bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECTS OF ULTRA‐RAPID CHILLING AND ELECTRICAL STIMULATION ON THE TENDERNESS OF LAMB CARCASS MUSCLES
Authors: SHERIDAN J.J. , McGEEHIN B. , BUTLER F.
Published: May 2007

Forty lambs were slaughtered in chilling experiments which used air temperatures of 4C and ‐20C. Low voltage electrical stimulation was used on 20 of the carcasses. Tenderness assessment was done on leg carcass muscles (M. biceps femoris, M. gluteus medius and M. semimembranosus) and on the M. longissimus lumborum. Muscle tenderness from ultra‐rapid chilling was not different from conventional chilling. Electrical stimulation had no effects on the tenderness of leg muscles but it resulted in more tender M. longissirnus lumborum than nonelectrically stimulated carcasses on day I postmortem. After further aging to day 5, these differences were no longer present. Muscle sarcomere length was a poor predictor of tenderness.
A RESEARCH NOTE DIETARY SUPPLEMENTATION OF VITAMIN E AFFECTS THE PEROXIDE VALUE OF SUBCUTANEOUS LAMB FAT
Authors: LI C.‐T. , WICK M. , MARRIOTT N.G. , McCLURE K.E.
Published: May 2007

Lipid oxidation is a major problem causing flavor deterioration in meat products. The objective of this research was to utilize an iodometric peroxide value method (PV) to analyze the effects of dietary Vitamin E on lipid oxidation of subcutaneous lamb fat. Peroxide value analyses demonstrated lower lipid oxidation in the fat from animals fed 300 IU (7 days and 21 days) of Vitamin E than in the fat from animals fed diets supplemented with 15 IU (control) (P < 0.05). At 9 and II days of storage, PV analyses also demonstrated a greater rate of increase (P < 0.05) in lipid oxidation in fat from lambs fed control diets than in fat from animals fed 300 IU of Vitamin E. Results indicate that higher dietaty Vitamin E for either 7 days or 21 days antemortem reduced the rate and initiation of lipid oxidation in subcutaneous lamb fat.
UTILIZATION OF RESPONSE SURFACE MODELING TO EVALUATE THE EFFECTS OF NONMEAT ADJUNCTS AND COMBINATIONS OF PSE AND RFN PORK ON THE TEXTURE OF BONELESS CURED PORK
Authors: SCHILLING M. W. , MARRIOTT N. G. , ACTON J. C. , ANDERSON‐COOK C. , DUNCAN S. E. , ALVARADO C. Z.
Published: May 2007

Combinations of pale, sop, and exudative (PSE) and red, firm. and nonexudative (RFN) semimembranosus muscle were utilized to manufacture chunked and formed, cured pork. Response Surface Methodology was utilized to investigate the effects of soy protein concentrate (SPC), sodium caseinate (SC), and modified food starch (MFS) on bind and texture profile analysis. Fifteen adjunct formulations for five PSE and RFN combinations provided 75 treatments for each of three replications. As CIE L* values of raw muscle increased, protein‐protein bind decreased (P<0.05). MFS, SC, and SPC decreased (P<0.05) cohesiveness. MFS and SC decreased (P<0.05) chewiness, and MFS decreased (P<0.05) hardness. Utilizing these adjuncts demonstrated that MFS improved texture in PSE and RFN pork. This research demonstrated that diluting RFN pork with no more than 25% PSE pork permits the formation of a high quality boneless deli ham roll.
THE EFFECT OF ORGANIC ACID MARINATION ON TENDERNESS, COOKING LOSS AND BOUND WATER CONTENT OF BEEF
Authors: AKTAŞ N. , AKSU M. I. , KAYA M.
Published: May 2007

Longissimus muscle obtained from beef carcasses was used in this research. Initially, 0.596, 1.0% and 1.5% lactic and citric acid solutions were prepared. Meat was marinated in these solutions (1:4 w/v) in polyethylene bags at 4C for 72h. Bound water, pH, weight gain, cooking loss and Warner Bratzler shear (WBS) were evaluated. Differential Scanning Calorimetry (DSC) was used to determine the bound water content in meat samples. The latent heat of melting (ΔHm) and bound water were found to be functions of moisture content of marinated meat. There was a significant decrease in pH due to marination. Compared to lactic acid, the samples marinated with citric acid held less water. The WS values in control samples were higher than in marinated samples. Cooking loss was lower in samples marinated with lactic acid compared to citric acid marinated samples.
EFFECT OF RN GENOTYPE ON YIELD AND SENSORY CHARACTERISTICS OF ENHANCED LONGISSIMUS SECTIONS
Authors: BIDNER B. S. , ELLIS M. , BREWER M. S. , ROMANS J. , MCKEITH F. K.
Published: May 2007

