bluuebunny/crossref_metadata_2025 huggingface dataset:
Neural correlates of the proximity and quantity of anticipated food rewards in the ventral striatum of domestic chicks
Authors: Izawa Ei‐Ichi , Aoki Naoya , Matsushima Toshiya
Published: September 2005

To identify the neuro‐cognitive substrates of valuation and choice, we analysed the neural correlates of anticipated food rewards in the ventral striatum of freely behaving chicks. One‐week‐old chicks were trained in a color‐discrimination task using four color cues (red, yellow, green and blue), each of which was associated with a different food reward. Choosing a red bead was immediately rewarded with a large amount of food, choosing a yellow bead resulted in an immediate‐small food reward, and choosing a green bead resulted in a late‐large food reward. We selected chicks that consistently chose a large and immediate food reward (red over yellow, and red over green), with the proximity of the food valued higher than the size of the food reward (yellow over green). Of the 47 neurons recorded from the ventral striatum of these chicks, 20 neurons selectively showed cue‐period responses to cues associated with food rewards. Five of these 20 neurons responded differentially during the cue period according to the expected delay to reward, and were thus assumed to code for the proximity of the reward. Additionally, three other neurons responded to the quantity of the reward. Furthermore, in the post‐operant delay period, many of these 20 neurons showed reward‐related activities that were linked to the proximity or presence of the food reward. We therefore propose that impulsive choice and behavioral perseveration observed after lesions of the ventral striatum could be due to impaired anticipation of rewards in the cue and delay periods, respectively.
Oil pollution and climate have wide‐scale impacts on seabird demographics
Authors: Votier Stephen C. , Hatchwell Ben J. , Beckerman Andrew , McCleery Robin H. , Hunter Fiona M. , Pellatt Jayne , Trinder Mark , Birkhead Tim R.
Published: September 2005

Oil spills often spell disaster for marine birds caught in slicks. However, the impact of oil pollution on seabird population parameters is poorly known because oil spills usually occur in wintering areas remote from breeding colonies where birds may be distributed over a wide area, and because it is difficult to separate the effects of oil pollution from the effect of natural environmental variation on seabird populations. Using a long‐term data set we show that over‐winter survival of adult common guillemots (Uria aalge) is negatively affected by both the incidence of four major oil‐spills in their wintering grounds and high values of the North Atlantic Oscillation (NAO) index. After controlling for the effect of the NAO index, we show that winter mortality of adult guillemots is doubled by major oil pollution incidents. Our results demonstrate that oil pollution can have wide‐scale impacts on marine ecosystems that can be quantified using populations of marked individuals to estimate survival.
Tracking Post‐school Destinations of Young People with Mild Intellectual Disabilities: The Problem of Attrition
Authors: Caton Sue , Kagan Carolyn
Published: September 2005

Background  This research was carried out as an assessment of the transition towards adult life for school leavers with mild intellectual disabilities. Ninety young people who were enrolled at three schools for people with mild intellectual disabilities were followed up for the first 12–18 months after they left school to assess how they experienced this transition.

Methods  Young people were interviewed using semi‐structured interviews before they left school regarding their aspirations for school leaving. They were then followed up and those who were traced were interviewed a second time regarding how they had experienced the previous year.

Results  There were a number of difficulties encountered in following up the school leavers. Most importantly, there were a high number of participants who were unable to be traced for the study, by the schools, the careers office, or other service providers. The attrition started early in the transition process and was largely overlooked by the schools and careers service, presenting a challenge for successful transition experiences.

Discussion  The implications of the high level of attrition are discussed. In addition, the impact of a number of new initiatives are discussed.
Barriers to Caregiver Compliance with Eating and Drinking Recommendations for Adults with Intellectual Disabilities and Dysphagia
Authors: Chadwick Darren D. , Jolliffe Jane , Goldbart Juliet , Burton Mark H.
Published: September 2005

Background  There is scant research on the subject of dysphagia and people with intellectual disabilities. This study explores the barriers which caregivers believe make following Speech and Language Therapists’ (SLTs) dysphagia management strategies more difficult.

Method  Semi‐structured open‐ended interviews were conducted with 46 caregivers who supported 40 intellectually disabled adults with dysphagia.

Results  Caregivers perceived particular difficulties in modifying food and drinks to safe consistencies, achieving the agreed positioning during mealtimes, and in using support and prompting strategies. Problematic support and prompting strategies included difficulties with pacing correctly; facilitating people to adequately relax and concentrate; observing and prompting people to pace suitably and take safe amounts of food and drink in each mouthful. Additional barriers identified included time pressures, staff turnover and insufficient reviewing of SLT management strategies by caregivers.

Conclusions  Findings suggest that additional training and monitoring is required to ensure caregivers are aware of their role and responsibility in promoting safe oral intake for adults with dysphagia and intellectual disabilities. Ongoing support is suggested for people with intellectual disabilities and dysphagia to help them understand the reasoning behind management strategies.
Emerging Trends in the Use of Drugs to Manage the Challenging Behaviour of People with Intellectual Disability
Authors: McGillivray Jane A. , McCabe Marita P.
Published: September 2005

Background  Concerns about the pharmacological management of the behaviour of individuals with intellectual disability have resulted in the development of legislative and procedural controls.

