bluuebunny/crossref_metadata_2025 huggingface dataset:
Sutured wounds: Factors associated with patient‐rated cosmetic scores
Authors: Lowe Tatiana , Paoloni Richard
Published: May 2006

Objective:  To determine the association between wound characteristics, wound management in the ED and patient‐rated cosmetic appearance of sutured wounds. Our hypothesis was that practitioner seniority would most strongly predict outcome.

Methods:  Prospective recruitment of patients with lacerations sutured at the primary ED visit was performed. Data collected included patient demographics, wound characteristics and wound management. A standardized telephone questionnaire was administered 14 days and 3 months later. Scar appearance was scored using a verbal rating scale from zero to 10. Data were obtained about suture removal, antibiotic compliance, infection and dehiscence rates at 2 weeks. Associations of variables with cosmetic scores were analysed using multivariate linear regression.

Results:  One hundred and thirty‐two patients were evaluated. Mean cosmetic scores were not significantly associated with seniority (P = 0.07). Lacerations repaired by senior practitioners were more likely to result from glass or general trauma (P = 0.007), be shorter (P = 0.03), be cleaned with antiseptic (P = 0.03), not to re‐open (P = 0.01) or require re‐suturing (P = 0.03). Following multivariate regression factors significantly associated with cosmetic scores at 14 days and 3 months were site of injury (P < 0.003) and time from injury to repair (P < 0.009). Wounds of the torso, leg or foot had lower cosmetic scores at both time‐points. An association with age (P = 0.04) was present at 3 months.

Conclusions:  Previous research found improvement between short‐term doctor‐rated cosmesis and training beyond internship. Our study demonstrated a non‐significant trend relationship between seniority and patient‐rated outcome, both short and long‐term. However, staff seniority was overshadowed by the site of laceration and time from injury to repair.
Head computed tomography guidelines are being followed
Authors: Brettig Tim , Clooney Megan , Kelly Anne‐Maree , Kerr Debra
Published: May 2006

Objective:  Several guidelines have been developed to direct the ordering of head computed tomography (CT) for patients, but most are clinical presentation‐specific. Recently, an integrated guideline for ordering emergent head CT for patients who present to the ED of Western Hospital, Footscray, Victoria, Australia, was developed in response to concerns raised regarding perceived over‐utilization of head CT for ED patients. Our aim was to determine compliance with the guideline.

Methods  This was an explicit retrospective medical record review of patients who presented to the ED of Western Hospital between 1/04/2004 and 17/6/2004 and had a head CT as part of their assessment. Clinical information for these cases was compared with guideline recommendations. Data are described by descriptive statistics.

Results  Of the 231 cases that were included in the study, 65 (28.1%, 95% confidence interval 23–35%) had abnormal CT findings. Guidelines were adhered to in 217 (93.9%, 95% confidence interval 91–97%) cases. For the cases where the guidelines were not adhered to (14; [6.1%]), there was only one abnormal scan the clinical significance of which is not clear.

Conclusion  The study found that compliance with head CT guideline was high. This suggests that the guideline is both clinically relevant and supported by ED doctors or conversely that the guideline is concordant with existing ordering practices of the ED.
NexTemp thermometer can be used interchangeably with tympanic or mercury thermometers for emergency department use
Authors: Rajee Mani , Sultana Ron V
Published: May 2006

Objectives  To determine the agreement between the chemical dot NexTemp thermometer with mercury and tympanic thermometers and the repeatability of measurements using these devices.

Methods  A prospective study involving a convenience sample of 194 consenting adult patients presenting to the ED, Freemasons Hospital, East Melbourne, Victoria, Australia. A survey of emergency medical staff was conducted to determine what they considered an acceptable level of agreement and repeatability for a putative new thermometer. The NexTemp thermometer’s performance was judged against this. For each thermometer, a set of two temperature measurements was made in every patient. The sequence of the set of readings (and hence device) was random between patients and the staff member performing one set was blinded to the results of the other two sets of readings in each patient. The method of Bland and Altman was used for assessing agreement and repeatability.

Results  Clinicians considered that a new thermometer should exhibit repeatability of ±0.3°C and agree with existing devices within ±0.5°C. The tympanic thermometer had 95% limits of repeatability of −0.8–0.5°C compared with the NexTemp (−0.3–0.4°C) and mercury thermometers (−0.3–0.4°C). The NexTemp thermometer agreed with mercury thermometer within −0.6–0.5°C. The tympanic thermometer agreed with the mercury thermometer within −1.0–1.1°C.