Pumping treatments with water or 4.5% sodium tripolyphosphate (STP) were evaluated on the fresh longissimus from pigs of different Rendement Napole genotypes. The longissimus muscle (32 RN/rn, 32 rn+/rn+) was divided into 3 sections and allocated to the: nonpumped, water pumped, and 4.5% STP, treatments. Following aging (14 days) chops were cut, packaged, and frozen. Boneless loin chops were cooked to internal temperatures of either 70C or 80C. Nonpumped loins resulted in the least amount of purge loss, whereas STP loins had the highest raw yield. Pumping loin sections with water and STP increased raw and cooked moisture contents. Pumping with STP increased juiciness and tenderness ratings. Increasing the endpoint temperature decreased juiciness and cooked moisture percentage. Pork from RN/rn+ pigs had lower shear force and higher tenderness and juiciness. These data indicate that increasing end point cooking temperature reduced pork palatability while STP pumping and the RN gene improved sensory properties.
COMPARISON OF MUSCLE COMPOSITION AND MEAT QUALITY TRAITS IN DIVERSE COMMERCIAL LAMB TYPES1
Authors: BERGE P. , SAÑUDO C. , SANCHEZ A. , ALFONSO M. , STAMATARIS C. , THORKELSSON G. , PIASENTIER E. , FISHER A. V.
Published: May 2007

Twenty‐two groups of lambs representative of local production were selected from six European countries. Considerable differences were observed between lamb types in the chemical composition (pigment, total lipids, collagen) and the textural traits (instrumental) of the meat in the M. longissimus muscle. Collagen heat solubility also differed among lamb types (range 21 to 50%) and showed a close relationship with animal age (r =−0.67; P < 0.001). Cooked meat toughness ranged from 1.6 to 4.1 kg. cm−2 peak shear stress value. The toughest lamb types included the oldest lambs (age 12 months) and three types of milk fed lamb that were among the four youngest types studied (age < 2.5 months). The data showed that the occurrence of tough lamb was associated with the combination of at least two of the following muscle characteristics: high myofibrillar strength or low extent of postmortem tenderization, high ultimate pH value, high collagen content and short sarcomeres. No evidence was found, however, that meat toughness was related to muscte lipid content or collagen heat stability.
EFFECT OF CHLORINATED WASH WATER ON QUALITY OF HEAT SHOCKED MUSSEL MEAT
Authors: AZANZA MA. PATRICIA V. , AZANZA RHODORA V. , VENTURA SHARON R.
Published: May 2007

Chlorine‐assisted chilled tumble washing of green mussel meats was done using 5 and 10ppm chlorine solutions maintained at 5 and 10C for 3 min. No significant difference (P < 0.05) was established in terms of meat yield, pH, Aw or sensory qualities for tumble washed samples. The mussel meats were given sensory acceptance ratings of up to “like slightly”. A 2% weight gain of mussel meats was established after washing. Heat shocking in tandem with tumble washing affected 1–3 unit log reduction in TPC and coliform counts and about a 4 log reduction in Vibrio spp. counts of mussel meats. The 2 protocols were presented as value‐adding steps to improve mussel meat quality. Philippine micro‐ and small‐scale shellfish processors and vendors were identified as potential users of the technology presented in the study.
Stochastic Hydrogeology: What Professionals Really Need?
Authors: Renard Philippe
Published: May 2007

Quantitative hydrogeology celebrated its 150th anniversary in 2006. Geostatistics is younger but has had a very large impact in hydrogeology. Today, geostatistics is used routinely to interpolate deterministically most of the parameters that are required to analyze a problem or make a quantitative analysis. In a small number of cases, geostatistics is combined with deterministic approaches to forecast uncertainty. At a more academic level, geostatistics is used extensively to study physical processes in heterogeneous aquifers. Yet, there is an important gap between the academic use and the routine applications of geostatistics. The reasons for this gap are diverse. These include aspects related to the hydrogeology consulting market, technical reasons such as the lack of widely available software, but also a number of misconceptions. A change in this situation requires acting at different levels. First, regulators must be convinced of the benefit of using geostatistics. Second, the economic potential of the approach must be emphasized to customers. Third, the relevance of the theories needs to be increased. Last, but not least, software, data sets, and computing infrastructure such as grid computing need to be widely available.
Use of decision rules for osteoporosis prevention and treatment: Implications for nurse practitioners
Authors: Anders Michael , Turner Lori , Wallace Lorraine Silver
Published: May 2007

Purpose: To describe the current literature regarding the benefits of bone mineral density (BMD) screening and to discuss clinical decision rules for BMD screening.

Data sources: Extensive review of the scientific literature regarding osteoporosis, BMD screening, and current clinical decision rules.

Conclusions: Osteoporosis is a disease characterized by deterioration of bone and increased susceptibility to fractures, crippling, and disfigurement. BMD testing is the best predictor for osteoporosis and associated fractures; however, routine global BMD testing is cost‐prohibitive. A need exists for a selective and practical clinical decision rule for referral for testing.

