CUNY Academic Works

Unafraid and Unapologetic, Still

Alyshia Gálvez — Fri, 07 Jul 2017 10:04:14 PDT

Luis Saavedra, Melissa García Vélez, and Marlen Fernández were among the cofounders of the Lehman College DREAM Team, the first official group organized by and specifically for undocumented students at the City University of New York (CUNY). From their first semester on campus, until they graduated in 2014, Luis, Melissa, and Marlen worked tirelessly on campus, around the city, regionally, and at the federal level, demanding better services for undocumented students at the college and throughout the CUNY system, while also helping college and high school students mobilize on their own campuses. They engaged with national activist groups and debates, and remained centrally involved in the New York State Young Leadership Council (NYSYLC), an organization Melissa had joined between high school and college. The three students consider themselves part of the “undocumented, unafraid, and unapologetic” movement, and, along with many other undocumented youth, they “came out of the shadows” to declare their immigration status as they became active in the immigrant youth organizing movement.

Cholinergic enhancement of brain activation in mild cognitive impairment during episodic memory encoding

Shannon L. Risacher et al. — Fri, 07 Jul 2017 07:16:56 PDT

Objective: To determine the physiological impact of treatment with donepezil (Aricept) on neural circuitry supporting episodic memory encoding in patients with amnestic mild cognitive impairment (MCI) using functional magnetic resonance imaging (fMRI).

Methods: Eighteen patients with MCI and 20 age-matched healthy controls (HC) were scanned twice while performing an event-related verbal episodic encoding task. MCI participants were scanned before treatment and after approximately 3 months on donepezil; HCwere untreated but rescanned at the same interval.Voxel-level analyses assessed treatment effects on activation profiles in MCI patients relative to retest changes in non-treated HC. Changes in task-related connectivity in medial temporal circuitry were also evaluated, as were associations between brain activation, task-related functional connectivity, task performance, and clinical measures of cognition.

Results: At baseline, the MCI group showed reduced activation during encoding relative to HC in the right medial temporal lobe (MTL; hippocampal/parahippocampal) and additional regions, as well as attenuated task-related deactivation, relative to rest, in a medial parietal lobe cluster. After treatment, the MCI group showed normalized MTL activation and improved parietal deactivation. These changes were associated with cognitive performance. After treatment, the MCI group also demonstrated increased task-related functional connectivity from the right MTL cluster seed region to a network of other sites including the basal nucleus/caudate and bilateral frontal lobes. Increased functional connectivity was associated with improved task performance.

Conclusion: Pharmacologic enhancement of cholinergic function in amnestic MCI is associated with changes in brain activation and functional connectivity during episodic memory processing which are in turn related to increased cognitive performance. fMRI is a promising biomarker for assessing treatment related changes in brain function.

Common Cell Shape Evolution of Two Nasopharyngeal Pathogens

Frédéric J. Veyrier et al. — Fri, 07 Jul 2017 07:16:52 PDT

Respiratory infectious diseases are the third cause of worldwide death. The nasopharynx is the portal of entry and the ecological niche of many microorganisms, of which some are pathogenic to humans, such as Neisseria meningitidis and Moraxella catarrhalis. These microbes possess several surface structures that interact with the actors of the innate immune system. In our attempt to understand the past evolution of these bacteria and their adaption to the nasopharynx, we first studied differences in cell wall structure, one of the strongest immune-modulators. We were able to show that a modification of peptidoglycan (PG) composition (increased proportion of pentapeptides) and a cell shape change from rod to cocci had been selected for along the past evolution of N. meningitidis. Using genomic comparison across species, we correlated the emergence of the new cell shape (cocci) with the deletion, from the genome of N. meningitidis ancestor, of only one gene: yacF. Moreover, the reconstruction of this genetic deletion in a bacterium harboring the ancestral version of the locus together with the analysis of the PG structure, suggest that this gene is coordinating the transition from cell elongation to cell division. Accompanying the loss of yacF, the elongation machinery was also lost by several of the descendants leading to the change in the PG structure observed in N. meningitidis. Finally, the same evolution was observed for the ancestor of M. catarrhalis. This suggests a strong selection of these genetic events during the colonization of the nasopharynx. This selection may have been forced by the requirement of evolving permissive interaction with the immune system, the need to reduce the cellular surface exposed to immune attacks without reducing the intracellular storage capacity, or the necessity to better compete for adhesion to target cells.

On Groups of Homological Dimension One

Jonathan Cornick — Thu, 06 Jul 2017 17:50:42 PDT

It has been conjectured that the groups of homological dimension one are precisely the nontrivial locally free groups. Some algebraic, geometric and analytic properties of any potential counter example to the conjecture are discussed.

Technology and Wonder in Thirteenth-Century Iberia and Beyond

Christopher B. Swift — Thu, 06 Jul 2017 11:10:11 PDT

As the desire for affective experiences of the sacred increased in communities across Europe in the late Middle Ages, the Christian faithful crafted lifelike, mechanized figures of Christ, the Virgin Mary, and saints for use in religious festivals. Although each devotional culture evidences unique body/object relationships and meanings, in general animated ritual objects encouraged lay participation in the celebration of saints and the Passion by engaging the senses, and, consequently, an emotional sense of God. In this essay I investigate the ritual alliances between moveable, prop-like saints and their Iberian devotees, in particular the performative meanings that arose from encounters with technologies of the sacred.

