Parents' understanding and experiences of blood component transfusion in the neonatal intensive care unit: A qualitative study.

AIM: Blood component transfusion is a common intervention in the neonatal intensive care unit (NICU). Parents consent on their babies' behalf. This study aimed to explore parents' understandings and experiences of consenting and the subsequent blood transfusion. METHODS: A "low inference" qualitative descriptive semi-structured interview approach was utilised. Grounded theory was employed. Parents described their memories of babies' transfusions, their responses to the consent process and assessed the written information they were given. RESULTS: A purposive sample of 17 parents whose babies required blood transfusion in the NICU participated. Parents talked about their initial fears of transfusion, later replaced by confidence in the process and results of transfusion and trust in the healthcare professional team. The main themes elicited by the interviews were parents' expectations and outcomes of transfusion, parents' prior and current opinions of transfusion, parents trust in healthcare professionals and how parents would like to receive information about transfusions in the NICU. CONCLUSION: Parents in our study trust information from the healthcare professionals caring for their baby and would like more specific information about how blood transfusion will impact their baby, in a variety of means. Parents felt that blood transfusions were beneficial for their babies.

Projecting the impact of an ebola virus outbreak on endangered mountain gorillas.

Ebola virus is highly lethal for great apes. Estimated mortality rates up to 98% have reduced the global gorilla population by approximately one-third. As mountain gorillas (Gorilla beringei beringei) are endangered, with just over 1000 individuals remaining in the world, an outbreak could decimate the population. Simulation modeling was used to evaluate the potential impact of an Ebola virus outbreak on the mountain gorilla population of the Virunga Massif. Findings indicate that estimated contact rates among gorilla groups are high enough to allow rapid spread of Ebola, with less than 20% of the population projected to survive at 100 days post-infection of just one gorilla. Despite increasing survival with vaccination, no modeled vaccination strategy prevented widespread infection. However, the model projected that survival rates greater than 50% could be achieved by vaccinating at least half the habituated gorillas within 3 weeks of the first infectious individual.

Pericardiocentesis by an Air Medical Service for Cardiac Tamponade Caused by Purulent Pericarditis.

This case presentation describes the clinical management and course of an adult patient found to be in cardiac tamponade secondary to purulent pericarditis. This etiology represents an uncommon cause of pericardial tamponade and highlights the importance of recognizing clinical signs of this physiological state despite the uncommon presentation. This also reinforces that critical care transport teams must be trained and facile with high acuity-low occurrence skills such as pericardiocentesis as such time-sensitive measures may be necessary to stabilize patients for transport. The patient in this case had clinical improvement after pericardiocentesis was performed and this allowed for the safe transport of the patient to a tertiary care center.

Implementation of Title X Family Planning Services in Primary Care: A Qualitative Study of a Primary Care Network in Georgia.

CONTEXT: There is increasing interest and value in integrating family planning services into primary care. Title X services provide an opportunity to expand low-cost access to these services. This study sought to identify and describe implementation factors that influenced the integration of a package of Title X services into a unique primary care setting within a Georgia primary care network whose community health center sites are primarily federally qualified health centers. METHODS: We used an implementation science approach and were guided by the Consolidated Framework for Implementation Research. From December 2019 to September 2020, we conducted interviews with administrators and providers working at grantee and sub-grantee organizations about their experiences integrating Title X services into their existing practice. RESULTS: Factors associated with the Inner Setting were especially important for integrating Title X in these settings. Participants identified specific needs related to resources such as electronic medical record (EMR) and reporting templates. Contextually specific clinical training for provision of long-acting reversible contraception and sexual health counseling, as well as administrative training for reporting and documentation efforts, was particularly needed. Grantee and sub-grantee organizations were able to leverage internal and external networks and adaptations to the intervention to successfully implement Title X services and to expand reach to new clients. CONCLUSIONS: Integrating family planning into primary care may expand access to low-income and underserved populations. Approaches that incorporate flexibility and provide tailored resources for primary care settings such as EMR and reporting templates and trainings, and that leverage multiple forms of support and knowledge sharing, may be particularly important for helping to implement Title X services.