Method  This Australian study provided a comparison of 873 reported cases where drugs were administered to manage behaviour in March 2000, with 762 cases reported in March 1993. Drug use in individuals who remained medicated across time (n = 316: recurrent sample) was also compared with those who were reported only in 1993 (n = 329: limited sample).

Results  A small decrease in the proportion of individuals who were reported to have received medication was evident over time (from 5% to 4.5% of total population). However, this was accompanied by an increase in drug diversity and interclass polypharmacy. An increase in antidepressant use was evident (from 7.4% to 13.8% of reported drugs), and there was a trend towards greater reporting of medication for acute behavioural problems and medication use with children. Greater use of antipsychotic drugs was evident in individuals who remained medicated across time compared with those who did not.

Conclusions  The findings suggest the need for continuous research into practice. The fact that many individuals receive medication over long periods makes it incumbent on service providers to engage in regular, comprehensive and individualized review and evaluation of medication regimes.
ENVIRONMENTAL FACTORS CORRELATED WITH CHRYSOPHYTE CYST ASSEMBLAGES IN LOW ARCTIC LAKES OF SOUTHWEST GREENLAND1
Authors: Pla Sergi , Anderson N. John
Published: September 2005

We analyzed the relationship between chrysophyte cyst assemblages in surface sediment samples and limnological and geographical variables for 70 lakes located along Søndre Strømfjord in southwest Greenland. Over 247 stomatocysts were identified and of these, 153 were sufficiently abundant for use in statistical analyses. Eight stomatocysts were considered to be new and are described formally. Canonical correspondence analysis indicated that conductivity was the dominant variable explaining cyst distribution, reflecting the large conductivity gradient in lake water chemistry in this area. High conductivity lakes had distinctive cyst assemblages with lower diversity than low alkalinity lakes, where assemblages were similar to alpine soft‐water lakes elsewhere. The high conductivity lakes, however, had similar cysts to other saline lakes elsewhere in the arctic. Additionally, pH, calcium, maximum depth, longitude, sulfate, total phosphorus, and altitude all explained significant amounts of variability of cyst assemblages. Longitude was the only geographical variable that explained cyst variability independently of other variables (i.e. had a unique effect), which suggests that the climatic gradient from the coast to the head of the fjord has a structuring effect on cyst assemblages. Conductivity (weighted‐averaging partial least squares, r2=0.917; root mean square error=0.142; r2jack=0.861, root mean square error of prediction=0.191) and pH inference models (weighted averaging, r2=0.924; root mean square error=0.158; r2jack=0.826, root mean square error of prediction=0.240) were developed. For the pH model, high conductivity lakes (>800 μS20·cm−1) were removed. Both models are statistically robust and could be applied to lakes in west Greenland to reconstruct conductivity and/or pH. Such paleolimnological reconstructions provide the means of acquiring long‐term data for use in the evaluation of, for example, regional paleoclimatic models.
Is Physical Activity Counseling Effective for Older People? A Cluster Randomized, Controlled Trial in Primary Care
Authors: Kerse Ngaire , Elley C. Raina , Robinson Elizabeth , Arroll Bruce
Published: September 2005

Objectives: To establish the effectiveness of the Green Prescription physical activity counseling program in increasing activity and quality of life in older community‐dwelling people.

Design: Post hoc subgroup analysis of a large cluster randomized, controlled trial.

Setting: One hundred seventeen doctors in 42 primary care practices (74% participation rate) in the Waikato region of New Zealand.

Participants: Two hundred seventy sedentary primary healthcare patients aged 65 and older (67% participation rate).

Intervention: Patients in intervention practices prompted their primary care doctors or practice nurse to deliver brief activity counseling. A “Green Prescription” was written involving the negotiation of activity goals. Trained exercise specialists from a regional sports foundation gave follow‐up telephone support over 3 months.

Measurements: Leisure moderate and vigorous physical activity, total energy expenditure, systolic and diastolic blood pressure, health‐related quality of life, musculoskeletal injuries, falls, and hospitalizations.

Results: After 12 months of follow‐up, leisure time moderate activity increased by 0.67 h/wk more in the intervention group than the control group (95% confidence interval (CI)=0.17–1.17) and energy expenditure increased by 2.67 kcal/kg per week (95% CI=0.87–4.47) more. For intervention group participants, vitality and general health scales of the 36‐item Short Form showed statistically and clinically relevant improvements, and there was a decrease in hospitalizations (P<.03). There were no observable changes in blood pressure, injuries, or falls as a result of the Green Prescription program.

Conclusion: This physical activity intervention improved activity, energy expenditure, health‐related quality of life, and hospitalizations for older primary care patients. Systematic inclusion of the Green Prescription in routine primary health care will probably lead to health gain for older people.
Treatment for Breast Cancer in Patients with Alzheimer's Disease
Authors: Gorin Sherri Sheinfeld , Heck Julia E. , Albert Steven , Hershman Dawn
Published: September 2005

Objectives: To report use of breast cancer treatment (surgery, radiation, and chemotherapy) by patients with Alzheimer's disease (AD).

Design: Retrospective cohort study.

Setting: Surveillance, Epidemiology, and End Results (SEER) is a population‐based cancer registry covering 14% of the U.S. population.

Participants: Fifty thousand four hundred sixty breast cancer patients aged 65 and older, of whom 1,935 (3.8%) had a diagnosis of AD before or up to 6 months after cancer diagnosis.

