Context Matters: Social Psychological Factors That Underlie Academic Performance across Seven Institutions.

To enhance equity and diversity in undergraduate biology, recent research in biology education focuses on best practices that reduce learning barriers for all students and improve academic performance. However, the majority of current research into student experiences in introductory biology takes place at large, predominantly White institutions. To foster contextual knowledge in biology education research, we harnessed data from a large research coordination network to examine the extent of academic performance gaps based on demographic status across institutional contexts and how two psychological factors, test anxiety and ethnicity stigma consciousness, may mediate performance in introductory biology. We used data from seven institutions across three institution types: 2-year community colleges, 4-year inclusive institutions (based on admissions selectivity; hereafter, inclusive), and 4-year selective institutions (hereafter, selective). In our sample, we did not observe binary gender gaps across institutional contexts, but found that performance gaps based on underrepresented minority status were evident at inclusive and selective 4-year institutions, but not at community colleges. Differences in social psychological factors and their impacts on academic performance varied substantially across institutional contexts. Our findings demonstrate that institutional context can play an important role in the mechanisms underlying performance gaps.

Pharmacological characterization of the serotonin-sensitive potassium channel of Aplysia sensory neurons.

The effects of a variety of K+ channel blockers on current flow through single serotonin-sensitive K+ channels (the S channels) of Aplysia sensory neurons were studied using the patch-clamp technique. Tetraethylammonium (TEA), 4-aminopyridine (4-AP), and Co2+ and Ba2+ were first applied to the external membrane surface using cell-free outside-out patches. At concentrations up to 10 mM, these agents had little or no effect on single S-channel currents. At higher concentrations, external TEA acted as a fast open-channel blocker, reducing the single-channel current amplitude according to a simple one-to-one binding scheme with an apparent Kd of 90 mM. Blockage by external TEA is voltage independent. Internal TEA also acts as an open-channel blocker, with an apparent Kd of approximately 40 mM and a relatively weak voltage dependence, corresponding to an apparent electrical distance to the internal TEA-binding site of 0.1. Both internal and external TEA block the open channel selectively, with an affinity that is 10-100-fold greater than the affinity for the closed channel. Internal Ba2+ acts as a slow channel blocker, producing long closures of the channel, and binding with an apparent Kd of approximately 25-30 microM. These results show that single S-channel currents share a similar pharmacological profile with the macroscopic S current previously characterized with voltage clamp. On the basis of these results, a structural model for S-channel opening is proposed.

Effects of homology, size and exchange of the meiotic segregation of model chromosomes in Saccharomyces cerevisiae.

In most eukaryotic organisms, chiasmata, the connections formed between homologous chromosomes as a consequence of crossing over, are important for ensuring that the homologues move away from each other at meiosis I. Some organisms have the capacity to partition the rare homologues that have failed to experience reciprocal recombination. The yeast Saccharomyces cerevisiae is able to correctly partition achiasmate homologues with low fidelity by a mechanism that is largely unknown. It is possible to test which parameters affect the ability of achiasmate chromosomes to segregate by constructing strains that will have three achiasmate chromosomes at the time of meiosis. The meiotic partitioning of these chromosomes can be monitored to determine which ones segregate away from each other at meiosis I. This approach was used to test the influence of homologous yeast DNA sequences, recombination intiation sites, chromosome size and crossing over on the meiotic segregation of the model chromosomes. Chromosome size had no effect on achiasmate segregation. The influence of homologous yeast sequences on the segregation of noncrossover model chromosomes was negligible. In meioses in which two of the three model chromosomes experienced a crossover, they nearly always disjoined at meiosis I.

Role of a Ca(2+)-dependent slow afterhyperpolarization in prostaglandin E2-induced sensitization of cultured rat sensory neurons.

To determine if inhibition of a Ca(2+)-dependent slow afterhyperpolarization (AHPslow) contributes to prostaglandin E2 (PGE2)-induced sensitization of DRG neurons, we have used patch-clamp electrophysiological techniques on cultured dorsal root ganglion (DRG) neurons from the adult rat. In support of a role for AHPslow in sensitization of DRG neurons, we demonstrate that: (1) AHPslow expression is restricted to a subpopulation of putative nociceptors; (2) burst duration is controlled by AHPslow in these neurons; and (3) in some neurons, PGE2 decreases AHPslow and produces a concomitant increase in the number of action potentials generated in response to depolarizing current injection. However, our results also demonstrate that AHPslow modulation is not sufficient to explain PGE2-induced sensitization in the majority of DRG neurons because: (1) the size of the population of DRG neurons expressing AHPslow is less than half the size of the population of DRG neurons sensitized by PGE2; (2) PGE2 produces a decrease in action potential threshold as well as an increase in the number of action potentials in response to current injection, while inhibition of AHPslow has little effect on threshold; and (3) the sensitizing effects of PGE2 are dissociated from its effects on AHPslow in more than half of neurons tested. We conclude that PGE2-induced sensitization must involve the modulation of ionic currents in addition to that underlying AHPslow.