Decision rules for an abbreviated administration of the Test of Memory Malingering.

The present study investigated abbreviation methods for the Test of Memory Malingering (TOMM) in relation to traditional manual-based test cutoffs and independently derived more stringent cutoffs suggested by recent research (≤48 on Trial 2 or 3). Consecutively referred outpatient U.S. military veterans (n = 260) were seen for neuropsychological evaluation for mild traumatic brain injury or possible attention-deficit/hyperactivity disorder. Performance on TOMM Trial 1 was evaluated, including the total score and errors on the first 10 items (TOMMe10), to determine correspondence and redundancy with Trials 2 and 3. Using the traditional cutoff, valid performance on Trials 2 and 3 was predicted by zero errors on TOMMe10 and by Trial 1 scores greater than 41. Invalid performance was predicted by commission of more than three errors on TOMMe10 and by Trial 1 scores less than 34. For revised TOMM cutoffs, a Trial 1 score above 46 was predictive of a valid score, and a TOMMe10 score of three or more errors or a Trial 1 score below 36 was associated with invalid TOMM performance. Conditional abbreviation of the TOMM is feasible in a vast majority of cases without sacrificing information regarding performance validity. Decision trees are provided to facilitate administration of the three trials.

After short interbirth intervals, captive callitrichine monkeys have higher infant mortality.

Life history theory predicts a trade-off between the quantity and quality of offspring. Short interbirth intervals-the time between successive births-may increase the quantity of offspring but harm offspring quality. In contrast, long interbirth intervals may bolster offspring quality while reducing overall reproductive output. Further research is needed to determine whether this relationship holds among primates, which have intensive parental investment. Using Cox proportional hazards models, we examined the effects of interbirth intervals (short, normal, or long) on infant survivorship using a large demographic dataset (n = 15,852) of captive callitrichine monkeys (marmosets, tamarins, and lion tamarins). In seven of the nine species studied, infants born after short interbirth intervals had significantly higher risks of mortality than infants born after longer interbirth intervals. These results suggest that reproduction in callitrichine primates may be limited by physiologic constraints, such that short birth spacing drives higher infant mortality.

Teleneuropsychology clinic development and patient satisfaction.

Objective: Telehealth offers the opportunity to address a growing need to improve access to specialty services, such as neuropsychology, particularly for older adults and those in rural areas. Initial research has examined the validity and acceptability of teleneuropsychology (teleNP) in research settings, but there is less information about teleNP implementation in clinical practice. Here we describe the development of a teleNP clinic and compare patient satisfaction to those completing in-person neuropsychological evaluations. Method: A teleNP clinic was developed at the VA Bedford Healthcare System to serve older Veterans with referral questions focused on cognitive aging concerns. Patients presented to affiliated VA satellite clinics and were connected to neuropsychology clinicians at the main hospital campus through synchronous video. An evaluation battery was compiled to closely approximate in-person evaluations. Trained staff members at the satellite clinic assisted with administration of select tasks. Patient satisfaction was evaluated using a self-report questionnaire and responses were compared to a group undergoing in-person neuropsychological evaluations. Results: Self-reported satisfaction was high for all aspects of the patient experience, with no significant difference found between teleNP (n = 67) and in-person (n = 64) groups. In particular, 90% of patients in the teleNP group and 98% of patients in the in-person group agreed or strongly agreed with the statement, "I was overall satisfied with this visit.". Conclusions: TeleNP is a feasible and acceptable alternative to traditional in-person neuropsychological evaluations in clinical practice focused on older adults. Future research should continue to validate evaluation measures used in telehealth settings, identify the populations that would benefit most from teleNP services, and explore the expansion of teleNP services.

Applying the zoo model to conservation of threatened exceptional plant species.

