bluuebunny/crossref_metadata_2025 huggingface dataset:
Do honeybees detect colour targets using serial or parallel visual search?
Authors: Spaethe Johannes , Tautz Jürgen , Chittka Lars
Published: March 2006

In humans, visual search tasks are commonly used to address the question of how visual attention is allocated in a specific task and how individuals search for a specific object (`target') among other objects (`distractors')that vary in number and complexity. Here, we apply the methodology of visual search experiments to honeybees, which we trained to choose a coloured disc(target) among a varying number of differently coloured discs (distractors). We measured accuracy and decision time as a function of distractor number and colour. We found that for all colour combinations, decision time increased and accuracy decreased with increasing distractor number, whereas performance increased when more targets were present. These findings are characteristic of a serial search in primates, when stimuli are examined sequentially. We found no evidence for parallel search in bees, which would be characterized by a`pop out' effect, in which the slope of decision time (and accuracy) over distractor number would be near zero. Additionally, we found that decision time and number of errors were significantly higher when bees had to choose a blue target among yellow distractors compared with the inverse colour combination, a phenomenon known as search asymmetry in humans.
The relative contributions of developmental plasticity and adult acclimation to physiological variation in the tsetse fly,Glossina pallidipes(Diptera, Glossinidae)
Authors: Terblanche John S. , Chown Steven L.
Published: March 2006

Recent reviews of the adaptive hypotheses for animal responses to acclimation have highlighted the importance of distinguishing between developmental and adult (non-developmental) phenotypic plasticity. There has been little work, however, on separating the effects of developmental plasticity from adult acclimation on physiological traits. Therefore, we investigated the relative contributions of these two distinct forms of plasticity to the environmental physiology of adult tsetse flies by exposing developing pupae or adult flies to different temperatures and comparing their responses. We also exposed flies to different temperatures during development and re-exposed them as adults to the same temperatures, to investigate possible cumulative effects. Critical thermal maxima were relatively inflexible in response to acclimation temperatures (21, 25, 29°C) with plasticity type accounting for the majority of the variation (49–67%,nested ANOVA). By contrast, acclimation had a larger effect on critical thermal minima with treatment temperature accounting for most of the variance(84–92%). Surprisingly little of the variance in desiccation rate could be explained by plasticity type (30–47%). The only significant effect of acclimation temperature on standard (resting) metabolic rate of adult flies was at 21°C, resulting in treatment temperature, rather than plasticity type, accounting for the majority of the variance (30–76%). This study demonstrates that the stage at which acclimation takes place has significant,though often different, effects on several adult physiological traits in G. pallidipes, and therefore that it is not only important to consider the form of plasticity but also the direction of the response and its significance from a life-history perspective.
Synthesis of Electroluminescent Polymer Containing Charge Transport and Emissive Chromophores on Polymer Skeleton
Authors: Kim Dong Uk , Tsutsui Tetsuo , Saito Shogo
Published: March 2006

Electroluminescent polymer with a distyrylbenzene unit as an emissive group and a triphenylamine unit as a charge transporting group on polymer backbone was designed and synthesized. A single-layer device was composed of ITO/electroluminescent polymer/MgAg, and the polymer layer was fabricated using a spin-coating method. Greenish blue electroluminescence was observed with an emission maximum at 488 nm. Maximum brightness of 22 cd/m2 was observed at a current density of 88 mA/cm2 under drive voltage of 28 V.
Audit of Web-based telemedicine in ophthalmology
Authors: Kennedy Craig , Bowman Richard , Fariza Nor , Ackuaku Edith , Ntim-Amponsah Christine , Murdoch Ian
Published: March 2006

A Web-based service was set up to link subspecialist ophthalmologists with those seeking advice on particular clinical problems in ophthalmology. The service operated between countries, with centres in Malaysia, Ghana, Tanzania, South Africa and Gambia seeking advice from Moorfields Eye Hospital in the UK. It also operated within country, where a rural clinic in The Gambia sought advice from the central hospital on difficult cases or cases for possible referral. Provision of Web access and training in image capture and manipulation were undertaken in each participating centre. During the first 12 months, 132 cases were posted to the Website from five of the six centres participating. The rate of case referral rose to about 12–14 cases per month by the end of the study. Overall, 24% of referrals did not use images. In the first four months the response time was 13 days, and in the last four months it was three days. Most cases were answered with a single response from the specialist. The main problem was the amount of Internet down-time in each of the locations. The main benefit was safe and reliable access to specialist advice for practitioners.
Nursing education in telehealth
Authors: Lamb Gerri S , Shea Kimberly
Published: March 2006

Many nurses around the world provide expert nursing care through distance technologies but few undergraduate programmes expose nursing students to the full range of technologies available. Nursing education in telehealth needs to reflect the roles, responsibilities and capacity for knowledge building and innovation of the various constituencies within the profession. Registered nurses and advanced practice nurses will need complementary but different knowledge and skills than nurse administrators. The former will need technical proficiency in using common telehealth modalities and the ability to integrate telehealth in their practices.
Benefits of Channel Discord in the Sale of Durable Goods
Authors: Arya Anil , Mittendorf Brian
Published: March 2006