Measurements: Diagnosis of AD was taken from International Classification of Diseases, Ninth Revision, diagnostic codes accompanying Medicare billing claims between 1992 and 1999. The SEER program reported surgery and radiation. Chemotherapy was taken from Medicare billing records.

Results: Subjects with AD were diagnosed with breast cancer at later stages, when tumors were larger and the likelihood of lymph node involvement had increased. Patients with AD had a lower likelihood of surgery (odds ratio (OR)=0.60, 95% confidence interval (CI)=0.46–0.81), radiation (OR=0.31, 95% CI=0.23–0.41), and chemotherapy (OR=0.44, 95% CI=0.34–0.58) than those without AD.

Conclusion: Overall, AD patients receive less treatment for breast cancer than do comparable female Medicare beneficiaries. Chemotherapy and radiation are administered less frequently to women with AD than to other comparable patients. It is unclear whether suboptimal medical care has an effect on their survival. Further research on the effect of screening and treatment decision‐making for these patients is warranted.
Accumulated snow and summer temperature – critical factors for recruitment to high mountain populations of brown trout (Salmo truttaL.)
Authors: Borgstrøm R. , Museth J.
Published: September 2005

Abstract – In lake Krokavatn, 1236 m a.s.l., only six strong year‐classes of brown trout appeared during the period 1970–2003. Eleven year‐classes were missing during the same period. The observed recruitment failure depended significantly on the accumulated snow depth in April, whereas the mean August temperature in the year of birth was significant for the appearance of strong year‐classes. Size of the young‐of‐the‐year (YOY) trout at onset of the winter seemed to be crucial for survival. Also little snow and low temperatures during the winter may have led to recruitment failure, as small nursery streams may freeze completely under such conditions, as happened during the winter of 1995/1996. Thus, the recruitment to brown trout populations in western high mountain areas of Norway seemed to be strongly affected by accumulated snow depth and summer temperatures. A climate change with more winter precipitation, as predicted for the present century, may therefore be detrimental to recruitment. However, warmer summers may increase recruitment to levels that lead to overpopulation, but also to establishment of brown trout populations at higher elevations than today.
Growth of pike larvae (Esox lucius) under different conditions of food quality and salinity
Authors: Engström‐Öst J. , Lehtiniemi M. , Jónasdóttir S. H. , Viitasalo M.
Published: September 2005

Abstract –  We measured growth of pike larvae (Esox lucius) fed with freshwater and brackish‐water zooplankton by monitoring larval wet weight during 18 days. The fish food was analysed for species composition, carbon, nitrogen and fatty acids. Further, we analysed fish larval faecal pellet production. Larval weight was significantly higher in fresh water than in brackish water with natural zooplankton as food. Growth, given as wet weight, showed a significant relationship with zooplankton (>100 μm) food carbon and highly unsaturated fatty acids, 20:5ω3, 22:6ω3, ω6 fatty acids and the ω3/ω6 fatty acid ratio. Phytoplankton fatty acids (10–50 μm), such as polyunsaturated fatty acids, 20:5ω3, 22:6ω3 and the ω3 fatty acids also correlated strongly with the wet weight of pike larvae. We demonstrated that several factors impact on pike larval growth.
Numerical Investigation of Road Salt Impact on an Urban Wellfield
Authors: Bester M.L. , Frind E.O. , Molson J.W. , Rudolph D.L.
Published: September 2005

The impact of road salt on a wellfield in a complex glacial moraine aquifer system is studied by numerical simulation. The moraine underlies an extensive urban and industrial landscape, which draws its water supply from >20 wellfields, several of which are approaching or have exceeded the drinking water limit for chloride. The study investigates the mechanisms of road salt infiltration, storage, and transport in the subsurface and assesses the effectiveness of mitigation measures designed to reduce the impact. The three‐dimensional transport model accounts for increases in salt loading, as well as growth of the urbanized area and road network over the past 50 years. The simulations, which focus on one impacted wellfield, show chloride plumes originating mainly at arterial roads and migrating through aquitard windows into the water supply aquifers. The results suggest that the aquifer system contains a large and heterogeneously distributed mass of chloride and that concentrations in the aquifer can be substantially higher than the concentrations in the well water. Future impact scenarios indicate that although the system responds rapidly to reductions in salt loading, the residual chloride mass may take decades to flush out, even if road salting were discontinued. The implications with respect to urban wellfields in typical snow‐belt areas are discussed.
Characterization and Identification of Na‐Cl Sources in Ground Water
Authors: Panno S.V. , Hackley K.C. , Hwang H.H. , Greenberg S.E. , Krapac I.G. , Landsberger S. , O'Kelly D.J.
Published: September 2005