Maintaining a living plant collection is the most common method of ex situ conservation for plant species that cannot be seed banked (i.e., exceptional species). Viability of living collections, and their value for future conservation efforts, can be limited without coordinated efforts to track and manage individuals across institutions. Using a pedigree-focused approach, the zoological community has established an inter-institutional infrastructure to support long-term viability of captive animal populations. We assessed the ability of this coordinated metacollection infrastructure to support the conservation of 4 plant species curated in living collections at multiple botanic gardens around the world. Limitations in current practices include the inability to compile, share, and analyze plant collections data at the individual level, as well as difficulty in tracking original provenance of ex situ material. The coordinated metacollection framework used by zoos can be adopted by the botanical community to improve conservation outcomes by minimizing the loss of genetic diversity in collections. We suggest actions to improve ex situ conservation of exceptional plant species, including developing a central database to aggregate data and track unique individuals of priority threatened species among institutions and adapting a pedigree-based population management tool that incorporates life-history aspects unique to plants. If approached collaboratively across regional, national, and global scales, these actions could transform ex situ conservation of threatened plant species.

Aplicación del Modelo Zoológico a la Conservación de Especies Excepcionales de Plantas Amenazadas Resumen El mantenimiento de una colección de plantas vivas es el método más común para de conservación ex situ para especies de plantas que no pueden almacenarse en bancos de semillas (i. e., especies excepcionales). La viabilidad de las colecciones vivientes, junto con el valor que representan para los futuros esfuerzo de conservación, puede estar limitada si no existen esfuerzos coordinados para rastrear y manejar a los individuos entre las instituciones. Mediante una estrategia enfocada en el linaje, la comunidad de zoológicos ha establecido una infraestructura interinstitucional que respalda la viabilidad a largo plazo de las poblaciones de animales en cautiverio. Evaluamos la habilidad de esta infraestructura coordinada de metacolecciones para apoyar en la conservación de cuatro especies de plantas curadas en colecciones vivientes en varios jardines botánicos de todo el mundo. Las limitaciones de las prácticas contemporáneas incluyen la incapacidad de recopilar, compartir y analizar los datos de las colecciones de plantas a nivel individual, así como la dificultad de rastrear la procedencia original del material ex situ. El marco de trabajo de metacolecciones coordinadas que utilizan los zoológicos puede ser adoptado por la comunidad botánica para mejorar los resultados de conservación al minimizar la pérdida de la diversidad genética que ocurre en las colecciones. Sugerimos acciones que aumenten la conservación ex situ de las especies excepcionales de plantas. Estas acciones incluyen el desarrollo de una base de datos central para acumular datos y rastrear entre las instituciones a los individuos únicos de las especies amenazadas prioritarias y la adaptación de una herramienta de manejo poblacional basada en el linaje que incorpore los aspectos únicos de la historia de vida de las plantas. Si estas acciones se plantean colaborativamente a escala regional, nacional y global, podrían transformar la conservación ex situ de las especies amenazadas de plantas.

Integrating a pharmacist into the perioperative setting.

This paper describes the integration of a pharmacist into a perioperative environment and the ensuing quality and economic benefits. Deficiencies were identified in medication management in operating theatres (OT) at a large tertiary hospital. A perioperative pharmacist was employed for a 6-month pilot period, with permanent funding dependent on demonstration of agreed economic benefits. A multidisciplinary committee set goals, drove strategic initiatives and was accountable for delivery of outcomes. Pharmaceutical expenditure was analysed and high expenditure items targeted. Cost savings and staff satisfaction were measured at 6 months. Savings of A$63884 were achieved during the pilot period, resulting from optimised pharmaceutical unit pricing, OT medication stock on hand (imprest) review and redesigned medication management strategies. Improvements in medication management included better access to medications in the OT, rationalising available products to minimise wastage and implementation of guidelines and protocols for high-cost and high-risk medications. At 6 months, 97% of theatre staff supported continuation of the role; the project was extended with demonstrated cost savings of A$157265 at 12 months. The integration of a perioperative pharmacist resulted in cost savings and medication management improvements in the OT setting. A permanent position was funded.

A comparative study of litter size and sex composition in a large dataset of callitrichine monkeys.