Minimizing strife through vertical integration is commonly seen as the “holy grail” for long-term success in product distribution. In this paper, we take a different slant, showing that sometimes a separated channel that embodies a degree of discord can be helpful, particularly when a long-term view is taken. This result is shown in the context of durable goods manufacturing. The quandary of durable goods production is that once demand for a certain time frame is met, there is a subsequent temptation to flood the market with additional goods. As such, consumers are reluctant to buy immediately, instead opting to wait for discounted prices. This problem can be alleviated by a degree of channel discord: High wholesale prices ensure future sales will slow to a trickle.
An Empirical Study of the Impact of Nonlinear Shipping and Handling Fees on Purchase Incidence and Expenditure Decisions
Authors: Lewis Michael , Singh Vishal , Fay Scott
Published: March 2006

Shipping-fee schedules are an important but underresearched element of the marketing mix for direct marketers. This paper provides an empirical study on the impact of shipping and handling charges on consumer-purchasing behavior. Using a database from an online retailer that has experimented with a wide variety of shipping-fee schedules, we investigate the impact of shipping charges on order incidence and order size. We use an ordered probability model that is generalized to account for the effects of nonlinear and discontinuous shipping fees on purchasing decisions, and to accommodate heterogeneity in response parameters. Results show that consumers are very sensitive to shipping charges and that shipping fees influence order incidence and basket size. Promotions such as free shipping and free shipping for orders that exceed some size threshold are found to be very effective in generating additional sales. However, the lost revenues from shipping and the lack of response by several segments are substantial enough to render such promotions unprofitable to the retailer. Heterogeneity across consumers also suggests interesting opportunities for the retailer to customize the shipping and other marketing-mix promotion offerings.
High Quality Acute Care for the Severely Injured is not Consistently Available in England, Wales and Northern Ireland: Report of a Survey by the Trauma Committee, The Royal College of Surgeons of England
Authors: Browne J , Coats TJ , Lloyd DA , Oakley PA , Pigott T , Willett KJ , Yates DW
Published: March 2006

INTRODUCTION

A survey was undertaken to determine the extent to which acute hospitals in England, Wales and Northern Ireland were meeting the acute trauma management standards published in 2000 by The Royal College of Surgeons of England and the British Orthopaedic Association.

METHODS

A questionnaire comprising 72 questions in 16 categories of management was distributed in July 2003 to all eligible hospitals via the link network of the British Orthopaedic Association. Data were collected over a 3-month period.

RESULTS

Of 213 eligible hospitals, 161 (76%) responded. In every category of acute care, failure to meet the standards was reported. Only 34 (21%) hospitals met all the 13 indicative standards that were considered pivotal to good trauma care, but all hospitals met at least 7 of these standards. Failures were usually in the organisation of services rather than a lack of resources, with the exception of the inadequate capacity for admission to specialist neurosurgery units. A minority of hospitals reported an inability to provide emergency airway control or insertion of chest tube. The data have not been verified and deficiencies in reporting cannot be excluded.

CONCLUSIONS

The findings of this survey suggest that high quality care for the severely injured is not available consistently across England, Wales and Northern Ireland, and appear to justify concerns about the ability of the NHS to deal effectively with the current trauma workload and the consequences of a major incident.
Subspecialisation and its Effect on the Management of Rectal Cancer
Authors: Ng Vivien V , Tytherleigh Matthew G , Fowler Lucy , Farouk Ridzuan
Published: March 2006

INTRODUCTION

To assess the impact of subspecialisation on surgical and oncological outcomes after rectal cancer surgery in a single surgical unit within a district general hospital.

PATIENTS AND METHODS

A total of 207 patients with rectal cancer treated surgically by two colorectal surgeons and four experienced general surgeons at the Royal Berkshire Hospital, Reading, England between January 1995 and December 1999 were studied. A retrospective case-note review of each patient's personal details, operative and histological findings, their subsequent clinical progress and oncological outcomes, including 5-year survival were recorded.

RESULTS

In the study group, 127 patients were treated by a colorectal surgeon and 80 by general surgeons. Pre-operative radiotherapy was more likely to be given to patients treated by a colorectal surgeon. Fewer permanent stomas were performed by colorectal surgeons. Postoperative morbidity, transfusion requirements, anastomotic leak rates and 30-day mortality were not significantly different. Tumour-involved circumferential resection margins, local recurrence rates and risk of distant metastases were similar between the two groups of surgeons.

CONCLUSIONS

Colorectal subspecialisation has resulted in an increased use of pre-operative radiotherapy and fewer permanent stomas. No significant improvement in surgical or oncological outcomes after rectal cancer surgery have been observed.
Current Management of Facial Wounds in UK Accident and Emergency Departments
Authors: Allonby-Neve CL , Okereke CD
Published: March 2006

INTRODUCTION

The objective of this study was to determine the current practice in the management of adult facial soft tissue injuries in patients presenting to UK accident and emergency departments.

MATERIALS AND METHODS

Questionnaire study to the lead clinicians of 217 UK emergency departments seeing over 30,000 new patients annually.

