suspended sediment concentrations were measured in 18 subbasins over 2 annual cycles to assess how land use and land cover (LULC) and stream discharge regulate water quality variables. The LULC was a primary driver of in‐stream constituent concentrations and nutrient speciation owing to differences in dominant sources and input pathways associated with agricultural, urban, and forested land uses. Stream discharge was shown to be a major factor that dictated not only the magnitude of constituent concentrations, but also the chemical form. In high discharge agricultural subbasins, where nitrate was the dominant nitrogen form, there was a negative correlation between discharge and nitrate concentration indicating groundwater inputs as the dominant pathway. In urban settings, however, nitrate was positively correlated with discharge, and, in forested subwatersheds, where dissolved organic nitrogen (DON) was the dominant nitrogen form, there was a positive correlation between discharge and DON, indicating washoff from the watershed as the dominant input pathway. Similarly, phosphorus concentrations were strongly regulated by LULC, discharge, and seasonality. This comparative study highlights that different mechanisms regulate different forms of nitrogen, phosphorus, and carbon, and thus field programs or water quality models used for regulatory purposes must assess these nutrient forms to accurately apply management plans for nutrient reductions.
Integrated Biological Treatment and Biogas Production in a Small‐Scale Slaughterhouse in Rural Ghana
Authors: Aklaku E. D. , Jones K. , Obiri‐Danso K.
Published: November 2006

A small‐scale anaerobic slaughter waste treatment plant in rural Ghana was tested for the production of energy and a microbiologically clean effluent suitable for use in irrigation. A typical day's slaughter, comprising 4 cattle, 12 sheep, and 12 goats, produced 8.5 m3 of biogas. Annually, this is equivalent to the energy from 17 metric tons of fuel wood, which is the annual productivity of 2 ha of savanna vegetation. Fecal indicator bacteria were reduced by 2 to 3 logs, nitrates by 86 to 90%, phosphates by 23%, biochemical oxygen demand by 42 to 92%, and suspended solids and dissolved solids by 73 to 86% and 19 to 37%, respectively. The effluent is used for irrigation, and the organic biomass from the digester is used as a biofertilizer. Besides energy and a cleaner effluent, the community benefited from a lessening dependency on fuel wood and reductions in unpleasant smells and nuisance animals, such as flies, dogs, and vultures.
Anion and Cation Leaching or Desorption from Activated Carbons from Municipal Sludge and Poultry Manure as Affected by pH
Authors: Fitzmorris Kari B. , Lima Isabel M. , Marshall Wayne E. , Reimers Robert S.
Published: November 2006

The conversion of municipal sludge and poultry manure to activated carbon results in a significant ash fraction that contains several different anions and cations. The objectives of this study were to determine whether the select ions are released or leached from virgin carbon into the sorption medium at different pH values. Activated carbon was placed in solutions of pH 1, 5, or 7, and the leaching of six cations (cadmium, chromium, copper, nickel, lead, and zinc) and two anions (arsenate and selenate) was recorded. Considerable quantities of zinc and copper were removed at pH 1 from all carbon sources. However, the amounts leached at pH 5 and 7 were small or undetectable. Our results indicate that leaching or desorption from carbons made from municipal sludge or poultry manure is pH‐dependent and occurs readily under highly acidic conditions but minimally under pH conditions typically seen in contaminated water or wastewater.
Effects of Nitrogen and Phosphorus Limitation on the Activated Sludge Biomass in a Kraft Mill Biotreatment System
Authors: Bhathena Jasmine , Driscoll Brian T. , Charles Trevor C. , Archibald Frederick S.
Published: November 2006

Unlike wastewater, pulp and paper mill effluents are generally severely deficient in bioavailable nitrogen and phosphorus. The influence of nitrogen and phosphorus limitations on steady‐state or typical pulp and paper mill activated sludge floc properties and performance was studied using a bioreactor‐fed synthetic raw mill effluent and seeded with mill activated sludge. Limitation of either nitrogen or phosphorus decreased growth, five‐day biochemical oxygen demand, and suspended solids removal. Nitrogen limitation greatly enhanced activated sludge floc poly‐β‐hydroxybutyrate (PHB), but not carbohydrate or extracellular polymeric substances (EPS). In contrast, phosphorus limitation increased total floc carbohydrate and EPS, but not PHB. The flocs showed little ability to store either nitrogen or phosphorus.    Nitrogen limitation, but not phosphorus limitation, produced much more negative net floc surface charge, increasing fines, while phosphorus limitation, but not nitrogen limitation, increased the floc bound water content and surface hydrophobicity and decreased fines.
Detection of Infectious Parasites in Reclaimed Water
Authors: Huffman Debra E. , Gennaccaro Angela L. , Berg Tracy L. , Batzer Glenda , Widmer Giovanni
Published: November 2006

