Postpartum changes in the GABAergic system in the bed nucleus of the accessory olfactory tract

The bed nucleus of the accessory olfactory tract (BAOT) is a sexually dimorphic structure which controls the inhibition/disinhibition of the medial preoptic area in the expression of maternal behavior. Therefore, in the present study we investigated sex differences and the modulation of gamma-aminobutiric-acid (GABA) in the BAOT during the first two postpartum days. Four groups of Wistar rats: control males, control females, 0 h postpartum females and 48 h postpartum females, were used in this experiment. Sex differences in glutamate decarboxylase (GAD) and GABA(A) alpha-chain receptor densities were apparent in the BAOT. The hormonal and behavioral postpartum state affects GABAergic activity in the females' BAOT in two ways: firstly, pregnancy and the first two postpartum days induce an increase in GABA(A)-receptor and GAD densities; secondly, the intensity of these activities are greater in the left hemisphere than in the right. These changes might be related to the BAOT's function of inhibiting/disinhibiting maternal behavior.     

Improved purification and PCR amplification of DNA from environmental samples

Purification and PCR amplification procedures for DNA extracted from environmental samples (soil, compost, and river sediment) were improved by introducing three modifications: precipitation of DNA with 5% polyethylene glycol 8000 (PEG) and 0.6 M NaCl; filtration with a Sepharose 4B-polyvinylpolypyrrolidone (PVPP) spin column; and addition of skim milk (0.3% w/v) to the PCR reaction solution. Humic substances' concentration after precipitation with 5% PEG was 2.57-, 5.3-, and 78.9-fold lower than precipitation with 7.5% PEG, 10% PEG, and isopropanol, respectively. After PEG precipitation, Sepharose, PVPP and the combined (Sepharose-PVPP) column removed 92.3%, 89.5%, and 98%, respectively, of the remaining humic materials. Each of the above-mentioned modifications improved PCR amplification of the 16S rRNA gene. DNA extracted by the proposed protocol is cleaner than DNA extracted by a commercial kit. Nevertheless, the improvement of DNA purification did not improve the detection limit of atrazine degradation gene atzA.     

Sun‐induced fluorescence – a new probe of photosynthesis: First maps from the imaging spectrometer HyPlant

Variations in photosynthesis still cause substantial uncertainties in predicting photosynthetic CO₂ uptake rates and monitoring plant stress. Changes in actual photosynthesis that are not related to greenness of vegetation are difficult to measure by reflectance based optical remote sensing techniques. Several activities are underway to evaluate the sun‐induced fluorescence signal on the ground and on a coarse spatial scale using space‐borne imaging spectrometers. Intermediate‐scale observations using airborne‐based imaging spectroscopy, which are critical to bridge the existing gap between small‐scale field studies and global observations, are still insufficient. Here we present the first validated maps of sun‐induced fluorescence in that critical, intermediate spatial resolution, employing the novel airborne imaging spectrometer HyPlant. HyPlant has an unprecedented spectral resolution, which allows for the first time quantifying sun‐induced fluorescence fluxes in physical units according to the Fraunhofer Line Depth Principle that exploits solar and atmospheric absorption bands. Maps of sun‐induced fluorescence show a large spatial variability between different vegetation types, which complement classical remote sensing approaches. Different crop types largely differ in emitting fluorescence that additionally changes within the seasonal cycle and thus may be related to the seasonal activation and deactivation of the photosynthetic machinery. We argue that sun‐induced fluorescence emission is related to two processes: (i) the total absorbed radiation by photosynthetically active chlorophyll; and (ii) the functional status of actual photosynthesis and vegetation stress.     

Accurate Prediction of the Dynamical Changes within the Second PDZ Domain of PTP1e

Experimental NMR relaxation studies have shown that peptide binding induces dynamical changes at the side-chain level throughout the second PDZ domain of PTP1e, identifying as such the collection of residues involved in long-range communication. Even though different computational approaches have identified subsets of residues that were qualitatively comparable, no quantitative analysis of the accuracy of these predictions was thus far determined. Here, we show that our information theoretical method produces quantitatively better results with respect to the experimental data than some of these earlier methods. Moreover, it provides a global network perspective on the effect experienced by the different residues involved in the process. We also show that these predictions are consistent within both the human and mouse variants of this domain. Together, these results improve the understanding of intra-protein communication and allostery in PDZ domains, underlining at the same time the necessity of producing similar data sets for further validation of thses kinds of methods.     