RESULTS

There was a 76% response rate. Suturing was the preferred method of closure, with the majority of clinicians preferring 6/0 or 5/0 non-resorbable sutures. Use of a regional nerve block would be considered by a quarter of clinicians, and adrenaline vasoconstrictor by a third. Referral rates ranged from 5–77% for a more complex wound. Maxillofacial services were preferred by 51% of respondents; on-site referral availability was indicated by only 28%, with an average journey of 16 miles for treatment. Up to 30% of clinicians considered prescribing antibiotics after wound closure, with flucloxacillin and co-amoxiclav most commonly suggested. Accident and emergency review rates ranged from 16% to 45%, with most wounds either being referred to the GP or no formal review being suggested.

CONCLUSIONS

The results of this survey suggest that there is considerable variation in the initial management, referral and review of facial wounds in the UK. Further work is required to formulate guidelines for optimal patient care, ideally in conjuncture with the receiving surgical specialties.
Validated Simple Tip to Aid Eliminating Light Scatter in Viewing Overexposed Radiographs
Authors: Hussainy Haydar AJ AL , Wong Smeeta
Published: March 2006

INTRODUCTION

Overexposed radiographs can hinder the diagnostic performance of the examining physician. We describe a new, simple technique to aid eliminating light scatter in overexposed radiographs and examine its effect objectively.

MATERIALS AND METHODS

The new technique is simply manufacturing a monocular device out of another rolled up XR sheet and examining the object radiograph through it to mask the light scatter. Controlled environments were created to examine five different radiographs and register the light scatter reduction using a digital high resolution camera.

RESULTS

The light scatter reduction was noted to be statistically significant by using the new technique. (P < 0.001).

CONCLUSIONS

This technique is simple, readily available and avoids the need to repeat radiographs with the associated increased cost, chronological delays and potential radiological harm.
Which Patients would Prefer to Walk to Theatre?
Authors: Nagraj Shobhana , Clark Celia Ingham , Talbot Janine , Walker Simon
Published: March 2006

INTRODUCTION

Increasing patient autonomy in the pre-operative period may help to lessen the anxiety associated with undergoing a surgical procedure, and may enhance patient satisfaction. This study seeks to explore patients’ preferences for mode of travel to the operating theatre.

PATIENTS AND METHODS

A questionnaire survey was undertaken with all patients having an in-patient or day-case surgical procedure over a 4-week period at one hospital. Results were analysed with respect to the patients’ age, gender and surgical specialty.

RESULTS

In all, 171 patients completed the questionnaire, 118 day-cases and 53 in-patients. In both sexes and in all age groups, the majority of patients expressed a preference to walk to theatre. The only sub-group which demonstrated an equal preference for a trolley transfer compared with walking were gynaecology patients.

CONCLUSIONS

These results suggest that a high proportion of patients would prefer to walk to theatre for their operation if given the choice. If the policy of offering choice were adopted, it would enhance patient autonomy and may reduce delays in transferring patients to theatre. It may also release portering resources for other purposes.
Day-Case Septoplasty and Unexpected Re-Admissions at a Dedicated Day-Case Unit: A 4-Year Audit
Authors: Georgalas Christos , Obholzer Rupert , Martinez-Devesa P , Sandhu G
Published: March 2006

INTRODUCTION

Septal surgery has been identified as suitable for day-surgery, but is not widely performed as such. Guidelines for day-surgery state that the unexpected admission rate should be 2–3%. Previous audits have not achieved this figure and septoplasty is not universally considered suitable for day-surgery. We have reviewed practice over 4 years in our institution to identify surgical and patient factors associated with unexpected admission following septoplasty.

PATIENTS AND METHODS

A retrospective case note based audit of day-case septoplasty procedures reviewed at the end of each year between October 1998 and October 2002.

RESULTS

A total of 432 septal surgery procedures were performed, comprising 378 septoplasties and 54 submucous resections. Thirty-eight patients were admitted, overwhelmingly because of haemorrhage in the immediate postoperative period, giving an overall admission rate of 8.8% within the first 24 h. Factors associated strongly with re-admission were the use of intranasal splints, the performance of revision surgery, submucous resection (as opposed to septoplasty) and, less so, the performance of additional procedures and the peri-operative administration of diclofenac. There was no correlation between unexpected admission and grade of surgeon, surgical technique or any of the patient factors analysed.

CONCLUSIONS

The unexpected admission rate of septal surgery performed at our unit is above that recommended for day-case procedures, but is within the range previously published. Patient satisfaction with day-case septoplasty has been shown to be high. We believe that septoplasty should be performed in this setting but there is a significant chance that patients may need admission, and a pathway should be in place for this to occur with minimal disruption to the patient.
The Rectal Administration of Lignocaine Gel and Periprostatic Lignocaine Infiltration During Transrectal Ultrasound-Guided Prostate Biopsy Provides Effective Analgesia
Authors: Siddiqui EJ , Ali S , Koneru S
Published: March 2006

INTRODUCTION

Transrectal ultrasound guided prostate needle biopsy (TRUS) is the standard procedure to diagnose or exclude prostate cancer. This procedure can be associated with significant discomfort, both on insertion of the ultrasound probe as well as on taking the biopsy. We evaluated a new technique for pain relief during TRUS biopsy.