In many birds and mammals, the size and sex composition of litters can have important downstream effects for individual offspring. Primates are model organisms for questions of cooperation and conflict, but the factors shaping interactions among same-age siblings have been less-studied in primates because most species bear single young. However, callitrichines (marmosets, tamarins, and lion tamarins) frequently bear litters of two or more, thereby providing the opportunity to ask whether variation in the size and sex composition of litters affects development, survival, and reproduction. To investigate these questions, we compiled a large dataset of nine species of callitrichines (n = 27,080 individuals; Callithrix geoffroyi, Callithrix jacchus, Cebuella pygmaea, Saguinus imperator, Saguinus oedipus, Leontopithecus chrysomelas, Leontopithecus chrysopygus, Leontopithecus rosalia, and Callimico goeldii) from zoo and laboratory populations spanning 80 years (1938-2018). Through this comparative approach, we found several lines of evidence that litter size and sex composition may impact fitness. Singletons have higher survivorship than litter-born peers and they significantly outperform litter-born individuals on two measures of reproductive performance. Further, for some species, individuals born in a mixed-sex litter outperform isosexually-born individuals (i.e., those born in all-male or all-female litters), suggesting that same-sex competition may limit reproductive performance. We also document several interesting demographic trends. All but one species (C. pygmaea) has a male-biased birth sex ratio with higher survivorship from birth to sexual maturity among females (although this was significant in only two species). Isosexual litters occurred at the expected frequency (with one exception: C. pygmaea), unlike other animals, where isosexual litters are typically overrepresented. Taken together, our results indicate a modest negative effect of same-age sibling competition on reproductive output in captive callitrichines. This study also serves to illustrate the value of zoo and laboratory records for biological inquiry.

Electrophysiological evidence for detrimental impact of a reappraisal emotion regulation strategy on subsequent cognitive control in schizophrenia.

In healthy individuals, there is evidence that effective implementation of an emotion regulation strategy has beneficial effects on temporally proximal cognitive control task performance. This effect occurs because both of these processes rely heavily on the prefrontal cortex. Individuals with schizophrenia (SZ) have impairments in both emotion regulation and cognitive control that are driven by structural and functional abnormalities of the prefrontal cortex; however, it is unknown whether emotion regulation attempts fail to benefit subsequently performed cognitive control tasks in people with SZ. The present study examined whether attempts to increase or decrease negative emotion via reappraisal have differential effects on subsequent cognitive control in a sample of outpatients diagnosed with SZ (n = 30) and demographically matched healthy controls (CN; n = 29). Participants completed a combined emotion regulation and cognitive control task in which numerical Stroop trials were presented immediately after unpleasant or neutral images that were either increased via reappraisal, decreased via reappraisal, or passively viewed. The electroencephalogram was recorded while participants performed the reappraisal-Stroop task and event related potentials (ERPs) were used to index emotion regulation effectiveness (late positive potential: LPP) and cognitive control (sustained potential: SP). Both CN and SZ evidenced higher LPP amplitude for unpleasant than neutral stimuli consistent with robust neural response to unpleasant stimuli. Although CN demonstrated neurophysiological evidence of effective use of reappraisal to increase and decrease negative emotion, SZ only showed an effective ability to increase negative emotion via reappraisal. CN displayed enhanced cognitive control following increase trials and impaired cognitive control following decrease trials, as indicated by modulation of SP amplitude. In SZ, increase instructions impaired cognitive control and decrease instructions had no effect on cognitive control. Findings suggest that emotion regulation abnormalities may play an underrecognized role in general cognitive control deficits that occur in SZ. (PsycINFO Database Record

Medical Care in a Free Clinic: A Comprehensive Evaluation of Patient Experience, Incentives, and Barriers to Optimal Medical Care with Consideration of a Facility Fee.