Toward Sustaining Women in Careers in Core Laboratories—A Workshop Review Including Recommendations from the Association of Biomolecular Resource Facilities

Review of “From Doctorate to Dean or Director: Sustaining Women Through Critical Transition Points in Science, Engineering, and Medicine” (workshop held by the Committee on Women in Science, Engineering, and Medicine of the National Academies, Washington DC, September 18–19, 2008).Approximately 50% of the membership in the Association of Biomolecular Resource Facilities (ABRF) includes scientists working in core facilities, i.e., a biological resource facility. A core facility, whether it resides in an academic, government, or industrial sector, provides affordable access to technologies and expertise in such fields as proteomics-related techniques, mass spectrometry, DNA sequencing and analysis, bioinformatics, and N-terminal protein sequence analysis, whih would otherwise be too expensive for most individual labs to acquire. Careers in core facilities, unless integrated into a tenure line, are distinct from traditional academic jobs. The critical transition point in a core facility career is from bench scientist to core facility director. The role of bench scientists is to maintain a high working level of technological proficiency in the techniques offered by the laboratory, while continuing to expand their skill set to incorporate the latest technological advances. The role of the director encompasses those of the bench scientist in addition to responsibilities for personnel and budget management, obtaining competitive grants, and developing and maintaining a satisfied customer base. In a workshop entitled “From Doctorate to Dean or Director: Sustaining Women Through Critical Transition Points in Science, Engineering, and Medicine” (held by the Committee on Women in Science, Engineering, and Medicine of the National Academies, Washington DC, September 18–19, 2008), the ABRF and sixteen other professional societies presented data relating to field-specific gender issues as well as recommendations to sustain women through transition points in their scientific careers.In an ABRF survey study published in Nature Biotechnology in 2000,¹ the percentage of male employees holding MDs or PhDs across all core facility sectors was significantly greater than the percentage of female employees (24% and 9%, respectively). The government core facilities showed the highest level of disparity: 39% of males with an MD or PhD vs. 7% of females with these degrees (N = 42 government employee respondents). Of all the male employees hired by government-run core facilities, 54.6% held MDs or PhDs; among female employees, 19.4% held MDs or PhDs. However, in contrast to national trends, there is no significant difference in salaries for men and women at the same degree level at core facilities¹ in all sectors. Since compensation for men and women holding PhDs in core facilities is equal, why do the numbers of men and women at the PhD level working in core facilities differ significantly? This discrepancy raises the important question as to whether women with PhDs are represented in the job applicant pool in the expected ratio, and whether women are selected for core facility director positions in numbers that reflect their overall numbers within the field. If women with PhDs are found not to be represented in the applicant pool in the expected ratio, then one potential reason for the disparity could be gender hiring biases. Alternatively, the number of years on the job could also have skewed the results if more female PhDs were newer hires (data not reported), as newer employees feel increased job stress and might be less likely to respond to such a survey. The critical question remaining is whether these skews translate into fewer female core facility scientists entering director positions, as most facility directors hold advanced degrees. Since this study is somewhat dated, it is important to readdress, perhaps with a new comprehensive survey, whether these disparities still exist in core facilities, especially now when women and men in the sciences are earning their PhDs at nearly equal rates.²This study was discussed at the workshop and overall there was great enthusiasm for a new survey to address the issues. At the workshop, the observation that the number of women scientists decreases with advancing professional rank was coined the “leaky pipeline.” The leaky pipeline itself may also be a mitigating factor for the skewed gender statistics in core facility laboratories, and the workshop panelists explored this phenomenon in great detail. Joan Girgus, Professor of Psychology and Special Assistant to the Dean of the Faculty for issues concerning faculty diversity at Princeton University, attributes the leaky pipeline in part to competing family commitments. To address this specifically, Princeton has a comprehensive family-benefits program that includes (1) travel awards to offset childcare expenses when scientific conferences are attended, and (2) a dependent-care backup program. Dr. Phoebe Leboy, President of the Association for Women in Science, attributes the leaky pipeline in part to family issues, self-confidence, and more entrenched obstacles of a “chilly climate” or “locker-room mentality” where women are demeaned and undervalued, and suggests that the culture of science is designed for men, in the sense that to succeed in the environment of a normal 12-hour-plus work day relies on there being a woman at home to take care of the family and family business. She offered thought-provoking ideas for culture change including basing hiring decisions on the quality of publications and grant scores, rather than the sheer numbers of publications and grants obtained. Pardis Sabeti, a young and enthusiastic new Assistant Professor of Systems Biology at Harvard University, attributes the leaky pipeline to self-confidence issues, claiming that women in general must feel “100% prepared to apply to a new position,” whereas men may be bolder and “apply if they feel only 60% qualified.” This type of discrepancy in gender psychology may well explain gender skews in job applicant pools.One other mitigating factor that was discussed is the length of time it takes to obtain a PhD degree. Michelle Cilia, a Postdoctoral Associate with the United States Department of Agriculture, Agricultural Research Service at Cornell University, pointed out an exemplary new PhD program that is aimed at shortening the length of time to get the degree by changing the culture of the PhD program without sacrificing the quality of education. This graduate school, The Watson School of Biological Sciences at Cold Spring Harbor Laboratory, combines innovative coursework, bi-yearly committee meetings organized by the graduate school administrators, and a two-tier mentoring system to assist students toward the goal of a 4-year PhD. Thus, while there are many “leaks in the pipeline,” both individuals and organizations are sealing these leaks to foster improvement in retaining women in their fields. What role can the ABRF play in helping to sustain women in their scientific professions?The ABRF as an organization could potentially provide the resources, such as a mentoring program, to help women scientists along the career track from bench scientist to core facility director in the absence of other institutional support such as tenure reviews and departmental support. Currently, no such programs are established. Female core facility scientists are not alone in feeling the adverse effects of the lack of resources such as mentoring programs, for the current cohort of women chemists in academia has reported mentoring gaps and gender biases at some point during their careers.³ It is not clear whether the lack of such programs indicates that there is limited interest in mentoring female scientists who wish to become core directors or if few female scientists are on such a track and seek assistance. With the growing need for proteomics, bioinformatics, and genome sequencing services, core facilities are in high demand and are now found at almost every major research university and medical center. This growth translates into more job opportunities for women scientists. Given the rapid growth of this relatively young career path, the absence of mentorship support, and the unequal numbers of male and female employees holding advanced degrees in core facilities, the ABRF and its members would benefit from learning about and implementing proven strategies to help female members rise from the ranks of scientist to core facility director. There are numerous things the ABRF as a professional society can do to directly address issues that disproportionately affect women:

1. Gather data through the ABRF Survey Committee to identify gaps between the genders in areas that might contribute to the leaky pipeline such as the job applicant pool, promotions, job satisfaction, number of years on the job, number of women in core director positions, and the availability of family-friendly benefits packages. The Survey Committee might consider enlisting the services of a survey research specialist in designing the survey.
2. Institute a mentoring program that encourages networking and additional training to tackle the added job responsibilities of a core facility director. This can be done at annual meetings in the form of professional development workshops. For example, the American Society for Cell Biology has two programs associated with their annual meeting: one geared toward new faculty, which helps new assistant professors tackle the demands of the pre-tenure phase, and “Reboot Camp” for older faculty who might be left behind advances in technology or policies.
3. Elevate the status of the profession. Core directors are critical to the advancement and achievement of research goals and technology in all sectors. However, many feel underappreciated and not fully recognized for their work, especially if their positions are not clearly defined by the university. Through the Survey Committee, the ABRF might gather data on how core facility directors feel they are perceived by their colleagues. Local meetings, such as the Northeast Regional Life Sciences Core Directors meeting, provide networking opportunities and a great platform for core facility directors to discuss specific issues pertaining to their position.
4. Encourage undergraduates, graduate students, and postdoctoral researchers to use core facilities for interdisciplinary aspects of their research. Doing so will expose young scientists to alternative career options and give them networking opportunities outside their field of study. The ABRF began this tradition at last year’s 2008 annual meeting when they presented two postdoctoral scientists with awards for collaborating with core facilities, and also gave them the opportunity to present their research at the annual meeting.