The Sacred Performative: Holy Wednesday and Colonial Ritual/Theatre

Christopher B. Swift — Thu, 06 Jul 2017 11:10:08 PDT

"Holy Wednesday" is a late sixteenth century adaptation of a Spanish auto sacramental (sacred play) written in alphabetized Nahuatl, the predominant pre-Columbian language spoken on the High Central Plateau of Mexico. The author remains unknown, however he was likely a Nahua amanuensis educated by Franciscans at Colegio de Santa Cruz in Tlatelolco. Religious drama was one of the important evangelizing tools of the Catholic brotherhoods in colonial Mexico and although a record of performance of Holy Wednesday does not exist, this dramatic depiction of the final meeting of Christ and Mary prior to the crucifixion was almost certainly performed as part of Holy Week celebrations.

This paper reads the play "Holy Wednesday" as it performs in wider social and linguistic frames and as a subject of two critical modes: transculturation and performativity. Likely staged on a church patio by the Franciscans with Nahua boy actors, "Holy Wednesday" intermingles European and Nahua collaborators, audiences, languages, and religious tropes while documenting the uprooting of pre-Columbian culture and development of an entirely new ritual performance form differing from both parent cultures in fundamental ways.

Robot Saints

Christopher B. Swift — Wed, 05 Jul 2017 14:27:22 PDT

In the Middle Ages, articulating religious figures like wooden Deposition crucifixes and ambulatory saints were tools for devotion, techno-mythological objects that distilled the wonders of engineering and holiness. Robots are gestures toward immortality, created in the face of the undeniable fact and experience of the ongoing decay of our fleshy bodies. Both like and unlike human beings, robots and androids occupy a nebulous perceptual realm between life and death, animation and inanimation. Masahiro Mori called this in-between space the “uncanny valley.” In this essay I argue that unlike a modern person apprehending an android (the uncanny human-like object that resides in the space between what is essentially human and what is essentially not human), the physical animation of late medieval devotional objects fulfilled the expectations of their puppeteers and audiences to move. Glittering precious metals and stones, liturgical music, and other environmental properties of the sanctuary materially inferred the presence and action of saints on earth, greatly enhancing the affective lives of devotees. I focus on later medieval Spanish statues of the Virgin Mary in order to transcend their familiar aesthetic and religious interpretations of anthropomorphic statues, and explore instead their functional aspects and performative relationships between ritual objects and their users.

A Penitent Prepares: Affect, Contrition, and Tears

Christopher B. Swift — Wed, 05 Jul 2017 14:27:18 PDT

This essay draws upon a poetic and devotional texts from late medieval Spain to show how public displays of emotion (weeping, in particular) during penitential processions could be learned and prepared for in advance.

Radical Theatricality: Jongleuresque Performance on the Early Spanish Stage

Christopher B. Swift — Wed, 05 Jul 2017 14:27:15 PDT

Radical Theatricality describes medieval and early modern oral traditions through the culture of “jongleuresque” performers: juglares, trovadores, and other itinerant players, who have been relegated to the fringes of theatre history.

Protein Sectors: Statistical Coupling Analysis versus Conservation

Tiberiu Teşileanu et al. — Wed, 05 Jul 2017 14:10:25 PDT

Statistical coupling analysis (SCA) is a method for analyzing multiple sequence alignments that was used to identify groups of coevolving residues termed “sectors”. The method applies spectral analysis to a matrix obtained by combining correlation information with sequence conservation. It has been asserted that the protein sectors identified by SCA are functionally significant, with different sectors controlling different biochemical properties of the protein. Here we reconsider the available experimental data and note that it involves almost exclusively proteins with a single sector. We show that in this case sequence conservation is the dominating factor in SCA, and can alone be used to make statistically equivalent functional predictions. Therefore, we suggest shifting the experimental focus to proteins for which SCA identifies several sectors. Correlations in protein alignments, which have been shown to be informative in a number of independent studies, would then be less dominated by sequence conservation.

Effects of Extreme Climate Events on Tea (Camellia sinensis) Functional Quality Validate Indigenous Farmer Knowledge and Sensory Preferences in Tropical China