Implications for practice: Several effective clinical decision rules are presented, and their uses and applications are described. The osteoporosis self‐assessment tool is recommended by the authors because of its predictive power and ease of use.
Does border enforcement deter unauthorized immigration? The case of Mexican migration to the United States of America
Authors: Cornelius Wayne A. , Salehyan Idean
Published: May 2007

This paper asks whether the migration decisions of unauthorized Mexican immigrants to the USA have been influenced by stronger US border enforcement efforts since 1993 that have sharply increased the physical risk and financial cost of illegal immigration. These measures were supposed to have decreased the probability of successful entry, thereby lowering the expected benefits of migration. We carried out a logistic regression analysis of data from a recent survey of 603 returned migrants and potential first‐time migrants in rural Mexico. Our findings indicate that tougher border controls have had remarkably little influence on the propensity to migrate illegally to the USA. Political restrictions on immigration are far outweighed by economic and family‐related incentives to migrate. An alternative, labor‐market approach to immigration control with higher probability of effectiveness is outlined.
Meat and Bone Meal as Partial Substitute for Fish Meal in Nursery Diet for Giant Freshwater Prawn, Macrobrachium rosenbergii (de Man)
Authors: Arshad Hossain M. , Farzana Islam S.
Published: May 2007

An experiment was conducted for 60 d in a recirculatory system consisting of 20 glass aquariums (each of size 41 × 41 × 46 cm) to evaluate meat and bone meal (MBM) as partial replacement for fish meal (FM) in Macrobrachium rosenbergii postlarvae (PLs) with a view to develop an inexpensive nursery diet. Three nursery diets were formulated to contain 32% protein and to be as isoenergetic as possible. FM in these diets was progressively replaced with MBM (Diet 1 contained 25% FM and 14% MBM, Diet 2 contained 20% FM and 20% MBM, and Diet 3 contained 15% FM and 26% MBM). Inclusion levels of mustard oilcake and sesame meal in diets were kept fixed at 10%. A commercial shrimp nursery diet (30% protein) from Saudi Bangla Fish Feed Ltd., Mymensingh, was used as the reference diet (Diet 4). Each treatment had three replicates. PLs of M. rosenbergii (26 ± 0.02 mg) were stocked at the rate of 60 PLs (1 PL/L) in each aquarium. At the beginning, PLs were fed three times daily at a rate of 20% of the body weight and it was gradually reduced to 10% at Day 30. The ranges of water quality parameters in the system were as follows: temperature, 27–29 C; dissolved oxygen, 6.5–8.4 mg/L; pH, 6.8–8.3; and total ammonia, 0.01–0.15 mg/L. The result of the study showed that there was no significant difference (P > 0.05) between the weight gains of PLs fed Diet 1 (containing 14% MBM) and Diet 4 (reference diet) but was significantly higher than other dietary groups containing higher levels of MBM. Diets 1 and 4 showed significantly lower (P < 0.05) apparent food conversion ratios (1.74 and 1.73, respectively). The survival (%) of PLs ranged between 62 and 76% with PLs fed Diets 1 and 4 showing significantly higher (P < 0.05) survival. The result of the study demonstrated that the MBM could be included at 14% level in a nursery diet, and a diet containing 25% FM, 14% MBM, 10% sesame meal, and 10% mustard oilcake may be recommended for profitable production of PLs of M. rosenbergii.
Catchment Classification and Hydrologic Similarity
Authors: Wagener Thorsten , Sivapalan Murugesu , Troch Peter , Woods Ross
Published: May 2007

Hydrology does not yet possess a generally agreed upon catchment classification system. Such a classification framework should provide a mapping of landscape form and hydro‐climatic conditions on catchment function (including partition, storage, and release of water), while explicitly accounting for uncertainty and for variability at multiple temporal and spatial scales. This framework would provide an organizing principle, create a common language, guide modeling and measurement efforts, and provide constraints on predictions in ungauged basins, as well as on estimates of environmental change impacts. In this article, we (i) review existing approaches to define hydrologic similarity and to catchment classification; (ii) discuss outstanding components or characteristics that should be included in a classification scheme; and (iii) provide a basic framework for catchment classification as a starting point for further analysis. Possible metrics to describe form, hydro‐climate, and function are suggested and discussed. We close the discussion with a list of requirements for the classification framework and open questions that require addressing in order to fully implement it. Open questions include: How can we best represent characteristics of form and hydro‐climatic conditions? How does this representation change with spatial and temporal scale? What functions (partition, storage, and release) are relevant at what spatial and temporal scale? At what scale do internal structure and heterogeneity become important and need to be considered?
The Business Improvement District Model: A Balanced Review of Contemporary Debates
Authors: Hoyt Lorlene , Gopal‐Agge Devika
Published: May 2007

This article presents an overview of the burgeoning literature on business improvement districts (BID) by highlighting its historical underpinnings, identifying the economic and political factors that explain its transnational proliferation, and demonstrating how the model varies within and across nations. It also provides a balanced review of the key debates associated with this relatively new urban revitalization strategy by asking the following questions: Are BIDs democratic? Are BIDs accountable? Do BIDs create wealth‐based inequalities in the delivery of public services? Do BIDs create spillover effects? Do BIDs over‐regulate public space?
Model answers or trivial pursuits? The role of mathematical models in influenza pandemic preparedness planning
Authors: McVernon J , McCaw CT , Mathews JD
Published: May 2007

The panzootic of H5N1 influenza in birds has raised concerns that the virus will mutate to spread more readily in people, leading to a human pandemic. Mathematical models have been used to interpret past pandemics and outbreaks, and to thus model possible future pandemic scenarios and interventions. We review historical influenza outbreak and transmission data, and discuss the way in which modellers have used such sources to inform model structure and assumptions. We suggest that urban attack rates in the 1918–1919 pandemic were constrained by prior immunity, thatR0for influenza is higher than often assumed, and that control of any future pandemic could be difficult in the absence of significant prior immunity. In future, modelling assumptions, parameter estimates and conclusions should be tested against as many relevant data sets as possible. To this end, we encourage researchers to access FluWeb, an on‐line influenza database of historical pandemics and outbreaks.
Rationale for treating human influenza infections by passive transfer of specific antibodies
Authors: Virelizier Jean‐Louis
Published: May 2007