Elevated concentrations of sodium (Na+) and chloride (Cl−) in surface and ground water are common in the United States and other countries, and can serve as indicators of, or may constitute, a water quality problem. We have characterized the most prevalent natural and anthropogenic sources of Na+ and Cl− in ground water, primarily in Illinois, and explored techniques that could be used to identify their source. We considered seven potential sources that included agricultural chemicals, septic effluent, animal waste, municipal landfill leachate, sea water, basin brines, and road deicers. The halides Cl−, bromide (Br−), and iodide (I−) were useful indicators of the sources of Na+‐Cl− contamination. Iodide enrichment (relative to Cl−) was greatest in precipitation, followed by uncontaminated soil water and ground water, and landfill leachate. The mass ratios of the halides among themselves, with total nitrogen (N), and with Na+ provided diagnostic methods for graphically distinguishing among sources of Na+ and Cl− in contaminated water. Cl/Br ratios relative to Cl− revealed a clear, although overlapping, separation of sample groups. Samples of landfill leachate and ground water known to be contaminated by leachate were enriched in I− and Br−; this provided an excellent fingerprint for identifying leachate contamination. In addition, total N, when plotted against Cl/Br ratios, successfully separated water contaminated by road salt from water contaminated by other sources.
Two‐Stage Aquifer Pumping Subject to Slow Desorption and Persistent Sources
Authors: Saez Jose A. , Harmon Thomas C.
Published: September 2005

This work focuses on improving pump‐and‐treat remediation by optimizing a two‐stage operational scheme to reduce volumes extracted when confronted with nonequilibrium desorption, low‐permeability units, and continuous contaminant sources such as non–aqueous phase liquids (NAPL). Q1 and Q2 are the initial short‐term high pumping rate and later long‐term low pumping rate, respectively. A two‐dimensional ground water flow and transport management model was used to test the proposed strategy for plumes developed from finite (NAPL‐free) and continuous (NAPL‐driven) contaminant sources in homogeneous and nonhomogeneous (zoned) aquifers. Remediation scenarios were simulated over durations of 2000, 6000, and 15,000 d to determine (1) the optimal time to switch from a preset Q1 to Q2 and (2) the value of Q2. The problem was constrained by mass removal requirements, maximum allowable downgradient concentrations, and practical bounds on Q2. Q1 was fixed at preset values 50% to 200% higher than the single‐stage pumping rates (i.e., steady pumping rates during entire remediation period) necessary to achieve a desired cleanup level and capture the plume. Results for the NAPL‐free homogeneous case under nonequilibrium desorption conditions achieved the same level of cleanup as single‐stage pumping, while reducing extracted volumes by up to 36%. Comparable savings were obtained with NAPL‐driven sources only when the source concentration was reduced by at least 2 orders of magnitude. For the zoned aquifer, the proposed strategy provided volume savings of up to 24% under NAPL‐free and reduced source conditions.
Nitrogen Loads to Estuaries from Waste Water Plumes: Modeling and Isotopic Approaches
Authors: Kroeger Kevin D. , Cole Marci L. , York Joanna K. , Valiela Ivan
Published: September 2005

We developed, and applied in two sites, novel methods to measure ground water–borne nitrogen loads to receiving estuaries from plumes resulting from land disposal of waste water treatment plant (WWTP) effluent. In addition, we quantified nitrogen losses from WWTP effluent during transport through watersheds. WWTP load to receiving water was estimated as the difference between total measured ground water–transported nitrogen load and modeled load from major nitrogen sources other than the WWTP. To test estimated WWTP loads, we applied two additional methods. First, we quantified total annual waste water nitrogen load from watersheds based on nitrogen stable isotopic signatures of primary producers in receiving water. Second, we used published data on ground water nitrogen concentrations in an array of wells to estimate dimensions of the plume and quantify the annual mass of nitrogen transported within the plume. Loss of nitrogen during transport through the watershed was estimated as the difference between the annual mass of nitrogen applied to watersheds as treatment plant effluent and the estimated nitrogen load reaching receiving water. In one plume, we corroborated our estimated nitrogen loss in watersheds using data from multiple‐level sampling wells to calculate the loss of nitrogen relative to a conservative tracer. The results suggest that nitrogen from the plumes is discharging to the estuaries but that substantial nitrogen loss occurs during transport through the watersheds. The measured vs. modeled and stable isotopic approaches, in comparison to the plume mapping approach, may more reliably quantify ground water–transported WWTP loads to estuaries.
The Use of Antibiotics for Viral Upper Respiratory Tract Infections: An Analysis of Nurse Practitioner and Physician Prescribing Practices in Ambulatory Care, 1997–2001
Authors: Ladd Elissa
Published: September 2005

Purpose

There are extensive data that describe the prescriptive behaviors of physicians (MDs) for upper respiratory tract infections; however, there is a paucity of data on the antibiotic‐prescribing patterns of nurse practitioners (NPs). The purpose of this study was to describe and predict factors that are associated with antibiotic prescribing by NPs and MDs for viral upper respiratory infections in the ambulatory setting.

Data sources

The study utilized a cross‐sectional retrospective design of data from the National Hospital Ambulatory Medical Care Survey and the National Ambulatory Medical Care Survey between 1997 and 2001. Data were collected on a national probability sample of 506 NP and 13,692 MD visits for patients with nonspecific upper respiratory tract infection, viral pharyngitis, and bronchitis.

Conclusions

Bivariate analysis found no significant differences in antibiotic prescribing for viral upper respiratory tract infections by NPs (50.4%) and MDs (53%). Broad‐spectrum antibiotics accounted for 36.6% of the NP antibiotic prescriptions and for 33.2% of the MD antibiotic prescriptions. Multivariate analysis identified several clinical and nonclinical factors that are associated with NP antibiotic prescribing. The strongest positive predictors of NP antibiotic prescribing were black race, Medicaid insurance, Northeast region, and diagnoses of viral pharyngitis and bronchitis. The significant negative predictor was Medicaid insurance status. The strongest positive predictors of MD prescribing were viral pharyngitis, bronchitis, and nonantibiotic prescription.