Selena Ahmed et al. — Wed, 05 Jul 2017 14:10:20 PDT

Climate change is impacting agro-ecosystems, crops, and farmer livelihoods in communities worldwide. While it is well understood that more frequent and intense climate events in many areas are resulting in a decline in crop yields, the impact on crop quality is less acknowledged, yet it is critical for food systems that benefit both farmers and consumers through high-quality products. This study examines tea (Camellia sinensis; Theaceae), the world’s most widely consumed beverage after water, as a study system to measure effects of seasonal precipitation variability on crop functional quality and associated farmer knowledge, preferences, and livelihoods. Sampling was conducted in a major tea producing area of China during an extreme drought through the onset of the East Asian Monsoon in order to capture effects of extreme climate events that are likely to become more frequent with climate change. Compared to the spring drought, tea growth during the monsoon period was up to 50% higher. Concurrently, concentrations of catechin and methylxanthine secondary metabolites, major compounds that determine tea functional quality, were up to 50% lower during the monsoon while total phenolic concentrations and antioxidant activity increased. The inverse relationship between tea growth and concentrations of individual secondary metabolites suggests a dilution effect of precipitation on tea quality. The decrease in concentrations of tea secondary metabolites was accompanied by reduced farmer preference on the basis of sensory characteristics as well as a decline of up to 50% in household income from tea sales. Farmer surveys indicate a high degree of agreement regarding climate patterns and the effects of precipitation on tea yields and quality. Extrapolating findings from this seasonal study to long-term climate scenario projections suggests that farmers and consumers face variable implications with forecasted precipitation scenarios and calls for research on management practices to facilitate climate adaptation for sustainable crop production.

Quality-space theory in olfaction

Benjamin D. Young et al. — Wed, 05 Jul 2017 14:10:17 PDT

Quality-space theory (QST) explains the nature of the mental qualities distinctive of perceptual states by appeal to their role in perceiving. QST is typically described in terms of the mental qualities that pertain to color. Here we apply QST to the olfactory modalities. Olfaction is in various respects more complex than vision, and so provides a useful test case for QST. To determine whether QST can deal with the challenges olfaction presents, we show how a quality space (QS) could be constructed relying on olfactory perceptible properties and the olfactory mental qualities then defined by appeal to that QS of olfactory perceptible properties. We also consider how to delimit the olfactory QS from other modalities. We further apply QST to the role that experience plays in refining our olfactory discriminative abilities and the occurrence of olfactory mental qualities in non-conscious olfactory states. QST is shown to be fully applicable to and useful for understanding the complex domain of olfaction.

Are characiform Fishes Gondwanan in Origin? Insights from a Time-Scaled Molecular Phylogeny of the Citharinoidei (Ostariophysi: Characiformes)

Jairo Arroyave et al. — Wed, 05 Jul 2017 14:10:14 PDT

Fishes of the order Characiformes are a diverse and economically important teleost clade whose extant members are found exclusively in African and Neotropical freshwaters. Although their transatlantic distribution has been primarily attributed to the Early Cretaceous fragmentation of western Gondwana, vicariance has not been tested with temporal information beyond that contained in their fragmentary fossil record and a recent time-scaled phylogeny focused on the African family Alestidae. Because members of the suborder Citharinoidei constitute the sister lineage to the entire remaining Afro-Neotropical characiform radiation, we inferred a time-calibrated molecular phylogeny of citharinoids using a popular Bayesian approach to molecular dating in order to assess the adequacy of current vicariance hypotheses and shed light on the early biogeographic history of characiform fishes. Given that the only comprehensive phylogenetic treatment of the Citharinoidei has been a morphology-based analysis published over three decades ago, the present study also provided an opportunity to further investigate citharinoid relationships and update the evolutionary framework that has laid the foundations for the current classification of the group. The inferred chronogram is robust to changes in calibration priors and suggests that the origins of citharinoids date back to the Turonian (ca 90 Ma) of the Late Cretaceous. Most modern citharinoid genera, however, appear to have originated and diversified much more recently, mainly during the Miocene. By reconciling molecular-clock- with fossilbased estimates for the origins of the Characiformes, our results provide further support for the hypothesis that attributes the disjunct distribution of the order to the opening of the South Atlantic Ocean. The striking overlap in tempo of diversification and biogeographic patterns between citharinoids and the African-endemic family Alestidae suggests that their evolutionary histories could have been strongly and similarly influenced by Miocene geotectonic events that modified the landscape and produced the drainage pattern of Central Africa seen today.

Phylogenomics of Reichenowia parasitica, an Alphaproteobacterial Endosymbiont of the Freshwater Leech Placobdella parasitica

Sebastian Kvist et al. — Wed, 05 Jul 2017 14:10:10 PDT

Although several commensal alphaproteobacteria form close relationships with plant hosts where they aid in (e.g.,) nitrogen fixation and nodulation, only a few inhabit animal hosts. Among these, Reichenowia picta, R. ornata and R. parasitica, are currently the only known mutualistic, alphaproteobacterial endosymbionts to inhabit leeches. These bacteria are harbored in the epithelial cells of the mycetomal structures of their freshwater leech hosts, Placobdella spp., and these structures have no other obvious function than housing bacterial symbionts. However, the function of the bacterial symbionts has remained unclear. Here, we focused both on exploring the genomic makeup of R. parasitica and on performing a robust phylogenetic analysis, based on more data than previous hypotheses, to test its position among related bacteria. We sequenced a combined pool of host and symbiont DNA from 36 pairs of mycetomes and performed an in silico separation of the different DNA pools through subtractive scaffolding. The bacterial contigs were compared to 50 annotated bacterial genomes and the genome of the freshwater leech Helobdella robusta using a BLASTn protocol. Further, amino acid sequences inferred from the contigs were used as queries against the 50 bacterial genomes to establish orthology. A total of 358 orthologous genes were used for the phylogenetic analyses. In part, results suggest that R. parasitica possesses genes coding for proteins related to nitrogen fixation, iron/vitamin B translocation and plasmid survival. Our results also indicate that R. parasitica interacts with its host in part by transmembrane signaling and that several of its genes show orthology across Rhizobiaceae. The phylogenetic analyses support the nesting of R. parasitica within the Rhizobiaceae, as sister to a group containing Agrobacterium and Rhizobium species.