Free and charitable clinics are important contributors to the health of the United States population. Recently, funding for these clinics has been declining, and it is, therefore, useful to identify what qualities patients value the most in clinics in an effort to allocate funding wisely. In order to identify targets and incentives for improvement of patients' health, we performed a comprehensive analysis of patients' experience at a free clinic by analyzing a patient survey (N=94). The survey also assessed patient opinions of a small facility fee, which could be used to offset the decrease in funds. Interestingly, our patients believed it is appropriate to be charged a facility fee (78%) because it increases involvement in their care (r = 0.69, p < 0.001) and self-respect (r = 0.66, p < 0.001). Incentives to medical care include continuity of care, faith-based care, having a patient medical provider partnership, and charging a facility fee. Barriers include affordable housing, transportation, medication, and accessible information. In order to improve medical care in the uninsured population, our study suggested that we need to: 1) offer continuity of medical care; 2) offer affordable preventive health screenings; 3) support affordable transportation, housing, and medications; and 4) consider including a facility fee.

Avolition in schizophrenia is associated with reduced willingness to expend effort for reward on a Progressive Ratio task.

The current study examined whether effort-cost computation was associated with negative symptoms of schizophrenia (SZ). Participants included outpatients diagnosed with SZ (n=27) and demographically matched healthy controls (n=32) who completed a Progressive Ratio task that required incrementally greater amounts of physical effort to obtain monetary reward. Breakpoint, the point at which participants was no longer willing to exert effort for a certain reward value, was examined as an index of effort-cost computation. There were no group differences in breakpoint for low, medium, or high value rewards on the Progressive Ratio task. However, lower breakpoint scores were associated with greater severity of avolition and anhedonia symptoms in SZ patients. Findings provide further evidence that impaired effort-cost computation is linked to motivational abnormalities in SZ.

Predictors of neuropsychological effort test performance in schizophrenia.

There is some evidence that insufficient effort may be common in schizophrenia, posing significant threats to the validity of neuropsychological test results. Low effort may account for a significant proportion of variance in neuropsychological test scores and the generalized cognitive deficit that characterizes the disorder. The current study evaluated clinical predictors of insufficient effort in schizophrenia using an embedded effort measure, the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Effort Index (EI). Participants were 330 patients meeting DSM-IV-TR criteria for schizophrenia, schizoaffective disorder, or another psychotic disorder who received a battery of neuropsychological tests, including: Wechsler Test of Adult Reading (WTAR), Wechsler Abbreviated Scale of Intelligence (WASI), and RBANS. Clinical assessments designed to measure functional outcome and symptoms were also obtained. Results indicated that 9.4% of patients failed the EI. Patients who failed had lower full-scale, verbal, and performance IQ, as well as poorer performance on RBANS domains not included in the EI (immediate memory, language, and visuospatial/construction). Patients who failed the EI also displayed poorer community-based vocational outcome, greater likelihood of having "deficit schizophrenia" (i.e., primary and enduring negative symptoms), and increased severity of positive symptoms. Regression analyses revealed that insufficient effort was most significantly predicted by a combination of low IQ, negative symptoms, and positive symptoms. Findings suggest that although insufficient effort may be relatively uncommon in schizophrenia, it is associated with important clinical outcomes. The RBANS EI may be a useful tool in evaluating insufficient effort in schizophrenia.

Endogenous oxytocin levels are associated with the perception of emotion in dynamic body expressions in schizophrenia.

Lower endogenous oxytocin levels have been associated with impaired social cognition in schizophrenia, particularly facial affect identification. Little is known about the relationship between oxytocin and other forms of emotion perception. In the current study, 41 individuals with schizophrenia (SZ) and 22 demographically matched healthy controls (CN) completed a forced-choice affective body expression classification task. Stimuli included dynamic videos of male and female actors portraying 4 discrete emotions: happiness, sadness, anger, and neutral. Plasma oxytocin levels were determined via radioimmunoassay. Results indicated that SZ had significantly higher plasma oxytocin concentrations than CN. SZ were also less accurate at identifying expressions of happiness and sadness; however, there were no group differences for anger or neutral stimuli. A group×sex interaction was also present, such that female CN were more accurate than male CN, whereas male SZ were more accurate than female SZ. Higher endogenous oxytocin levels were associated with better total recognition in both SZ and CN; this association was specific to females in SZ. Findings indicate that sex plays an important role in identifying emotional expressions in body gestures in SZ, and that individual differences in endogenous oxytocin predict emotion perception accuracy.

