Developmental Nutrition Affects the Structural Integrity of a Sexually Selected Weapon.

Males in many species engage in physical combat over access to mates, and sexual selection has led to the evolution of weapons to enhance contest performance. The size of these often-elaborate structures is known to be exquisitely sensitive to nutrition. However, we know very little about the degree to which nutrition affects other attributes of animal weapons that can be crucial to fighting. In this study, we investigated the impact of natural dietary variation on weapon structural integrity in a fighting insect, Narnia femorata (Hemiptera: Coreidae). Males in this species display their enlarged, spiny hind legs to other males, and these legs serve as weapons in aggressive physical contests where they are used to strike and squeeze opponents. N. femorata feeds on the fruit of prickly pear cactus and sets up territories on this plant. In North Central Florida the prickly pear Opuntia mesacantha ssp. lata blooms and begins to produce fruits in April and May. N. femorata has multiple, overlapping generations while the green fruits slowly ripen over the next several months. We examined insects reaching adulthood at two nearby time points in this range, June and July, to test the influence of the nutrition provided by ripening green cactus fruit on weapon size and its ability to resist puncture. We also raised insects on cactus with red, ripe fruit for comparison. We found a striking effect of cactus fruit phenology on weapons. Insects raised with the more mature green fruit (those in the second cohort) had 71% larger weapon area and 4.4 times greater puncture resistance than those raised on the early green fruit (those in the first cohort). In contrast, insects raised on red, ripe fruit were moderate in size, had high puncture resistance, and they changed little phenotypically from the first to second cohort. Increased structural integrity of the hind femur weapon was associated with the increased body size that came with better nutrition. This pattern highlights that cuticle thickness increased or its material properties changed when weapons were larger. Importantly, effects of nutrition on puncture resistance also transcended size. Insects of the same size had greater structural integrity if they received superior nutrition. Sexually selected weapons are often used as visual signals to conspecifics before fights, and this work hints that the size of the weapons may be a poor signal of weapon performance when nutrition is variable.

Identification of Parameters That Predict Sport Climbing Performance.

In recent years, extreme sport-related pursuits including climbing have emerged not only as recreational activities but as competitive sports. Today, sport climbing is a rapidly developing, competitive sport included in the 2020 Olympic Games official program. Given recent developments, the understanding of which factors may influence actual climbing performance becomes critical. The present study aimed at identifying key performance parameters as perceived by experts in predicting actual lead sport climbing performance. Ten male (M age = 28, SD = 6.6 years) expert climbers (7a+ to 8b on-sight French Rating Scale of Difficulty), who were also registered as climbing coaches, participated in semi-structured interviews. Participants' responses were subjected to inductive-deductive content analysis. Several performance parameters were identified: passing cruxes, strength and conditioning aspects, interaction with the environment, possessing a good climbing movement repertoire, risk management, route management, mental balance, peer communication, and route preview. Route previewing emerged as critical when it comes to preparing and planning ascents, both cognitively and physically. That is, when optimizing decision making in relation to progressing on the route (ascent strategy forecasting) and when enhancing strategic management in relation to the effort exerted on the route (ascent effort forecasting). Participants described how such planning for the ascent allows them to: select an accurate and comprehensive movement repertoire relative to the specific demands of the route and reject ineffective movements; optimize effective movements; and link different movements upward. As the sport of climbing continues to develop, our findings provide a basis for further research that shall examine further how, each of these performance parameters identified, can most effectively be enhanced and optimized to influence performance positively. In addition, the present study provides a comprehensive view of parameters to consider when planning, designing and delivering holistic and coherent training programs aimed at enhancing climbing performance.

Aminopiperidine based complexes for lactide polymerisation.

Herein we report the synthesis and characterisation of a series of salalen and salan ligands derived from 2-(aminomethyl)piperidine. Depending on the choice of starting salicylaldehyde, a bicyclic salan type ligand (1-3H2) or imino salalen type ligand (4-6H, 7-9H2) were prepared. The ligands were successfully complexed to group 4 metals and aluminium; with hafnium and zirconium octahedral complexes, M(1-3)2, were realised; whilst with aluminium tetrahedral and trigonal bipyramidal complexes, Al(1-9)Mex (x = 1,2), were isolated. The complexes have been characterised in solution via(1)H and (13)C{(1)H} NMR spectroscopy and in the solid state by X-ray crystallography. The group 4 complexes were observed to have a fac-fac arrangement of ligands and there were two isomers present when 3H2 was ligated. The imino aluminium complexes Al(7-9)Me were isolated as a mixture of diastereoisomers. The resultant complexes were trialed in the ring opening polymerisation of rac-lactide with both heterotactic and isotactic PLA being demonstrated. Tacticity was found to be dependent on the nature of the ligand and metal used; the M(1-3)2 complexes were generally found to have a heterotactic preference (Pr = 0.67-0.76) and the aluminium polymerisation outcome was dictated more by the steric influence of the ligand, particularly for Al(4/6)Me2/Al(7/9)Me.