PATIENTS AND METHODS

In Group 1 (n = 60), the biopsies were taken without any analgesia. In Group 2 (n = 60), 11 ml of Instillagel (2% lignocaine) was administered rectally prior to probe insertion and 5 ml of 1% lignocaine periprostatic injection was administered before taking the biopsy. The discomfort encountered during the procedure was graded by the patient on a scale ranging from no discomfort to mild, moderate and severe pain.

RESULTS

In Group 2, there was a marked reduction in the pain experienced during the procedure. The Chi-squared test for trend showed a significant association between the rectal administration of local anaesthetic gel and reduction in pain on probe insertion (P = 0.0001). There was also a significant association between the use of periprostatic lignocaine injection and reduction in pain on taking the biopsy (P < 0.0001).

CONCLUSIONS

The use of lignocaine gel prior to probe insertion and periprostatic infiltration of lignocaine before taking the needle biopsy significantly reduces the pain experienced by the patient during TRUS-guided prostate biopsy.
The (Soon Forgotten) Art of Open Stone Surgery: To Train or Not To Train?
Authors: Buchholz Noor NP , Hitchings Andrew , Albanis Stephanos
Published: March 2006

To date, open stone surgery is now performed in a very limited number of selected cases. A review of our own cases revealed that open surgery constituted 1% of all procedures. These procedures were mostly ablative, or operations to deal with complications of failed minimally invasive therapies. Given two continuing trends towards sub-specialisation in urology on the one hand, and minimally invasive therapy on the other, the question arises whether and how sub-specialised stone surgeons should and can learn open stone surgery. Is it merely a lost art not to be bothered with, or is it something worthwhile preserving? This article discusses the pros and cons of the argument and suggests centralisation of complex stone cases as a possible way out of the dilemma.
The Positive Predictive Value of Diagnostic Ultrasound for Occult Herniae
Authors: Bradley M , Morgan J , Pentlow B , Roe A
Published: March 2006

INTRODUCTION

The aim of this study is to ascertain the accuracy of diagnostic ultrasound in the assessment of the occult abdominal and groin herniae. The authors have previously demonstrated its efficacy in diagnosing the type of clinical groin herniae but occult herniae provide a further diagnostic problem.

PATIENTS AND METHODS

A total of 113 consecutive patients were referred prospectively for ultrasound examinations with clinically suspected occult herniae. All positive scans were offered surgery whilst the negative results were offered further imaging or other diagnostic tests depending on the clinical criteria. The end point for negative scans was based on 18-month follow-up or resolution of symptoms.

RESULTS

Overall, 59 scans showed positive results for herniae and 56 of these had surgery. In the other three patients, two refused an operation, and one had no hernia detected at operation. In the remaining 57 scans, ultrasound offered alternative soft tissue diagnoses in 23 patients and surgical/endoscopic diagnoses accounted for a further 8 patients.

CONCLUSIONS

Ultrasound offered a diagnosis for the symptomology in 82 patients (70.6%) of which 59 were herniae. The positive predictive value for hernia is 98.3%. Twenty-six patients with no diagnosis or confirmation of herniae on follow-up showed symptom resolution in 22 cases, and four patients were treated by the pain clinic.
Surgical Skills and Lessons from Other Vocations
Authors: Kirk RM
Published: March 2006

Formerly, a few lucky trainees, attached to talented masters * keen to teach, derived excellent, well-rounded training – but many others struggled alone. Now, formal courses allow experts to teach simple, safe methods, often using simulations. Courses are usually delivered as modules – each unit designed to provide an assessable competence. Simulations are, however, imperfect substitutes for living tissues. Such courses are aids, not substitutes, for operative experience – but this, for many irreversible reasons, is restricted.

Successful operators in all specialties and all countries, have in common the combination of good judgement, commitment, intimate knowledge of anatomy and pathology, together with technical skills that are more easily recognised than described. We need to identify good trainers and relieve them of commitments that reduce their ability to pass on their skills. As a trainee, try to identify and copy their characteristics. This advice comes not from a gifted surgeon but from one fortunate to have worked with, and watched, surgical masters – and who is still privileged to teach.
Promoted Ignition of a Cylinder Valve in NF3
Authors: Chiffoleau G , Newton B , Chou T , Wilson B
Published: March 2006