The role of low cognitive effort and negative symptoms in neuropsychological impairment in schizophrenia.

OBJECTIVE: Two experiments were conducted to examine whether insufficient effort, negative symptoms (e.g., avolition, anhedonia), and psychological variables (e.g., anhedonia and perception of low cognitive resources) predict generalized neurocognitive impairment in individuals with schizophrenia (SZ). METHOD: In Experiment 1, participants included 97 individuals with SZ and 63 healthy controls (CN) who completed the Victoria Symptom Validity Test (VSVT), the MATRICS Consensus Cognitive Battery (MCCB), and self-report anhedonia questionnaires. In Experiment 2, participants included 46 individuals with SZ and 33 CN who completed Green's Word Memory Test (WMT), the MCCB, and self-reports of anhedonia, defeatist performance beliefs, and negative expectancy appraisals. RESULTS: RESULTS indicated that a low proportion of individuals with SZ failed effort testing (1.0% Experiment 1; 15.2% Experiment 2); however, global neurocognitive impairment was significantly predicted by low effort and negative symptoms. CONCLUSIONS: Findings indicate that low effort does not threaten the validity of neuropsychological test results in the majority of individuals with schizophrenia; however, effort testing may be useful in SZ patients with severe negative symptoms who may be more likely to put forth insufficient effort due to motivational problems. Although the base rate of failure is relatively low, it may be beneficial to screen for insufficient effort in SZ and exclude individuals who fail effort testing from pharmacological or cognitive remediation trials.

Importance of c-Type cytochromes for U(VI) reduction by Geobacter sulfurreducens.

BACKGROUND: In order to study the mechanism of U(VI) reduction, the effect of deleting c-type cytochrome genes on the capacity of Geobacter sulfurreducens to reduce U(VI) with acetate serving as the electron donor was investigated. RESULTS: The ability of several c-type cytochrome deficient mutants to reduce U(VI) was lower than that of the wild type strain. Elimination of two confirmed outer membrane cytochromes and two putative outer membrane cytochromes significantly decreased (ca. 50-60%) the ability of G. sulfurreducens to reduce U(VI). Involvement in U(VI) reduction did not appear to be a general property of outer membrane cytochromes, as elimination of two other confirmed outer membrane cytochromes, OmcB and OmcC, had very little impact on U(VI) reduction. Among the periplasmic cytochromes, only MacA, proposed to transfer electrons from the inner membrane to the periplasm, appeared to play a significant role in U(VI) reduction. A subpopulation of both wild type and U(VI) reduction-impaired cells, 24-30%, accumulated amorphous uranium in the periplasm. Comparison of uranium-accumulating cells demonstrated a similar amount of periplasmic uranium accumulation in U(VI) reduction-impaired and wild type G. sulfurreducens. Assessment of the ability of the various suspensions to reduce Fe(III) revealed no correlation between the impact of cytochrome deletion on U(VI) reduction and reduction of Fe(III) hydroxide and chelated Fe(III). CONCLUSION: This study indicates that c-type cytochromes are involved in U(VI) reduction by Geobacter sulfurreducens. The data provide new evidence for extracellular uranium reduction by G. sulfurreducens but do not rule out the possibility of periplasmic uranium reduction. Occurrence of U(VI) reduction at the cell surface is supported by the significant impact of elimination of outer membrane cytochromes on U(VI) reduction and the lack of correlation between periplasmic uranium accumulation and the capacity for uranium reduction. Periplasmic uranium accumulation may reflect the ability of uranium to penetrate the outer membrane rather than the occurrence of enzymatic U(VI) reduction. Elimination of cytochromes rarely had a similar impact on both Fe(III) and U(VI) reduction, suggesting that there are differences in the routes of electron transfer to U(VI) and Fe(III). Further studies are required to clarify the pathways leading to U(VI) reduction in G. sulfurreducens.

Liver biopsy in cirrhotic patients.