The presence of infectious protozoan pathogens in reclaimed water may present an unacceptable health risk. This study was designed similar to a study reported by Garcia et al. (2002), which detected no infectious Giardia cysts in the final effluent of a tertiary treatment facility as determined by animal infectivity (dose 1000 cysts/gerbil). This study also included evaluation of Cryptosporidium oocyst infectivity. Infectious Giardia cysts were detected in the final effluent with 1 gerbil out of 3 inoculated with 250 cysts from reclaimed water showing signs of infection 15 days postinoculation. None of the Cryptosporidium oocysts concentrated from the reclaimed water samples appeared to be infectious.
Pareto Improving Lotteries and Voluntary Public Goods Provision
Authors: Karaivanov Alexander
Published: November 2006

This paper characterizes the utility possibility frontier resulting in a model of private voluntary provision of a public good. It is shown that ex-ante lotteries over resource distributions among the agents can be Pareto improving. A corollary is that an equal distribution of resources among the agents, or any distribution where all agents contribute in equilibrium, is always Pareto dominated by a lottery between two unequal distributions.
The Effect of Switching Private Insurance Plans on Health Care Utilization
Authors: Liu Fei , Zimmer David M.
Published: November 2006

The switching of health insurance plans and health care utilization are potentially correlated with both observable and unobservable information. This paper presents a two-period model of health care utilization, and attempts to account for unobserved heterogeneity that simultaneously affects utilization and the decision to switch plans. Data used in this paper are drawn from the Medical Expenditure Panel Survey. Results indicate that non-HMO enrollees increase their utilization of non-emergency related care prior to switching to HMOs, and they decrease utilization after switching. Conversely, individuals enrolled in HMOs report lower levels of utilization before and higher utilization after they switch to non-HMOs.
Rational or Confused Polluters? Evidence from Hazardous Waste Compliance
Authors: Stafford Sarah L
Published: November 2006

Although most models of environmental compliance are based on a variation of the rational polluter model, regulated entities may not always intentionally decide to violate based on the relative costs and benefits of doing so. According to the complexity critique, a significant amount of noncompliance may be the result of ignorance about the requirements of the law. Using hazardous waste regulations as a case study, this paper examines the role that rationality and complexity play in environmental compliance. The results suggest that both are necessary to explain hazardous waste compliance behavior. In support of the rational polluter model, the results show that factors which increase the cost of compliance also increase the likelihood of a violation while factors that increase the likelihood of inspections and detection decrease the probability of a violation. In support of the complexity critique, the results show that larger facilities and facilities of multi-plant companies are less likely to violate, while facilities that are subject to more complex regulations are more likely to violate. Also in support of the complexity critique, facilities learn from past inspections and facilities in states with programs directed toward reducing complexity are less likely to violate. This mixed support holds across various subgroup of facilities, although there does appear to be some difference in the factors that contribute to different types of violations. In particular, non-management violations appear to be driven less by a rational comparison of the costs and benefits of violations than by the complexity of regulations.
End of Life Issues Action: Impact of Education
Authors: Kurz Jane M. , Hayes Evelyn R.
Published: November 2006

There is an increased momentum to improve nurses' expertise in dealing with end of life issues via a standardized education program, ELNEC. This program has not been evaluated systematically. This quasi-experimental, longitudinal study's goal was to measure ELNEC Program's impact on registered nurses' death anxiety, death attitudes, and knowledge over time. General Systems Theory provided the foundation. Nurses completed surveys prior to and 3 times after the program. Research and control groups were similar. Research group's death anxiety scores increased immediately post- program, decreased 6 months later (t=-2.65, p=.02) and returned to pre-program levels at 12 months. Death attitudes varied. Knowledge levels improved significantly. The control group had steady increases in death anxiety scores. The program was associated with decreased death anxiety. Recommendations include timing evaluations after participants have time for reflection and planning "booster programs" to sustain effects. Future studies should include larger samples, incentives, and research method triangulation.
Digital Image Processing of Palm Oil Fruits
Authors: Choong Thomas S.Y. , Abbas Saad , Shariff Abdul Rashid , Halim Rohaya , Ismail Mohd Halim S. , Yunus Robiah , Ali Salmiaton , Ahmadun Fakhrul-Razi
Published: November 2006

The oil content of the flesh of mesocarp has direct relationship with color bands red, green and blue. By running intensive experiments, it was found that oil content correlated with the red color band, with a regression value of 0.86. The finding of this study may be useful for determining the ripeness of oil palm for harvesting and for the use in the operation and control of continuous steriliser in palm oil mill.
Osmotic Membrane Distillation - A Brief Review
Authors: Nagaraj Naveen , Patil Balaji Shivaji , Biradar Prashant Maharudrappa
Published: November 2006

In recent years, osmotic membrane distillation is gaining importance as an attractive/ complementary athermal membrane process. Osmotic membrane distillation is having potential to concentrate the biomolecules/liquids to a very high level under mild operating condition, without product damage. Further, this process can be employed as a pre-concentration step to reduce water load significantly on subsequent processing steps. The present review exclusively deals with process features, theoretical aspects involving water transport mechanism, influence of various process conditions on transmembrane flux along with recent application of osmotic membrane distillation process. Also, suggestions for future work and possible process integration of osmotic membrane distillation with other processes are also discussed.