Nitrogen trifluoride (NF3) is used in the manufacturing process of semiconductors and is believed to be 1.5 times more oxidizing than oxygen. Compatibility data of materials with NF3 is limited and has only recently been addressed by companies which routinely handle NF3. Even more limited is the ability to conduct configuration testing of components in NF3 to evaluate kindling chain and reaction effects. In NF3 systems, the cylinder valve is subjected to severe operating conditions, and is known to have experienced fires in service. A new test approach was developed to positively ignite the non-metallic seat of a cylinder valve pressurized with NF3. The goal of the work was to investigate whether the ignition of the seat would kindle the surrounding sub-components of the valve and ultimately whether a kindling reaction would develop that could breach the valve body. The ignition concept of the test method consists of electrically heating a thin section of wire positioned across the seat to act as a promoter. The concept required minimal modifications to the valve and the overall valve design remained consistent with normal operation. The assembled valves were tested at a pressure of 1500 psig and no burn-through was observed during any test. The post-test valve disassembly and inspection confirmed the wire fused and successfully ignited the seat but the seat retainer and surrounding sub-components did not kindle. All of the other parts of the valve were unaffected by the ignition and consumption of the non-metallic seat. The new test provides an approach for evaluating the propagation propensity of NF3 components containing nonmetallic materials.
Hormonal regulation of expression of growth differentiation factor-9 receptor type I and II genes in the bovine ovarian follicle
Authors: Jayawardana Barana C , Shimizu Takashi , Nishimoto Hiromi , Kaneko Etsushi , Tetsuka Masafumi , Miyamoto Akio
Published: March 2006

Growth differentiation factor-9 (GDF-9) and bone morphogenetic proteins (BMPs) are crucial factors in follicular growth and development. GDF-9 and BMPs initiate signaling by assembling type I (ALK-3, ALK-5 and ALK-6) and type II (BMPRII) receptors. However, the mechanism regulating the expression of these receptors in the process of bovine follicle development is still unknown. The aim of the present study was to clarify the involvement of receptor systems for GDF-9 and BMPs in follicular selection by examining the effects of FSH and estradiol-17β (E2) on the regulation of BMPRII, ALK-3, ALK-5 and ALK-6 mRNA expression in bovine granulosa cells (GCs). To observe mRNA expression during follicular development, follicles were obtained from heifers and classified into two groups: pre-selection follicles (PRFs) (an average of 7.7 mm follicles with low E2) and post-selection follicles (POFs) (an average of 15 mm follicles with high E2). Theca layer cells (TCs) and GCs were harvested from aspirated follicles. For in vitro studies, GCs were obtained from bovine follicles of 4–7 mm diameter and cultured in Dulbecco’s modified Eagle’s/F12 (DMEM/F-12) medium with 10% fetal calf serum for 24 h. The medium was then replaced with serum-free DMEM/F-12 supplemented with different doses of E2 (1, 10, 100 ng/ml) or FSH (1, 5, 10 ng/ml) or combinations of 1 ng/ml of E2 with different FSH doses. Total RNA was extracted and the mRNA expression of BMPRII, ALK-3, ALK-5 and ALK-6 was estimated by the quantitative real-time PCR method using a LightCycler. BMPRII and ALK-5 expression was significantly higher in the GCs of POFs than in those of PRFs, whereas ALK-3 expression was significantly lower in the GCs of POFs than in those of PRFs. There was no difference in ALK-6 expression in GCs between PRFs and POFs. The expression of BMPRII, ALK-5, ALK-3 and ALK-6 genes in the TCs was not significantly different between PRFs and POFs. Treatment of GCs with E2 alone increased BMPRII mRNA expression at a concentration of 100 ng/ml and ALK-5 mRNA expression at 10 ng/ml. BMPRII and ALK-5 mRNA levels were up-regulated by the combination of E2 (1 ng/ml) and FSH (5 ng/ml). On the other hand, FSH alone down-regulated the expression of BMPRII and ALK-5 in GCs. The results of the present study provide the first evidence that FSH and E2 regulate the expression of BMPRII and ALK-5 genes in bovine GCs. Thus, our data suggest that the GDF-9/BMPRII/ALK-5 system may be critically involved in the process of selection of bovine follicles.
Glucose affects monocarboxylate cotransporter (MCT) 1 expression during mouse preimplantation development
Authors: Jansen Sarah , Esmaeilpour Tahereh , Pantaleon Marie , Kaye Peter L
Published: March 2006

Cleavage-stage embryos have an absolute requirement for pyruvate and lactate, but as the morula compacts, it switches to glucose as the preferred energy source to fuel glycolysis. Substrates such as glucose, amino acids, and lactate are moved into and out of cells by facilitated diffusion. In the case of lactate and pyruvate, this occurs via H+-monocarboxylate cotransporter (MCT) proteins. To clarify the role of MCT in development, transport characteristics for dl-lactate were examined, as were mRNA expression and protein localisation for MCT1 and MCT3, using confocal laser scanning immunofluorescence in freshly collected and cultured embryos. Blastocysts demonstrated significantly higher affinity for dl-lactate than zygotes (Km 20 ± 10 vs 87 ± 35 mmol lactate/l; P = 0.03 by linear regression) but was similar for all stages. For embryos derived in vivo and those cultured with glucose, MCT1 mRNA was present throughout preimplantation development, protein immunoreactivity appearing diffuse throughout the cytoplasm with brightest intensity in the outer cortical region of blastomeres. In expanding blastocysts, MCT1 became more prominent in the cytoplasmic cortex of blastomeres, with brightest intensity in the polar trophectoderm. Without glucose, MCT1 mRNA was not expressed, and immunoreactivity dramatically reduced in intensity as morulae died. MCT3 mRNA and immunoreactivity were not detected in early embryos. The differential expression of MCT1 in the presence or absence of glucose demonstrates that it is important in the critical regulation of pH and monocarboxylate transport during preimplantation development, and implies a role for glucose in the control of MCT1, but not MCT3, expression.
The role of bone morphogenetic proteins 2, 4, 6 and 7 during ovarian follicular development in sheep: contrast to rat
Authors: Juengel Jennifer L , Reader Karen L , Bibby Adrian H , Lun Stan , Ross Ian , Haydon Lisa J , McNatty Kenneth P
Published: March 2006