The fear of a potential pandemic with a highly pathogenic influenza A virus, such as the avian virus H5N1, has rightly prompted multidisciplinary reflections and calls for better preparedness all over the world. In terms of therapeutic aspects, most of the focus has been on vaccines and antivirals. The present ‘opinion paper’ intends to discuss a different therapeutic approach, although not mutually exclusive to the two others quoted above. We here propose an approach, based on well‐documented experimental evidence in animal models, in which a short series of human monoclonal antibodies adapted to the probable pandemic strain, specific for external antigens of that influenza virus and shown in vitro and in experimental models to have neutralizing properties, are prepared and stockpiled for administration to people recently exposed to the pandemic virus.
The main source of ambient GABA responsible for tonic inhibition in the mouse hippocampus
Authors: Glykys Joseph , Mody Istvan
Published: May 2007

The extracellular space of the brain contains γ‐aminobutyric acid (GABA) that activates extrasynaptic GABAA receptors mediating tonic inhibition. The source of this GABA is uncertain: it could be overspill of vesicular release, non‐vesicular leakage, reverse transport, dying cells or glia. Using a novel approach, we simultaneously measured phasic and tonic inhibitory currents and assessed their correlation. Enhancing or diminishing vesicular GABA release in hippocampal neurons caused highly correlated changes in the two inhibitions. During high‐frequency phasic inhibitory bursts, tonic current was also enhanced as shown by simulating the summation of IPSCs and by recordings in knockout mice devoid of tonic inhibitory current. When vesicular release was reduced by blocking action potentials or the vesicular GABA transporter, phasic and tonic currents decreased in a correlated fashion. Our results are consistent with most of hippocampal tonic inhibitory current being mediated by GABA released from the very vesicles responsible for activating phasic inhibition.
The Effect of Cross-Sectional Stem Shape on the Torsional Stability of Cemented Implant Components
Authors: Kedgley Angela E. , Takaki Sarah E. , Lang Pencilla , Dunning Cynthia E.
Published: May 2007

Stability of a cemented implant, once the stem-cement interface has debonded, is reliant upon stem geometry and surface finish. There are relatively few studies addressing the effect of cross-sectional stem shape on cemented implant fixation. The purpose of this investigation was to compare the torsional stability of five different stem cross-sectional shapes—circular, oval, triangular, rectangular with rounded edges, and rectangular with sharp edges—under monotonically increasing and cyclic loading conditions. Seven samples of each stem geometry were tested. Stems were potted in bone cement and loaded to 5 deg of rotation. For monotonic loading, torque was applied at a constant rate of 2.5 deg/min. For cyclic loading, a sine wave torque pattern was applied, with a maximum magnitude that began at 4.5 Nm for 1500 cycles and then increased by 2.25 Nm every 1500 cycles until 5 deg of rotation. The rectangular stem with the sharp edges always provided the greatest resistance to torque, followed by the rectangular with rounded edges, triangular, oval, and circular. These results, including the effects of sharp corners, may differ for modes of loading other than torsion. These experimental results support the findings of earlier finite element models, indicating stem shape has a significant effect on resistance to torsional loading.
Change in Properties of the Glycocalyx Affects the Shear Rate and Stress Distribution on Endothelial Cells
Authors: Wang Wen
Published: May 2007

The endothelial glycocalyx mediates interactions between the blood flow and the endothelium. This study aims to evaluate, quantitatively, effects of structural change of the glycocalyx on stress distribution and shear rate on endothelial cells. In the study, the endothelial glycocalyx is modeled as a surface layer of fiber matrix and when exposed to laminar shear flow, the matrix deforms. Fluid velocity and stress distribution inside the matrix and on cell membranes are studied based on a binary mixture theory. Parameters, such as the height and porosity of the matrix and the drag coefficient between fluid and matrix fibrils, are based on available data and estimation from experiments. Simple theoretical solutions are achieved for fluid velocity and stress distribution in the surface matrix. Degradation of the matrix, e.g., by enzyme digestion, is represented by reductions in the volume fraction of fibrils, height, and drag coefficient. From a force balance, total stress on endothelial surface remains constant regardless of structural alteration of the glycocalyx. However, the stress that is transmitted to endothelial cells by direct “pulling” of fiber branches of the glycocalyx is reduced significantly. Fluid shear rate at the cell membrane, on the other hand, increases. The study gives quantitative insight into the effect of the structural change of the glycocalyx on the shear rate and pulling stress on the endothelium. Results can be used to interpret experiments on effects of the glycocalyx in shear induced endothelial responses.
Numerical Simulation on Mass Transport in a Microchannel Bioreactor for Co-culture Applications
Authors: Zeng Yan , Lee Thong-See , Yu Peng , Low Hong-Tong
Published: May 2007