Conclusion  Based on temperature measurement only, the NexTemp thermometer can be used interchangeably with current mercury and tympanic thermometers.
Paramedic intubation of patients with severe head injury: a review of current Australian practice and recommendations for change
Authors: Bernard Stephen A
Published: May 2006

Secondary brain injury may occur early after severe traumatic brain injury due to hypoxia and/or hypotension. Prehospital care by ambulance paramedics has the goal of preventing and treating these complications and, thus, improving outcomes. In Australia, most ambulance services recommend paramedics attempt endotracheal intubation in patients with severe head injury. Even though most patients with severe head injury retain airway reflexes, most states do not allow the use of appropriate drugs to facilitate intubation. In contrast, recent evidence from trauma registries suggests that this approach may be associated with significantly worse outcomes compared with no intubation. Two states allow intubation facilitated by sedative (but not relaxant) drugs, but this has a low success rate and could worsen brain injury because of a decrease in cerebral perfusion pressure. For road‐based paramedics, the role of rapid sequence intubation is uncertain. Given the risks of this procedure and the lack of proven benefit, this procedure should not be introduced without supportive evidence from randomised, controlled trials. In contrast, for safety reasons, comatose patients transported by helicopter should undergo rapid sequence intubation prior to flight. However, this is not authorised in most states, despite good supportive evidence that this can be safely and effectively undertaken by paramedics. Finally, there is evidence that inadvertent hyperventilation is associated with adverse outcome, yet only two ambulance services use waveform capnography in head injury patients who are intubated. Overall, current paramedic airway practice in most states of Australia is not supported by the evidence and is probably associated with worse patient outcomes after severe head injury. For road‐based paramedics, rapid transport to hospital without intubation should be regarded as the current standard of care. Rapid sequence intubation should be limited to use within appropriate clinical trials, or patients transported by helicopter. For patients who are intubated, waveform capnography is essential to confirm tracheal placement and to prevent inadvertent hyperventilation.
Fingertip injuries
Authors: De Alwis Waruna
Published: May 2006

Fingertip injuries are a potential cause of significant morbidity within the workplace and the community. Although they account for a low proportion of ED presentations, importantly they can frequently be managed entirely by emergency staff. A literature review was undertaken to identify the epidemiology, the assessment process and the management options for fingertip injuries as relevant to emergency medicine.
Procedural skills quality assurance among Australasian College for Emergency Medicine fellows and trainees
Authors: McD Taylor David , Harrison Glenn
Published: May 2006

Objective:  Presently, no objective quality control mechanism exists for monitoring procedural skills among Australasian College for Emergency Medicine trainees. The present study examined trainee and fellow procedural experience and perceived competency, participation in accredited training courses and support for a procedural logbook.

Methods:  A cross‐sectional mail survey of Australasian College for Emergency Medicine advanced trainees and fellows was performed. Experience and perceived competency in 23 common and important ED procedures were examined.

Results:  In total, 202 fellows and 264 trainees responded (overall response rate 39.0%). Overall, fellow procedural experience and perceived competency were reasonable. However, some fellows had never performed a number of procedures including some common procedures (e.g. nasal packing, fracture reduction) and there were reports of ‘very poor’ competency for 17 (73.9%) procedures. Trainee experience and perceived competency were less than the fellows but showed similar patterns. Perceived numbers of each procedure required to achieve competency varied considerably between the procedures and among the respondents. However, there were no significant differences in the perceived numbers reported by the trainees and the fellows (P > 0.05). Variable proportions of trainees and fellows had undertaken courses that incorporated procedural skills training. More fellows (75.7%, 95% confidence interval 69.1–81.4) than trainees (59.9%, 95% confidence interval 53.6–65.8) supported the use of a procedural logbook (P = 0.003).

Conclusions:  Lack of experience in some procedures among some fellows, especially commonly performed procedures, might represent a deficiency in existing quality assurance mechanisms for procedural skills training. Greater participation in skills courses, to improve experience in difficult and uncommonly encountered procedures, is recommended. Improved quality assurance mechanisms, including a procedural logbook, should be considered.
Medical student education in emergency medicine: New model from South Africa
Authors: MacFarlane Campbell , Green‐Thompson Lionel
Published: May 2006

See also pp. 219–220

Emergency medicine is a new specialty in South Africa. Postgraduate training, degrees and diplomas have been introduced and this should make a significant difference, in due course, to emergency care in the country. The University of the Witwatersrand, Johannesburg, South Africa, like many universities in Australia, embarked upon a Graduate Entry Medical Programme. This implied significant curriculum change and gave opportunity for the development of formal emergency medicine training for students, for the first time. After considerable debate over the needs of the graduate in South Africa a new block was developed, called the Acute and Perioperative Care block. This encompasses forensic medicine, emergency medicine, trauma and anaesthetics. The training is integrated and progressive. No similar programme has been detected elsewhere. At the end of the first year there is considerable satisfaction on the part of both teachers and students and many of the students, finding the module exciting, have indicated a wish to become involved in emergency medicine in the future. The structure of the course is laid out and might be of relevance to colleagues with an interest in medical education.
National Emergency Department Overcrowding Study tool is not useful in an Australian emergency department
Authors: Raj Kamini , Baker Kylie , Brierley Stephan , Murray Duncan
Published: May 2006

Objective:  To determine the accuracy and usefulness of the National Emergency Department Overcrowding Study (NEDOCS) tool in an urban hospital ED in Australia by direct comparison with subjective assessment by senior ED staff.