Preparation, attitudes and behaviour in nonhospital cardiac emergencies: evaluating a community's readiness to act.

OBJECTIVE: To determine how people in a moderately sized Ontario city believe they will react if they witness someone colapsing. DESIGN: Telephone survey. SETTING: The cities of Kitchener and Waterloo, part of the Regional Municipality of Waterloo, Ontario, with a combined population of 378,000. PARTICIPANTS: Households were randomly contacted and a questionnaire was administered, provided the respondent was over 44 years of age and agreed to be interviewed. Of 2479 households with eligible respondents, 811 (33%) completed the questionnaire. OUTCOMES: Age, sex, educational level, cardiac risk factors and cardiopulmonary resuscitation (CPR) training of respondents were determined, as well as actions they would take if cardiac arrest occurred in a family member at home or in stranger in the street, and associated emotions and barriers to implementing actions. RESULTS: Among the first three actions that respondents who were not prompted with possible responses said they would take, 311 (72%) witnessing a collapse at home, compared with 166 (44%) witnessing a collapse on the street, would call 911, the police or an ambulance. Other 'first three actions' in home collapse were checking for breathing (120 [28%]), checking for pulse (91 [21%]) and administering CPR (34 [8%]); these actions were less commonly selected in response to a strangers collapse and when respondents were not prompted. Respondents felt they would be more likely to perform CPR on a friend than on a stranger (OR 1.38, 95% CI 1.10 to 1.58). When asked how likely they would be to perform specific acts when witnessing a collapse, 254 (69%) of respondents thought they would call their family doctor and 179 (48%) thought they were likely to begin chest compressions. Barriers to performing CPR centred around legalities and disease transmission. CONCLUSION: Older people do not know how to act effectively in a cardiac emergency. Traditional CPR and public awareness programs have been ineffective in reaching this population; alternative means are required to help the public respond more effectively to cardiac emergencies.

Intra-uterine infection in women with preterm premature rupture of membranes: maternal and neonatal characteristics.

OBJECTIVE: Our purpose was to determine the prevalence of intra-uterine infection in patients with preterm premature rupture of membranes and to evaluate the clinical characteristics of women and neonates according to the presence or absence of intrauterine infection. STUDY DESIGN: Trans-abdominal amniocentesis was performed in 90 consecutive patients admitted with preterm premature rupture of membranes. Maternal clinical parameters evaluated included maternal age, origin, gravidity, parity, habitual abortion, previous perinatal death, previous preterm birth, urinary tract infection, fetal distress, abruptio placentae, gestational diabetes, admission-delivery interval and cesarean rate. Neonatal clinical parameters evaluated were gestational age at delivery, birth weight, Apgar score, neonatal gender, perinatal death and neonatal sepsis. RESULTS: The prevalence of intra-uterine infection was 66.6% (60/90). No differences between patients with intra-uterine infection and those without intra-uterine infection were observed in maternal age, origin, gravidity, parity, habitual abortion, previous perinatal death, fetal distress, abruptio placentae, gestational diabetes, admission-delivery interval, cesarean section, neonate's gender, Apgar score at 5 min and neonatal sepsis. On the other hand, gestational age at delivery, birth weight and Apgar score at 1 min were significantly different between the groups. CONCLUSION: An intra-uterine infection was found in two thirds of women presenting with preterm premature rupture of membranes. Women presenting with preterm premature rupture of membranes and intra-uterine infection had a lower gestational age at delivery and consequently had a lower neonatal birth weight than those without intra-uterine infection.

Who should write admission orders?

The rural hospital environment differs from the urban hospital environment in that there are fewer physicians available to share the workload and to help out in an emergency. When a rural physician on call for emergency writes admission orders rather than disturb the patient's family physician, that rural physician accepts full responsibility for the patient until the patient's physician actually examines the patient and assumes care.

[Treatment of trigeminal neuralgia, ganglioneuritis of the pterygopalatine ganglion and other types of prosopalgias by helium-neon laser irradiation of the pterygopalatine ganglion]. / Lechenie nevralgii troinichnogo nerva, ganglionevrita krylonebnoogo uzla i drugikh vidov prozopalgii oblucheniem krylonebnogo uzla gelii-neonovym lazerom.

The authors describe a method of contact helium-neon laser irradiation of the pterygopalatine node through lateral wall of the nasal cavity. The technique was employed in patients with trigeminal neuralgia, ganglioneuritis of pterygopalatine node, other forms of prosopalgia. Altogether 78 patients were treated. The initial course relieved pain in 56 patients. In 44 patients the remission has been persisting for 2 years.