Implication for practice

The excessive use of antibiotics for upper respiratory infections of viral etiology by both NPs and MDs suggests the continuing need for educational initiatives such as “academic detailing” as well as increasing involvement by both groups of providers in the dissemination of clinical guidelines and system‐based quality assurance programs. Also, the lower rate of antibiotic prescribing for viral infections by NPs for patients with Medicaid insurance suggests more appropriate cost‐effective care in this population of patients. More study is needed in general on prescribing by NPs for Medicaid patients. Finally, the strong association of nonclinical factors suggests the need for awareness and improvement of prescribing decisions by both NPs and MDs.
The Benefits of Early Vasoactive Therapy in the Treatment of Acute Decompensated Heart Failure
Authors: Albert Nancy M.
Published: September 2005

Purpose

To review current issues in the management of acute decompensated heart failure (ADHF), focusing on the early initiation of intravenous (i.v.) vasoactive therapy and including the effects of vasoactive drugs on patient outcomes and the benefits and limitations of each medication class.

Data sources

Review of the worldwide scientific literature on ADHF.

Conclusions

The management of ADHF may be improved by early initiation of i.v. vasoactive therapy, reduced use of inotropic agents, and judicious use of diuretics. Data to date suggest that early treatment with the natriuretic peptide nesiritide reduces duration of hospitalization, in‐hospital mortality, and requirements for i.v. inotropes and diuretics.

Implications for practice

Advance practice nurses play an integral role in the management of patients with ADHF from initial triage in the emergency department through final discharge from the hospital. Because they are typically responsible for administering medications and monitoring patient status, nurses need to be familiar with the benefits and limitations of each class of vasoactive agent. They need to recognize that prompt initiation of i.v. vasodilator therapy is important for improving patient outcomes. Further, advance practice nurses should participate in team management that promotes the use of evidence‐based ADHF care by developing, using, and assertively communicating the need for processes of care that facilitate best practices.
Altered reflex cardiovascular control during exercise in heart failure: animal studies
Authors: O'Leary Donal S.
Published: September 2005

This brief review summarizes recent studies describing the potential role of the muscle metaboreflex in mediating the altered cardiovascular responses to dynamic exercise in heart failure and the interaction between the muscle metaboreflex and the arterial baroreflex in these responses. In normal dogs, activation of the muscle metaboreflex (via partial reductions in hindlimb blood flow) during submaximal exercise, elicits a powerful pressor response. This increase in arterial pressure is mediated by an increase in cardiac output with little, if any, peripheral vasoconstriction. The metaboreflex pressor response is buffered by the arterial baroreflex via baroreflex‐mediated inhibition of metaboreflex‐induced peripheral vasoconstriction. In contrast, after induction of heart failure, the mechanisms involved in the muscle metaboreflex are shifted to vasoconstriction with little, if any, increase in cardiac output. The loss of the cardiac output response of the metaboreflex in heart failure probably stems from inability to improve ventricular function. The shift towards vasoconstriction in this setting may be due to depressed ability of the arterial baroreflex to buffer metaboreflex‐induced peripheral vasoconstriction. The relative underperfusion of active skeletal muscle in heart failure may tonically activate the metaboreflex and this probably contributes to the enhanced sympatho‐excitation seen during exercise in heart failure.
Channel or transporter? The CLC saga continues
Authors: Pusch M. , Zifarelli G. , Murgia A. R. , Picollo A. , Babini E.
Published: September 2005

It was recently shown that the putative bacterial Cl− channel, ClC‐ec1, is in reality a Cl−–H+ antiporter. Our group has now shown that this is also the case for two human CLCs, ClC‐4 and ClC‐5. We found that the flux of Cl− in one direction is stoichiometrically coupled to the movement of protons in the opposite direction, unveiling a behaviour that is typical of a transporter rather than a channel. This discovery will surely stimulate further research to elucidate the molecular elements responsible for the behaviour as a transporter. On the physiological level, the antiport activity of ClC‐4/ClC‐5 must lead to a review of the role of CLC proteins in intracellular compartments. Small organic molecules have been extremely useful tools for studying ion channels and many commercial drugs target specific ion channel proteins. Several blockers have been found to inhibit the plasma membrane‐localized CLC channels ClC‐0, ClC‐1 and ClC‐Ka. These compounds include 9‐anthracene‐carboxylic acid (9‐AC), p‐chlorophenoxy‐propionic acid (CPP) and its derivatives, and 4,4′‐diisothiocyanatostilbene‐2,2′‐disulphonic acid (DIDS). Two different binding sites have been identified, one extracellular and one intracellular. However, high‐affinity ligands for most CLC proteins are still missing. Apart from being useful biophysical tools, such drugs may provide a way to modulate protein function in vivo. With these tasks to be accomplished, it is definitely an exciting time in the chloride transport field.
Depolarization‐induced suppression of excitation in murine autaptic hippocampal neurones
Authors: Straiker Alex , Mackie Ken
Published: September 2005