Liver biopsy remains an important tool for the evaluation of patients with hepatic disease. However, clinicians utilize a variety of biopsy techniques including automated cutting needle devices, manual cutting needles, and aspiration needles. Using a large study cohort of patients with advanced fibrosis/cirrhosis we sought to evaluate practices and outcomes of the biopsy technique used by study investigators across the United States. All biopsy samples were from patients with suspected advanced fibrosis or cirrhosis because of hepatitis C virus (HCV) infection. Individual study investigators were permitted to use any biopsy technique. Biopsy specimens were centrally evaluated for tissue adequacy and fragmentation, and were histologically scored using accepted criteria. We evaluated a total of 923 liver biopsy specimens from 502 patients performed at 62 clinical sites. The average duration of HCV infection was 27.9 +/- 0.46 yr. Automated cutting needles were significantly more likely to provide adequate specimens for evaluation than aspiration needles (P < 0.005). Automated cutting needles produced significantly longer biopsies than other techniques (P < 0.05), except for a limited number of cases in which a surgical wedge biopsy was obtained. Tissue fragmentation was observed in 39.2% of liver biopsies obtained using an aspiration technique, but in only 4.7% of samples collected using an automated cutting needle (P < 0.001). We conclude that automated cutting needles provide superior liver biopsy specimens compared with aspiration techniques in subjects with advanced fibrosis/cirrhosis. No specific safety issues attributable to a particular biopsy method were identified.

Role of RelGsu in stress response and Fe(III) reduction in Geobacter sulfurreducens.

Geobacter species are key members of the microbial community in many subsurface environments in which dissimilatory metal reduction is an important process. The genome of Geobacter sulfurreducens contains a gene designated rel(Gsu), which encodes a RelA homolog predicted to catalyze both the synthesis and the degradation of guanosine 3',5'-bispyrophosphate (ppGpp), a regulatory molecule that signals slow growth in response to nutrient limitation in bacteria. To evaluate the physiological role of Rel(Gsu) in G. sulfurreducens, a rel(Gsu) mutant was constructed and characterized, and ppGpp levels were monitored under various conditions in both the wild-type and rel(Gsu) mutant strains. In the wild-type strain, ppGpp and ppGp were produced in response to acetate and nitrogen deprivation, whereas exposure to oxygen resulted in an accumulation of ppGpp alone. Neither ppGpp nor ppGp could be detected in the rel(Gsu) mutant. The rel(Gsu) mutant consistently grew to a higher cell density than the wild type in acetate-fumarate medium and was less tolerant of oxidative stress than the wild type. The capacity for Fe(III) reduction was substantially diminished in the mutant. Microarray and quantitative reverse transcription-PCR analyses indicated that during stationary-phase growth, protein synthesis genes were up-regulated in the rel(Gsu) mutant and genes involved in stress responses and electron transport, including several implicated in Fe(III) reduction, were down-regulated in the mutant. The results are consistent with a role for Rel(Gsu) in regulating growth, stress responses, and Fe(III) reduction in G. sulfurreducens under conditions likely to be prevalent in subsurface environments.

Exploratory data analysis reveals visuovisual interhemispheric transfer in functional magnetic resonance imaging.

We used an exploratory data analysis approach to detect interhemispheric processing of complex visual stimuli in functional magnetic resonance imaging (fMRI). A crossed-uncrossed visual field paradigm was used to elicit interhemispheric transfer of picture/word information. Under the uncrossed (control) condition, the stimuli were presented to the preferential hemispheres (pictures to the left visual field/right hemisphere and words to the right visual field/left hemisphere). Under the crossed condition, the visual field presentation was switched in order to elicit increased interhemispheric processing. Fuzzy cluster analysis revealed significantly more crossed activity in cortical areas near the splenium of the corpus callosum. As expected, examination of the activation revealed smaller responses in perisplenial regions (relative to visual responses in the medial extrastriate regions). The exploratory results were compared with those obtained from parametric and masked analyses. The findings confirm that fMRI can be used to detect interhemispheric transfer of picture/word information. The activation was optimally characterized using exploratory data analysis.