The intraovarian roles of BMP family members such as BMP2, 4, 6 and 7 are not well understood, particularly in species with low ovulation rates such as sheep. Therefore, the objectives of these experiments were to determine the expression patterns of mRNAs encoding BMP2, 4, 6 and 7 during ovarian follicular development in sheep, and to determine the effects of these growth factors on ovine granulosa cell functions in vitro. For comparative purposes, the effects of these BMPs were also determined in rat granulosa cells since these factors have been most widely studied in this poly-ovulatory species. As assessed by in situ hybridization, non-atretic ovine follicles expressed mRNA for BMP6 but not 2, 4 or 7. Furthermore, expression of BMP6 was limited to the oocyte of primordial as well as primary, pre-antral and antral follicles. Reverse transcription-PCR of granulosa cell mRNA detected low levels of all the BMPs in some pools of cells. BMP2, 4, 6 and 7 each inhibited progesterone production from ovine granulosa cells without affecting cellular proliferation/survival. Similarly, these BMPs inhibited progesterone production from rat granulosa cells. However, they also stimulated cellular proliferation/survival of the rat granulosa cells highlighting a species-specific difference for these growth factors. In conclusion, in sheep, BMP2, 4, 6 and 7 inhibit granulosa cell differentiation without affecting proliferation. However, as BMP2, 4 and 7 were not detectable by in situ hybridization in any cells of non-atretic ovarian follicles, it seems unlikely that these proteins would have an important intra-ovarian role in regulating follicular development in sheep. In contrast, localization of BMP6 mRNA in the oocyte suggests that this BMP family member may have a paracrine and/or autocrine role in regulating follicular growth in sheep, as has been shown for two other oocyte derived from members of the transforming growth factor superfamily, BMP15 and growth differentiation factor 9.
Joint Evolution of Dispersal and Inbreeding Load
Authors: Guillaume Frédéric , Perrin Nicolas
Published: March 2006

Inbreeding avoidance is often invoked to explain observed patterns of dispersal, and theoretical models indeed point to a possibly important role. However, while inbreeding load is usually assumed constant in these models, it is actually bound to vary dynamically under the combined influences of mutation, drift, and selection and thus to evolve jointly with dispersal. Here we report the results of individual-based stochastic simulations allowing such a joint evolution. We show that strongly deleterious mutations should play no significant role, owing to the low genomic mutation rate for such mutations. Mildly deleterious mutations, by contrast, may create enough heterosis to affect the evolution of dispersal as an inbreeding-avoidance mechanism, but only provided that they are also strongly recessive. If slightly recessive, they will spread among demes and accumulate at the metapopulation level, thus contributing to mutational load, but not to heterosis. The resulting loss of viability may then combine with demographic stochasticity to promote population fluctuations, which foster indirect incentives for dispersal. Our simulations suggest that, under biologically realistic parameter values, deleterious mutations have a limited impact on the evolution of dispersal, which on average exceeds by only one-third the values expected from kin-competition avoidance.
Estimating Relatedness Between Individuals in General Populations With a Focus on Their Use in Conservation Programs
Authors: Oliehoek Pieter A , Windig Jack J , van Arendonk Johan A M , Bijma Piter
Published: March 2006

Relatedness estimators are widely used in genetic studies, but effects of population structure on performance of estimators, criteria to evaluate estimators, and benefits of using such estimators in conservation programs have to date received little attention. In this article we present new estimators, based on the relationship between coancestry and molecular similarity between individuals, and compare them with existing estimators using Monte Carlo simulation of populations, either panmictic or structured. Estimators were evaluated using statistical criteria and a diversity criterion that minimized relatedness. Results show that ranking of estimators depends on the population structure. An existing estimator based on two-gene and four-gene coefficients of identity performs best in panmictic populations, whereas a new estimator based on coancestry performs best in structured populations. The number of marker alleles and loci did not affect ranking of estimators. Statistical criteria were insufficient to evaluate estimators for their use in conservation programs. The regression coefficient of pedigree relatedness on estimated relatedness (β2) was substantially lower than unity for all estimators, causing overestimation of the diversity conserved. A simple correction to achieve β2 = 1 improves both existing and new estimators. Using relatedness estimates with correction considerably increased diversity in structured populations, but did not do so or even decreased diversity in panmictic populations.
The Genetic Basis of Postzygotic Reproductive Isolation BetweenDrosophila santomeaandD. yakubaDue to Hybrid Male Sterility
Authors: Moehring Amanda J , Llopart Ana , Elwyn Susannah , Coyne Jerry A , Mackay Trudy F C
Published: March 2006