Odor Fear Conditioning Modifies Piriform Cortex Local Field Potentials Both during Conditioning and during Post-Conditioning Sleep

Dylan C. Barnes et al. — Wed, 05 Jul 2017 14:10:07 PDT

Background: Sleep plays an active role in memory consolidation. Sleep structure (REM/Slow wave activity [SWS]) can be modified after learning, and in some cortical circuits, sleep is associated with replay of the learned experience. While the majority of this work has focused on neocortical and hippocampal circuits, the olfactory system may offer unique advantages as a model system for exploring sleep and memory, given the short, non-thalamic pathway from nose to primary olfactory (piriform cortex), and rapid cortex-dependent odor learning.

Methodology/Principal Findings: We examined piriform cortical odor responses using local field potentials (LFPs) from freely behaving Long-Evans hooded rats over the sleep-wake cycle, and the neuronal modifications that occurred within the piriform cortex both during and after odor-fear conditioning. We also recorded LFPs from naı¨ve animals to characterize sleep activity in the piriform cortex and to analyze transient odor-evoked cortical responses during different sleep stages. Naı¨ve rats in their home cages spent 40% of their time in SWS, during which the piriform cortex was significantly hyporesponsive to odor stimulation compared to awake and REM sleep states. Rats trained in the paired odor-shock conditioning paradigm developed enhanced conditioned odor evoked gamma frequency activity in the piriform cortex over the course of training compared to pseudo-conditioned rats. Furthermore, conditioned rats spent significantly more time in SWS immediately post-training both compared to pre-training days and compared to pseudo-conditioned rats. The increase in SWS immediately after training significantly correlated with the duration of odor-evoked freezing the following day.

Conclusions/Significance: The rat piriform cortex is hypo-responsive to odors during SWS which accounts for nearly 40% of each 24 hour period. The duration of slow-wave activity in the piriform cortex is enhanced immediately post-conditioning, and this increase is significantly correlated with subsequent memory performance. Together, these results suggest the piriform cortex may go offline during SWS to facilitate consolidation of learned odors with reduced external interference.

Metallic nanoparticle on micro ring resonator for bio optical detection and sensing

Ali Haddadpour et al. — Wed, 05 Jul 2017 14:10:04 PDT

We have numerically investigated the unique effects of metallic nanoparticle on the ring resonator, especially multiple Au nanoparticles on the micro ring resonator with the 4-port configuration on chip. For the Au nanoparticle, because it has smaller real refractive index than air and large absorption refractive index, we found that there is a blue shift for the ring resonance wavelength, instead of red shift normally observed for dielectric nanoparticles. The drop port intensity is strongly dependent on both number and size of nanoparticles, while relatively independent on position of nanoparticles. The correlation between the penetration depth of Au and the resonance mode evanescent tail is also discussed to reveal the unique properties of Au nanoparticle to be used for detection, sensing and nano medicine.

Identification of an Archaeal Presenilin-Like Intramembrane Protease

Celia Torres-Arancivia et al. — Wed, 05 Jul 2017 14:10:00 PDT

Background: The GXGD-type diaspartyl intramembrane protease, presenilin, constitutes the catalytic core of the c-secretase multi-protein complex responsible for activating critical signaling cascades during development and for the production of b-amyloid peptides (Ab) implicated in Alzheimer’s disease. The only other known GXGD-type diaspartyl intramembrane proteases are the eukaryotic signal peptide peptidases (SPPs). The presence of presenilin-like enzymes outside eukaryots has not been demonstrated. Here we report the existence of presenilin-like GXGD-type diaspartyl intramembrane proteases in archaea.

Methodology and Principal Findings: We have employed in vitro activity assays to show that MCMJR1, a polytopic membrane protein from the archaeon Methanoculleus marisnigri JR1, is an intramembrane protease bearing the signature YD and GXGD catalytic motifs of presenilin-like enzymes. Mass spectrometry analysis showed MCMJR1 could cleave model intramembrane protease substrates at several sites within their transmembrane region. Remarkably, MCMJR1 could also cleave substrates derived from the b-amyloid precursor protein (APP) without the need of protein co-factors, as required by presenilin. Two distinct cleavage sites within the transmembrane domain of APP could be identified, one of which coincided with Ab40, the predominant site processed by c-secretase. Finally, an established presenilin and SPP transition-state analog inhibitor could inhibit MCMJR1.

Conclusions and Significance: Our findings suggest that a primitive GXGD-type diaspartyl intramembrane protease from archaea can recapitulate key biochemical properties of eukaryotic presenilins and SPPs. MCMJR1 promises to be a more tractable, simpler system for in depth structural and mechanistic studies of GXGD-type diaspartyl intramembrane proteases.