Method:  A sample of simultaneous subjective and objective data pairs were collected six times a day for a period of 3 weeks. All senior medical staff in the ED answered a brief questionnaire along with the senior charge nurse for the ED. Simultaneously, the senior charge nurse also documented the total number of patients in the ED, the number of patients awaiting admission, the number of patients on ventilators, the longest time waited by an ED patient for ward bed, and the waiting time for the last patient from the Waiting Room placed on a trolley. The objective indicators were entered into a Web‐based NEDOCS tool and transformed scores were compared with the averaged and transformed subjective scores for each sample time. Bland–Altmann and Kappa statistics were used to test the agreement between the objective and subjective measuring methods.

Results:  The mean difference between the subjective and objective methods was small (3.5 [95% confidence interval −0.875–7.878] ); however, the 95% limits of agreement was wide (−46.52–53.43). The Kappa statistic used to assess the extent of reproducibility between categorical variables was 0.31 (95% confidence interval 0.17–0.45).

Conclusion:  The present study suggests that NEDOCS method of processing the objective overcrowding data does not accurately reflect the subjective assessment of the senior staff working at that time in the ED. This might be because the assumptions of the original NEDOCS study are flawed.
Evolution of health information management and information technology in emergency medicine
Authors: Dinh Michael , Chu Matthew
Published: May 2006

The implementation of information technology will continue to have important effects on the practice of emergency medicine. Patient registration and tracking systems, telemedicine electronic order entry systems, and the advent of electronic health records are some examples of applications that influence patient care in emergency departments. We review the literature regarding information technology advances in emergency medicine and outline the important role that emergency physicians play in developing and implementing a national health information technology strategy.
Acute retrobulbar haemorrhage: An ophthalmic emergency
Authors: Shek Kam Chuen , Chung Kin Lai , Kam Chak Wah , Yau Hon Hung
Published: May 2006

Acute retrobulbar haemorrhage is a rare complication of blunt eye trauma. It can be sight‐threatening but is reversible when recognized and treated promptly. We presented a case of acute retrobulbar haemorrhage with profound reduction of vision. Emergency surgical decompression was performed to preserve the vision. Clinical features and management are discussed.
Supernova remnant energetics and magnetars: no evidence in favour of millisecond proto-neutron stars
Authors: Vink Jacco , Kuiper Lucien
Published: May 2006

It is generally accepted that anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs) are magnetars, i.e. neutron stars with extremely high surface magnetic fields (B > 1014 G). The origin of these high magnetic fields is uncertain, but a popular hypothesis is that magnetars are born with an initial spin period not much exceeding the convective overturn time (∼3 ms), which results in a powerful dynamo action, amplifying the seed magnetic field to ≳1015 G. Part of this rotation energy is then expected to power the supernova through rapid magnetic braking. It is therefore possible that magnetar creation is accompanied by supernovae that are an order of magnitude more energetic than normal supernovae, provided their initial spin period is ∼1 ms. However, we list here evidence that the explosion energies of these supernova remnants associated with AXPs and SGRs - Kes 73 (AXP 1E 1841-045), CTB 109 (AXP 1E2259+586) and N49 (SGR 0526-66) - are close to the canonical supernova explosion energy of 1051 erg, suggesting an initial spin period of P0≳ 5 ms.

We therefore do not find evidence that magnetars are formed from rapidly rotating proto-neutron stars, allowing for the possibility that they descend from stellar progenitors with high magnetic field cores, and discuss the merits of both formation scenarios.

In an appendix we describe the analysis of XMM-Newton observations of Kes 73 and N49 used to derive the explosion energies for these remnants.
Subsurface Imaging of an Abandoned Solid Waste Landfill Site in Norman, Oklahoma
Authors: Zume Joseph T. , Tarhule Aondover , Christenson Scott
Published: May 2006

Leachate plume emanating from an old unlined municipal landfill site near the city of Norman, Oklahoma, is discharging into the underlying alluvial aquifer. Subsurface imaging techniques, electrical resistivity tomography and electrical conductivity (EC) logging, were used on the site to detect and map the position of the leachate plume. Anomalous EC zones, delineated with the two methods, correlated with the occurrence of the plume detected by water chemistry analyses from multilevel monitoring wells. Specific conductance, a potential indicator of leachate contamination, ranged from 1861 to 7710 μS/cm in contaminated zones and from 465 to 2180 μS/cm in uncontaminated ground water. Results are in agreement with those from earlier studies that the leachate plume emerges from the landfill along preferential pathways. Additionally, there are indications that the leading edge of the plume has migrated, at least, 200 m away from the landfill in the direction of ground water flow.
Monitoring Subsurface Microbial Ecology in a Sulfate‐Amended, Gasoline‐Contaminated Aquifer
Authors: Sublette Kerry , Peacock Aaron , White David , Davis Greg , Ogles Dora , Cook David , Kolhatkar Ravi , Beckmann Dennis , Yang Xiaomin
Published: May 2006