Depolarization‐induced suppression of excitation and inhibition (DSE and DSI) appear to be important forms of short‐term retrograde neuronal plasticity involving endocannabinoids (eCB) and the activation of presynaptic cannabinoid CB1 receptors. We report here that CB1‐dependent DSE can be elicited from autaptic cultures of excitatory mouse hippocampal neurones. DSE in autaptic cultures is both more robust and elicited with a more physiologically relevant stimulus than has been thus far reported for conventional hippocampal cultures. An additional requirement for autaptic DSE is filled internal calcium stores. Pharmacological experiments favour a role for 2‐arachidonyl glycerol (2‐AG) rather than arachidonyl ethanolamide (AEA) or noladin ether as the relevant endocannabinoid to elicit DSE. In particular, the latter two compounds fail to reversibly inhibit EPSCs, a quality inconsistent with the role of bona fide eCB mediating DSE. Δ9‐Tetrahydrocannabinol (Δ9‐THC) fails to inhibit EPSCs, yet readily occludes both DSE and EPSC inhibition by a synthetic CB1 agonist, WIN 55212‐2. With long‐term exposure (∼18 h), Δ9‐THC also desensitizes CB1 receptors. Lastly, a functional endocannabinoid transporter is necessary for the expression of DSE.
Economy of locomotion in high‐altitude Tibetan migrants exposed to normoxia
Authors: Marconi Claudio , Marzorati Mauro , Sciuto Daniele , Ferri Alessandra , Cerretelli Paolo
Published: September 2005

High‐altitude Tibetans undergo a pattern of adaptations to chronic hypoxia characterized, among others, by a more efficient aerobic performance compared with acclimatized lowlanders. To test whether such changes may persist upon descent to moderate altitude, oxygen uptake of 17 male Tibetan natives lifelong residents at 3500–4500 m was assessed within 1 month upon migration to 1300 m. Exercise protocols were: 5 min treadmill walking at 6 km h−1 on increasing inclines from +5 to +15% and 5 min running at 10 km h−1 on a +5% grade. The data (mean ±s.e.m.) were compared with those obtained on Nepali lowlanders. When walking on +10, +12.5 and +15% inclines, net of Tibetans was 25.2 ± 0.7, 29.1 ± 1.1 and 31.3 ± 0.9 ml kg−1 min−1, respectively, i.e. 8, 10 and 13% less (P < 0.05) than that of Nepali. At the end of the heaviest load, blood lactate concentration was lower in Tibetans than in Nepali (6.0 ± 0.9 versus 8.9 ± 0.6 mm; P < 0.05). During running, of Tibetans was 35.1 ± 0.8 versus 39.3 ± 0.7 ml kg−1 min−1 (i.e. 11% less; P < 0.01). In conclusion, during submaximal walking and running at 1300 m, Tibetans are still characterized by lower aerobic energy expenditure than control subjects that is not accounted for by differences in mechanical power output and/or compensated for by anaerobic glycolysis. These findings indicate that chronic hypoxia induces metabolic adaptations whose underlying mechanisms still need to be elucidated, that persist for at least 1 month upon descent to moderate altitude.
Synthesis of a Stable Compound with Fivefold Bonding Between Two Chromium(I) Centers
Authors: Nguyen Tailuan , Sutton Andrew D. , Brynda Marcin , Fettinger James C. , Long Gary J. , Power Philip P.
Published: September 2005

Although in principle transition metals can form bonds with six shared electron pairs, only quadruply bonded compounds can be isolated as stable species at room temperature. Here we show that the reduction of {Cr(μ-Cl)Ar′}
2
[where Ar′ indicates C
6
H
3
-2,6(C
6
H
3
-2,6-Pr
i
2
)
2
and Pr indicates isopropyl] with a slight excess of potassium graphite has produced a stable compound with fivefold chromium-chromium (Cr–Cr) bonding. The very air- and moisture-sensitive dark red crystals of Ar′CrCrAr′ were isolated with greater than 40% yield. X-ray diffraction revealed a Cr–Cr bond length of 1.8351(4) angstroms (where the number in parentheses indicates the standard deviation) and a planar transbent core geometry. These data, the structure's temperature-independent paramagnetism, and computational studies support the sharing of five electron pairs in five bonding molecular orbitals between two 3d
5
chromium(I) ions.
Role of Land-Surface Changes in Arctic Summer Warming
Authors: Chapin F. S. , Sturm M. , Serreze M. C. , McFadden J. P. , Key J. R. , Lloyd A. H. , McGuire A. D. , Rupp T. S. , Lynch A. H. , Schimel J. P. , Beringer J. , Chapman W. L. , Epstein H. E. , Euskirchen E. S. , Hinzman L. D. , Jia G. , Ping C.-L. , Tape K. D. , Thompson C. D. C. , Walker D. A. , Welker J. M.
Published: September 2005

A major challenge in predicting Earth's future climate state is to understand feedbacks that alter greenhouse-gas forcing. Here we synthesize field data from arctic Alaska, showing that terrestrial changes in summer albedo contribute substantially to recent high-latitude warming trends. Pronounced terrestrial summer warming in arctic Alaska correlates with a lengthening of the snow-free season that has increased atmospheric heating locally by about 3 watts per square meter per decade (similar in magnitude to the regional heating expected over multiple decades from a doubling of atmospheric CO
2
). The continuation of current trends in shrub and tree expansion could further amplify this atmospheric heating by two to seven times.
Biomechanics of the head for Olympic boxer punches to the face
Authors: Walilko T J , Viano D C , Bir C A
Published: September 2005

Objective:The biomechanics of the head for punches to the jaw and the risk of head injury from translational and rotational acceleration were studied.