Tyrannobdella rex N. Gen. N. Sp. and the Evolutionary Origins of Mucosal Leech Infestations

Anna J. Phillips et al. — Wed, 05 Jul 2017 14:09:56 PDT

Background: Leeches have gained a fearsome reputation by feeding externally on blood, often from human hosts. Orificial hirudiniasis is a condition in which a leech enters a body orifice, most often the nasopharyngeal region, but there are many cases of leeches infesting the eyes, urethra, vagina, or rectum. Several leech species particularly in Africa and Asia are well known for their propensity to afflict humans. Because there has not previously been any data suggesting a close relationship for such geographically disparate species, this unnerving tendency to be invasive has been regarded only as a loathsome oddity and not a unifying character for a group of related organisms.

Principal Findings: A new genus and species of leech from Peru´ was found feeding from the nasopharynx of humans. Unlike any other leech previously described, this new taxon has but a single jaw with very large teeth. Phylogenetic analyses of nuclear and mitochondrial genes using parsimony and Bayesian inference demonstrate that the new species belongs among a larger, global clade of leeches, all of which feed from the mucosal surfaces of mammals.

Conclusions: This new species, found feeding from the upper respiratory tract of humans in Peru´ , clarifies an expansion of the family Praobdellidae to include the new species Tyrannobdella rex n. gen. n.sp., along with others in the genera Dinobdella, Myxobdella, Praobdella and Pintobdella. Moreover, the results clarify a single evolutionary origin of a group of leeches that specializes on mucous membranes, thus, posing a distinct threat to human health.

Poly-Paraphyly of Hirudinidae: many lineages of medicinal leeches

Anna J. Phillips et al. — Wed, 05 Jul 2017 14:09:53 PDT

Background: Medicinal leeches became infamous for their utility in bloodletting popularized in the 19th century, and have seen a recent resurgence in post-operative treatments for flap and replantation surgeries, and in terms of characterization of salivary anticoagulants. Notorious throughout the world, the quintessential leech family Hirudinidae has been taken for granted to be monophyletic, as has the non-bloodfeeding family Haemopidae.

Results: This study is the first to evaluate molecular evidence from hirudinid and haemopid leeches in a manner that encompasses the global scope of their taxonomic distributions. We evaluated the presumed monophyly of the Hirudinidae and assessed previous well-accepted classification schemes. The Hirudinidae were found not to be monophyletic, falling instead into two distinct and unrelated clades. Members of the non-bloodfeeding family Haemopidae were scattered throughout the tree and among traditional hirudinid genera. A combination of nuclear 18S rDNA and 28S rDNA with mitochondrial 12S rDNA and cytochrome c oxidase I were analyzed with Parsimony and with Bayesian methods.

Conclusion: The family Hirudinidae must be refined to include only the clade containing Hirudo medicinalis (European medicinal leech) and related leeches irrespective of bloodfeeding behavior. A second clade containing Macrobdella decora (North American medicinal leech) and its relatives may yet be recognized in Semiscolecidae in order to avoid paraphyly. The African distribution of species from each of the divergent hirudinid clades suggests that a deep divergence took place in the history of the medicinal leeches hundreds of millions of years ago.

A Quantitative Synthesis of the Medicinal Ethnobotany of the Malinké of Mali and the Asháninka of Peru, with a New Theoretical Framework

Nathaniel Bletter — Wed, 05 Jul 2017 14:09:49 PDT

Background: Although ethnomedically and taxonomically guided searches for new medicinal plants can improve the percentage of plants found containing active compounds when compared to random sampling, ethnobotany has fulfilled little of its promise in the last few decades to deliver a bounty of new, laboratory-proven medicinal plants and compounds. It is quite difficult to test, isolate, and elucidate the structure and mechanism of compounds from the plethora of new medicinal plant uses described each year with limited laboratory time and resources and the high cost of clinical trials of new drug candidates.

Methods: A new quantitative theoretical framework of mathematical formulas called "relational efficacy" is proposed that should narrow down this search for new plant-derived medicines based on the hypothesis that closely related plants used to treat closely related diseases in distantly related cultures have a higher probability of being effective because they are more likely to be independent discoveries of similar plant compounds and disease mechanisms. A prerequisite to this hypothesis, the idea that empirical testing in traditional medicine will lead to choosing similar medicinal plants and therefore the medicinal flora of two distant cultures will prove to be more similar than their general flora, is tested using resampling statistics on cross-cultural field data of the plants used by the Malinké of Mali and the Asháninka of Peru to treat the diseases malaria, African sleeping sickness, Chagas' disease, leishmaniasis, diabetes, eczema, asthma, and uterine fibroids.

Results: In this case, the similarity of the medicinal floras is found to be significantly greater than the similarity of the general floras, but only when the diseases in question are grouped into the categories of parasitic and autoimmune diseases.

Conclusion: If the central theoretical framework of this hypothesis is shown to be true, it will allow the synthesis of medicinal plant information from around the world to pinpoint the species with the highest potential efficacy to take into the laboratory and analyze further, ultimately saving much field and laboratory time and resources.