An unconfined, gasoline‐contaminated aquifer (2.3 to 5 m water table) in fractured sedimentary bedrock has been under remediation since 1999 in Bellingham, Washington. The central portion of the ground water plume has been difficult to remediate because of the fractured sedimentary bedrock and the presence of significant utilities that have prevented aerobic in situ cleanup methods. A 15‐month field trial was conducted to determine the efficacy of enhancing the attenuation of benzene, toluene, ethylbenzene, and xylenes (BTEX) hydrocarbons at the site by continuously amending the aquifer with sulfate that was initially introduced into the aquifer using an infiltration trench in 3.8‐m3 batches at a concentration of 500 mg/L. The goal was to stimulate anaerobic bacteria and enhance dissolved‐phase gasoline and BTEX biodegradation rates. The subsurface microbial ecology in the aquifer was monitored during sulfate injection using Bio‐Sep® biotraps (Microbial Insights Inc., Rockford, Tennessee). Bio‐Sep beads have been shown to be very effective in collecting biofilms, which are more indicative of in situ microbial ecology than planktonic organisms from ground water samples. Sulfate injection was shown to increase the rates of biodegradation of BTEX components by more than twofold for toluene, for example, and about fivefold for gasoline‐range hydrocarbons. The subsurface microbial community became more anaerobic in character as sulfate utilization increased as evidenced by its depletion in the aquifer. Bead biofilms were also compared to planktonic samples from ground water monitoring wells. During sulfate injection, bead biofilm biomarkers were shown to correlate with changes in ground water geochemistry, while planktonic samples from ground water remained relatively unchanged over time.
New Approach for Ground Water Detection Monitoring at Lined Landfills
Authors: Buket Yenigül N. , Elfeki Amro M.M. , Van Den Akker Cees
Published: May 2006

The design of a ground water detection monitoring system at a lined landfill is complicated due to uncertainties in contaminant source characteristics and variability of hydrogeological conditions. Maximizing the likelihood of detecting contaminants and minimizing the contaminated area are the conflicting design objectives. Mostly, a large number of wells may be required to achieve the desired efficiency. However, the cost might be quite high from a practical point of view. Moreover, with the conventional monitoring approach, a widely applied three‐well monitoring system (minimum regulatory requirement) is more often inadequate to accomplish these objectives at lined landfills due to the limited capture zone of monitoring wells. Therefore, implementation of a new monitoring approach has been proposed in this study to design a highly efficient, cost‐effective, three‐well system. In this new approach, the main idea is to increase the interception of contaminant plumes at early stages by broadening the capture zone of monitoring well(s) simply by continuous pumping from the monitoring well(s) with a small pumping rate. A hypothetical problem is presented where a Monte Carlo framework is used to incorporate uncertainties due to subsurface heterogeneity and the leak location. A finite‐difference ground water model coupled with a random‐walk particle‐tracking model simulates a contaminant plume released from the landfill for each Monte Carlo realization. The efficiency and the cost of the three‐well monitoring network have been compared for conventional and proposed monitoring approaches (PMA). It has been observed that the efficiency of the monitoring system improves significantly by the application of the PMA.
Precision Ground Water Sampling in Coastal Aquifers Using a Direct‐Push, Shielded‐Screen Well‐Point System
Authors: Charette Matthew A. , Allen Matt C.
Published: May 2006

Conventional ground water sampling methods are often expensive and lack the sampling resolution required to categorize geochemical processes in surficial aquifers. Here, we describe the application of a commercially available gas vapor sampling probe to ground water sampling in shallow coastal aquifers. The system involves a small‐diameter, shielded‐screen well‐point sampler that can provide high resolution (∼10 cm) to depths of 10 m or greater depending on the aquifer matrix. Examples of the system’s utility are presented for two geologically contrasting environments (Waquoit Bay, Massachusetts, USA; Ubatuba, Brazil). In Waquoit Bay, the sampler allowed us to resolve a sharp saline transition zone (∼2 m) and the associated changes in nutrients and trace metals that were associated with biogeochemical reactions at this interface. The system also proved useful in Ubatuba, Brazil, where small‐scale gradients in sediment composition and permeability controlled the ground water salinity profile.
Surveying Ground Water Level Using Remote Sensing: An Example over the Seco and Hondo Creek Watershed in Texas
Authors: Chen Pei‐yu , Arnold Jeffrey G. , Srinivasan Raghavan , Volk Martin , Allen Peter M.
Published: May 2006

The Normalized Difference Vegetation Index (NDVI) derived from satellite data has been applied to various vegetation studies. The objective of this study was to assess the feasibility of using the NDVI response to plant water content to predict ground water level over a watershed located in the Edwards Aquifer of Texas, USA. Results showed that the precipitation data collected inside the watershed were not highly correlated to ground water depth within 10 d of the event, though a 60‐foot sinkhole in the study site was expected to collect rainfall and recharge ground water in a short time. Alternatively, the NDVI derived from SPOT‐VEGETATION satellite data and potential evapotranspiration (PET) based on the Hargreaves PET model were significantly correlated to ground water depth. Moreover, the stream flow measurements were correlated to ground water level as well. Two simple models were developed for estimating ground water levels in the artesian and recharge zones. Independent validations were performed to verify both models. All three variables (NDVI, PET, and stream flow) were directly or indirectly related to the precipitation. The PET was mainly controlled by air temperature, and the temperature was negatively related to precipitation. The NDVI values were affected by both temperature and precipitation, and the amount of rainfall was strongly correlated to the stream flow. This study initiated a unique approach to surveying ground water level based on satellite information and meteorological data.
Design of an MTBE Remediation Technology Evaluation
Authors: Azadpour‐Keeley Ann , Barcelona Michael J.
Published: May 2006