[Ear surgeon's tactics in temporal bone fractures with injury of the facial nerve and sound-conducting system]. / O taktike otokhirurga pri perelomakh visochnoi kosti s povrezhdeniem litsevogo nerva i zvukoprovodiashchego apparata.

Out of 486 patients with basilar skull fracture, 74 developed peripheral paralysis of the facial nerve (28 cases of early and 39 of late posttraumatic paralysis). 19 (67.8%) patients with early paralysis recovered function of the facial nerve, whereas only 9 (32.2%) with late paralysis were cured. Indications to surgical management of relevant paralyses are specified. Cases of one-stage tympanoplasty are described.

[Hemangioma of the larynx in children]. / Gemangioma gortani u detei.

Hemangiomas were diagnozed in 11 patients (4.6%) out of 235 children with chronic laryngeal stenoses of various etiology. The most frequent symptom was hoarse voice. The children examined were not older than 5 months. In 5 patients, laryngeal hemangiomas were associated with hemangiomas of other body compartments--most frequently on the skin of the face, neck or upper chest. Out of the 11 laryngeal hemangiomas 6 were located below vocal folds, 4 on gastric and aryepiglottic folds and only 1 on vocal folds. The first line method of treatment was cryosurgery. Local freezing was performed on 6 patients. They all were decannulated within 2 to 4 months after intervention. There children with disseminated hemangiomas of the face, neck and upper chest were exposed to radiotherapy. A year after, two of them were decannulated and the third one developed a postradiation scar below vocal cords. In 2 children when they were 2 or 3 years of age, laryngeal hemangiomas disappeared spontaneously without any treatment.

[Functional methods of study in the evaluation of the effectiveness of laser therapy of vasomotor rhinitis and some forms of prosopalgia]. / Funktsional'nye metody issledovaniia v otsenke éffektivnosti lazernoi terapii vazomotornogo rinita i nekotorykh vidov prozopalgii.

Highly sensitive instrumental methods such as rhinopneumography, rhinorheography, rheoencephalography and segmented sphygmography were used to measure the efficacy of contact laser therapy of the pterygopalatine ganglion to treat vasomotor rhinitis and trigeminal neuralgia. This method proved efficient in the case of the nervous form of vasomotor rhinitis, Sluder syndrome, and trigeminal neuralgia. Stable remission developed in 60% of patients.

[Role of computerized tomography in the diagnosis of encapsulated cerebellar abscesses in acute otitis media]. / Rol' kompiuternoi tomografii v diagnostike inkapsulirovannykh abstsessov mozzhechka pri ostrykh srednikh otitakh.

Two rare cases of encapsulated cerebellar abscesses that developed 2-2.5 months after acute otitis media are described. In both patients, otitis media was cured using conservative therapy although it was aggravated by mastoiditis in one case and antritis in the other. Abscesses were removed by means of a neurosurgical trans-occipital approach. Computer tomography detected "volume formations" in the cerebellum but failed to differentiate between an abscess and tumor. It is concluded that in such cases antrotomy (mastoidotomy) is not necessary.

[Ultrasonic disintegration of laryngeal papilloma in children]. / Ul'trazvukovaia dezintegratsiia papillom gortani u detei.

As of today, 238 children with laryngeal papillomas were treated by ultrasonic disintegration in the ENT Department of the Moscow District Research Clinical Institute and in the ENT Department of the Rostov District Clinical Hospital. The children varied from 5 months to 14 years of age. A commercial apparatus LORA-DON was used. Immediate and remote effects of ultrasonic disintegration were quite satisfactory. During the last 8 years none of the treated patients underwent tracheotomy. The number of relapses decreased two times in the Moscow clinic and four times in the Rostov clinic.

[Improved method of ultrasonic diagnosis of maxillary sinus diseases in children]. / Usovershenstvovannaia metodika ul'trazvukovoi diagnostiki zabolevanii verkhnecheliustnykh pazukh u detei.

A modified technique of ultrasonic diagnosis of accessory nasal sinus diseases based on an analysis of the profile of echograms has been developed. A correlation between the profile and pathological changes in the Highmore antrum has been found. It has been shown that the cystic fluid has a characteristic difference between the intensity of the start and echo impulses. Echograms of a cyst and its capsule reveal that they are significantly heterogeneous. Pus is characterized by a pronounced ultrasound absorption, fluid pus and thick pus showing different response. Plasma and blood are characterized by a significant ultrasound absorption and sufficient homogeneity. An interpretation of an echogram obtained under clinical conditions is presented.

Patterning small-molecule biocapture surfaces: microcontact insertion printing vs. photolithography.

Chemical patterns prepared by self-assembly, combined with soft lithography or photolithography, are directly compared. Pattern fidelity can be controlled in both cases but patterning at the low densities necessary for small-molecule probe capture of large biomolecule targets is better accomplished using microcontact insertion printing (µCIP). Surfaces patterned by µCIP are used to capture biomolecule binding partners for the small molecules dopamine and biotin.