Daily rhythm of cerebral blood flow velocity

Deirdre A. Conroy et al. — Wed, 05 Jul 2017 14:09:45 PDT

Background: CBFV (cerebral blood flow velocity) is lower in the morning than in the afternoon and evening. Two hypotheses have been proposed to explain the time of day changes in CBFV: 1) CBFV changes are due to sleep-associated processes or 2) time of day changes in CBFV are due to an endogenous circadian rhythm independent of sleep. The aim of this study was to examine CBFV over 30 hours of sustained wakefulness to determine whether CBFV exhibits fluctuations associated with time of day.

Methods: Eleven subjects underwent a modified constant routine protocol. CBFV from the middle cerebral artery was monitored by chronic recording of Transcranial Doppler (TCD) ultrasonography. Other variables included core body temperature (CBT), end-tidal carbon dioxide (EtCO2), blood pressure, and heart rate. Salivary dim light melatonin onset (DLMO) served as a measure of endogenous circadian phase position.

Results: A non-linear multiple regression, cosine fit analysis revealed that both the CBT and CBFV rhythm fit a 24 hour rhythm (R2 = 0.62 and R2 = 0.68, respectively). Circadian phase position of CBT occurred at 6:05 am while CBFV occurred at 12:02 pm, revealing a six hour, or 90 degree difference between these two rhythms (t = 4.9, df = 10, p < 0.01). Once aligned, the rhythm of CBFV closely tracked the rhythm of CBT as demonstrated by the substantial correlation between these two measures (r = 0.77, p < 0.01).

Conclusion: In conclusion, time of day variations in CBFV have an approximately 24 hour rhythm under constant conditions, suggesting regulation by a circadian oscillator. The 90 degree-phase angle difference between the CBT and CBFV rhythms may help explain previous findings of lower CBFV values in the morning. The phase difference occurs at a time period during which cognitive performance decrements have been observed and when both cardiovascular and cerebrovascular events occur more frequently. The mechanisms underlying this phase angle difference require further exploration

A Funny Thing Happened On The Way To The 21st Century

Peter R. Bales — Wed, 05 Jul 2017 12:10:33 PDT

A humorous but entirely factual account of American history from the beginning up to the present.

The Mathematics of Nutrition Science

Lana Zinger et al. — Wed, 05 Jul 2017 12:05:23 PDT

The Mathematics of Nutrition Science is a workbook designed to integrate and contextualize developmental mathematics into an introductory college level Nutrition class. Definitions and skills from Community College Level Elementary Algebra and Quantitative Literacy courses are explained through examples analyzing the nutritional content of different foods. The book contains exercises for students to practice these skills, and also to reflect on the concepts through short writing assignments aligned with developmental English. These materials could be used by Nutrition course instructor in many different ways, and are designed to be self-contained and require minimal mathematical instruction.

Best Practices for Recruiting and Retaining Diverse Faculty for Institutions of Higher Education.

Aldemaro Romero Jr. — Mon, 03 Jul 2017 12:07:13 PDT

Research has shown that increasing diversity in organizations and the workplace is not only a matter of social justice. It suggests that including diverse voices and experiences makes groups more knowledgeable, sensitive, efficient, creative, and successful. Examples cited claim that increased diversity (in its broadest sense, i.e., gender, ethnicity, national origin, age, sexual orientation, disability, religious and socioeconomic background) affords groups rich opportunities to respond more effectively to the challenges of society that require multiple perspectives and broad approaches to complex problem-solving. Unfortunately, among the faculty represented in higher education, diversity remains an issue. And, the proportion of diverse individuals in positions of leadership in academia has been decreasing, even among minority-serving institutions. Also, women suffer widespread discrimination in many forms.

What follows is a list of suggestions for improving both recruitment and retention of diverse faculty in institutions of higher education. Given the tremendous diversity of institutions of higher education in this country, some may work better than others for your institution. Another key factor is the majority of recommendations herein require financial resources which demands commitment from the top authorities of the institution, from the board of trustees to the deans’ level.

Contrasting Infection Strategies in Generalist and Specialist Wasp Parasitoids of Drosophila melanogaster

Todd A. Schlenke et al. — Mon, 03 Jul 2017 09:41:31 PDT

Although host–parasitoid interactions are becoming well characterized at the organismal and cellular levels, much remains to be understood of the molecular bases for the host immune response and the parasitoids’ ability to defeat this immune response. Leptopilina boulardi and L. heterotoma, two closely related, highly infectious natural parasitoids of Drosophila melanogaster, appear to use very different infection strategies at the cellular level. Here, we further characterize cellular level differences in the infection characteristics of these two wasp species using newly derived, virulent inbred strains, and then use whole genome microarrays to compare the transcriptional response of Drosophila to each. While flies attacked by the melanogaster group specialist L. boulardi (strain Lb17) up-regulate numerous genes encoding proteolytic enzymes, components of the Toll and JAK/STAT pathways, and the melanization cascade as part of a combined cellular and humoral innate immune response, flies attacked by the generalist L. heterotoma (strain Lh14) do not appear to initiate an immune transcriptional response at the time points post-infection we assayed, perhaps due to the rapid venom-mediated lysis of host hemocytes (blood cells). Thus, the specialist parasitoid appears to invoke a full-blown immune response in the host, but suppresses and/or evades downstream components of this response. Given that activation of the host immune response likely depletes the energetic resources of the host, the specialist’s infection strategy seems relatively disadvantageous. However, we uncover the mechanism for one potentially important fitness tradeoff of the generalist’s highly immune suppressive infection strategy.