This study examines the intrinsic variability of dissolved methyl tert‐butyl ether (MTBE) concentrations in ground water during the course of a pilot‐scale bioremedial technology trial in Port Hueneme, California. A pretrial natural gradient tracer experiment using bromide was conducted in an anaerobic test section of the aquifer to characterize hydrogeology. The results showed the presence of a complex velocity field in terms of vertical stratification and preferential flowpaths. The hydraulic conductivity at the test area varied by >2 orders of magnitude, and the effects of vertical stratification were made apparent by the tracers’ detection pattern, which was predominately higher in the lower part of the aquifer. Since historically the lower portion of the aquifer significantly influenced MTBE transport, it was emphasized by increasing the sampling frequency for MTBE and tracers during the pilot test that involved the intermittent addition of oxygen and propane into the aquifer. A second tracer experiment using bromide and deuterated MTBE (2H12‐MTBE) was conducted at the onset of the technology trial and after the aquifer was made aerobic. The continuous metering of the tracer solutions into the test area was maintained for 300 d. The results showed that 2H12‐MTBE behaved as a conservative tracer since (1) its concentrations increased throughout the study approaching its designed injected level and (2) the pattern of its detection resembled that of bromide. On the other hand, 2H12‐MTBE, which was purposefully introduced into the aquifer, behaved differently from that of the existing dissolved MTBE plume that emanated from a non–aqueous phase liquid (NAPL) source over a decade ago, thereby undergoing years of diffusion. The data imply that a detailed understanding of the complexity of the flow field was not possible by observing the intrinsic MTBE data alone.
Quantifying PCE and TCE in DNAPL Source Zones: Effects of Sampling Methods Used for Intact Cores at Varied Contaminant Levels and Media Temperatures
Authors: Siegrist Robert L. , Lowe Kathryn S. , Crimi Michelle L. , Urynowicz Michael A.
Published: May 2006

An experimental study was completed to assess the impact of sampling methods, contaminant levels, and subsurface temperatures on the quantification of tetrachloroethylene (PCE) and trichloroethylene (TCE) in source zones contaminated by dense non–aqueous phase liquids (DNAPLs). Intact cores of clean aquifer solids (fine‐grained uniform sand with low foc) from a DNAPL site in Florida were spiked with neat PCE and TCE to yield concentrations such that DNAPL‐phase contamination would be absent or present. Three methods characterized by different levels of media disaggregation and atmospheric exposure (MDE) were used to obtain samples from intact cores, which were at temperatures of 2°C, 20°C, and 38°C. The results of this study demonstrated that sampling of intact cores can yield negative bias, ranging from 0% to 98% or more, in the concentrations of PCE and TCE measured. Larger negative bias was correlated with higher MDE methods, presumably due to elevated volatilization losses during sample collection and containerization. Larger negative bias was also correlated with higher temperatures but only during sampling using higher MDE methods. The results of this study suggest that intact core sampling procedures may or may not lead to erroneous conclusions about a DNAPL source zone. For example, sampling data may lead to a conclusion that a potential source zone has no DNAPL‐phase contamination present when in fact it is present, or that remediation has achieved source zone cleanup to a residual concentration goal, when in fact the goal was not met. Conversely, if a remediation goal is to achieve a specified mass depletion level (e.g., 90%), measurement bias may not result in an erroneous conclusion. Further research is planned to examine a wider range of aquifer properties and sampling conditions and to assess the impacts of measurement errors on DNAPL source zone characterization and assessment of remediation performance.
Protein Requirements of the Freshwater Prawn Macrobrachium rosenbergii Evaluated by the Factorial Method
Authors: Teshima Shin‐Ichi , Koshio Shunsuke , Ishikawa Manabu , Alam Md. Shah , Hernandez Hernandez Luis Hector
Published: May 2006

The dietary protein requirement of the freshwater prawn Macrobrachium rosenbergii to obtain the maximum body protein retention was assessed by the estimated protein needed daily for maintenance (M) and body protein increment (G). The body protein increment was estimated by quantifying body nitrogen increments when the prawn was fed high‐protein diets composed primarily of casein. The protein required for maintenance was estimated by regressing weight gains in feeding experiments using graded dietary levels of casein. The true daily retention (R) or increase in body protein of the prawn corresponds to the sum of M and G. The values of M, G, and R determined in the present study were 3.86, 0.24, and 4.10 g/kg body weight/d, respectively. On the basis of the daily body protein increment and the net protein utilization of casein (58%), dietary protein requirement of the juvenile M. rosenbergii for maximum body protein retention was suggested to be about 7.1 g/kg body weight/d.
Effect of Diet Processing Method and Ingredient Substitution on Feed Characteristics and Survival of Larval Walleye, Sander vitreus
Authors: Barrows Frederic T. , Lellis William A.
Published: May 2006