A major unresolved challenge of evolutionary biology is to determine the nature of the allelic variants of “speciation genes”: those alleles whose interaction produces inviable or infertile interspecific hybrids but does not reduce fitness in pure species. Here we map quantitative trait loci (QTL) affecting fertility of male hybrids between D. yakuba and its recently discovered sibling species, D. santomea. We mapped three to four X chromosome QTL and two autosomal QTL with large effects on the reduced fertility of D. yakuba and D. santomea backcross males. We observed epistasis between the X-linked QTL and also between the X and autosomal QTL. The X chromosome had a disproportionately large effect on hybrid sterility in both reciprocal backcross hybrids. However, the genetics of hybrid sterility differ between D. yakuba and D. santomea backcross males, both in terms of the magnitude of main effects and in the epistatic interactions. The QTL affecting hybrid fertility did not colocalize with QTL affecting sexual isolation in this species pair, but did colocalize with QTL affecting the marked difference in pigmentation between D. yakuba and D. santomea. These results provide the basis for future high-resolution mapping and ultimately, molecular cloning, of the interacting genes that contribute to hybrid sterility.
A Genetic and Cytogenetic Map for the Duck (Anas platyrhynchos)
Authors: Huang Yinhua , Zhao Yonghui , Haley Chris S , Hu Shengqiang , Hao Jinping , Wu Changxin , Li Ning
Published: March 2006

A genetic linkage map for the duck (Anas platyrhynchos) was developed within a cross between two extreme Peking duck lines by linkage analysis of 155 polymorphic microsatellite markers, including 84 novel markers reported in this study. A total of 115 microsatellite markers were placed into 19 linkage groups. The sex-averaged map spans 1353.3 cM, with an average interval distance of 15.04 cM. The male map covers 1415 cM, whereas the female map covers only 1387.6 cM. All of the flanking sequences of the 155 polymorphic loci—44 monomorphic loci and a further 41 reported microsatellite loci for duck—were blasted against the chicken genomic sequence, and corresponding orthologs were found for 49. To integrate the genetic and cytogenetic map of the duck genome, 28 BAC clones were screened from a chicken BAC library using the specific PCR primers and localized to duck chromosomes by FISH, respectively. Of 28 BAC clones, 24 were detected definitely on duck chromosomes. Thus, 11 of 19 linkage groups were localized to 10 duck chromosomes. This genetic and cytogenetic map will be helpful for the mapping QTL in duck for breeding applications and for conducting genomic comparisons between chicken and duck.
Synthetic Gene Recruitment Reveals Adaptive Reprogramming of Gene Regulation in Yeast
Authors: Stolovicki Elad , Dror Tali , Brenner Naama , Braun Erez
Published: March 2006

The recruitment of a gene to a foreign regulatory system is a major evolutionary event that can lead to novel phenotypes. However, the evolvability potential of cells depends on their ability to cope with challenges presented by gene recruitment. To study this ability, we combined synthetic gene recruitment with continuous culture and online measurements of the metabolic and regulatory dynamics over long timescales. The gene HIS3 from the histidine synthesis pathway was recruited to the GAL system, responsible for galactose utilization in the yeast S. cerevisiae. Following a switch from galactose to glucose—from induced to repressed conditions of the GAL system—in histidine-lacking chemostats (where the recruited HIS3 is essential), the regulatory system reprogrammed to adaptively tune HIS3 expression, allowing the cells to grow competitively in pure glucose. The adapted state was maintained for hundreds of generations in various environments. The timescales involved and the reproducibility of separate experiments render spontaneous mutations an unlikely underlying mechanism. Essentially all cells could adapt, excluding selection over a genetically variable population. The results reveal heritable adaptation induced by the exposure to glucose. They demonstrate that genetic regulatory networks have the potential to support highly demanding events of gene recruitment.
jing Is Required for Wing Development and to Establish the Proximo-Distal Axis of the Leg in Drosophila melanogaster
Authors: Culi Joaquim , Aroca Pilar , Modolell Juan , Mann Richard S
Published: March 2006

The establishment of the proximo-distal (PD) axis in the legs of Drosophila melanogaster requires the expression of a nested set of transcription factors that are activated in discreet domains by secreted signaling molecules. The precise regulation of these transcription factor domains is critical for generating the stereotyped morphological characteristics that exist along the PD axis, such as the positioning of specific bristle types and leg joints. Here we provide evidence that the Zn-finger protein encoded by the gene jing is critical for PD axis formation in the Drosophila legs. Our data suggest that jing represses transcription and that it is necessary to keep the proximal gene homothorax (hth) repressed in the medial domain of the PD axis. We further show that jing is also required for alula and vein development in the adult wing. In the wing, Jing is required to repress another proximal gene, teashirt (tsh), in a small domain that will give rise to the alula. Interestingly, we also demonstrate that two other genes affecting alula development, Alula and elbow, also exhibit tsh derepression in the same region of the wing disc as jing− clones. Finally, we show that jing genetically interacts with several members of the Polycomb (Pc) group of genes during development. Together, our data suggest that jing encodes a transcriptional repressor that may participate in a subset of Pc-dependent activities during Drosophila appendage development.
Assessment and Optimization of Mortality Prediction Tools for Admissions to Pediatric Intensive Care in the United Kingdom
Authors: Brady Anthony R. , Harrison David , Black Stephanie , Jones Sam , Rowan Kathy , Pearson Gale , Ratcliffe Jane , Parry Gareth J. ,   on behalf of the UK PICOS Study Group
Published: March 2006

OBJECTIVE. To assess the Pediatric Risk of Mortality (PRISM, PRISM III-12, and PRISM III-24) systems and the Pediatric Index of Mortality (PIM and PIM2) systems for use in comparing the risk-adjusted mortality of children after admission for pediatric intensive care in the United Kingdom.