Methods:Seven Olympic boxers from five weight classes delivered 18 straight punches to the frangible face of the Hybrid III dummy. Translational and rotational head acceleration, neck responses, and jaw pressure distribution were measured. High speed video recorded each blow and was used to determine punch velocity. Equilibrium was used to determine punch force, energy transfer, and power.

Results:Punch force averaged 3427 (standard deviation (SD) 811) N, hand velocity 9.14 (SD 2.06) m/s, and effective punch mass 2.9 (SD 2.0) kg. Punch force was higher for the heavier weight classes, due primarily to a higher effective mass of the punch. Jaw load was 876 (SD 288) N. The peak translational acceleration was 58 (SD 13)g, rotational acceleration was 6343 (SD 1789) rad/s2, and neck shear was 994 (SD 318) N.

Conclusions:Olympic boxers deliver straight punches with high impact velocity and energy transfer. The severity of the punch increases with weight class.
Adult women with mitral valve prolapse are more flexible
Authors: Araújo C G S , Chaves C P G
Published: September 2005

Background:Mitral valve prolapse (MVP) is common in women. Other clinical features such as flexibility and hyperlaxity are often associated with MVP, as there is a common biochemical and histological basis for collagen tissue characteristics, range of joint motion, and mitral leaflet excursion.

Objective:To confirm whether adult women with MVP are more flexible and hypermobile than those without.

Methods:Data from 125 women (mean age 50 years), 31 of them with MVP, were retrospectively analysed with regard to clinical and kinanthropometric aspects. Passive joint motion was evaluated in 20 body movements using Flexitest and three laxity tests. Flexitest individual movements (0 to 4) and overall Flexindex scores were obtained in all subjects by the same investigator.

Results:Women with MVP were lighter, less endomorphic and mesomorphic, and more linear. The Flexindex was significantly higher in the women with MVP, both absolute (48 (1.6)v41 (1.3); p<0.01) and centile for age (67v42; p<0.01) values. In 13 out of 20 movements, the Flexitest scores were significantly higher for the women with MVP. Signs of hyperlaxity were about five times more common in these women: 74%v16% (p<0.01). Scores of 0 and 1 in elbow extension, absence of hyperlaxity, and a Flexindex centile below 65 were almost never found in women with MVP.

Conclusion:Flexitest, alone or combined with hyperlaxity tests, may be useful in the assessment of adult women with MVP.
Physique traits of lightweight rowers and their relationship to competitive success
Authors: Slater G J , Rice A J , Mujika I , Hahn A G , Sharpe K , Jenkins D G
Published: September 2005

Objectives:Physique traits and their relationship to competitive success were assessed amongst lightweight rowers competing at the 2003 Australian Rowing Championships.

Methods:Full anthropometric profiles were collected from 107 lightweight rowers (n = 65 males, n = 45 females) competing in the Under 23 and Open age categories. Performance assessments were obtained for 66 of these rowers based on results in the single sculls events. The relationship between physique traits and competitive success was then determined.

Results:Lower body fat (heat time estimate −8.4 s kg−1, p<0.01), greater total body mass (heat time estimate −4.4 s kg−1, p = 0.03), and muscle mass (heat time estimate −10.2 s kg−1, p<0.01) were associated with faster 2000 m heat times.

Conclusions:The more successful lightweight rowers were those who had lower body fat and greater total muscle mass.
High reproducibility of patellar tendon vascularity assessed by colour Doppler ultrasonography: a reliable measurement tool for quantifying tendon pathology
Authors: Cook J L , Ptazsnik R , Kiss Z S , Malliaras P , Morris M E , De Luca J
Published: September 2005

Background:This study examined whether patellar tendon vascularity could be quantified accurately in the clinical setting using colour Doppler ultrasonography.

Methods:A sonographer and two radiologists visually estimated tendon vascularity in millimetres in 74 tendons during ultrasound (US) examination and from hard copy films. These estimates were then compared to the length of vessels measured from the digital image in millimetres and the correlation between them was determined. A subset of 16 tendons was used to compare the estimates of vascularity by two examiners at US examination.

Results:The estimation of vascular length at US examination correlated highly with the measured vascular length (r = 0.92; 95% confidence interval (CI) 0.87 to 0.94), as did the length estimated from the films (r = 0.94; 95% CI 0.9 to 0.96). The correlation between examiners was 0.84 (95% CI 0.51 to 0.94) for the estimates made during US examination and 0.85 (95% CI 0.59 to 0.95) for the vessel lengths measured from the digital images.