Two methods were developed for the production of larval fish diets. The first method, microextrusion marumerization (MEM), has been tested in laboratory feeding trials for many years and produces particles that are palatable and water stable. The second method, particle‐assisted rotational agglomeration (PARA), produced diets that have lower density than diets produced by MEM. Each method was used to produce diets in the 250‐ to 400‐ and 400‐ to 700‐μm range and compared with a reference diet (Fry Feed Kyowa* [FFK]) for feeding larval walleye in two experiments. The effect of substituting 4% of the fish meal with freeze‐dried artemia fines was also investigated. In the first experiment, 30‐d survival was greater (P < 0.05) for fish fed a diet produced by PARA without Artemia (49.1.0%) than for fish fed the same diet produced by MEM (27.6%). The addition of Artemia to a diet produced by MEM did not increase survival of larval walleye. Fish fed the reference diet had 24.4% survival. In the second experiment, there was an effect of both processing method and Artemia supplementation, and an interaction of these effects, on survival. Fish fed a diet produced by PARA without Artemia supplementation had 48.4% survival, and fish fed the same diet produced by MEM had only 19.6% survival. Inclusion of 4% freeze‐dried Artemia improved (P < 0.04) survival of fish fed MEM particles but not those fed PARA particles. Fish fed FFK had greater weight gain than fish fed other diets in both experiments. Data indicate that the PARA method of diet processing produces smaller, lower density particles than the MEM process and that diets produced by the PARA process support higher survival of larval walleye with low capital and operating costs.
Effects of Gender and Size on Feed Acquisition in the Pacific White Shrimp Litopenaeus vannamei
Authors: Moss Dustin R. , Moss Shaun M.
Published: May 2006

Pacific white shrimp, Litopenaeus vannamei, are sexually dimorphic for growth, where subadult and adult females typically are larger than males of the same age. This character may be attributed to physiological and/or behavioral differences between the sexes. To determine if growth differences are the result of a more aggressive feeding behavior by females, four concurrent feeding trials were conducted to study the effects of gender and size on feed acquisition time. Feeding trials consisted of tanks (three replicate tanks per trial) stocked with (1) all females with small‐ and large‐size groups, (2) all males with small‐ and large‐size groups, (3) a random selection of males and females (resulting in larger females than males), and (4) males and females of equal size. Depending on the trial, tanks were stocked with either an equal number of males and females or small and large shrimp. Shrimp were fed a limited ration of squid, and the total feeding time (TFT) of shrimp between groups within a tank was compared. Results show that both gender and size are important factors in TFT as large shrimp out‐competed small shrimp in both all‐female and all‐male feeding trials. Gender is more important than size as males out‐competed females for feed even when they were smaller than competing females. These results suggest that sexual growth dimorphism is not the result of more aggressive feeding by females. In fact, males have a competitive advantage over females in acquiring feed. These results are counterintuitive because females typically are larger than males. Additional research is needed to investigate the physiological basis for sexual growth dimorphism in this commercially important shrimp.
Compensatory Growth of Juvenile Olive Flounder, Paralichthys olivaceus L., and Changes in Proximate Composition and Body Condition Indexes during Fasting and after Refeeding in Summer Season
Authors: Cho Sung Hwoan , Lee Sang‐Mok , Park Byum Hee , Ji Sung‐Choon , Lee Jinhwan , Bae Jeanhee , Oh Sung‐Yong
Published: May 2006

Compensatory growth of juvenile olive flounder, Paralichthys olivaceus L., and changes in proximate composition and body condition indexes of fish during fasting and after refeeding were investigated during the summer season. Groups of 25 fish each (initial body weight of 16 g) were randomly distributed into fifteen 180‐L flow‐through tanks. Fish were fed the experimental diet containing crude protein 46.9% and crude lipid 8.0% with estimated energy level of 14.6 kJ/g diet for 6 d/wk. Five treatments in triplicate were prepared for this study: C, S1, S2, S3, and S4. Fish in the control group (C) were hand‐fed to apparent satiation twice daily. Fish in treatments S1, S2, S3, and S4 experienced 1, 2, 3, and 4 wk of starvation and were then hand‐fed to apparent satiation twice daily during the remaining 7, 6, 5, and 4 wk of the experiment, respectively. A group of starved fish in the similar size was stocked and fasted throughout the 8‐wk feeding trial for chemical and blood analysis. The feeding trial lasted for 8 wk. Weight of fish linearly decreased with week of starvation (P < 0.0001). Linear relationship between condition factor (CF) and hepatosomatic index (HSI) against week of starvation was observed in the starved group of fish. Survival was not significantly (P > 0.05) affected by feeding strategy. However, weight gain and specific growth rate (SGR) of olive flounder in C, S1, and S2 were significantly (P < 0.05) higher than those of fish in S3 and S4. The poorest weight gain and specific growth rate (SGR) were obtained in fish of S4. Feed consumption of olive flounder in C, S1, and S2 was significantly (P < 0.05) higher than that of fish in S3 and S4. Feed efficiency, protein efficiency ratio, and protein retention of olive flounder in C and S1 were not significantly (P > 0.05) different from those of fish in S2 but significantly (P < 0.05) higher than those of fish in S3 and S4. Hematocrit, CF, and HSI of olive flounder were not significantly (P > 0.05) affected by feeding strategy. Chemical composition of fish was not significantly (P > 0.05) affected by feeding strategy. In considering these results, it can be concluded that juvenile olive flounder have the ability to fully compensate for 2‐wk feed deprivation during the summer season. Besides, feed efficiency in fish fed for 7 and 6 wk after 1‐ and 2‐wk feed deprivation was comparable to that in fish fed for 8 wk.
Proteolytic Activity in California Halibut Larvae (Paralichthys californicus)
Authors: Zacarias‐Soto Magali , Muguet Jean B. , Lazo Juan P.
Published: May 2006