Influence of fear of falling on anticipatory postural control of medio-lateral stability during rapid leg flexion.

During leg flexion from erect posture, postural stability is organized in advance during "anticipatory postural adjustments" (APA). During these APA, inertial forces are generated that propel the centre of gravity (CoG) laterally towards stance leg side. This study examined how fear of falling (FoF) may influence this anticipatory postural control of medio-lateral (ML) stability. Ten young healthy participants performed a series of leg flexions at maximal velocity from low and high surface heights (6 and 66 cm above ground, respectively). In this latter condition with increased FoF, stance foot was placed at the lateral edge of the support surface to induce maximal postural threat. Results showed that the amplitude of ML inertial forces generated during APA decreased with FoF; this decrease was compensated by an increase in APA duration so that the CoG position at time of swing foot-off was located further towards stance leg side. With these changes in ML APA, the CoG was propelled in the same final (unipodal) position above stance foot as in condition with low FoF. These results contrast with those obtained in the literature during quiet standing which showed that FoF did not have any influence on the ML component of postural control. It is proposed that ML APA are modified with increased FoF, in such a way that the risk of a sideway fall induced by the large CoG motion is attenuated.

Learning throughout life: can a progress file help?

UNLABELLED: Modern dentistry demands continuous professional development. This paper reports part of a project to develop a lifelong learning tool known as a progress file for members of the dental team. AIM: To elucidate the views of dentists (as employers/managers) and dental therapists (as employees) on the potential use at work of a progress file. To obtain feedback from these groups on a prototype progress file for dental therapists. METHOD: Consultations were conducted with an opportunistic sample of 15 dentists and 32 dental therapists. Twenty eight dental therapists trialled the prototype for 6 months and 15 dentists appraised it. Opinion was obtained through interview and questionnaire, yielding largely qualitative data, which was content-analysed. FINDINGS: Both dentists and therapists were positively disposed towards a progress file at work but considered its success conditional upon factors including input from the team leader and rewarding dentists for time spent on supporting file users. Evaluation of the prototype was mainly positive. Trial data bore out many impressions from the consultations. CONCLUSION: A progress file that addresses the needs of both employers and employees has potential to help all members of the dental team meet the demands of lifelong learning.

Practice-based learning: views on the development of a reflective learning tool.

CONTEXT: This study reports the first part of a funded project to develop a tool to improve and record learning, known as a Progress File. A Progress File typically contains an element of reflection and a means of recording achievement. AIM: The aim of the study was to collect and understand the attitudes and experiences of students and tutors with regard to reflection, and to determine their views on the development and implementation of a Progress File for one member of the dental team, the dental therapist. METHOD: A consultation exercise was undertaken in four institutions which train dental therapists. A total of 76 students and tutors were interviewed individually or in groups. Examples of reflective tools were used to prompt discussion and feedback. Emergent themes were derived from content analysis. RESULTS: Participants identified many uses for the Progress File within and beyond their courses. They also expressed concerns regarding the effectiveness and feasibility of Progress File learning within present educational environments. DISCUSSION AND CONCLUSION: Successful integration of the Progress File into courses of medical and dental education may depend upon institutional culture change and a move towards a system which facilitates and rewards reflection on learning. The results will inform development of the File.

Disinfection of eyelid speculums for retinopathy of prematurity examination.

OBJECTIVE: To evaluate the effectiveness of 70% isopropyl alcohol swabs in disinfecting eyelid speculums after examination for retinopathy of prematurity. METHODS: Two phases. Phase 1: 46 autoclave-sterilized eyelid speculums randomized into either a cleaned or control group following examination for retinopathy of prematurity. Speculums in the cleaned group were disinfected with a 70% isopropyl alcohol swab while control speculums were not cleaned. Bacterial and fungal cultures were then obtained. Phase 2: 20 autoclave-sterilized eyelid speculums inoculated with a clinically relevant dilution of adenovirus serotype 5 or herpes simplex virus type 2. Inoculated speculums were randomized into either a cleaned or control group. RESULTS: Phase 1: 17 (70.8%) of 24 cultures from the cleaned group yielded bacteria compared with 21 (95.5%) of 22 controls. Fungi were isolated from only 1 control and from no cleaned speculums. Phase 2: all speculums inoculated with adenovirus supported growth of the organism irrespective of cleaning with 70% isopropyl alcohol swabs. None of 5 cleaned speculums inoculated with herpes simplex virus type 2 supported viral growth, compared with 3 (60%) of 5 cultures positive for growth in the control group. CONCLUSION: Cleaning eyelid speculums with 70% isopropyl alcohol swabs provided inadequate disinfection against bacteria following examination for retinopathy of prematurity and against adenovirus in a laboratory simulation.