Conclusions:These excellent correlations indicate that tendon vascularity can be reliably estimated using colour Doppler ultrasonography and tendon vascularity could therefore be used by clinicians to rate clinical change. This method of quantifying tendon vascularity could also be used in research to investigate the effects of tendon treatments on vascularity.
Time for tea, anyone?
Authors: Turner M , McCrory P , Johnston A
Published: September 2005

There have been suggestions that urine samples positive for benzoylecognine, the diagnostic metabolite of cocaine, may be the result of consumption Mate de Coca, a commercially available tea made from coca (Erythroxylon coca) leaves. The Jockey Club in Great Britain commissioned research into this subject as several jockeys have tested positive for benzoylecognine over the past few years. Urine samples collected at various time points within 24 h after ingestion of a 250 ml infusion of Mate de Coca tea were analysed using three different methods. All samples tested positive for benzoylecognine.
Characterising the individual performance responses to mild illness in international swimmers
Authors: Pyne D B , Hopkins W G , Batterham A M , Gleeson M , Fricker P A
Published: September 2005

Objectives:To determine individual differences in the impact of illness on the change in performance of swimmers in international competitions.

Methods:Subjects were members of the Australian swimming team(33 male and 39 female, aged 15–27 years). Swimmers provided a weekly seven day recall of symptoms of illness during final six weeks of preparations for international competition over a three year period. Swimmers were categorised as either ill (one or more episodes of illness) or healthy. The measure of performances was the international point score. Mean changes in points score were calculated for healthy and ill swimmers between a national championship and an international competition (∼16 weeks later). Likelihoods of substantial effects of illness on an individual’s true change in performance (beneficial/trivial/harmful) were estimated from means and standard deviations, assuming a smallest substantial change of 6 points.

Results:Illness was reported before international performances by 38% of female and 35% of male swimmers. For female swimmers the change in performance was −3.7 (21.5) points (mean (SD)) with illness and −2.6 (19.0) points when healthy; for male swimmers the changes were −1.4 (17.5) points with illness and 5.6 (13.2) points when healthy. The likelihoods that illness had a substantial beneficial/trivial/harmful effect on performance of an individual swimmer were 32%/31%/37% for female and 17%/31%/52% for male participants (90% confidence limits ∼±10% to 20%).

Conclusions:Although mild illness had only a trivial mean effect on female swimmers and a small harmful mean effect on male swimmers, there were substantial chances of benefit and harm for individuals.
Gender identity and sport: is the playing field level?: Table 1
Authors: Reeser J C
Published: September 2005

This review examines gender identity issues in competitive sports, focusing on the evolution of policies relating to female gender verification and transsexual participation in sport. The issues are complex and continue to challenge sport governing bodies, including the International Olympic Committee, as they strive to provide a safe environment in which female athletes may compete fairly and equitably.
EXPLORATORY MODELING OF YEAST STRESS RESPONSE AND ITS REGULATION WITH gCCA AND ASSOCIATIVE CLUSTERING
Authors: NIKKILÄ JANNE , ROOS CHRISTOPHE , SAVIA EERIKA , KASKI SAMUEL
Published: September 2005

We model dependencies between m multivariate continuous-valued information sources by a combination of (i) a generalized canonical correlations analysis (gCCA) to reduce dimensionality while preserving dependencies in m - 1 of them, and (ii) summarizing dependencies with the remaining one by associative clustering. This new combination of methods avoids multiway associative clustering which would require a multiway contingency table and hence suffer from curse of dimensionality of the table. The method is applied to summarizing properties of yeast stress by searching for dependencies (commonalities) between expression of genes of baker's yeast Saccharomyces cerevisiae in various stressful treatments, and summarizing stress regulation by finally adding data about transcription factor binding sites.
EQUIVALENCE BETWEEN "FEELING THE PULSE" ON THE HUMAN WRIST AND THE PULSE PRESSURE WAVE AT FINGERTIP
Authors: ZHAO YI , SMALL MICHAEL
Published: September 2005

Feeling the pulse on the wrist is the regular diagnostic method in traditional Chinese medicine. However it is natural to ask whether there is any difference between feeling the pulse on the wrist or at any other part of the body: such as the fingertips at which it is easily measured by electronic devices. We employ a series of neural networks to model blood pressure propagation from the wrist to the fingertip. In order to avoid the problem of over-fitting we apply information theoretic criterion to determine the optimal model in these networks and then apply surrogate data method to the residuals in this model. We demonstrate the application of this method to recordings of human pulse in six subjects. Our result indicates that there is no significant difference between pulse waveform measure on the lateral arterial artery (wrist) and at the fingertip.
ON CONSTRUCTION OF STOCHASTIC GENETIC NETWORKS BASED ON GENE EXPRESSION SEQUENCES
Authors: CHING WAI-KI , NG MICHAEL M. , FUNG ERIC S. , AKUTSU TATSUYA
Published: September 2005

Reconstruction of genetic regulatory networks from time series data of gene expression patterns is an important research topic in bioinformatics. Probabilistic Boolean Networks (PBNs) have been proposed as an effective model for gene regulatory networks. PBNs are able to cope with uncertainty, corporate rule-based dependencies between genes and discover the sensitivity of genes in their interactions with other genes. However, PBNs are unlikely to use directly in practice because of huge amount of computational cost for obtaining predictors and their corresponding probabilities. In this paper, we propose a multivariate Markov model for approximating PBNs and describing the dynamics of a genetic network for gene expression sequences. The main contribution of the new model is to preserve the strength of PBNs and reduce the complexity of the networks. The number of parameters of our proposed model is O(n2) where n is the number of genes involved. We also develop efficient estimation methods for solving the model parameters. Numerical examples on synthetic data sets and practical yeast data sequences are given to demonstrate the effectiveness of the proposed model.