The ABRF presented these suggestions at the workshop so as to highlight a distinct, new career path for women scientists and some of the unique barriers they may have to overcome while pursuing the career as core director, and to highlight what the ABRF can do to help sustain women through their career transitions. During the transition from scientist to director, a woman faces the same professional challenges as faculty members and university administrators, while also having to deal with the personal challenges that confront all working female scientists.² Women would thus benefit greatly from the same training and mentoring programs available to these other professionals.To address the issues facing women in core facility careers, the ABRF has taken the important first step of organizing a workshop at the upcoming 2009 annual meeting. Much can be learned from the workshop reviewed here—“From Doctorate to Dean or Director: Sustaining Women Through Critical Transition Points in Science, Engineering, and Medicine”—and its lessons might be useful as discussion points for the ABRF 2009 workshop. The overall themes that guided the panelist’s discussions and the suggestions offered by other professional societies mirror the concerns of the ABRF. Gathering information and disseminating the results of studies on issues pertaining to women, in particular women of color, is critical to the success of any workshop examining the lives of women in the world of science. Professional societies must be engaged as a vehicle for bringing change about in the culture of science; however, administrators must also be brought on board for change to occur in any systematic way. Basic issues like self-confidence, learning how to prioritize at work, and how to manage the work–family juggle have a big impact on a woman’s decision to stay in science. Outreach and education are important so senior women scientists can serve as examples for the aspiring youth, in particular with regard to teaching young women how to advantageously use their professional network. Mentorship and family-friendly benefit programs can can have a profound effect on the effort to retain women in science. Even more than a mentor, women need champions who will go to bat for them for the big promotion at the critical transition. An example of such a champion is Dr. Eugene P. Orringer, Professor of Medicine at the University of North Carolina–Chapel Hill, and the school’s Executive Associate Dean for Faculty Affairs. As the principal investigator of a $2.5-million grant from the National Institutes of Health—“Building Interdisciplinary Research Careers in Women’s Health” (BIRCWH, pronounced “birch”)—he has directly helped, through instituting a mentorship program, 24 young faculty (22 of them women) obtain National Institutes of Health “K” or “R” grants at a rate of nearly 100%. Finally, leadership and inspiration are vital to success in every scientific endeavor and the ABRF is in a unique position, being an active professional society with a significant membership population of core facility directors, to provide such leadership and inspiration to their core facilities scientists who aspire to directorships or beyond.     

A Comparison of Protein Extraction Methods Suitable for Gel-Based Proteomic Studies of Aphid Proteins

Protein extraction methods can vary widely in reproducibility and in representation of the total proteome, yet there are limited data comparing protein isolation methods. The methodical comparison of protein isolation methods is the first critical step for proteomic studies. To address this, we compared three methods for isolation, purification, and solubilization of insect proteins. The aphid Schizaphis graminum, an agricultural pest, was the source of insect tissue. Proteins were extracted using TCA in acetone (TCA-acetone), phenol, or multi-detergents in a chaotrope solution. Extracted proteins were solubilized in a multiple chaotrope solution and examined using 1-D and 2-D electrophoresis and compared directly using 2-D Difference Gel Electrophoresis (2-D DIGE). Mass spectrometry was used to identify proteins from each extraction type. We were unable to ascribe the differences in the proteins extracted to particular physical characteristics, cell location, or biological function. The TCA-acetone extraction yielded the greatest amount of protein from aphid tissues. Each extraction method isolated a unique subset of the aphid proteome. The TCA-acetone method was explored further for its quantitative reliability using 2-D DIGE. Principal component analysis showed that little of the variation in the data was a result of technical issues, thus demonstrating that the TCA-acetone extraction is a reliable method for preparing aphid proteins for a quantitative proteomics experiment. These data suggest that although the TCA-acetone method is a suitable method for quantitative aphid proteomics, a combination of extraction approaches is recommended for increasing proteome coverage when using gel-based separation techniques.     

Synthesis and alpha4beta2 nicotinic affinity of unichiral 5-(2-pyrrolidinyl)oxazolidinones and 2-(2-pyrrolidinyl)benzodioxanes

The RS and SR enantiomers of 2-oxazolidinone and 1,4-benzodioxane bearing a 2-pyrrolidinyl substituent at the 5- and 2-position, respectively, were synthesized as candidate nicotinoids. One of the two benzodioxane stereoisomers reasonably fits the pharmacophore elements of (S)-nicotine and binds at alpha4beta2 nicotinic acetylcholine receptor with submicromolar affinity. Interestingly, both the synthesized pyrrolidinylbenzodioxanes exhibit analogous affinity at alpha(2) adrenergic receptor resembling the behaviour of some known alpha(2)-AR ligands recently proved to possess neuronal nicotinic affinity.