The relation of the kinetics of pirmenol to its antiarrhythmic efficacy.

In a single-blind study the multiple oral dose kinetics of pirmenol were related to its efficacy in eight patients with frequent (mean, 631; range, 167-1374 beats/hour) premature ventricular contractions (PVC). Oral pirmenol was started at 100 mg bid for 48 hours and increased to 150 mg bid in six patients to obtain more than 70% suppression of PVC counts. Efficacy was achieved without side effects. Pirmenol decreased heart rate but not PR interval, QRS duration, or QTc interval. Peak plasma levels after the first 100-mg dose occurred at 1 to 3 hours and ranged from 0.6 to 1.9 micrograms/mL. Plasma elimination half-life ranged from 9.7 to 31 hours (mean, 18.3). From 67.4 to 171.3 mg pirmenol (mean, 102.3 mg) were recovered in the urine in 48 hours after the last dose. Cumulative excretion in divided urine collections was consistent with a mean elimination half-life of 15 to 20 hours. The pharmacokinetics of pirmenol support oral twice-daily administration. The minimum PVC suppressing plasma level is between 0.5 and 1.5 micrograms/mL.

Salivary concentrations of pirmenol as a possible cause of unpleasant taste.

Salivary concentrations of the anti-arrhythmic, pirmenol, were compared with plasma concentrations in six patients. Group mean salivary values tended to be higher despite high plasma protein binding, suggesting the possibility of an active transport process. The observed salivary concentrations are reasonably close to those detectable in healthy volunteers as tasting unpleasant.

Stability of stored methacholine chloride solutions: clinically useful information.

Methacholine inhalation challenge (MIC) has been shown to be an extremely useful diagnostic test. Because a decrease in the time and expense involved in the preparation of methacholine chloride solutions might encourage more laboratories to perform MIC, we assessed the stability of several different concentrations of methacholine chloride in solution over a period of 4 months. We used and compared 2 different assay techniques: a high pressure liquid chromatography assay and a colorimetric assay. Comparable results were obtained by both assays and demonstrated that methacholine solutions stored either at room temperature or at 4 degrees C showed no significant decomposition over a period of 4 months. From our results, we conclude that: (1) methacholine chloride solutions are much more stable than stated in the Merck Manual, (2) the original data of MacDonald and coworkers on the stability of methacholine chloride solution are accurate, (3) our high pressure liquid chromatography method is an accurate and highly specific technique for measuring methacholine chloride solutions. The major clinical implication of our results is that the time and cost necessary to prepare methacholine chloride solutions is much less than previously thought. This should encourage a more widespread use of this important diagnostic technique for the demonstration of bronchial hyperreactivity.

High pressure liquid chromatography on labetalol in serum or plasma.

A sensitive method for monitoring serum or plasma labetalol (2-hydroxy-5-[1- hydroxy-2-(1-methyl-3-phenylpropylamino) ethyl] benzamide hydrochloride) is described. The method is designed to study single dose kinetics and assess predose labetalol levels during chronic treatment. The applicable range of the assay is 10 to 400 ng/ml using 1 ml of plasma or serum. The method uses reverse-phase high pressure liquid chromatography (HPLC), a mobile phase of acetonitrile/pH 3.0 phosphate, and ultraviolet detection at 207 nm. The percentage recovery of labetalol and internal standard (propericiazine) (3-cyano-10-[3-4-hydroxypiperidino) propyl] phenothiazine from serum was 95.6% and 75.5%, respectively. Th precision of the method at labetalol serum concentrations of 400 and 50 ng/ml was indicated by a coefficient of variation of 4.3% and 6.9%, respectively. An approximate fourfold variation in plasma labetalol concentration, with plasma levels ranging from 20 to 93 ng/ml, was seen 10 to 11 hours after a dose in a group of patients taking 200 mg twice daily.

Interference of allopurinol and alloxanthine in ultraviolet theophylline assay.

A modification of several spectrophotometric methods for assaying theophylline in biological fluids is presented; the maximum absorbances of theophylline, allopurinol and alloxanthine solutions were measured. Plots of absorbance vs wavelength from 320 to 190 nm wer made for four samples in 0.1 N sodium hydroxide. The maximum absorbances for the theophylline sample (20 microgram/ml) were at 274-275 and 217 nm; for allopurinol (1 microgram/ml), at 274, 275 and 216 nm; for alloxanthine (10 microgram/ml), a plot similar to that for allopurinol; and for an equal mixture of the three solutions, at 274 and 218 nm. Especially with allopurinol and alloxanthine, and possibly in the presence of drugs with similar basic structures, one might wich to use a method other than spectrophotometry for the assay of theophylline or discontinue administration of the interfering medication.