The digestive tract of many marine fish larvae undergoes numerous morphological and functional changes during ontogeny that can substantially influence larval survival under culture conditions. Increasing our knowledge of the digestive capacity and nutritional requirements of the larvae of new candidate species for aquaculture will aid in the development of optimal feeding protocols and greatly improve production under hatchery conditions. In this study, we assess the proteolytic capacity of California halibut (Paralichthys californicus) larvae using biochemical and histological analyses. Newly hatched larvae were reared in a semiclosed recirculating system and fed with highly unsaturated fatty acid (HUFA)–enriched rotifers from hatching until 19 d posthatch (dph) and HUFA‐enriched Artemia nauplii thereafter. Total and specific activity of trypsin and leucine‐aminopeptidase (LAP) and acid and alkaline protease activities were assessed throughout development using spectrophotometric techniques. Trypsin‐like activity and LAP and alkaline protease activities were detected shortly after hatching and before the opening of the mouth. Acid protease activity was not detected until 36–40 dph, concomitant with the development of the gastric glands. The specific activity of trypsin and LAP showed two distinct peaks at 8 and 20 dph. The second peak coincided with the shift from rotifers to Artemia. Hence, newly hatched California halibut larvae possess alkaline proteolytic activity before first feeding. Based on the digestive capacity evaluated in this study and the timing of the development of the functional stomach, we propose that California halibut can be adequately weaned to formulated microdiets around 36 dph.
Larviculture of Red Front Shrimp, Caridina gracilirostris (Atyidae, Decapoda)
Authors: Heerbrandt Thomas C. , Lin Junda
Published: May 2006

Aquatic ornamental species trade is a growing multimillion dollar industry. Over the past several years, many freshwater shrimp have been growing in popularity in the aquarium industry. This study evaluated the larval culture of the popular aquarium red front shrimp, Caridina gracilirostris (Atyidae). We found that the optimal larval and postlarval rearing conditions were 15 ppt, 27 C, fed with a phytoplankton mixture (Phycopure), and at the stocking density of 25 per L. Under these conditions, the newly hatched larvae developed, through six zoeal stages, into postlarvae in 15 d, with a survivorship of 90 ± 8%. The postlarvae acclimated to freshwater when they reached 69 d posthatch.
Screening and Evaluation of Alum and Polymer Combinations as Coagulation/Flocculation Aids to Treat Effluents from Intensive Aquaculture Systems
Authors: Rishel Kata L. , Ebeling James M.
Published: May 2006

As the application of intensive aquaculture systems continues to grow worldwide, so does the need for environmentally sound waste management and waste disposal techniques. The use of coagulants and flocculants to assist in removing suspended solids has long been a standard in the waste treatment field. Recently, The Conservation Funds Freshwater Institute has continued its research into coagulation/flocculation aids by examining the performance of alum coupled with various commercially available polymers. Alum is efficient in sequestering phosphorus through chemical precipitation and coagulation of fine solids through charge neutralization. Synthetic polymers are efficient in flocculating small particles together but do not efficiently remove dissolved phosphorus. The specific intention of this work was to use the qualities that distinguish both the alum and the polymer individually and combine the two to optimize wastewater treatment for the removal of both suspended solids and phosphorus. The alum/polymer combinations were first screened to determine which polymers worked best with our waste and with the alum. Once the screening was completed, the six best performing combinations were further evaluated with triplicate tests in a jar test apparatus to determine a standard optimal dosage based on phosphorus and suspended solids removal. Using a combination of alum/polymer, the effluent total suspended solids (TSS) removal rate was close to 99%, with final TSS values ranging from 4 to 20 mg/L. Reactive phosphorus was reduced by 92 to 99% to as low as 0.16 mg/L‐P. Finally, total phosphorus was also significantly reduced (98%), with treated effluent concentrations from 0.9 to 3.0 mg/L‐P. Although not intended for nitrogen removal, total ammonia‐nitrogen (TAN), nitrite‐nitrogen, nitrate‐nitrogen, and total nitrogen in the effluent were reduced on average by 64, 50, 68, and 87%, respectively. Removal rates for both 5 d carbonaceous biochemical oxygen demand (CBOD5) and chemical oxygen demand (COD) were also significant, with an average value of 97.3 and 96.4%.
Resource partitioning and interspecific competition in snakes: the search for general geographical and guild patterns
Authors: Luiselli Luca
Published: May 2006