Prenatal Cocaine Exposure Increases Synaptic Localization of a Neuronal RasGEF, GRASP-1 via Hyperphosphorylation of AMPAR Anchoring Protein, GRIP

Kalindi Bakshi et al. — Mon, 03 Jul 2017 09:41:28 PDT

Prenatal cocaine exposure causes sustained phosphorylation of the synaptic anchoring protein, glutamate receptor interacting protein (GRIP1/2), preventing synaptic targeting of the GluR2/3-containing alpha-amino-3-hydroxy-5-methyl-4- isoxazolepropionic acid-type glutamate receptors (AMPARs; J. Neurosci. 29: 6308–6319, 2009). Because overexpression of GRIP-associated neuronal rasGEF protein (GRASP-1) specifically reduces the synaptic targeting of AMPARs, we hypothesized that prenatal cocaine exposure enhances GRASP-1 synaptic membrane localization leading to hyper-activation of ras family proteins and heightened actin polymerization. Our results show a markedly increased GRIP1-associated GRASP-1 content with approximately 40% reduction in its rasGEF activity in frontal cortices (FCX) of 21-day-old (P21) prenatal cocaineexposed rats. This cocaine effect is the result of a persistent protein kinase C (PKC)- and downstream Src tyrosine kinasemediated GRIP phosphorylation. The hyperactivated PKC also increased membrane-associated GRASP-1 and activated small G-proteins RhoA, cdc42/Rac1 and Rap1 as well as filamentous actin (F-actin) levels without an effect on the phosphorylation state of actin. Since increased F-actin facilitates protein transport, our results suggest that increased GRASP-1 synaptic localization in prenatal cocaine-exposed brains is an adaptive response to restoring the synaptic expression of AMPA-GluR2/ 3. Our earlier data demonstrated that persistent PKC-mediated GRIP phosphorylation reduces GluR2/3 synaptic targeting in prenatal cocaine-exposed brains, we now show that the increased GRIP-associated GRASP-1 may contribute to the reduction in GluR2/3 synaptic expression and AMPAR signaling defects.

Sexual Orientation and Functional Pain in U.S. Young Adults: The Mediating Role of Childhood Abuse

Andrea L. Roberts et al. — Mon, 03 Jul 2017 09:41:24 PDT

Objective: Pain without known pathology, termed ‘‘functional pain,’’ causes much school absenteeism, medication usage, and medical visits. Yet which adolescents are at risk is not well understood. Functional pain has been linked to childhood abuse, and sexual orientation minority youth (gay, lesbian, bisexual, ‘‘mostly heterosexual,’’ and heterosexual with same-sex sexual contact) are more likely to be victims of childhood abuse than heterosexuals, thus may be at greater risk of functional pain.

Methods: We examined sexual orientation differences in past-year prevalence of functional headache, pelvic, and abdominal pain and multiple sites of pain in 9,864 young adults (mean age = 23 years) from a large U.S. cohort. We examined whether childhood abuse accounted for possible increased risk of functional pain in sexual minority youth.

Results: Sexual minority youth, except for gays and lesbians, were at higher risk of functional pelvic and abdominal pain and multiple sites of pain than heterosexuals. Gay and lesbian youth had elevated prevalence only of abdominal pain. Childhood abuse accounted for 14% to 33% of increased experience of multiple sites of pain in minority youth.

Conclusions: Youth who identify as ‘‘mostly heterosexual’’ or bisexual or who identify as heterosexual and have had samesex partners comprised 18% of our sample. Clinicians should be aware that patients with these orientations are at elevated risk of functional pain and may be in need of treatment for sequelae of childhood abuse. Conventional categorization of sexual orientation as heterosexual or homosexual may fail to distinguish a large number of youth who do not wholly identify with either group and may be at elevated risk of health problems.

Iconic memory requires attention

Marjan Persuh et al. — Mon, 03 Jul 2017 09:41:21 PDT

Two experiments investigated whether attention plays a role in iconic memory, employing either a change detection paradigm (Experiment 1) or a partial-report paradigm (Experiment 2). In each experiment, attention was taxed during initial display presentation, focusing the manipulation on consolidation of information into iconic memory, prior to transfer into working memory. Observers were able to maintain high levels of performance (accuracy of change detection or categorization) even when concurrently performing an easy visual search task (low load). However, when the concurrent search was made difficult (high load), observers' performance dropped to almost chance levels, while search accuracy held at single-task levels. The effects of attentional load remained the same across paradigms. The results suggest that, without attention, participants consolidate in iconic memory only gross representations of the visual scene, information too impoverished for successful detection of perceptual change or categorization of features.