Microchannel bioreactors have applications for manipulating and investigating the fluid microenvironment on cell growth and functions in either single culture or co-culture. This study considers two different types of cells distributed randomly as a co-culture at the base of a microchannel bioreactor: absorption cells, which only consume species based on the Michaelis-Menten process, and release cells, which secrete species, assuming zeroth order reaction, to support the absorption cells. The species concentrations at the co-culture cell base are computed from a three-dimensional numerical flow-model incorporating mass transport. Combined dimensionless parameters are proposed for the co-culture system, developed from a simplified analysis under the condition of decreasing axial-concentration. The numerical results of species concentration at the co-culture cell-base are approximately correlated by the combined parameters under the condition of positive flux-parameter. Based on the correlated results, the critical value of the inlet concentration is determined, which depends on the effective microchannel length. For the flow to develop to the critical inlet concentration, an upstream length consisting only of release cells is needed; this upstream length is determined from an analytical solution. The generalized results may find applications in analyzing the mass transport requirements in a co-culture microchannel bioreactor.
Multiphysics Simulation of Blood Flow and LDL Transport in a Porohyperelastic Arterial Wall Model
Authors: Koshiba Nobuko , Ando Joji , Chen Xian , Hisada Toshiaki
Published: May 2007

Atherosclerosis localizes at a bend and∕or bifurcation of an artery, and low density lipoproteins (LDL) accumulate in the intima. Hemodynamic factors are known to affect this localization and LDL accumulation, but the details of the process remain unknown. It is thought that the LDL concentration will be affected by the filtration flow, and that the velocity of this flow will be affected by deformation of the arterial wall. Thus, a coupled model of a blood flow and a deformable arterial wall with filtration flow would be invaluable for simulation of the flow field and concentration field in sequence. However, this type of highly coupled interaction analysis has not yet been attempted. Therefore, we performed a coupled analysis of an artery with multiple bends in sequence. First, based on the theory of porous media, we modeled a deformable arterial wall using a porohyperelastic model (PHEM) that was able to express both the filtration flow and the viscoelastic behavior of the living tissue, and simulated a blood flow field in the arterial lumen, a filtration flow field and a displacement field in the arterial wall using a fluid-structure interaction (FSI) program code by the finite element method (FEM). Next, based on the obtained results, we further simulated LDL transport using a mass transfer analysis code by the FEM. We analyzed the PHEM in comparison with a rigid model. For the blood flow, stagnation was observed downward of the bends. The direction of the filtration flow was only from the lumen to the wall for the rigid model, while filtration flows from both the wall to the lumen and the lumen to the wall were observed for the PHEM. The LDL concentration was high at the lumen∕wall interface for both the PHEM and rigid model, and reached its maximum value at the stagnation area. For the PHEM, the maximum LDL concentration in the wall in the radial direction was observed at the position of 3% wall thickness from the lumen∕wall interface, while for the rigid model, it was observed just at the lumen∕wall interface. In addition, the peak LDL accumulation area of the PHEM moved about according to the pulsatile flow. These results demonstrate that the blood flow, arterial wall deformation, and filtration flow all affect the LDL concentration, and that LDL accumulation is due to stagnation and the presence of filtration flow. Thus, FSI analysis is indispensable.
Measurement of Impact Loads Applied to an Implanted Drug Pump Connector in a Porcine Cadaver Specimen
Authors: Bischoff Thomas C. , Martens Marty D. , Adams Matthew H. , Gallagher William J. , Iaizzo Paul A.
Published: May 2007

Anecdotal and documented reports from both patients and doctors have described unanticipated breaks in connections between implanted catheters and drug pumps. In extreme cases, such disconnections in patient-required therapies could result in either withdrawal symptoms or possible deaths. Patients typically attribute such device failures to falls or impacts associated with vigorous physical activity; subsequent failure analyses most often have indicated pump connector uncouplings. We fabricated a facsimile of the Medtronic®SynchroMed® II pump that included both an accelerometer and a force sensor. The force sensor measured forces imparted on the pump connector via the attached catheter and surrounding tissues. The test pump was implanted in the lower left abdominal areas of porcine cadavers in various orientations. Wire-reinforced catheters were tunneled for 20–25cm under the abdominal epidermis, anteriorly toward the head, and the non-connector pump ends were secured by sutures. Following each simulated implant, the cadaver specimens were loaded into a harness and hoisted to a height where either their buttocks or backs were 80–86cm above the floor, simulating a worst-case scenario in which a patient might have fallen down a flight of stairs or off a step stool. The cadavers were then quick released from the hoist attachment, while forces (X, Y, and Z) and accelerations (X, Y, and Z) versus time were simultaneously recorded. Six porcine cadaver specimens were utilized for a total of 72 trials. Subsequent Monte Carlo analyses allowed us to model the variation in stress imparted onto the pump connectors and the estimated variation of the pump connector strength, as a means of predicting required connector retention impact specification for future designs. The recorded forces applied onto the connectors, including data from all three connector axes (X, Y, and Z), were typically within the range of 4.5–9N. However, in several trials, applied forces ranged as high as 30–49N. Monte Carlo modeling provided a maximum resultant load specification of 100.4N for a 0.033msec duration. Based on this value, due to predicted impact events, subsequent failures of future designs would be estimated at 7ppm. Based on our data, a new design requirement has been generated to ensure that implantable drug pump connector assemblies will, in high probability, perform their intended functions.
Abraxas and RAP80 Form a BRCA1 Protein Complex Required for the DNA Damage Response
Authors: Wang Bin , Matsuoka Shuhei , Ballif Bryan A. , Zhang Dong , Smogorzewska Agata , Gygi Steven P. , Elledge Stephen J.
Published: May 2007