METHODS. All PICUs in the United Kingdom were invited to participate. Predicted probability of PICU mortality was calculated using the published algorithms for PIM, PIM2, and PRISM and compared with observed mortality. These scores, along with PRISM III-12 and PRISM III-24, whose algorithms are not published, were optimized for the United Kingdom.

RESULTS. Of 26 PICUs in the United Kingdom, 22 (85%) were recruited, and sufficient prospective data were collected from 18 (69%) units on 10197 (98%) of 10385 admissions between March 2001 and February 2002. All published tools were found to have poor calibration but provided good discriminatory power. After estimation of UK-specific coefficients, only PIM2, PRISM III-12, and PRISM III-24 had satisfactory calibration. All models provided good discriminatory power. Funnel plots for all of the recalibrated models indicated that the risk-adjusted mortality for all units was consistent with random variation.

CONCLUSIONS. PIM2, PRISM III-12, and PRISM III-24 all were found to be suitable for use in a UK PICU setting. All tools provided similar conclusions in assessing the distribution of risk-adjusted mortality in UK PICUs. It now is important that these tools be used to monitor outcome and improve the quality of pediatric intensive care within the United Kingdom.
A Population Study of Alzheimer’s Disease: Findings From the Cache County Study on Memory, Health, and Aging
Authors: Tschanz Joann T. , Treiber Katherine , Norton Maria C. , Welsh-Bohmer Kathleen A. , Toone Leslie , Zandi Peter P. , Szekely Christine A. , Lyketsos Constantine , Breitner John C. S.
Published: March 2006

There are several population-based studies of aging, memory, and dementia being conducted worldwide. Of these, the Cache County Study on Memory, Health and Aging is noteworthy for its large number of “oldest-old” members. This study, which has been following an initial cohort of 5,092 seniors since 1995, has reported among its major findings the role of the Apolipoprotein E gene on modifying the risk for Alzheimer’s disease (AD) in males and females and identifying pharmacologic compounds that may act to reduce AD risk. This article summarizes the major findings of the Cache County study to date, describes ongoing investigations, and reports preliminary analyses on the outcome of the oldest-old in this population, the subgroup of participants who were over age 84 at the study’s inception.
Concerned About Client Decision-Making Capacity? Considerations for Practice
Authors: Black Kathy , Osman Hana
Published: March 2006

Many more people are reaching old age than ever before, and older people are increasingly living longer. As the nation experiences this unprecedented growth of older Americans, geriatric case managers are likely to encounter many clients at very advanced ages. Concomitantly, practitioners will confront elders with questionable decision-making capacity, as dementia and other cognitive impairments are more common among the older age groups. These clients pose potential safety and well-being concerns and may be vulnerable to exploitation, neglect, and abuse in their homes. Case managers’ responses to such client scenarios may range from little involvement, by acquiescing to the client’s right to make autonomous decisions, to resorting to legal action, which may lead to a substantial loss of rights for the elder. This article provides considerations for practice with elders presenting with questionable decision-making capacity and precarious living situations. The distinction between capacity and competency is presented and factors affecting decision making are discussed. Ethical aspects are addressed and the process of assessing capacity is reviewed to enhance case managers’ practices in this area.
The Cash and Counseling Demonstration and Evaluation: Focus Groups Inform Design of a Consumer-Directed Cash Option
Authors: Simon-Rusinowitz Lori , Mahoney Kevin J. , Marks Lori N. , Zacharias B. Lee , Loughlin Dawn M.
Published: March 2006

The purposes of the study were to explore consumer preferences for a cash option, to inform the ongoing CCDE survey and program design, and to identify the messages that the CCDE and other states should include when informing consumers about a cash option. The preference study consisted of 3 parts: 11 presurvey focus groups, a telephone survey in each of the 4 participating states, and 16 post-survey focus groups. This article highlights unique results from pre- and post-survey focus groups. Focus group discussions were audiotaped and videotaped and transcribed. Transcripts were manually coded and text was clustered according to the moderator’s guide questions and some new and recurrent themes that emerged. Overall, focus group participants, including elders, expressed positive feelings about the CCDE, especially about having a role in hiring workers and determining the workers’ schedules and responsibilities. Focus groups provided important lessons about features to highlight when presenting program information to potential consumers and their families. Program planners must also bear in mind consumer concerns, especially considering that less than 10% of eligible Medicaid consumers volunteered for the cash option. These findings will be useful in guiding other states as they develop new cash and counseling programs, especially those in the current Cash and Counseling replication project.