CREATE Cornerstone: Introduction to Scientific Thinking, a New Course for STEM-Interested Freshmen, Demystifies Scientific Thinking through Analysis of Scientific Literature

Alan J. Gottesman et al. — Mon, 03 Jul 2017 09:41:18 PDT

The Consider, Read, Elucidate hypotheses, Analyze and interpret data, Think of the next Experiment (CREATE) strategy for teaching and learning uses intensive analysis of primary literature to improve students’ critical-thinking and content integration abilities, as well as their self-rated science attitudes, understanding, and confidence. CREATE also supports maturation of undergraduates’ epistemological beliefs about science. This approach, originally tested with upper-level students, has been adapted in Introduction to Scientific Thinking, a new course for freshmen. Results fromthis course’s initial semesters indicate that freshmen in a one-semester introductory course that uses a narrowly focused set of readings to promote development of analytical skills made significant gains in critical-thinking and experimental design abilities. Students also reported significant gains in their ability to think scientifically and understand primary literature. Their perceptions and understanding of science improved, and multiple aspects of their epistemological beliefs about science gained sophistication. The course has no laboratory component, is relatively inexpensive to run, and could be adapted to any area of scientific study.

Using a Paradigm Shift to Teach Neurobiology and the Nature of Science—a C.R.E.A.T.E.-based Approach

Sally G. Hoskins — Mon, 03 Jul 2017 09:41:14 PDT

Decades ago, classic experiments established the phenomenon of “neural induction” (Spemann and Mangold, 1924; Holtfreter, 1933). It appeared clear that amphibian ectoderm was pre-programmed to form epidermis, and that the neural phenotype was induced by a chemical signal from mesoderm. The “ectoderm makes skin, unless induced to make nervous system” model appeared in many textbooks. This interpretation, however, was not simply incorrect but 180 degrees out of alignment with the actual situation. As subsequently demonstrated, the default state of amphibian ectoderm is neuronal, and the expression of the epidermal phenotype requires cell signaling (Hemmati-Brivanlou and Melton, 1992; 1994; 1997). In this activity, students are presented with key experiments in a stepwise fashion. At several points, they work in groups to devise models that explain particular experimental results. The stepwise presentation of results mirrors the history of discoveries in this experimental system. Eventually, faced with seemingly contradictory data, students must revise their models substantially and in doing so, experience the paradigm shift. The lesson also examines the history of this paradigm shift. Data inconsistent with the “epidermal default” model were published years before the “neural default” model was proposed, but the significance of the surprising new data was underemphasized by the scientists who made the discovery. Discussing this situation provides insight into how science works and highlights the possibility that working scientists may become entrenched in prevailing paradigms. Such “nature of science” discussions emphasize research as a human activity, and help to dispel student misconceptions about science and scientists.

Kolb studies, teaches Shakespeare and his times

Aldemaro Romero Jr. — Mon, 03 Jul 2017 08:57:24 PDT

Laura Kolb was not sure what she wanted to major in when she went to college at Columbia University, but at some point she decided in favor of English. This was not surprising, given her upbringing. “Ever since I was really small my parents read to me, and I loved to read,” she says.

A native of South Bend, Indiana, she grew up in Floyd, Virginia, went on to do her masters in Humanities and her doctorate in English at the University of Chicago, and today she is an assistant professor in the Department of English in the Weissman School of Arts and Sciences at Baruch College, CUNY.

College presidents mostly white and aging

Aldemaro Romero Jr. — Mon, 03 Jul 2017 08:52:50 PDT

Despite the fact that the leadership of colleges and universities in this country is in dire need of fresh ideas, a report released last week by the American Council on Education (ACE) shows that the people in these positions continue to be largely white, male – and getting older. And while women represent the majority of undergraduate and graduate students in this country and that the number of minorities attending colleges and universities keeps growing and will continue to grow in the years to come, by 2016 less than a third of college presidents were women and less than a fifth were members of any ethnic minority.

The ACE report found that the average president was 61.7 years old, up from 60.7 years old in 2011 and 59.9 years old in 2006. Also, there is an increasing proportion of leaders (nearly a fourth) who had already led other colleges and universities. This seems to indicate that the people in charge of selecting college presidents care more about experience than new ideas.

Brooks studies how Asians have been viewed by Americans

Aldemaro Romero Jr. — Mon, 03 Jul 2017 08:52:46 PDT

“I went to a high school in northern California, up in the foothills near where gold was discovered in a little town called Auburn, and one thing I remember is that we didn’t really have any kind of world history.” Those are the first memories of the historian Charlotte Brooks about her profession.

Further, when it comes to her area of specialization—the history of Asians in America—her beginnings are even more modest. “Growing up in the gold rush country, I saw the old Chinese immigrant markers on the land and on the buildings everywhere. I knew my town had been a big center of Japanese immigration. Japanese-Americans were moved in 1942, and most of them never returned because of racist agitation. But nobody talked about it. When I went to college, I tried to take courses to remedy what I felt was my awful lack of knowledge about anything besides U.S. history, and I really got hooked on China.”