The BRCT repeats of the breast and ovarian cancer predisposition protein BRCA1 are essential for tumor suppression. Phosphopeptide affinity proteomic analysis identified a protein, Abraxas, that directly binds the BRCA1 BRCT repeats through a phospho-Ser-X-X-Phe motif. Abraxas binds BRCA1 to the mutual exclusion of BACH1 (BRCA1-associated C-terminal helicase) and CtIP (CtBP-interacting protein), forming a third type of BRCA1 complex. Abraxas recruits the ubiquitin-interacting motif (UIM)–containing protein RAP80 to BRCA1. Both Abraxas and RAP80 were required for DNA damage resistance, G
2
-M checkpoint control, and DNA repair. RAP80 was required for optimal accumulation of BRCA1 on damaged DNA (foci) in response to ionizing radiation, and the UIM domains alone were capable of foci formation. The RAP80-Abraxas complex may help recruit BRCA1 to DNA damage sites in part through recognition of ubiquitinated proteins.
Evolution and Development of Inflorescence Architectures
Authors: Prusinkiewicz Przemyslaw , Erasmus Yvette , Lane Brendan , Harder Lawrence D. , Coen Enrico
Published: May 2007

To understand the constraints on biological diversity, we analyzed how selection and development interact to control the evolution of inflorescences, the branching structures that bear flowers. We show that a single developmental model accounts for the restricted range of inflorescence types observed in nature and that this model is supported by molecular genetic studies. The model predicts associations between inflorescence architecture, climate, and life history, which we validated empirically. Paths, or evolutionary wormholes, link different architectures in a multidimensional fitness space, but the rate of evolution along these paths is constrained by genetic and environmental factors, which explains why some evolutionary transitions are rare between closely related plant taxa.
Engineering Complex Dynamical Structures: Sequential Patterns and Desynchronization
Authors: Kiss István Z. , Rusin Craig G. , Kori Hiroshi , Hudson John L.
Published: May 2007

We used phase models to describe and tune complex dynamic structures to desired states; weak, nondestructive signals are used to alter interactions among nonlinear rhythmic elements. Experiments on electrochemical reactions on electrode arrays were used to demonstrate the power of mild model-engineered feedback to achieve a desired response. Applications are made to the generation of sequentially visited dynamic cluster patterns similar to reproducible sequences seen in biological systems and to the design of a nonlinear antipacemaker for the destruction of pathological synchronization of a population of interacting oscillators.
Evidence for a Late Supernova Injection of
60
Fe into the Protoplanetary Disk
Authors: Bizzarro Martin , Ulfbeck David , Trinquier Anne , Thrane Kristine , Connelly James N. , Meyer Bradley S.
Published: May 2007

High-precision
60
Fe-
60
Ni isotope data show that most meteorites originating from differentiated planetesimals that accreted within 1 million years of the solar system's formation have
60
Ni/
58
Ni ratios that are ∼25 parts per million lower than samples from Earth, Mars, and chondrite parent bodies. This difference indicates that the oldest solar system planetesimals formed in the absence of
60
Fe. Evidence for live
60
Fe in younger objects suggests that
60
Fe was injected into the protoplanetary disk ∼1 million years after solar system formation, when
26
Al was already homogeneously distributed. Decoupling the first appearance of
26
Al and
60
Fe constrains the environment where the Sun's formation could have taken place, indicating that it occurred in a dense stellar cluster in association with numerous massive stars.
Dicamba Resistance: Enlarging and Preserving Biotechnology-Based Weed Management Strategies
Authors: Behrens Mark R. , Mutlu Nedim , Chakraborty Sarbani , Dumitru Razvan , Jiang Wen Zhi , LaVallee Bradley J. , Herman Patricia L. , Clemente Thomas E. , Weeks Donald P.
Published: May 2007

The advent of biotechnology-derived, herbicide-resistant crops has revolutionized farming practices in many countries. Facile, highly effective, environmentally sound, and profitable weed control methods have been rapidly adopted by crop producers who value the benefits associated with biotechnology-derived weed management traits. But a rapid rise in the populations of several troublesome weeds that are tolerant or resistant to herbicides currently used in conjunction with herbicide-resistant crops may signify that the useful lifetime of these economically important weed management traits will be cut short. We describe the development of soybean and other broadleaf plant species resistant to dicamba, a widely used, inexpensive, and environmentally safe herbicide. The dicamba resistance technology will augment current herbicide resistance technologies and extend their effective lifetime. Attributes of both nuclear- and chloroplast-encoded dicamba resistance genes that affect the potency and expected durability of the herbicide resistance trait are examined.
Views regarding the training of ethics consultants: a survey of physicians caring for patients in ICU
Authors: Chwang Eric , Landy David C , Sharp Richard R
Published: May 2007

Background:Despite the expansion of ethics consultation services, questions remain about the aims of clinical ethics consultation, its methods and the expertise of those who provide such services.