The role of interspecific competition as a key factor in the ecology of natural communities where species exploit limited resources is well established, and the study of competition dynamics in snake communities has received much attention in recent years. Twenty years ago, an acclaimed review (Toft 1985) suggested that snakes were atypical among vertebrates because sympatric species usually partition the food niche. Here, I review the articles published in the last two decades with the aim of finding any general geographical or guild patterns and assessing if Toft's main conclusion is still supported by new evidence. Where appropriate, I use Monte Carlo simulations to establish whether observed patterns of niche overlap are real, or if they have occurred by chance. My study shows clear congruence in the patterns of coexistence exhibited by snake communities in different regions of the world, i.e.: (1) cold regions of the northern hemisphere (high latitudes and altitudes) exhibit low species richness and a very low, or even absent, potential for interspecific competition; (2) aquatic snakes that form communities in temperate regions generally partition the food type available and exhibit a broad similarity in habitat use with subtle differences in microhabitat use; (3) terrestrial snake communities in temperate regions are very variable in terms of their coexistence dynamics and show no evidence of generalised patterns; (4) sympatric viperids in Europe, North America and, most interestingly, tropical Asia partition the available habitat but not the prey resource; (5) competition is much stronger in tropical snake communities, and the intensity of this process fluctuates throughout the year being most intense during periods of low food availability; (6) in general, tropical snakes partition the food resource (prey type and/or prey size), but when this resource is not partitioned competitive exclusion can occur.

Prey resource availability is a fundamental variable for all snake communities; this is clearly documented by studies on terrestrial snakes in Australia where, due to a relative scarcity of prey availability in the field, sympatry among species is much rarer than in other continents. I conclude that, although there are several notable exceptions, Toft's main conclusion is still supported by empirical evidence. However, I disagree with Toft's conclusion that most snakes are food specialists, and I contend that interspecific competition is important in structuring many (if not most) of the snake communities around the world.
What shapes amino acid and sugar composition in Mediterranean floral nectars?
Authors: Petanidou Theodora , Van Laere André , N. Ellis Willem , Smets Erik
Published: May 2006

We studied the amino acid (AA) composition of the floral nectars of 73 plant species occurring in a phryganic (East Mediterranean garrigue) community and investigated whether AA and sugar composition is shaped by evolutionary (plant phylogeny), ecological (flowering time as a direct effect of summer drought) and coevolutionary (pollinator partnership) constraints. Our study utilised an extensive plant–pollinator matrix compiled in the same area where the plants had been sampled.

Using HPLC we detected 22 AA compounds/groups of compounds, out of which 15 were commonly present in almost all nectars. Among all AAs, phenylalanine was the most abundant, especially in keystone (“cornucopian”) plant species visited by many insect species, such as the majority of the Lamiaceae. Amino acid quantities were transformed into percentages (% of each AA over the total AA content of a flower). Sugar composition was similarly expressed as % of each of the three sugars (glucose, fructose, sucrose) over the total content of these sugars; a number of other sugars, occurring in only a few plant species and in very low quantities were disregarded. The number of insect species of a particular family or guild was taken as a measure of the attraction of a nectar compound for such a family (guild).

We found that taxonomical plant group had a weakly significant effect on nectar composition while neither life form nor flowering season had a discernable effect. Pollinators’ preference had the most important effect, with phenylalanine being the most consequent discriminatory compound for the response of the nectar consumers in phrygana, predominantly for long tongued bees, especially for Megachilidae. Gamma‐aminobutyric acid (GABA) had a similar, even stronger influence on bees (long tongued bees, Anthophoridae, Andrenidae) and flies (Syrphidae and other Diptera), whereas asparagine behaved as a general repellent together with tryptophane (rather as repellent). Considering total sugar and AA contents, as well as the volume of nectar, we found that total AA content was positively related to the number of species of long tongued bees and included families visiting the phryganic species; nectar volume was negatively related to flies (both hover flies and remaining Diptera), whereas total sugar content was not significant for any guild. We argue that due to the highly concentrated nectars in the dry Mediterranean communities that are characterised by outstanding melittophily, sugars play a less important role as phagostimulants compared to AAs in floral nectars. This is why phenylalanine, a phagostimulant tested earlier on honeybees, appears to be of high importance in phrygana, especially with long tongued bees and Megachilids as the main selective agents for phenylalanine‐rich nectars. The role of GABA, a strongly NaCl‐dependent AA, may be similar, probably because of the associated presence of NaCl.