Objective:To describe physicians’ expectations regarding the training and skills necessary for ethics consultants to contribute effectively to the care of patients in intensive care unit (ICU).

Design:Mailed survey.

Participants:Physicians responsible for the care of at least 10 patients in ICU over a 6-month period at a 921-bed private teaching hospital with an established ethics consultation service. 69 of 92 (75%) eligible physicians responded.

Measurements:Importance of specialised knowledge and skills for ethics consultants contributing to the care of patients in ICU; need for advanced disciplinary training; expectations regarding formal-training programmes for ethics consultants.

Results:Expertise in ethics was described most often as important for ethics consultants taking part in the care of patients in ICU, compared with expertise in law (p<0.03), religious traditions (p<0.001), medicine (p<0.001) and conflict-mediation techniques (p<0.001). When asked about the formal training consultants should possess, however, physicians involved in the care of patients in ICU most often identified advanced medical training as important.

Conclusions:Although many physicians caring for patients in ICU believe ethics consultants must possess non-medical expertise in ethics and law if they are to contribute effectively to patient care, these physicians place a very high value on medical training as well, suggesting a “medicine plus one” view of the training of an ideal ethics consultant. As ethics consultation services expand, clear expectations regarding the training of ethics consultants should be established.
Placebos: the nurse and the iron pills
Authors: Ambrose Ella Grace
Published: May 2007

In sub-Saharan Africa, a nurse gives iron pills as placebos to terminally ill patients. She tells them, acting in what she believes is in their best interests, “these will make you feel better”. The patients believe it will help their AIDS and their well-being improves. Do the motive and the patient’s positive outcome in well-being make the deceit justifiable when other issues such as consent, autonomy and potential consequences regarding the patient and the wider community are considered? Is there a difference between lying and non-lying deception when the end result is the same? The patients feel better, but at what cost if the deceit was found out? It will be argued that although the actions of the nurse are understandable and to some extent defensible, they are unethical. It is not ethically acceptable to take away the patient’s autonomy and risk the health of the community even though the risk of deceit being discovered is a small one.
Moral theories in teaching applied ethics
Authors: Lawlor Rob
Published: May 2007

It is argued, in this paper, that moral theories should not be discussed extensively when teaching applied ethics. First, it is argued that, students are either presented with a large amount of information regarding the various subtle distinctions and the nuances of the theory and, as a result, the students simply fail to take it in or, alternatively, the students are presented with a simplified caricature of the theory, in which case the students may understand the information they are given, but what they have understood is of little or no value because it is merely a caricature of a theory. Second, there is a methodological problem with appealing to moral theories to solve particular issues in applied ethics. An analogy with science is appealed to. In physics there is a hope that we could discover a unified theory of everything. But this is, of course, a hugely ambitious project, and much harder than, for example, finding a theory of motion. If the physicist wants to understand motion, he should try to do so directly. We would think he was particularly misguided if he thought that, to answer this question, he first needed to construct a unified theory of everything.
Spectral absorbance, structure, and population density of photoreceptors in the retina of the lake sturgeon (Acipenser fulvescens)
Authors: Sillman A.J. , Ong E.K. , Loew E.R.
Published: May 2007

Lake sturgeon ( Acipenser fulvescens Rafinesque, 1817) photoreceptors were studied with scanning electron microscopy and microspectrophotometry. The retina contains both rods and cones, with cones estimated composing about 30% of the photoreceptor population. Only large single cones were identified and they are similar to those found in other species of the order Acipenseriformes. The rods are large, with long, broad outer segments, and are similar to the dominant rod found in other sturgeons and the North American paddlefish ( Polyodon spathula (Walbaum, 1792)). Mean (SD) rod packing density at 22 624 ± 3 509 rods/mm2 is low compared with those of other animals that function primarily in dim light. The visual pigment of the rods has a mean (SD) peak absorbance (λmax) at 541 ± 2 nm. Three different cone populations were identified: a long wavelength sensitive cone containing a visual pigment with λmax at 619 ± 3 nm; middle wavelength sensitive cone with λmax at 538 ± 1 nm; and short wavelength sensitive cone with λmax at 448 ± 1 nm. All the visual pigments are based on the vitamin A2 chromophore.
Importance of diel behaviour when studying habitat selection: examples from female Scandinavian brown bears (Ursus arctos)
Authors: Moe T.F. , Kindberg J. , Jansson I. , Swenson J.E.
Published: May 2007

The goal of habitat selection studies is to identify important habitats for a particular species. However, most studies using radiotelemetry have focused on habitat-selection patterns using daytime positions only. We used 24 h data from six female brown bears ( Ursus arctos L., 1758) equipped with GPS–GSM collars and activity loggers to analyse variations in habitat selection related to diel variations in activity (foraging and resting). We found that the bears rested mainly during the daylight hours and foraged mainly during the crepuscular and nocturnal hours. The bears selected habitats differently when they were resting than when they were foraging. We found no selection for tall coniferous forest using all data, but this habitat was selected by resting bears and avoided by foraging bears. Thus, for studies of habitat selection, our results show the importance of obtaining data from all 24 h and dividing these data into relevant categories based on the diel activity pattern of the studied species.
Gastrointestinal dysfunction induced by early weaning is attenuated by delayed weaning and mast cell blockade in pigs
Authors: Moeser Adam J. , Ryan Kathleen A. , Nighot Prashant K. , Blikslager Anthony T.
Published: May 2007

Our previous work has demonstrated that weaning at 19 days of age has deleterious effects on mucosal barrier function in piglet intestine that are mediated through peripheral CRF receptor signaling pathways. The objectives of the present study were to assess the impact of piglet age on weaning-associated intestinal dysfunction and to determine the role that mast cells play in weaning-induced breakdown of mucosal barrier function. Nursing Yorkshire-cross piglets were either weaned at 19 days of age (early-weaned, n = 8) or 28 days of age (late-weaned, n = 8) and housed in nursery pens. Twenty-four hours postweaning, segments of midjejunum and ascending colon from piglets within each weaning age group were harvested and mounted on Ussing chambers for measurements of transepithelial electrical resistance and serosal-to-mucosal [3H]mannitol fluxes. Early weaning resulted in reductions in transepithelial electrical resistance and increases in mucosal permeability to [3H]mannitol in the jejunum and colon ( P < 0.01). In contrast, postweaning reductions in intestinal barrier function were not observed in piglets weaned at 28 days of age. Early-weaned piglet intestinal mucosa had increased expression of CRF receptor 1 protein, increased mucosal mast cell tryptase levels, and evidence of enhanced mast cell degranulation compared with late-weaned intestinal mucosa. Pretreatment of piglets with the mast cell stabilizer drug cromolyn, injected intraperitoneally 30 min prior to weaning, abolished the early-weaning-induced intestinal barrier disturbances. Our results indicate that early-weaning stress induces mucosal dysfunction mediated by intestinal mast cell activation and can be prevented by delaying weaning.
Cystic Fibrosis and Formes Frustes of CFTR-Related Disease
Authors: Southern Kevin W.
Published: May 2007

Cystic fibrosis (CF) is the commonest genetic cause of bronchiectasis in the Caucasian population. Since identification of the putative gene in 1989, the molecular basis of the condition has become clearer with characterisation of the unique pathophysiology. The small airways are the primary site of lung disease, with an intense but localised inflammatory picture, dominated by neutrophils. The clinical heterogeneity is explained to some degree by the distinct molecular consequences of the many mutations that have been recognised to affect the CF transmembrane conductance regulator (CFTR) gene; however other genes appear to modify the phenotype as well as environmental exposure. It has become increasingly apparent that certain conditions may result from CFTR dysfunction without fulfilling diagnostic criteria for CF. In some cases this may result in single organ disease for which the term CF (or CFTR)-related disease has been advocated. Congenital bilateral absence of the vas deferens is the most clearly characterised of these. In other cases where a mild CF phenotype is apparent, atypical CF is probably a better term. It remains unclear whether carrier status predisposes to certain conditions such as chronic rhinosinusitis or pancreatitis.
A Unified Approach for Quantifying, Testing and Correcting Population Stratification in Case-Control Association Studies
Authors: Gorroochurn Prakash , Hodge Susan E. , Heiman Gary A. , Greenberg David A.
Published: May 2007

The HapMap project has given case-control association studies a unique opportunity to uncover the genetic basis of complex diseases. However, persistent issues in such studies remain the proper quantification of, testing for, and correction for population stratification (PS). In this paper, we present the first unified paradigm that addresses all three fundamental issues within one statistical framework. Our unified approach makes use of an omnibus quantity (δ), which can be estimated in a case-control study from suitable null loci. We show how this estimated value can be used to quantify PS, to statistically test for PS, and to correct for PS, all in the context of case-control studies. Moreover, we provide guidelines for interpreting values of δ in association studies (e.g., at α = 0.05, a δ of size 0.416 is small, a δ of size 0.653 is medium, and a δ of size 1.115 is large). A novel feature of our testing procedure is its ability to test for either strictly any PS or only ‘practically important’ PS. We also performed simulations to compare our correction procedure with Genomic Control (GC). Our results show that, unlike GC, it maintains good Type I error rates and power across all levels of PS.
Sustained Leukocyte Count during Rising Cortisol Level
Authors: Deutsch Varda , Lerner-Geva Liat , Reches Adi , Boyko Valentina , Limor Rona , Grisaru Dan
Published: May 2007

Aims: To follow the trend of leukocyte counts relative to the serum cortisol levels in hospitalized patients. Methods: We retrospectively reviewed the charts of 59 hospitalized patients who had sequential blood profiles during a 2-week period. Results: The study cohort was divided into two subgroups according to the categorical cortisol levels: those within the normal range (<25 µg/dl; n = 31 patients) and those above the normal range (≧25 µg/dl; n = 28 patients). The baseline white blood cell counts (WBCCs) were similar in both groups. After 1 week, however, the WBCCs dropped significantly in the presence of normal cortisol levels and increased in the presence of elevated cortisol levels (p = 0.002). This pattern was not followed by the platelet counts. A significant correlation was observed between the cortisol levels and the 1 week concomitant WBCC (r = 0.33). Conclusion: Cortisol may be the mechanism with a positive effect on the maintenance of elevated leukocyte counts.